The Many Flavors Of ILI

 

 
Photo Credit CDC

 

# 6868

 

Although flu reports figure prominently in this winter’s news headlines, not every influenza-like-illness (ILI) out there is caused by an influenza virus. In fact, of the more than 12,300 specimens tested by U.S., WHO and NREVSS collaborating labs last week, less than 30% were positive for influenza.

 

 

The rest of the respiratory miseries out there are caused by a variety of viral villains (some unidentified, and some flu-negatives may really be positive), that include RSV (respiratory syncytial virus), respiratory Adenoviruses, parainfluenza viruses, rhinoviruses, coronaviruses, and metapneumovirus (to name a few).

The latest Ontario Respiratory Virus Bulletin, 2012-2013 (Week 2: January 6, 2012 – January 12, 2013) provides a fascinating graph that shows both the variety and seasonal fluctuation of respiratory viruses in institutional outbreaks over the past year.

 

While influenza A is the dominant player this winter, you’ll notice that last season was truly a mixed bag, with comparatively little flu.  The summer months were dominated by Rhino/enterovirus detections.

 

The DARK BLUE part of  the chart represent unidentified organisms.

 

The truth is - in a clinical setting - most influenza-like-illnesses go unidentified. Viral respiratory infections are generally self-limiting illnesses, treatment is pretty much the same regardless of etiology, and so there is little point in trying to identify the cause of every illness.

 

Scientists – with better tools available today – are indentifying `new’ viruses all of the time. A few well distributed viruses that until recently, were unknown, include:

 

• The human metapneumovirus (HMPV) was identified in Dutch children with bronchiolitis about a dozen years ago.  Since then, it has been found to be ubiquitous around the world, and responsible for a significant percentage of childhood respiratory infections . . . yet until 2001, no one knew it existed.
• Human Bocavirus-infection (HBoV) wasn’t identified until 2005, when it was detected in 48 (9.1%) of 527 children with gastroenteritis in Spain (cite).  It has since been found around the globe using PCR testing.

 

And the list grows longer every year.

 

Adding to our misery, it is fairly common to be infected by more than one virus at the same time.

 

In 2008 a study (see Frequent detection of viral coinfection in children hospitalized with acute respiratory tract infection using a real-time polymerase chain reaction) looked at clinical samples taken from 254 children treated in Germany over a 10 month period, finding:

 

Respiratory syncytial virus (RSV) was the most frequently detected pathogen in 112 samples (44.1%), followed by human bocavirus (hBoV) in 49 (19.3%), and rhinovirus in 17 samples (6.7%).

 

Viral coinfection was detected in 41 (16.1%) samples with RSV and hBoV being the most dominating combination (27 cases, 10.6%). Viral coinfection was found in 10 cases (17%) of children with bronchitis (n = 58) and in 7 cases (23%) of bronchiolitis (n = 30). In patients with pneumonia (n = 51), 17 cases (33%) were positive for 2 or more viral pathogens.

 

This plethora of pathogens helps to explain – in part -why so many people who get the flu shot every year complain they still caught `the flu’.   Often, they’ve caught one of these ubiquitous `flu-like illnesses’.

 

So today, a closer look at three common non-influenza respiratory viruses, and one rare one. 

 

RSV (Respiratory Syncytial Virus)

One of the most common infections of young children, it has been estimated that by the age of two, nearly all children in the United States have endured at least one bout with this virus. 

 

For those wondering, `syncytial’ is pronounced (sin-SISH-uhl).

 

While for most people this virus produces a mild illness, often indistinguishable from a `cold’, it is also considered by the CDC to be the the primary cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia in children under 1 year of age in the United States (cite).

 

The CDC estimates between 75,000 and 125,000 children are hospitalized each year with RSV, and while normally thought of as a childhood illness, adults with weakened immune systems and those over 65 are also at increased risk of severe disease.

 

The CDC maintains an extensive RSV information page.

 

 

Respiratory Adenoviruses

 

With more than 50 varieties identified, respiratory adenoviruses are one of the most common causes of respiratory illness in the world.

 

The CDC’s Adenovirus Information page describes the virus this way:

 

Adenoviruses most commonly cause respiratory illness. The symptoms can range from the common cold to pneumonia, croup, and bronchitis. Depending on the type, adenoviruses can cause other illnesses such as gastroenteritis, conjunctivitis, cystitis, and less commonly, neurological disease.

 

Infants and people with weakened immune systems are at high risk for severe complications of adenovirus infection. Also, adenoviruses commonly cause acute respiratory illness in military recruits.

 

Interestingly, a person can have – and shed – adenovirus for weeks or even months without showing symptoms. 

 

While no vaccine is currently available for the public, the military is using a recently approved (March, 2011) oral vaccine against types 4 and 7 on new recruits to help prevent outbreaks.

 

Over the years we’ve seen some high-profile outbreaks of adenovirus infections that have, at least until they were identified, sounded alarm bells, including  China: Hebei Outbreak Identified As Adenovirus 55.

 

On rare occasions, outbreaks of emerging strains of adenovirus that have caused more serious illness, including one serotype (Ad14) that has been associated with a number of deaths during the past decade (see 2007 MMWR Acute Respiratory Disease Associated with Adenovirus Serotype 14 --- Four States, 2006—2007).

 

 

Parainfluenza Viruses

Human parainfluenza viruses (HPIVs) belong to the Paramyxoviridae family, of which there are 4 types (1-4) and two subtypes  (4a & 4b). Each type has its own set of clinical and epidemiological features.

 

From the CDC’s HPIV page:

Symptoms and Illnesses

The incubation period, the time from exposure to HPIV to onset of symptoms, is generally 2 to 7 days.

• HPIV-1 and HPIV-2 are most often associated with croup (laryngotracheobronchitis). HPIV-1 often causes croup in children, whereas HPIV-2 is less frequently detected. Both types can cause upper and lower respiratory tract illnesses. People with upper respiratory tract illness may have cold-like symptoms.
• HPIV-3 is more often associated with bronchiolitis, bronchitis, and pneumonia.
• HPIV-4 is not recognized as often, but may cause mild to severe respiratory tract illnesses.

Reinfection

People can get multiple HPIV infections in their lifetime. These reinfections usually cause mild upper respiratory tract illness with cold-like symptoms. However, reinfections can cause serious lower respiratory tract illness, such as pneumonia, bronchitis, and bronchiolitis in some people. Older adults and people with compromised immune systems, in particular, have a higher risk for severe infections.

Most children 5 years of age and older have antibodies against HPIV-3 and approximately 75% have antibodies against HPIV-1 and HPIV-2.

 

 

Our last stop is with Human Enterovirus 68 (HEV68), which made headlines in 2011, but of which we’ve heard little of since. In MMWR: Clusters Of HEV68 Respiratory Infections 2008-2010 we looked at reports of six clusters of this rare, emerging enterovirus over the previous couple of years.

