Building Disaster Resilient Cities

 

 

 

# 6326

 

Around the globe cities are increasingly where jobs are to be found, and where goods and services are most likely to be available. And so not surprisingly, today, half the world’s population – some 3.5 billion people – now live in urban areas.

 

With the clustering of millions of people into relatively small areas, we’ve created a scores of `target-rich environments’ for natural disasters such as earthquakes, floods, and severe storms. 

 

The equation is pretty simple. More people in a small space = more potential casualties.

 

And the more densely populated a region is, the more economic impact a disaster will have as well.

 

Last year, in UNDP: Supercities At Seismic Risk, we looked at the concerns that half of the world’s supercities  (urban areas with 2 million – 15 million inhabitants) are at risk of significant seismic activity.

 

Last December, in WHO e-Atlas Of Natural Disaster Risks To Europe, we looked at some of the disaster threats facing Europe, and in January of this year I blogged that a UN Agency Warns On Global Seismic Risks.

 

 

In 2010, more than 200,000 inhabitants in and around Port-au-Prince, Haiti died during their 7.0 magnitude earthquake. Much of that death toll can be attributed to the poor construction standards in that region that led to tens of thousands of building collapses.

 

 

While we can’t stop earthquakes from striking, or hurricanes from making landfall, we can design our cities to be more resilient for when they do.  Not only can this reduce the death toll and human suffering, it can reduce the economic impact as well.

 

Which brings us to a new publication from the United Nations International Strategy For Disaster Reduction (ISDR).

 

 

 

How to make cities more resilient: a handbook for local government leaders

A contribution to the global campaign 2010-2015 Making Cities Resilient – 'My City is Getting Ready!':

This handbook provides mayors, governors, councillors and other local government leaders with a generic framework for risk reduction and points to good practices and tools that are already being applied in different cities for that purpose. It discusses why building disaster resilience is beneficial; what kind of strategies and actions are required; and how to go about the task. It offers practical guidance to understand and take action on the "Ten Essentials for Making Cities Resilient" as set out in the global campaign "Making Cities Resilient: My City is Getting Ready!".

 

A web-based information platform, where cities and local governments can share their own tools, plans, regulations and practices, complements the Handbook and will be available through the Campaign website.

While billed as a handbook primarily for city officials, citizens and residents of these urban areas have a deep seated interest in seeing that the proper steps are taken to mitigate potential disaster losses.

 

I’m a firm believer that true resilience is built from the bottom up, not the top down.  And so it behooves everyone – no matter where they live, or what position in their community they may hold – to look at their surroundings and do a basic threat assessment. 

And then take whatever prudent steps they can to to reduce those risks, and to encourage those around them to do the same.

 

 

No matter where you live in the world, the resources of the FEMA, and READY.GOV websites can be used to help make you and your community better prepared to deal with disasters.

 

While designed specifically for the threats facing southern California, the The L. A. County Emergency Survival Guide provides an excellent starting place for any family doing `all threats’ emergency planning.

 

 

 

Most importantly, everyone needs an appropriate disaster plan, just as everyone should have a good first aid kit, a `bug-out bag’, and sufficient emergency supplies to last a bare minimum of 72 hours.

 

For more on  disaster preparedness, I would invite you revisit these blogs:

 

When 72 Hours Isn’t Enough

In An Emergency, Who Has Your Back?

An Appropriate Level Of Preparedness

The Gift Of Preparedness 2011

»» Read More

Study: Pandemic Mitigation by Early School Closure

 

 

# 4758

 

 

One of the first steps taken by many countries to reduce the spread of novel H1N1 last year was the closing of schools in affected communities.

 

By early May (2009) it was apparent that the severity of this particular influenza virus was less than originally feared, and many public health agencies moderated their recommendations  (see CDC No Longer Recommending School Closures For A/H1N1).

 

But a future, more severe pandemic, the extended closing of schools will once again likely be considered to help reduce the spread of the virus.

 

It isn’t an easy decision, however.  School closings are controversial, and the issues complex  (see The Debate Over School Closures).

 

Working parents rely on schools to watch their kids for much of the year during the day, and many low income families benefit from the school lunch program.  And of course, when schools are closed during a pandemic, some kids may congregate elsewhere and spread the virus anyway.

 

Many parents, however, would take exception to the notion of sending their kids to school during a pandemic.  Not only would it, in their estimation - endanger their children – it increases the odds of them bringing the virus home to the rest of the family as well.

