# 6036
Over the past year I’ve posted more than 900 blogs, dozens of which looked at some of the latest research into influenza and other emerging infectious diseases.
Since these studies oft times make an initial splash only to get lost in the passing parade of new reports, today I’ve some brief summaries (with links back to the original blogs) on some of the research of 2011 I believe is deserving of a second look.
This is the second such roundup, the first one may be accessed at this link.
Last April in Lancet Study: NDM-1 In New Delhi Water Supply, we saw a report authored by Timothy Walsh, Janis Weeks , David M Livermore, and Mark A Toleman that looked for – and found – bacteria carrying the NDM-1 enzyme in New Delhi's drinking water supply.
We’ve a press release on this study, issued by Cardiff University, that gives the highlights of the research, but the `money quote’ (emphasis mine) buried about halfway down is:
Resistant bacteria were found in 4 per cent of the water supplies and 30 per cent of the seepage sites. The researchers identified 11 new species of bacteria carrying the NDM-1 gene, including strains which cause cholera and dysentery.
Below is a link to the Lancet study, which you can read in its entirety (a free registration is required).
The Lancet Infectious Diseases, Early Online Publication, 7 April 2011
doi:10.1016/S1473-3099(11)70059-7
Dissemination of NDM-1 positive bacteria in the New Delhi environment and its implications for human health: an environmental point prevalence study
Prof Timothy R Walsh PhD , Janis Weeks BS, David M Livermore PhD , Mark A Toleman PhD
Again in April, we saw research seeking to answer the question over why there was such a wide variance in death rates around the world with the 1918 Spanish influenza.
In 2006, in a Lancet journal (doi:10.1016/S0140- 6736(06) 69895-4) article cited as much as a 30-fold difference in mortality rates around the world:
Christopher JL Murray , Alan D Lopez , Brian Chin , Dennis Feehan , Kenneth H Hill
Excess mortality ranged from 0·2% in Denmark to 4·4% in India. Since there was some under-registration of mortality in India, total pandemic mortality could have been even higher.
This wide disparity in mortality rates – much of it based on anecdotal accounts – has long intrigued researchers. This new study from the Norwegian Institute of Public Health that attempts to answer some of these questions.
What they found was that the mortality rate varied nearly 100 fold between remote, rural regions and urban populations, and that in the more remote areas, older persons were just as susceptible to the virus as those who were younger.
This study appears in the Journal Epidemics.
Geography May Explain Adult Mortality from the 1918–20 Influenza Pandemic
Original Research Article
Pages 46-60
Svenn-Erik Mamelund
The theory that a similar H1 virus circulated prior to 1890 – and that provided some immunity to those over the age of 30 – is bolstered by this study.
Given the current flap over the H5N1 experiments conducted by Ron Fouchier in the Netherlands and Yoshihiro Kawaoka at the University of Wisconsin (see The Biosecurity Debate On H5N1 Research) the next two studies deserve a second look as well.
Simplified Illustration of a Serial Passage Experiment.
In H5N1: A Rite Of Passage we looked at how serial passage studies are conducted, and at one in particular that appeared in the Journal of Animal and Veterinary Advances that looked at increases in pathogenicity (in mice) of two H5N1 viruses after six serial passages in quail.
The study is called:
The Pathogenicity Variation of Two Quail-Origin H5N1 HPAV to BALB/c Mice after Six Passages in Quail
Hailiang Sun, Peirong Jiao, Yuqiang Cheng, Runyu Yuan, Pengfei Cui, Liming Jin, Chaoan Xin and Ming Liao
Another study, profiled in PNAS: Reassortment Potential Of Avian H9N2, looked at the reassortment potential of the avian H9N2 virus and H1N1. Research was done using ferrets whose respiratory physiology is considered relatively close to humans.
Compatibility of H9N2 avian influenza surface genes and 2009 pandemic H1N1 internal genes for transmission in the ferret model
J. Brian Kimble, Erin Sorrell, Hongxia Shao, Philip L. Martin, and Daniel Roberto Perez
(Excerpt from the abstract)
Four reassortant viruses were generated, with three of them showing efficient respiratory droplet transmission. Differences in replication efficiency were observed for these viruses; however, the results clearly indicate that H9N2 avian influenza viruses and pH1N1 viruses, both of which have occasionally infected pigs, have the potential to reassort and generate novel viruses with respiratory transmission potential in mammals.
The entire study is available online, and open access.
And in Study: Prior Antibiotic Use & MRSA In Children Canadian researchers, examining 13 years worth of data from the UK’s General Practice Research Database (GPRD), came up with what they called a `robust association’ between a prior history of antibiotic use and rates of CA-MRSA (Community Acquired Methicillin Resistant Staph Aureus) infection in children.
The study appeared Aug. 1st in the Archives of Pediatrics & Adolescent Medicine.
Verena Schneider-Lindner, MD, MSc; Caroline Quach, MD, MSc; James A Hanley, PhD; Samy Suissa, PhD
Arch Pediatr Adolesc Med. Published online August 1, 2011. doi:10.1001/archpediatrics.2011.143
What these researchers found was that while nearly half of children with MRSA in this study had no recent history of antibiotic use, the adjusted relative risk (RR) of developing MRSA was 3.5 times higher among children who had received antibiotic treatment in the previous 30-180 days before infection.
And that relative risk increased substantially among children who received more than one course of antibiotics.
To find more blogs specific to research you can use the RESEARCH quick link on my sidebar.
As news is often slow during the holiday season, over the next couple of weeks I plan to post one or two more retrospectives on the news and research of the year that was.
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