 

Enteroviruses encompass a large family of small RNA viruses that include the three Polioviruses, along with myriad non-polio serotypes of Human Rhinovirus, Coxsackievirus, echovirus, and human, porcine, and simian enteroviruses.

 

First detected in California in 1962, but rarely seen since that time, the CDC was notified of six clusters of HEV68 from Asia, Europe, and the United States between 2008-2010.  These clusters included severe illness, and three fatalities.

 

Occurrence of human enterovirus 68, by month, duration, and geographic location --- Asia, Europe, and United States, 2008—2010 –MMWR

 

The summary provided for this MMWR release reads:

 

What is already known on this topic?

Human enterovirus 68 (HEV68) is a unique enterovirus that shares epidemiologic and biologic features with human rhinoviruses.

What is added by this report?

Although isolated cases of HEV68 have been reported since the virus was described in 1962, clusters of cases have been recognized only recently. The clusters described in this report occurred late in the typical enterovirus season and included severe cases, three of which were fatal.

What are the implications for public health practice?

Clinicians should be aware of HEV68 as one of many possible causes of viral respiratory disease. Some diagnostic tests might not detect HEV68 or might misidentify it as a human rhinovirus.

 

The number of `known’ respiratory viruses increases practically every year, due to advances in microbiology and sequence-independent amplification of viral genomes.

 

There is, no doubt, much more to discover about the myriad of non-influenza respiratory viruses in circulation around the world.

 

Most of these viruses will prove clinically indistinguishable from the respiratory viruses we already know. 

 

But outliers like SARS CoV in 2003,  HEV68 in 2008-10, or recent infections in the Middle East with the novel coronavirus EMC/2012 – all capable of producing significant levels of serious illness - show that novel viruses can emerge with little warning.

Which makes the surveillance and identification of these respiratory viruses more than just an academic exercise.

»» Read More

WHO Coronavirus Update

 

Photo Credit NIAID

# 6799

 

My thanks to Lisa Schnirring at CIDRAP NEWS for the head’s up this morning on the recently posted update by the World Health Organization on their ongoing investigation into the novel coronavirus.

While no new cases have been discovered, WHO investigators have delved deeper into the outbreak last April at a hospital in Zarqua, Jordan (including 8 healthcare workers) that resulted in two deaths.

 

(See ECDC Report and FluTrackers Thread)

 

Although there were two confirmed (fatal) infections by this coronavirus in the Jordanian cluster, a number of other pneumonia cases (and milder cases) are suspected. These cases suggest that limited human transmission of the virus may have occurred in this hospital setting. 

 

Unfortunately, testing for this virus is still very limited, and no serological test for antibodies (indicating prior infection) is currently available.

 

Interestingly, none of the cases in Jordan developed renal failure – which was a hallmark in 5 of the 7 cases reported over the summer. 

 

One of the confirmed Jordanian cases developed Pericarditis (inflammation of the sac around the heart) and another developed DIC (Disseminated intravascular coagulation).

 

The Jordanian cluster also suggests that milder cases of this infection may occur, although antibody testing will be needed in order to confirm that.

 

The entire update is worth reading.

 

 

Background and summary of novel coronavirus infection – as of 21 December 2012

Over the past three months, WHO has received reports of nine cases of human infection with a novel coronavirus. Coronaviruses are a large family of viruses; different members of this family cause illness in humans and animals. In humans, these illnesses range from the common cold to infection with Severe Acute Respiratory Syndrome (SARS) coronavirus (SARS CoV).

 

This summary provides the latest information on all reported cases and provides details of a WHO mission to Jordan, which has concluded since the last web update.

 

Thus far, the laboratory confirmed cases have been reported by Qatar (two cases), Saudi Arabia (five cases) and Jordan (two cases). All patients were severely ill, and five have died.

 

A total of five confirmed cases have been reported from Saudi Arabia. The first two are not linked to each other and lived in different parts of the country; one of these has died. Three other confirmed cases are epidemiologically linked and occurred in one family living within the same household; two of these have died. One additional family member in this household also became ill, with symptoms similar to those of the confirmed cases. This person has recovered and tested negative, by polymerase chain reaction (PCR) tests, for the virus.

 

Two confirmed cases have been reported in Jordan. Both of these patients have died. These cases were discovered through testing of stored samples from a cluster of pneumonia cases in health care workers that occurred in April 2012.

 

In November 2012 staff from WHO Headquarters and the Eastern Mediterranean Regional Office were invited to Jordan to assess severe acute respiratory infection (SARI) surveillance and infection prevention and control measures, and to review the April 2012 outbreak. The mission included hospital site visits, interviews with patients, relatives and caregivers, and review of case files. In addition to the two previously confirmed cases, a number of health care workers with pneumonia associated with the cases were also included in the review and are now considered probable case.

The main findings of this mission are:

• The index case among this cluster could not be determined.
• All patients had significant respiratory disease presenting as pneumonia. Disease was generally milder in the unconfirmed probable cases. One patient who is a probable case had symptoms that were mild enough to be managed at home and was not admitted to hospital.
• No patient in this cluster had renal failure.
• One patient presented with pneumonia and was discovered to also have pericarditis. This patient had laboratory confirmation of infection and has died.
• A second patient developed disseminated intravascular coagulation as a complication of severe respiratory disease. This patient also had laboratory confirmation of infection and has died.
• The method of exposure is uncertain.
• There was no history of travel or contact with animals among confirmed or probable cases.

Most family members and health care workers who were closely exposed to confirmed and probable cases did not develop respiratory disease. However, the appearance of pneumonia in some who provided care and in at least two family members with direct personal contact increases the suspicion that person-to-person transmission may have occurred. The possibility of exposure to a common source has not been definitively excluded.

Further investigation with serological testing (when it becomes available) to confirm additional cases may help determine the types of exposures that result in infection.

 

The current understanding of this novel virus is that it can cause a severe, acute respiratory infection presenting as pneumonia. The additional unconfirmed probable cases in Jordan indicate that milder presentations may also be a part of the clinical appearance associated with infection. Acute renal failure has occurred in five of the nine confirmed cases but was not a prominent feature of the Jordanian cluster. In addition, pericarditis and disseminated intravascular coagulation have now been seen in two confirmed cases.

 

WHO recognizes that the emergence of a new coronavirus capable of causing severe disease raises concerns because of experience with SARS. Although this novel coronavirus is distantly related to the SARS CoV, they are different. Based on current information, it does not appear to transmit easily or sustainably between people, unlike the SARS virus.

 

WHO has closely monitored the situation since detection of the first case and has been working with partners to ensure a high degree of preparedness should the new virus be found to be sufficiently transmissible to cause community outbreaks. Some viruses are able to cause limited human-to-human transmission under condition of close contact, as occurs in families, but are not transmissible enough to cause larger community outbreaks.

