What kind of work is the trope of the Next Pandemic doing? Might it not be worth investigating the current pandemic first, before we jump to the next? Before we orient ourselves towards the near future, it might be necessary to first inhabit the recent past in some meaningful way. What, in fact, has just happened? Apparently, it is easier for experts to take responsibility for the future than for the past.

Just to remind ourselves:

1. Most experts predicted the emergence of an H5 virus. It was an H1 virus.

2. Most experts predicted that the pandemic would start off in South-East Asia. It turned out to be closer to home.

3. Most experts predicted that it would be a devastating event. WHO now calls it a “moderate” pandemic.

4. Most experts predicted serious consequences for critical infrastructure.

Good luck with the next predictions! Trust your expert!

Now, in a report issued on December 12th by CDC, we have some more numbers about how many people have caught the pandemic flu, how many have been hospitalized and how many have died in the United States.  The summarized data presented in the media is distilled in the number 9,820: deaths from H1N1.  This is usually presented either to downplay the severity, by comparing the number to the 36,000 seasonal flu deaths estimated to occur each year; or, conversely, to demonstrate the danger of the outbreak through a comparison with the previous estimate, one month ago, of only 3,900 H1N1 deaths.  But as we know with influenza, it is important to get behind the numbers.  How are these calculations made?

The comparison with seasonal flu is complicated because the numbers are calculated in significanly different ways.

1) The Seasonal Flu deaths estimate is a famous and important one, and I have encountered references to it again and again during fieldwork among syndromic surveillance developers and users (this at the time that they were trying to demonstrate the utility of s.s. by its early detection of seasonal flu outbreaks).  The numbers are based on a study by William Thomson published in 2003 in JAMA and updated for intervening years in 2009.  The study attempted to correlate excess deaths from circulatory and respiratory illness during flu season with flu isolates collected by viral surveillance laboratories.  The mathematics behind the study is explained in simple terms in this recent Slate article.  Basically, the study used a regression analysis to solve a multi-variable equation that looks like this:

[Total R and I deaths] = [R and I Deaths if there were no such thing as flu] + X*[number of confirmed flu cases]

Once the two variables are found that best fit reported data, the product of X*[number of confirmed flu cases] is the number of flu deaths.

2) H1N1 deaths are calculated for the recent report with a completely different method.  These deaths are calculated using data from the Emerging Infections Program (EIP)—a ‘sentinel’ surveillance system set up in 1994.  The EIP is a collaboration of ten state health departments with the CDC.  In each state, the health deparmtnet assembles a network of local health departments, academic institutions, laboratories, and doctors offices or hospitals.  The network is especially attuned to monitor for emerging or unusual diseases, and research or active surveillance efforts are undertaken through this network.  The H1N1 flu deaths were calculated by first assessing flu hospitalizations in this network.  The actual number of hospitalizations in the EIP network are “extrapolated” into ‘national data’ and corrected using a probabalistic multiplier model developed for an earlier CDC estimate of H1N1 prevalence  (and originally used to assess the impact of foodborne illness).  Then deaths are calculated from the national hospitalization data.  This calculation is made using a ratio derived elsewhere of laboratory-confirmed deaths to laboratory-confirmed hospitalizations.

Discussion:  Its hard for me to think how to begin to compare these two numbers based on the vastly different techniques used to calculate them.  Certainly it seems premature to use them in the glib fashion that says there have been only 1/3 as many deaths from H1N1 as seasonal influenza.  Perhaps more worth noting (in classic nineteenth century, hygiene publique fashion) is the differential mortality associated with H1N1 pandemic.  According to CDC numbers, this has been two-fold.  First, the H1N1 pandemic disproportionately effects those under 65.  A full 7,500 of the estimate 10,000 deaths occurred in the 18-64 age bracket, an age bracket that makes up only a modest portion of the ‘seasonal flu’ deaths.  Such an age-shift is a classic sign of pandemic strains and was observed in many previous pandemics.  Second, the pandemic H1N1 has caused four times more deaths among “American Indians and Alaskan Natives” according to a recent study.  The CDC study attributes this differential mortality to “environmental” conditions, which they go on to specify as poverty, delayed access to healthcare, and low vaccination coverage, along with underlying risk-conditions such as asthma and diabetes.

So to say this outbreak is not severe seems wrong, although an accurate metric of severity is still waiting.  Moreover, the delays in calculating severity seem to point up some of the weaknesses of statistical risk calculation for dealing with emerging infections.  How would a preparedness system judge severity differently?