 

So it is important to get some approximation of the benefits that school closings would generate.  To that end we’ve seen several studies over the past year that have produced varying estimates.

 

Study: Student Behavior During Pandemic School Closings

School Closures Revisited

Study: Effect Of School Closures On Viral Transmission

 

Today we’ve another study appearing in BMC Infectious Diseases, this time from the School of Computer Science and Software Engineering at the the University of Western Australia.

 

Here is the abstract (slightly reformatted for readability).

 

Developing guidelines for school closure interventions to be used during a future influenza pandemic

Nilimesh Halder , Joel K Kelso  and George J Milne

BMC Infectious Diseases 2010, 10:221doi:10.1186/1471-2334-10-221

Published: 27 July 2010

Abstract (provisional)

Background

The A/H1N1 2009 influenza pandemic revealed that operational issues of school closure interventions, such as when school closure should be initiated (activation trigger), how long schools should be closed (duration) and what type of school closure should be adopted, varied greatly between and within countries. Computer simulation can be used to examine school closure intervention strategies in order to inform public health authorities as they refine school closure guidelines in the light of experience with A/H1N1 2009 pandemic.

Methods

An individual-based simulation model was used to investigate the effectiveness of school closure interventions for influenza pandemics with R0 of 1.5, 2.0 and 2.5. The effectiveness of individual school closure and simultaneous school closure were analyzed for 2, 4 and 8 weeks closure duration with a daily diagnosed case based intervention activation trigger scheme. The effectiveness of combining antiviral drugs with school closure was also investigated.

Results

Attack rate was reduced from 33% to 19% (14% reduction in overall attack rate) by 8 weeks school closure activating at 30 daily diagnosed cases in a community for an influenza pandemic with R0 = 1.5; whereas combined with antivirals, 19% (from 33% to 14%) reduction in attack rate was obtained.

 

For R0 >= 2.0, school closure would be less effective. An 8 weeks school closure strategy gives 9% (from 50% to 41%) and 4% (from 59% to 55%) reduction in attack rate for R0 = 2.0 and 2.5 respectively; however, school closure plus antivirals would give a significant reduction (~15%) in over all attack rate. The results also suggest that an individual school closure strategy would be more effective than simultaneous school closure.

Conclusions

Our results indicate that the particular school closure strategy to be adopted depends both on the disease severity, which will determine the duration of school closure deemed acceptable, and its transmissibility.

 

For epidemics with a low transmissibility (R0 < 2.0) and/or mild severity, individual school closures should begin once a daily community case count is exceeded. For a severe, highly transmissible epidemic (R0 >= 2.0), long duration school closure should begin as soon as possible and be combined with other interventions.

 

 

George E. P. Box, Professor Emeritus of Statistics at the University of Wisconsin, is often credited with coining the familiar adage:

 

“All models are wrong, but some models are useful.”

 

While imperfect, we use computer models every day to try to mathematically simulate real-life events;  everything from highway traffic flow to weather forecasting.

 

The authors describe some of the limitations to their study, including:

 

As the model is based on a population in a developed country the outcomes may not be applicable to populations in a developing country, where populations may be less mobile and have higher population densities.

 

We have focused on the reduction in the number of daily symptomatic cases and the cumulative illness attack rate as they are used for determining intervention effectiveness rather than focusing on influenza-related adverse events such as hospitalizations and deaths.

 

We also do not take account of possible antiviral drug resistance [40] [41] that may arise due to the implementation of antiviral drug strategies, as our main goal is to suggest refinements to policy guidelines for school closure.

  

In this case, the authors based their modeling on a medium sized (pop. 30,000) town in Western Australia. 

 

They find a substantial reduction in the spread of a future pandemic influenza can be achieved by the (extended) closing of schools at the optimum point in the local spread of the virus.

 

Gauging when and how long to close schools, however, may require information that isn’t always immediately available.  Such as the R0 (basic reproductive number) of the virus, the CFR (Case Fatality Ratio) or, the number of people actually infected in a community. 

 

Despite the fact that life is messy, and computer models aren’t perfect at depicting it, the entire report is worth reading.

 

This is how the authors sum up their study.