 

Actions taken by WHO in coordination with national authorities and technical partners include the following:

• Investigations are ongoing to determine the likely source of infection and the route of exposure. Close contacts of confirmed cases are being identified and followed up.
• An interim surveillance recommendation has been updated to assist clinicians to determine which patients should undergo laboratory testing for the presence of novel coronavirus.
• Laboratory assays for the virus have been developed. Reagents and other materials for testing are available, as are protocols, algorithms and reference laboratory services. WHO has activated its laboratory network to assist in testing and other services. WHO has now issued preliminary guidance for laboratory biorisk management.
• The three affected countries either have already or are in the process of acquiring the capacity to test for the novel coronavirus in national laboratories and have enhanced their surveillance activities according to WHO guidance along with other countries in the area.
• WHO has created a webpage for coronavirus infections, with guidance for surveillance, infection control, biorisk management, and laboratory testing, which can be found at: http://www.who.int/csr/disease/coronavirus_infections/en/index.html

Based on the current situation and available information:

• WHO encourages all Member States to continue their surveillance for severe acute respiratory infections (SARI) and to carefully review any unusual patterns.
• Further, testing for the new coronavirus of patients with unexplained pneumonias should be considered, especially in persons residing in or returning from the Arabian peninsula and neighboring countries. Any new cases should be promptly reported both to national health authorities and to WHO.
• When collecting specimens for testing, priority should be given to collection of lower respiratory tract specimens such as sputa and endotracheal aspirates (for intubated patients).
• In addition, any clusters of SARI or SARI in health care workers should be thoroughly investigated, regardless of where in the world they occur. These investigations will help determine whether the virus is distributed more widely in the human population beyond the three countries that have identified cases.
• Health care workers should be advised to scrupulously adhere to standard infection control precautions for all patients. Droplet precautions should be added to standard precautions for any patient known or suspected to have an acute respiratory infection, including patients with suspected or confirmed infection with novel coronavirus. Airborne precautions should be used for aerosol-generating procedures, including intubation and related interventions. Details can be found on the website listed above.
• WHO does not advise special screening at points of entry with regard to this event nor does it recommend that any travel or trade restrictions be applied.

WHO continues to monitor this situation closely. Unless information is received that changes our understanding of this virus and the disease it causes, the next web update is expected to be posted during the second week of January 2013.

 

»» Read More

mBio: Coronavirus Has An Affinity For Multiple Hosts

 

Photo Credit NIAID

# 6772

 

Most of the infectious diseases that afflict mankind today began in a different animal species, but jumped to humans and then adapted to our physiology.  

 

• The scourge of Tuberculosis, which now infects 1/3rd of humanity, likely jumped species when man began to corral and raise its traditional hosts; goats and cattle.
• Measles appears to have evolved from canine distemper and/or the Rinderpest virus of cattle.  
• Influenza, as most of you know, is native to aquatic birds – but jumped species thousands of years ago and many strains have adapted to humans, pigs, and other species.

 

The list of zoonotic diseases (those shared between humans and animals) is long and continually expanding, and includes: SARS, Babesiosis, Borrelia (Lyme), Nipah, Hendra, Malaria, Hantavirus, Ebola, Bartonella, Leptospirosis, Q-Fever, bird flu and many, many others

 

Most viruses are fairly selective about the type of cells they will invade, what organ systems they will attack, and even what species they will infect.

 

Horse viruses generally attack equines, and not say, cats and dogs.   Cat viruses tend to attack felines, and not birds.  Bird viruses usually only infect avian species.

 

But some viruses are more promiscuous than others.

Rabies can infect nearly all warm-blooded animals, and we’ve seen the H5N1 `avian flu’ virus infect a wide range of mammals, including humans, dogs, cats, and pigs.

 

Later today, mBio®, the online open-access journal of the American Society for Microbiology, will publish a study that looks at the host range of the newly discovered coronavirus (hCoV-EMC) in the Middle East.

Although researchers are still looking for the receptor cell that allows entry of the virus into the host’s cells, they have found that the hCoV-EMC virus can infect a number of bat species, along with pigs, and of course, humans.

 

We’ll have to wait a few hours to see the study, but the ASM has a press release with some of the details, and we also have an excellent write up by Helen Branswell of the Canadian Press.

 

First, excerpts from the press Release

Public release date: 11-Dec-2012

New coronavirus has many potential hosts, could pass from animals to humans repeatedly

The SARS epidemic of 2002-2003 was short-lived, but a novel type of human coronavirus that is alarming public health authorities can infect cells from humans and bats alike, a fact that could make the animals a continuing source of infection, according to a study to be published in in mBio®, the online open-access journal of the American Society for Microbiology, on December 11. The new coronavirus, called hCoV-EMC, is blamed for five deaths and several other cases of severe disease originating in countries in the Middle East.

 

According to the new results, hCoV-EMC uses a different receptor in the human body than the SARS virus, and can infect cells from a wide range of bat species and pigs, indicating there may be little to keep the virus from passing from animals to humans over and over again.

 

First identified in a patient in Saudi Arabia in June, nine laboratory-confirmed cases of hCoV-EMC infection have now been identified, five of whom have died. Although the virus does not apparently pass from person-to-person very readily, the case fatality rate and the fact that the source of the virus has not been identified have caused concern among global public health authorities. Cases of hCoV-EMC infection are marked by severe pneumonia and often by kidney failure.

 

"This virus is closely related to the SARS virus, and looking at the clinical picture, it causes the same pattern of disease," says Christian Drosten of the University of Bonn Medical Centre in German, a lead author of the study.

 

Given the similarities, Drosten and his colleagues wanted to know whether hCoV-EMC and SARS might use the same receptor, a sort of molecular "dock" on human cells that the virus latches onto to gain entry to the cell. The SARS receptor, called ACE2, is found mostly on pneumocytes deep within the human lung, so an individual must breathe in many, many SARS viruses for a sufficient number of them to reach this susceptible area and cause an infection. Drosten says this simple fact helped ensure the SARS outbreak didn't spread like wildfire and was mostly limited to healthcare workers and residents of overcrowded housing in Hong Kong. Also, once a person was infected with SARS in the deep part of their lungs, he or she felt sick almost immediately and therefore was not active in the community and infecting others, another aspect of the receptor that helped curb the outbreak.

 

Does hCoV-EMC use the same receptor? If so, the means of controlling this new virus might become clearer.

 

"The answer is a clear no," says Drosten. "This virus does not use ACE2." This leaves open the possiblity that hCoV-EMC could use a receptor in the human lung that is easier to access and could make the virus more infectious than SARS, but it is still not known what receptor the virus does use.