Behemoth – A peer-reviewed journal published by the Akademie Verlag, Berlin

Special Issue: Epidemic Orders

In the past few years, epidemic events, both actual and virtual, have made a spectacular comeback. Emerging and re-emerging infectious diseases such as avian and swine flu have generated great anxiety the world over, resulting in a pervasive sense of vulnerability, insecurity, and uncertainty. A powerful spirit of urgency, based on a genuine concern for human health and well-being, overdetermined by a variety of scientific, political, and economic interests, engendered a real flurry of action. In the epic battle against germs, the biopolitical state mobilized material and symbolic resources at an unprecedented scale.

In the shadow of the emerging infectious disease threat, significant shifts in public health, medical care, and scientific research have occurred. The aim of this special issue of Behemoth is to offer an initial set of diagnostic accounts. What are the domains in which fundamental shifts have occurred over the past few years? Who are the actors involved and what are the underlying logics animating these shifts in public health, medical care, and scientific research? The key aim of this issue is to draw analytic attention to recent reconfigurations and to identify the kind of epidemic orders that are taking shape today at the heart of the biopolitical state.

Please send abstracts for this special issue of Behemoth to the editor Carlo Caduff (carlocaduff@access.uzh.ch) and to Kathrin Franke (behemoth@rz.uni-leipzig.de). Deadline for submission of abstracts: 30 January 2010. Deadline for submission of articles: 30 June 2010.

Hopefully some of our resident second order observers of pandemic preparedness can do some parsing for us…

At its core, situation awareness, or SA, basically describes knowing the right information, at the right time, in the right way and in the right amount, in order to make the right decisions to improve or protect health. Although it is ostensibly applicable across all domains of public health, as a concept it is usually associated – or in any event, it eventually ties itself back to – public health emergency preparedness and response. To give an example from H1N1, response has been very much guided by demands for information that go beyond what we might call “traditional” public health surveillance and epidemiological investigation. Certain disease detection and surveillance technologies have been employed in tracking the disease, but the sources of information are disparate and varied, requiring a great deal of filtering and integration to paint a meaningful picture. From aggregate disease reporting to case level data; media and internet search term tracking to hospital bed and patient tracking; virologic surveillance to border surveillance, the array of data being produced across heterogeneous sites that constitute an increasingly global health security apparatus is staggering. Contrast these information needs with the 1976 Swine Flu event, and one begins to see a stark shift in terms of the kinds of techniques brought to bear in developing useful information for response.

Many of us blogging on VSS are familiar with various public health capabilities in the context of preparedness and response. Community mitigation strategies, countermeasure delivery, mass prophylaxis and vaccination – these are just some of the capabilities to which public health is held accountable in carrying out its preparedness and response functions. More to the point, knowledge about the state of readiness and performance of these various capabilities is also very much at the core of situation awareness. Think of knowledge about capabilities as something like the second half of a feedback loop in the production of situation awareness, the first half of which is information gleaned from signals (like flu surveillance, or internet search term use, or BioSense, etc.) in the external environment. In theory, marrying these two produces a picture not just of a health threat in near real-time, it also produces a picture of what can be done about it – what resources can be brought to bear – in like time, suggesting what likely outcomes will be. This, in turn, can suggest future states, with future interventions and future outcomes, etc etc.

For students of public health, this is a far cry from the kind of rationality that has governed public health surveillance historically: namely, a focus on the aggregation of a variety of population-level data to determine risk factors (and interventions) associated with health outcomes. I would like to suggest that public health’s traditional techniques – surveillance, epidemiological investigations, laboratory testing, etc.- are, at least at certain sites and in certain contexts, being marshaled and modified in service to the emergent need (rationality?) for situation awareness. My core argument, which I’d like to test out in this forum, is that situation awareness embodies the demand for a new kind of knowledge, one premised less on the need for ever greater quantities of data, per se, and more on the need for timely, actionable information. Again turning to H1N1, this may account for the seemingly odd development that public health officials are no longer concerned, per se, with the accuracy of aggregate case counts. Generating that information is extremely resource-intensive and, to the point I am trying to make, not all that useful for public health decision-making. At the level of actual practice, this number, the all-important “numerator” in calculating disease incidence, and “denominator” in calculating case fatality ratios – and the very core of traditional epidemiological techniques – has been backgrounded in favor of additional types of information: characteristics in severe cases, transmissibility in specific settings, such as schools and hospitals, utility of community mitigation strategies such as school closures (VERY controversial, for about a thousand reasons), and viral susceptibility to treatment and prophylaxis.