Conclusions 

Our simulation results give guidance as to public health policy decisions in the refinement of school closure strategies to be used in a future influenza pandemic. We have systematically evaluated school closure operational issues to determine when schools should be closed and re-opened to achieve the maximum reduction in influenza spread.

 

We found that the optimal timing of school closure depends both on the duration of school closure (which we assume will depend on the severity of the influenza strain, with strains that are more severe in terms of serious infection outcomes making longer periods of school closure acceptable) and on the transmissibility of the influenza strain (which influences the rate of growth and spread of the epidemic).

 

Accurate early estimates of epidemic characteristics such as the basic reproduction number and disease severity are thus necessary to achieve the maximum case reduction from school closure.

 

We found that a policy of allowing schools to close individually was much less sensitive to the precise timing of the intervention than a policy of simultaneous community-wide school closure, a valuable observation given the difficulty in determining the true degree of epidemic spread in the early stages of an outbreak.

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Updating CIDRAP’s Promising Practices

 

 

# 4478

 

 

It’s been awhile since I last highlighted CIDRAP’s Promising Practices Website, and since that time they’ve added a number of locally created preparedness programs that can serve as an outline for other communities to learn from or follow.  

 

If you are interested in starting a community preparedness program, rather than re-invent the wheel, a visit to this website makes a lot of sense.  

 

 

Some of the newest entries on the site include:

 

• Public health and faith-based organizations partner to offer food and vaccine to the homeless (SC, CA, FL) describes several efforts to provide homeless and low-income people with access to H1N1 vaccine. View Practice

• Telephone Survey Used to Understand Community Vaccine Uptake (KY) describes how Kentucky conducted a telephone survey to determine vaccine coverage among target groups. View Practice

• State Police Transport Influenza Samples to State Lab (LA) details how the Louisiana State Police transported large volumes of influenza samples from numerous regional locations to the state laboratory. View Practice

• Zoo Vaccination Clinic Targets Daycare Children (VA) explains how combining a vaccination clinic with an entertaining field trip can be successful. View Practice

• Food Workers Learn about Flu (IL) details how Illinois utilized sanitation workers to share H1N1 messages with their clients. View Practice

• Mobile Vaccination Clinic Reaches Rural Areas (WV) describes how a mobile clinic traveled to nine rural locations to deliver H1N1 vaccines. View Practice

• Vaccination Clinics for State Employees (AR, AZ, IN, UT) details the approaches used by four states to vaccinate members of state governmental organizations. View Practice

 

 

With more than 280 practices now available, you could spend days combing through this repository of good ideas.   

 

To assist in navigating the site, you can of course do a search.  But the webmaster has also provided a handful of predefined searches as well. 

 

Personal Preparedness

Vulnerable Populations

Home Care

School Toolkits

Other Toolkits

By Language

By Ethics Projects

By State

 

 

A highly recommended treasure trove of good preparedness information and ideas. 

 

Plan on visiting often.

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UK: National Pandemic Flu Service Stands Down

 

 

 

# 4343

 

In another sign that the pandemic of 2009 is winding down – at least for now –  the UK has closed their pandemic flu hotline.  If needed, it could be reactivated in a week’s time, according to officials.

 

The Pandemic Flu Hotline has not been without its critics, of course.

 

Some have felt that the liberal dispensing of antivirals – based solely on a telephone questionnaire – was an inappropriate and potentially dangerous mitigation measure.

 

Others believe that rapid access to antivirals saved lives and took a tremendous burden off of their National Health Service.

 

No doubt post-pandemic analyses will be conducted of this mitigation strategy, along with those run by other countries, to see what worked well . . .  and what didn’t.

 

One of the advantages of not having everyone on the same mitigation page is that we now have some data for comparisons, and hopefully will be able to make better informed decisions in the next global health crisis.

 

This from Emergency Services News.

 

Swine Flu services close

February 11th, 2010

The National Pandemic Flu Service, set up to support the NHS in dispensing drugs to patients at the height of the pandemic, has closed today.

 

The service has closed after a sharp decline in the number of recorded new cases of the virus.

 

Official shave said that both the hotline and website that were established as part of the service could be up and running again in seven days if new cases begin to rise again.

 

Britain was among the first countries hit by swine flu after it emerged in Mexico early last year, and at one point recorded more than 100 000 new cases a week as the virus was officially declared a pandemic.

 

The latest update from the Department of Health, on February 4, said new cases of swine flu remain near their lowest level since the virus first appeared here. However, the vaccination programme is continuing.