 

To help identify how hCoV-EMC might have originated and moved between humans and animals, the second part of the study focused on the animal species the virus can infect. SARS is closely related to viruses from bats, but Drosten says the virus changed in the transition from bats to civet cats to humans and could no longer infect bats, so SARS was not present in the wild and did not pass repeatedly from bats to humans like a classical zoonotic disease. "So the [SARS] virus lost its old host and gained a new one," says Drosten.

 

Like SARS, hCoV-EMC is most closely related to coronaviruses from bats, but unlike SARS, this study found that hCoV-EMC can still infect cells from many different species of bats. "This was a big surprise," says Drosten. "It's completely unusual for any coronavirus to be able to do that – to go back to its original reservoir." The virus is also able to infect cells from pigs, indicating that it uses a receptor structure that all these animals have in common. If that receptor is present in mucosal surfaces, like the lining of the lung, it is possible the virus could pass from animals to humans and back again, making animals an ongoing source of the virus that would be difficult or impossible to eliminate.

(Continue . . . )

 

The study should be published online at http://mbio.asm.org/ later today.

 

Meanwhile, Helen Branswell has the following report.

 

Study finds puzzling behaviour of new coronavirus, may hint at pattern of spread

By Helen Branswell, The Canadian Press | Associated Press – 7 hrs ago

TORONTO - A new study reveals that the new SARS-like virus which has been causing infections in the Middle East behaves unusually in laboratory testing

(Continue . . . )

»» Read More

ECDC: Updated Novel Coronavirus Risk Assessment

Photo Credit NIAID

 

# 6770

 

Although we’ve no fresh reports of infection by the novel coronavirus which appeared in the Middle East last April, and has been confirmed in 9 patients (see WHO: Background & Summary Of Coronavirus Cases), health officials around the globe continue to assess the situation and make provisions to detect and contain the virus.

 

A week ago the World Health Organization  released new Interim surveillance recommendations and an updated Coronavirus FAQ (see WHO Coronavirus Updates).

 

Today, in the wake of the announcement of two cases from Jordan last spring, the ECDC updates their Coronavirus Risk Assessment, previously updated on November 26th.

 

Novel coronavirus: ECDC updates its risk assessment

10 Dec 2012

 

ECDC has published another update of its risk assessment on the novel coronavirus. Two cases in Jordan have retrospectively been confirmed. These additional cases have increased the geographical area in which transmission of the virus has occurred. The two fatal cases were part of a cluster of 11 patients with respiratory symptoms linked to a hospital. The limited information available about this outbreak does not allow for an assessment of whether human-to-human transmission has occurred or indeed whether the cases in this cluster had the same cause.

 

The ECDC risk assessment highlights that healthcare workers should be alerted to the possibility of attending to patients who meet specific characteristics which would require an investigation according to the WHO case definition. The new WHO recommendations favour the investigation of patients returning from the Arabian Peninsula or its neighbouring countries, but do not exclude the testing of patients with unexplained pneumonia in the absence of such travel.

 

A specific serological test and seroepidemiological studies are needed to investigate the occurrence of mild and asymptomatic infections. The diagnostic capacity for novel coronavirus is adequate in the EU. This is confirmed by a newly published article in Eurosurveillance on the results of a survey undertaken by ECDC and WHO. The virus genome is in the public domain and mechanisms for sharing samples and diagnostic methods between countries and laboratories are in place.

 

As of 4 December 2012, a total of nine laboratory-confirmed cases of severe pneumonia caused by the novel coronavirus have been reported to WHO. Five of the nine cases were fatal. Onset of disease was from April to October 2012 and all cases were resident in Saudi Arabia, Qatar or Jordan during the presumed 10 days incubation period.

 

ECDC endorses the WHO travel advice and does not advise any travel or trade restrictions for Saudi Arabia or Qatar.

 

The entire Risk Assessment may be downloaded here.

 

This document’s main conclusions and recommendations reads:

 

• As of 4 December 2012, nine laboratory-confirmed cases of severe pneumonia caused by the novel coronavirus have been reported to WHO. Five of the nine cases were fatal. Onset of disease was from April to October 2012; all cases were resident in Saudi Arabia, Qatar or Jordan during the presumed 10 days incubation period.
• Two retrospectively tested and confirmed cases in Jordan in April 2012 have increased the geographical area in which transmission has occurred. The two fatal cases were part of a cluster of 11 patients with respiratory symptoms linked to a hospital, but the limited information available about this outbreak does not allow for an assessment of whether any human-to-human transmission occurred or whether the cases in this cluster had the same cause.
• Healthcare workers should be alerted to the possibility of attending to patients who meet the WHO case definition. Such cases should be investigated rapidly and managed according to WHO recommendations or national guidance documents.
• The new WHO recommendations for the investigation of patients favour the investigation of patients returning from the Arabian Peninsula or its neighbouring countries, but do not exclude the testing of patients with unexplained pneumonia in the absence such travel.
• Healthcare workers caring for patients under investigation should exercise stringent infection control measures as indicated by national or international guidance. Similarly, health professionals engaged in the medical evacuation of patients presenting with acute respiratory distress syndrome (ARDS) should be particularly vigilant, especially if patients originate from the Arabian Peninsula or its neighbouring countries.
• Testing for the novel coronaviruses should be considered in patients undergoing medical evacuation for ARDS prior to their transfer out of the Arabian Peninsula or its neighbouring countries. All public and private hospitals and private healthcare facilities should test patients on admission for the novel coronaviruses if they present with ARDS and have been medically evacuated from the Arabian Peninsula or its neighbouring countries. Referring providers should inform the recipient hospital if testing for novel coronavirus has been performed.
• Healthcare workers caring for confirmed cases should be monitored for early symptoms of infection. This includes healthcare workers who provided direct clinical or personal care, or performed examination of the cases while they were symptomatic. Close contacts of confirmed cases must be monitored for symptoms as well.
• Any probable or confirmed case diagnosed in the EU/EEA should be reported to national authorities through the Early Warning and Response System (EWRS) and to WHO under the International Health Regulations (2005). Reporting through EWRS allows for an automatic IHR notification and avoids double reporting.
• Patients still under investigation do not need to be reported internationally before confirmation. However, notification at state and national levels needs to follow national legislation or guidance to allow the implementation of infection control measures, initiation of outbreak investigation, and epidemiological monitoring.
• A specific serological test and seroepidemiological studies are needed to investigate the occurrence of mild and asymptomatic infections.
• ECDC endorses WHO's travel advice and does not advise any travel or trade restrictions for Saudi Arabia or Qatar.
• WHO and ECDC re-emphasise the importance of timely and thorough investigations; this includes the reporting of any clusters of severe acute respiratory infections in the community or in healthcare workers, regardless of where in the world they occur.

»» Read More

WHO Coronavirus Updates

Photo Credit NIAID

# 6760

 

While we have no indication of sustained community transmission, the emergence of a novel coronavirus in the Middle East that has infected at least 9 people (with another 9 either probable or suspected cases under investigation) since April, continues to capture the world’s public health agencies attentions.

 

The World Health Organization has updated two of their coronavirus documents; their coronavirus FAQ, and their interim surveillance recommendations.

 

Both are dated December 3rd, 2012.

 

 

First, the Frequently Asked Questions file, which has seen some minor modifications since the posting yesterday.

 

Frequently Asked Questions on novel coronavirus - update

3 December 2012

What is the novel coronavirus?

This is a new strain of coronavirus that has not been previously identified in humans.
Coronaviruses are a large family of viruses that are known to cause illness in humans and animals. In humans, this large family of viruses are known to cause illness ranging from the common cold to Severe Acute Respiratory Syndrome (SARS).

What are the symptoms of novel coronavirus?

In confirmed cases of illness in humans, common symptoms have been acute, serious respiratory illness with fever, cough, shortness of breath, and breathing difficulties. Based on current clinical experience, the infection generally presents as pneumonia. It has caused kidney failure and death in some cases. It is important to note that the current understanding of the illness caused by this infection is based on a limited number of cases and may change as more information becomes available.

Can it be transmitted from person to person?

This is not known with certainty at this time. The cases occurring in the same family raises the possibility of limited human-to-human transmission. Alternatively, it is possible that the infected family members were exposed to the same source of infection, for example, in a household or workplace.

How could I become infected with this virus?

To date, we do not know how humans have become infected with this virus. Investigations are underway to determine the virus source, types of exposure that lead to infection, mode of transmission and the clinical pattern and course of disease.

(Continue . . . )

 

The Interim surveillance recommendations have been reworded for clarity, but remain pretty much the same.

 

Interim surveillance recommendations for human infection with novel coronavirus

 
3 December 2012 
Update

Based on additional information received since the original surveillance recommendations were published, WHO is updating its guidance for surveillance. WHO will continue to update these recommendations as more information becomes available.

This document has been revised to emphasize the recommendations, rather than to summarize current
case reports. Current numbers and descriptions of reported cases are found at

http://www.who.int/csr/disease/coronavirus_infections/update_20121130/en/index.html.

The substance of the recommendations has not changed. Some wording has been changed for the sake of clarity. 

<SNIP>

The following should be carefully investigated and tested for novel coronavirus:

1.  Patients under investigation

A person with an acute respiratory infection, which may include history of fever or measured fever (≥ 38°C, 100.4°F) and cough

AND 

Suspicion of pulmonary parenchymal disease (e.g. pneumonia or Acute Respiratory Distress
Syndrome (ARDS)), based on clinical or radiological evidence of consolidation. 

AND

Residence in or history of travel to the Arabian Peninsula or neighboring countries within 10 days
before onset of illness. 

AND

Not already explained by any other infection or aetiology1 , including all clinically indicated tests
for community-acquired pneumonia according to local management guidelines. It is not necessary
to wait for all test results for other pathogens before testing for novel coronavirus.

2.  Ill contacts

Individuals with acute respiratory illness of any degree of severity who, within 10 days before onset of illness, were in close physical contact 2 with a confirmed or probable case of novel coronavirus infection, while the case was ill.

Any person who has had close contact with a probable or confirmed case while the probable or confirmed case was ill should be carefully monitored for the appearance of respiratory symptoms.

If symptoms develop within the first 10 days after contact, the individual should be considered a “patient under investigation”, regardless of the severity of illness, and investigated accordingly.

3.  Clusters

Any cluster 3 of severe acute respiratory infection (SARI) 4  , particularly clusters of patients requiring intensive care, without regard to place of residence or a history of travel

AND

Not already explained by any other infection or aetiology, including all clinically indicated tests
for community-acquired pneumonia according to local management guidelines.

4.  Health care workers 

Health care workers with pneumonia, who have been caring for patients with severe acute
respiratory infections, particularly patients requiring intensive care, without regard to place of
residence or history of travel. 

AND

Not already explained by any other infection or aetiology, including all clinically indicated tests
for community-acquired pneumonia according to local management guidelines.

-------------------------------------------------------------

1 Examples of other aetiologies include Streptococcus pneumoniae, Haemophilus influenzae type B, Legionella pneumophila, other recognized primary bacterial pneumonias, influenza, and respiratory syncytial virus.

2 Close contact is defined as: 

• Anyone who provided care for the patient, including a health care worker or family member, or who had other
  similarly close physical contact;
• Anyone who stayed at the same place (e.g. lived with, visited) as a probable or confirmed case while the case was ill.
  

3  A “cluster” is defined as two or more persons with SARI, with onset of symptoms within the same two-week period and who are associated with a specific setting, such as a classroom, workplace, household, extended family, hospital, other residential institution, military barracks or recreational camp.

4  Severe Acute Respiratory Infection (SARI) is defined as:   An acute respiratory infection with:

• history of fever or measured fever of ≥ 38 C° (100.4°F) and cough;
• onset within the last seven days; and
• requiring hospitalization.

 

 

With the onset of winter finding individual coronavirus infections becomes more difficult against the background noise of seasonal ILIs (influenza-like-illness).

 

Mild cases – if they exist – are unlikely to be detected unless purely by chance. 

 

We’ve seen in H5N1 endemic countries that clusters of severe influenza or pneumonia immediately become suspect – and fodder for the local press - but most of the time have turned out to be something other than bird flu.

Given the concerns over this emerging virus, we should probably expect to see that pattern repeated here. 

 

The price we pay for vigilance against emerging diseases is the possibility of false alarms. 

 

Unless and until we start seeing a lot of lab confirmed cases coming out of these reports, it is probably best to take any preliminary (and often hyperbolic) news reports with a hefty grain of salt.

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WHO: Background & Summary Of Coronavirus Cases

Photo Credit NIAID

# 5755

 

In addition to today’s GAR Update , the World Health Organization has published the following background & summary document on the novel Coronavirus.

 

 

 

Background and summary of novel coronavirus infection – as of 30 November 2012

Over the past two months, WHO has received reports of nine cases of human infection with a novel coronavirus. Coronaviruses are a large family of viruses; different members of this family cause illness in humans and animals. In humans, these illnesses range from the common cold to infection with Severe Acute Respiratory Syndrome (SARS) coronavirus (SARS CoV).

 

Thus far, the cases reported have come from Qatar, Saudi Arabia and Jordan. All patients were severely ill, and five have died.

 

The two Qatari patients are not linked. Both had severe pneumonia and acute renal failure. Both are now recovering.

 

A total of five confirmed cases have been reported from Saudi Arabia. The first two are not linked to each other; one of these has died. Three other confirmed cases are epidemiologically linked and occurred in one family living within the same household; two of these have died. One additional family member in this household also became ill, with symptoms similar to those of the confirmed cases. This person has recovered and tested negative, by polymerase chain reaction (PCR) tests, for the virus.