 

So far, about five million of the 90 million doses of antiviral drugs that were made available have actually been dispensed.

(Continue . . . )

 

»» Read More

School Closures Revisited

 

 

 

#4328

 

In case anyone had any doubts beforehand, the pandemic of 2009 demonstrated that NPIs (non-pharmaceutical interventions) such as school closures, hand washing, and staying home when sick are our first line of defense during a disease outbreak. 

Vaccines take months to manufacture, and would likely remain in short supply for months beyond that.  

 

While novel H1N1 proved to be a moderate pandemic virus, with a low CFR (Case Fatality Ratio), the next global health challenge may prove far more daunting.

 

The good news is novel H1n1 afforded us an excellent opportunity to try various mitigation strategies around the world, and we can now begin to compare their relative efficacies.

 

School closures were already part of the US government’s NPI plans for a severe pandemic, and were instituted in the early days of the swine flu outbreak.   But school closures have a cost in terms of social and economic impacts, and must be balanced against the benefits.

 

Although the assumption has been that school closures would reduce transmission of a pandemic virus, the question has always been: How much?

We now have a study, based on school closures in Hong Kong last summer, that give us at least a partial answer to that question.

 

Of course, the old saw that `If you’ve seen one pandemic, you’ve seen one pandemic’ still holds. Methods and rates of transmission can vary from one virus to another, and quite frankly, from one region or society to another. 

 

That said, researchers in Hong Kong have come up with a number they feel illustrates the benefits of early and sustained school closures during this past summer.  

 

Their work appears in this month’s CDC’s Journal of Emerging Infectious Diseases.

 

DOI: 10.3201/eid1603.091216

Wu JT, Cowling BJ, Lau EHY, Ip DKM, Ho L-M, Tsang T, et al. School closure and mitigation of pandemic (H1N1) 2009, Hong Kong. Emerg Infect Dis. 2010 Mar; [Epub ahead of print]

School Closure and Mitigation of Pandemic (H1N1) 2009, Hong Kong

In Hong Kong, kindergartens and primary schools were closed when local transmission of pandemic (H1N1) 2009 was identified. Secondary schools closed for summer vacation shortly afterwards. By fitting a model of reporting and transmission to case data, we estimated that transmission was reduced ≈25% when secondary schools closed

 

A 25% reduction in transmission is actually better than some previous studies had suggested, and as the authors point out below, the benefits of school closures probably extended into the greater community as well.

 

Furthermore, assuming that children are responsible for up to half of all community transmission (8), it is likely that protection of younger children had substantial indirect benefits. Previous studies have suggested that sustained school closures during a pandemic could reduce peak attack rates and prevent 13%–17% of total cases in France (8) or <20% of total cases in the United Kingdom (3).

 

Our finding that the reproductive number declined from 1.5 during the kindergarten and primary school closures to 1.1 during summer vacation suggests that a much more substantial drop in attack rates would result from sustained school closures.

 

 

This study, when combined with others that will no doubt arise from the pandemic, should give public health officials better data to base their school closing decisions on for the next pandemic.

 

It still remains a judgment call, of course.   You still have to balance the severity of the illness against the impact of closing schools.

But at least now we are getting a better idea of what might be gained by such measures.

»» Read More

Take The Pledge

 

 

# 3825

 

 

Yesterday, on Twitter, this `tweet’ came across my desktop from @Caroldn. 

 

It was so good, I immediately re-tweeted it. 

 

If you get sick, pledge to yourself: "This germ stops with me" Don't pass it forward.

 

A simple enough message.

 

Yet - if we all followed this advice -  we could substantially reduce the impact of this pandemic virus practically overnight.

You see, this novel H1N1 virus needs fresh, susceptible hosts in order to survive.  Each person who gets infected, on average, ends up passing on the virus to between 1.5 to 2.0 other people.  

 

If we can reduce that number, we slow the pandemic.  We break the chain of infection. 

 

Which means, if you are sick.  Please stay home.  

 

Vow, if you get sick, to become a dead-end for the virus.

 

Let the virus you caught, and all of the billions of copies it will generate during your illness, die with your infection.   You can do that by simply not exposing others while you are sick. 

If you are an employer, send home anyone who appears ill. 

 

The marginal gain you might get out of having that person working isn’t worth the risk of their infecting other employees or your customers.