 

Two confirmed cases have been reported in Jordan. Both of these patients have died. These cases were discovered through testing of stored samples from a cluster of pneumonia cases that occurred in April 2012.

 

The two clusters (Saudi Arabia, Jordan) raise the possibility of limited human-to-human transmission or, alternatively, exposure to a common source. Ongoing investigation may or may not be able to distinguish between these possibilities.

 

The current understanding of this novel virus is that it can cause a severe, acute respiratory infection presenting as pneumonia. Acute renal failure has also occurred in five cases.

 

WHO recognizes that the emergence of a new coronavirus capable of causing severe disease raises concerns because of experience with SARS. Although this novel coronavirus is distantly related to the SARS CoV, they are different. Based on current information, it does not appear to transmit easily between people, unlike the SARS virus.

 

WHO has closely monitored the situation since detection of the first case and has been working with partners to ensure a high degree of preparedness should the new virus be found to be sufficiently transmissible to cause community outbreaks. Some viruses are able to cause limited human-to-human transmission under condition of close contact, as occurs in families, but are not transmissible enough to cause larger community outbreaks. Actions taken by WHO in coordination with national authorities and technical partners include the following:

• Investigations are ongoing to determine the likely source of infection and the route of exposure. Close contacts of confirmed cases are being identified and followed up.
• An interim surveillance recommendation has been updated to assist clinicians to determine which patients should undergo laboratory testing for the presence of novel coronavirus.
• Laboratory assays for the virus have been developed. Reagents and other materials for testing are available, as are protocols, algorithms and reference laboratory services. WHO has activated its laboratory network to assist in testing and other services. WHO has also issued preliminary guidance for laboratory biorisk management.
• Guidance is available for infection control.

Based on the current situation and available information:

• WHO encourages all Member States to continue their surveillance for severe acute respiratory infections (SARI) and to carefully review any unusual patterns.
• Further, testing for the new coronavirus of patients with unexplained pneumonias should be considered, especially in persons residing in or returning from the Arabian peninsula and neighboring countries. Any new cases should be promptly reported both to national health authorities and to WHO.
• In addition, any clusters of SARI or SARI in health care workers should be thoroughly investigated, regardless of where in the world they occur. These investigations will help determine whether the virus is distributed more widely in the human population beyond the three countries that have identified cases.
• WHO does not advise special screening at points of entry with regard to this event nor does it recommend that any travel or trade restrictions be applied.

WHO continues to work with Member States and international health partners to gain a better understanding of the novel coronavirus and the disease in humans and will continue to provide updated information. As the situation evolves, WHO will reassess its guidance and revise it accordingly.

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WHO Coronavirus Update: 9 Confirmed Cases

Coronavirus – Credit CDC PHIL

# 6754

 

Today the World Health Organization is reporting two more confirmed cases of infection from the novel coronavirus, this time from Jordan, and stemming from last April.

 

The two cases were part of an of cluster of an up-until-now unidentified severe respiratory illness that infected at least 11 people at a hospital in Zarqua (including 8 healthcare workers), last spring - killing two.  (See ECDC Report and FluTrackers  Thread)

 

Today’s revelation (which has been hinted at the past couple of weeks) raises additional questions over just how transmissible this virus may actually be.

 

Here is the latest update, bringing the total of confirmed cases to 9.

 

 

Novel coronavirus infection - update

30 November 2012 - In addition to the fatal case of novel coronavirus in Saudi Arabia reported to WHO on 28 November, two fatal cases in Jordan have been reported to WHO today, bringing the total of laboratory-confirmed cases to nine.

 

The latest confirmed case from Saudi Arabia occurred in October 2012 and is from the family cluster of the two cases confirmed earlier.

 

The two cases from Jordan occurred in April 2012. At that time, a number of severe pneumonia cases occurred in the country and the Ministry of Health (MOH) Jordan promptly requested a WHO Collaborating Centre for Emerging and Re-emerging Infectious Diseases (NAMRU – 3) team to immediately assist in the laboratory investigation. The NAMRU-3 team went to Jordan and tested samples from this cluster of cases.

 

On 24 April 2012 the NAMRU-3 team informed the MOH that all samples had tested negative for known coronaviruses and other respiratory viruses. As the novel coronavirus had not yet been discovered, no specific tests for it were available.

 

In October 2012, after the discovery of the novel coronavirus, stored samples were sent by MOH Jordan to NAMRU-3. In November 2012 NAMRU-3 provided laboratory results that confirmed two cases of infection with the novel coronavirus.

 

The MOH Jordan has requested WHO assistance in investigating these infections. A mission from WHO Eastern Mediterranean Regional Office (EMRO) and headquarters arrived in Amman on 28 November 2012 to assist in further epidemiological surveillance and to strengthen the sentinel surveillance systems for severe acute respiratory infections (SARIs).

 

In summary, to date a total of nine laboratory-confirmed cases of infection with the novel coronavirus have been reported to WHO – five cases (including 3 deaths) from Saudi Arabia, two cases from Qatar and two cases (both fatal) from Jordan.

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WHO Corrects Coronavirus Statement

 

 

Photo Credit NIAID 

# 6749

 

The `buzz’ in flublogia yesterday centered around the low-profile release of a new statement on the novel Coronavirus by the World Health Organization.  Not unexpectedly, it increased the number of confirmed cases to 7 (with 1 probable).

 

Somewhat confusingly, however, it cited only one death, contradicting earlier reports of two deaths (see WHO Confirms 7th Coronavirus Case for the original statement).

Sometime over the past 12 hours or so, a corrected version of the statement has been uploaded to the WHO site, and now they cite three deaths.

 

The corrected paragraph (a h/t to sharp-eyed Gert van der Hoek on FluTrackers for catching this) now reads (bolding mine):

 

The clinical picture in all cases was an acute respiratory infection presenting with signs and  symptoms of pneumonia. Of the seven confirmed cases, five developed acute renal failure and three of these died. The remaining two confirmed cases had pneumonia that required intensive support, without renal failure, and recovered. Three of the seven confirmed cases and the one probable case all belong to the same family and were living in the same household. 

 

The corrected document may be downloaded from:

Novel coronavirus technical guidance - surveillance

Interim surveillance recommendations for human infection with novel coronavirus
pdf, 93kb
• 
  28 November 2012

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Referral: CIDRAP News Summarizes The Coronavirus Story

Coronavirus – Credit CDC PHIL

# 6648

 

Yesterday Robert Roos, News Editor at CIDRAP News, undertook a difficult assignment; taking the often fragmentary (and sometimes contradictory) reports on the 7 confirmed (and 1 suspected) coronavirus cases in the Middle East - and putting them into a coherent narrative. 