 

And although they like seem small things, it really does matter that we cover our coughs and wash our hands.

 

Even when we don’t think we are sick.  

 

While this virus does not pose a serious health threat to the vast majority of people, for a small number, it can be life threatening.

 

The virus you pass  on to a co-worker could end up being passed on to their toddler with asthma, or an aunt with diabetes, or a neighbor on chemotherapy.

 

You may never know what ill effects your going to work or to school with this virus may have, but that won’t change the reality. 

 

Our actions have consequences.  

 

Every person who gets vaccinated, by the way, is (generally speaking) one less susceptible host for the virus to infect, replicate in, and spread from.

 

During a pandemic, we owe it to our friends, our neighbors, our co-workers, and our society to make smart, responsible choices. 

 

We need to think of this as our social responsibility. Our contribution to the pandemic effort.

 

Remember:

 

If you get sick, pledge to yourself: "This germ stops with me" Don't pass it forward.

 

Take the pledge.

»» Read More

They Walk Among Us

 

 

# 3678

 

I’m hearing a good deal of consternation on the net, and in my travels in the `real’ world, over the use of `fever’ as the determining factor in whether it is safe for a flu patient to return to work or school.

 

The CDC originally stated that students and employees with suspected H1N1 should stay home for 7 days, or 24 hours after symptoms disappeared . . which ever was longer.

 

This recommendation was based, I’m certain, on studies that have shown that adults shed the flu virus for about 7 days.  Children may potentially shed the virus for several days longer.

 

Recently, the CDC changed their recommendations to staying home until 24 hours after the abatement of (an untreated) fever.  

 

In other words, stay home until 24 hours after a fever disappears without the use of aspirin, Tylenol, or ibuprofen.

 

This has immediately raised concerns that flu victims who may still be shedding virus, are being told it is okay to return to work or school. 

 

Critics also point out that we’ve seen reports that some percentage of H1N1 patients never develop a fever to begin with.

 

Fever, critics maintain, is an imperfect gauge of infection.

 

And they are right, of course. 

 

Using fever as a criteria will, no doubt, allow some infected people to walk among us; at work, at school, at the mall . . .  and these people will probably be shedding some quantity of virus, and may go on to infect others.

 

Of course, we also know that those infected with the flu virus can begin shedding virus 24 hours before they show symptoms, and that some percentage of infected remain asymptomatic for the full course of the infection.  

 

They walk among us, too.

 

Like it or not, there is no easy litmus test for infection (and viral shedding) when it comes to influenza.   The array of symptoms (or lack thereof) displayed by those infected with the H1N1 virus preclude any kind of 100% accurate `checklist for infection’.

 

Sure, we could lock up everyone who sneezes, coughs, or spikes a fever for 2-weeks.  But even that wouldn’t catch those who are shedding the virus before developing symptoms, or those who remain asymptomatic for the full course of their illness.

 

So the new guidelines are a compromise, based on the knowledge that there is nothing that can be done to completely stop the spread of the virus. 

 

The best you can hope for is to slow it down.

 

The belief is, that those who are the sickest (i.e. coughing, sneezing, fever) are probably shedding the most virus.  And so keeping them home, away from work or school, makes sense.

 

Fever is an easy enough symptom for most people to check.  It is an objective sign, one that can be measured with a thermometer.  It may not catch all of those who are shedding the virus, but it probably catches the most contagious among them.

 

With thousands of people walking among us quietly shedding the virus it simply makes little sense to tell those who are probably only shedding very low amounts of the virus – but who feel well enough to work or study - to stay home for a full week. 

 

Of course, if you are coughing your head off, sneezing every 5 minutes, or running to the bathroom 3 times an hour . . . you might want to give yourself an extra day or two to recover. 

 

We are allowed to use some common sense here. 

 

So yes, using fever as a criteria for staying home is a compromise. It balances public safety with economic and societal considerations.  It isn’t perfect, by any means.

 

But as compromises go, it is a reasonable one.  

 

Which is why it is so important to remember to wash your hands frequently, clean and disinfect shared objects like phones, keyboards, and door handles, and to try to maintain some space between yourself and others during a pandemic.

 

All of these steps are basically delaying actions, which will hopefully help keep you and your family virus-free until a vaccine can become available later this fall. 

As imperfect as all this may be, for the next couple of months they are going to be your best defense against this virus.

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