 

Extremely well done, and highly recommended.

 

 

WHO cites 7th coronavirus case, gives surveillance guidance

Robert Roos News Editor

Nov 29, 2012 (CIDRAP News) – A third case in a family cluster of novel coronavirus infections has been confirmed, raising the global case count to seven, and the fourth illness in the family is now listed as a probable case, the World Health Organization (WHO) has announced.

 

In a statement dated yesterday, the WHO also indicated that only one death has been attributed to the novel virus so far, contradicting a Nov 23 announcement that reported two deaths among the first six cases.

(Continue . . . )

»» Read More

Branswell On Expanded Surveillance For The Coronavirus

 

Coronavirus – Credit CDC PHIL

# 6743

 

Helen Branswell, ace health reporter for The Canadian Press, has an excellent look this morning at the reasons behind the World Health Organization’s request for enhanced global surveillance for the novel coronavirus recently detected in the Middle East.

 

Rather than detract from what is already a concise and informative report, I’ll simply step aside and invite you to read:

 

 

The Canadian Press - ONLINE EDITION

New coronavirus cases suggest source may be more widespread, WHO says

By: Helen Branswell, The Canadian Press

Posted: 3:02 AM |

Clues gleaned from the most recent infections with the new coronavirus are behind the World Health Organization's decision to warn countries to broaden their surveillance for cases, an expert with the agency says.

 

The Geneva-based global health body now believes the risk of exposure to the new virus may exist beyond Saudi Arabia and Qatar, so telling countries they need only look for sick people with travel or residency links to those countries may be misleading and counterproductive.

(Continue . . . )

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ECDC Updates Their Coronavirus Risk Assessment

 

 

# 6741

 

 

The announcement late last week that several new coronavirus cases have been detected in the MIddle East, including what appears to have been a limited cluster of cases in a household, has prompted an update from the ECDC of their risk assessment.

 

Available as PDF in the following languages:

 

ABSTRACT

Since June 2012 and up to 25 November 2012, a total of six confirmed cases of infection with the novel coronavirus (of whom two died) have been reported to WHO. All cases share a history of residence in, or travel to, the Kingdom of Saudi Arabia (KSA) or Qatar. The source and possible routes of transmission of the virus remain unknown.

 

ECDC updated risk assessment concludes that in the absence of evidence of sustained person-to-person transmission outside of household settings, the current facts still point towards a hypothesis of a zoonotic or environmental source with occasional transmission to exposed humans. WHO does not advise any travel or trade restrictions at this point for KSA or Qatar.

 

 

The main conclusions from this report include:

 

•  In September 2012, a group of novel coronaviruses were identified in two patients presenting with a severe acute respiratory illness. Both had a travel history to the Kingdom of Saudi Arabia (KSA) or Qatar. These novel coronaviruses are genetically different from the virus that in 2003 caused the SARS outbreaks (SARS-CoV).

 
•  Since June 2012 and up to 25 November 2012, a total of six confirmed cases of infection with the novel coronavirus (of whom two died) have been reported to WHO, meeting the requirements of its case definitions. Severe respiratory disease was the common factor in all of these. Two of the cases were diagnosed after being transferred to Europe for further medical care. 

•  All six confirmed cases reside or travelled to KSA or Qatar. Two confirmed cases in KSA are from the same family household. A further person in this household is under investigation for infection with the novel coronavirus.

•  The source and possible routes of transmission of the virus remain unknown. Investigations have yet to identify the source or route of infection and infectiousness. At this stage, the detection of a household cluster does not provide conclusive evidence for or against limited person-to-person transmission. It is possible that enhanced surveillance in KSA, Qatar and elsewhere will detect additional sporadic cases and clusters.

 

•  Initial laboratory analyses in Europe of the first of these viruses (known as hCoV-EMC) suggest that it may be able to infect a range of mammalian cells including human cells making human-to-human transmission theoretically possible.

 
•  Healthcare workers should be made aware of the possibility of attending to patients matching the characteristics of patients requiring investigation as per WHO case-definition; however, the geographical area should be extended from KSA and Qatar to include the whole of the Middle East. Healthcare workers caring for patients under investigation should exercise stringent infection control measures following national or international guidance. Testing for the novel coronaviruses should be considered in patients potentially undergoing medical evacuation for acute respiratory distress syndrome (ARDS) prior to their transfer. Healthcare workers caring for confirmed cases and close contacts of confirmed cases should be monitored for symptoms.

•  Patients returning from the Middle East with unexplained pneumonia or ARDS, i.e. where full diagnostic workup for respiratory pathogens (bacterial and viral) is negative, should be considered for investigation and tested for novel coronavirus by EU national reference and research laboratories capable of such testing.

 
•  Any probable or confirmed case being diagnosed in the EU/EEA should be reported to national authorities, through the Early Warning Response System (EWRS) and to WHO under the International Health Regulations (2005) (most easily via the option to report to IHR through EWRS to avoid double report entry).

 

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Hong Kong’s Coronavirus Response

Coronavirus – Credit CDC PHIL

# 6738

 

No city experienced a greater impact from the SARS epidemic a decade ago than did Hong Kong in 2003. Between March 11th and June 6th, a total of 1750 cases were identified, and of those, 286 died.

 

From the JRSM (Journal of the The Royal Society of Medicine) in August of 2003, we get this description of the spread of the disease in the city.

 

 The SARS epidemic in Hong Kong: what lessons have we learned?)

Lee Shiu Hung, MD FFCM

(Excerpt)

The SARS epidemic in Hong Kong has gone through three phases. The first was an explosive outbreak in a teaching hospital, affecting a large number of hospital staff and medical students. This phase took place in March 2003.

The second phase was an outbreak in the community as a result of the spread of infection from the hospital to the community. This reached its peak in early April 2003 when the disease affected a housing estate known as Amoy Gardens; a total of 329 residents in that estate came down with the disease and 33 died.

The third phase began in early May, with continuing occurrence of the disease in eight hospitals and more than 170 housing estates throughout the city but with the daily number of new cases declining from double to single digits in mid-June (the time of writing).

(Continue . . .)

 

Out of this trial by fire, Hong Kong’s Centre For Health Protection was born, and today it arguably runs one of the most proactive disease surveillance systems in the world.

So one should not be surprised to find a link to the new coronavirus front and center on the CHP’s home page.

 

On September 27th, just 3 days after being notified of the first coronavirus case, Hong Kong modified their Prevention and Control of Disease Ordinance (Cap. 599) to include “Severe Respiratory Disease associated with Novel Coronavirus”  as one of the statutorily notifiable diseases (see Letter To Doctors).

 

You’ll find a variety of notices, and letters to institutions regarding this emergent coronavirus on this page.

 

Today the Hong Kong government posted some remarks by their Secretary for Food and Health, Dr Ko Wing-man. As you’ll see, that while they are watching this situation carefully, at this time they have no plans to upgrade their alert level.

 

 

SFH on overseas cases of Severe Respiratory Disease associated with Novel Coronavirus

Following is the transcript of remarks made by the Secretary for Food and Health, Dr Ko Wing-man, after attending a public function this afternoon (November 25):

Secretary for Food and Health: Regarding the new novel coronavirus causing severe respiratory disease, there is a concern that over a span of two months, another batch of four new cases (three from Kingdom of Saudi Arabia and one from Qatar) was confirmed by the World Health Organization (WHO). The WHO also pointed out that we cannot assume the source of infection is only present in the countries concerned. Patients who have not got a history of travel to these two particular middle-east countries but developed symptoms of illness similar to the diseases caused by this new novel coronavirus, they might still be considered necessary to undertake the test for the new coronavirus.

Reporter: (On emergency level in Hong Kong for an outbreak of the new disease)

Secretary for Food and Health: The Centre for Health Protection of the Department of Health is consistently conducting risk assessment, following up on whether there will be any new information or new cases reported. Up to this moment, there is no need to upgrade our response level for the infectious disease outbreak. However, the new reported cases (due to infection with the novel coronavirus) highlighted the need to enhance our surveillance measures, both at the hospitals as well as at the immigration check points. 

(Please also refer to the Chinese portion of the transcript.)

Ends/Sunday, November 25, 2012
Issued at HKT 20:23

 

You can pretty much expect an enhanced level of surveillance around the world in the coming days as a result of last week’s announcement from the World Health Organization (see WHO Announces Additional Coronavirus Cases).

 

It is far too soon to know whether this virus will pose a major public health threat, but one of the lessons learned from the SARS outbreak of 2003 is that delays in reporting can have deadly consequences.

 

It is far better for public health officials to be hyper-vigilant today, than to have to play catch up tomorrow.

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Novel Coronavirus: More Questions Than Answers

 

Coronavirus – Credit CDC PHIL

 

 

# 6736

 

While we wait for more information on the novel coronavirus that continues to pop up in the Middle East (see WHO Announces Additional Coronavirus Cases), it isn’t lost on most infectious disease geeks that this month (November) marks the 10th anniversary of the initial outbreak of SARS in Guangdong Province, China. 

 

Over the next eight months SARS (Severe Acute Respiratory Syndrome) infected more than 8,000 people, killing roughly 10%.  China, Hong Kong, and Taiwan were the hardest hit, but a handful of cases made it into Canada, the United States, and across Europe.

 

Source World Health Organization

 

By mid-April of 2003 we learned the illness was due to a novel coronavirus (SARS-CoV). A bit of a surprise really, since human coronaviruses had previously only been linked to mild respiratory illnesses.

 

Although eventually contained, SARS was the first genuine pandemic threat of the 21st century. It also served to remind us that influenza isn’t the only virus with pandemic potential.

 

One of the most authoritative accounts of the SARS outbreak, and how it appears to have been linked to the practice of consuming bushmeat in China, comes from Karl Taro Greenfeld’s book The China Syndrome: The True Story of the 21st Century's First Great Epidemic.

 

While civet cats, which were served in `wild flavor’ restaurants in China, were first implicated in this outbreak (see A Civets Lesson), bats have also been shown to carry this Coronavirus, and may be the primary host.

 

The jury is out on whether the virus was transmitted directly to man from bats, or perhaps from bats to civits to humans.

 

Now the world is watching another coronavirus – definitely not SARS – but of the same general family, and capable of producing serious, even fatal illness in humans.

 

And like SARS, this new virus may be of bat-origin.

 

What we don’t know (yet) is the source of this virus, how it has managed to jump to at least 6 people in two countries, and whether – once contracted – it can be passed on to other humans.

 

Up until this week, the reassuring mantra has been that the virus does not transmit from human-to-human (H2H). The reason for that assumption has been the lack of nosocomial infection in hospitals where the first couple of cases were treated.

 

But this week we’ve learned of two family members in Saudi Arabia who tested positive for the virus, and that there were two other family members with similar symptoms, one of whom died.   

 

One of the two additional family members tested negative, but we’ve little actual experience with the recently developed tests for this virus, and so its sensitivity isn’t well established. Tests are pending on the fourth family member who died.

 

Although a common environmental exposure is always possible, these latest revelations put H2H transmission back on the table.

 

The lack of human-to-human transmission in the earlier cases doesn’t rule out H2H transmission now, or in the future. When a virus jumps to a new species, it isn’t necessarily completely optimized for its new environment.

 

So one of the things we watch for are signs of further adaptation as the virus `figures out’ its new host. 

 

Influenza viruses are the absolute master at this type of evolutionary adaptation, but are by no means the only virus with this ability.

 

One of the ways researchers test viruses is via a serial passage experiment.  It is essentially how Ron Fouchier created a `mammalian-adapted’ H5N1 virus in the laboratory last year, and it mimics what viruses do in the wild.

 

Last year, in H5N1: A Rite Of Passage, I described how serial passage studies are conducted, but briefly, an experimental animal is infected with a virus, and that virus is then collected and used to inoculate another lab animal. 

 

Simplified Illustration of a Serial Passage Experiment. 

 

The process is repeated, and after 10 or so iterations, the virus is then examined for `adaptive changes’. Sometimes, after multiple passes through a series of hosts, the virus picks up mutations that favor its survival in the new species.

 

This process happens outside of the laboratory as well, which is why – when a virus jumps to a new species – we watch it carefully to see if it develops `legs’; the ability to spread efficiently.

 

Over the summer we watched as swine-variant H3N2v viruses tried – and for the time being, failed – to make a sustained jump to humans (see MMWR: H3N2v Related Hospitalizations In Ohio – Summer 2012). But past performance is no guarantee of future results.

There’s always next year.

 

And so it is with this new coronavirus. It could recede back into the woodwork, or it could sputter ineffectually for years, threatening occasionally - but never quite succeeding -  as a major public health threat.

 

Or it could develop `legs’ and become the next big global health threat.  At this point, no one knows.

 

For those looking for comfort, pandemics are a fairly rare occurrence. Many viruses emerge and threaten, but few are truly ready for prime time.

 

Like with H5N1, H3N2v, Nipah, and a handful of other emerging viruses that continue to make the occasional foray into the human population, we remain in a watchful waiting mode with this new coronavirus. 

 

 

 

For more coverage of this developing story, I’d recommend Maryn McKenna’s blog from last night:

 

WHO Announces Family Cluster of Cases of New Coronavirus

 

Any article or report from Helen Branswell is worth reading, but specifically this one from yesterday, and this one from today.

 

And finally, Crofsblog for the best news round up on the coronavirus, and many other EIDs.

 

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