* * *

How has situation awareness emerged? What problems does it seek to address? What are its techniques? Its boundaries? What configuration of practices and knowledge arose to form it? What demands does it place on individuals? On other assemblages and apparatuses? These are complex questions worthy, I think, of further pursuit. Lyle, of course, has done a stellar job of getting at many of these issues in his discussion of BioSense and syndromics, and I should very much like to see continued discussion of, for example, the employment (failure?) of real-time disease detection technologies in the context of H1N1. A broader investigation tracing back the concept may prove fruitful. A cursory look shows situation awareness to have a very extensive history in military applications, notably around operator performance of a variety of technologies, including aircraft and other combat vehicles. (Good) pilots have, in fact, been held as exemplars in the field, having been very heavily scrutinized for how they are able to make sense of, and inject order into, a vast amount of very disparate and very quickly changing information in a high-stress environment – and achieve desired outcomes on top of that. Tracing back contemporary public health situation awareness across its various lineages in aviation, psychology, operations research and the military, could prove a very informative project.

“Drawing on an inquiry into Israel’s preparedness for biological threats, in this article I suggest a new analysis of biosecurity events. A complex and dynamic assemblage emerges to prepare for biological threats, one that I call a “pre-event configuration.” The assemblage is composed of three core elements—the scientific element, the security element, and the public health element—each of which diagnoses threats and suggests appropriate solutions. This configuration also determines what will be perceived as an event for which preparation is needed and what will remain a nonevent. I maintain that the constitution of an event takes place beyond the actual time of its occurrence and is determined by the pre-event configuration in the “time of event.” Therefore, a comprehensive analysis of events should combine an examination of actual events and their aftermath with an inquiry into their potentialities as determined by the pre-event configuration.”

Apparently, the WHO is now “very close” to declaring a pandemic. See below for an interesting CIDRAP piece.

WHO ‘very close’ to declaring a pandemic

Robert Roos * News Editor

Jun 9, 2009 (CIDRAP News) – The World Health Organization (WHO) is getting “very close” to declaring that a novel H1N1 influenza pandemic has arrived, but the agency wants to spend more time preparing the world for that step so it won’t cause panic, a WHO official said today.

In view of the virus’s spread in Australia, far from the epidemic epicenter in North America, “We are getting really very close to knowing that we’re in a pandemic situation or declaring that we’re in a pandemic situation,” Dr. Keiji Fukuda, the WHO’s assistant director-general for health security and environment, said at a press briefing today.

But before declaring a pandemic, the WHO wants to do more to reduce the risk of panic and overreactions such as trade embargoes, border closures, travel restrictions, and a flood of “worried well” people in hospital emergency departments, Fukuda said.

“One of the things we’re really focusing on right now is to help countries, help institutions, help the media really understand what are pandemics and provide as much information as possible so we reduce any adverse effects . . . and prevent misunderstanding that may lead to actions that really increase anxiety in people,” he said.

Meanwhile, WHO Director-General Dr. Margaret Chan told the Associated Press (AP) today that “on the surface of it,” a pandemic appears to be under way. She said she would confer with governments tomorrow to verify some of the reports she has received before making a formal announcement, the AP story said.

“Once I get indisputable evidence, I will make the announcement,” the AP quoted Chan as saying.

Scary terminology
The WHO has had its pandemic alert level at phase 5 since Apr 29. Phase 5 means a novel virus has achieved sustained community transmission in more than one country within one global region, and it suggests that a pandemic is imminent.

Phase 6, the peak stage, means a novel virus is spreading in more than one global region and the pandemic has arrived. The WHO’s phase definitions characterize only the disease’s geographic spread, not its severity.

Because the virus is well-established in North America and now seems entrenched in Australia as well, the current situation seems to fit the WHO’s criterion for phase 6. But the WHO has held off on announcing phase 6 out of concern that it would cause unnecessary alarm, given that the novel virus causes mild disease in most cases.

The problem, WHO officials have said, is that after years of preparing for the threat of a pandemic strain of the deadly H5N1 avian influenza virus, many governments and people think of a pandemic as a deadly worldwide plague.

Last week Fukuda said the WHO would come up with a way to describe the severity of the H1N1 threat and couple that with any pandemic declaration, in an effort to prevent undue alarm. Today he indicated that the agency is still working on a severity scale and other information to provide when announcing the move to phase 6.

“One of the things many countries have been struggling with is that their existing pandemic plans have been based on a more severe scenario, the H5N1 virus, so some of the things their plans called for may be inappropriate,” he said.

As for the kinds of adverse effects the WHO fears if it declares a pandemic too soon, Fukuda cited several things that have already happened in some places since the novel virus emerged: misguided culling of pigs because of the term “swine flu,” trade embargoes, concern about travelers from affected countries, concern about border closures, and travel restrictions.

“In the past, people who were worried but not particularly sick have overrun hospitals,” he added.

Managing the media?
Fukuda was asked if, in delaying the pandemic declaration, the WHO is just trying to “manage the media.”

He replied that moving to phase 6 “is not simply getting up in front of press cameras and making an announcement, it’s really a way to prepare the world to deal with the situation.” He said countries need information and tools for dealing with the epidemic and added that much work is being done on communication, vaccine development, antiviral drug supplies, and clinical guidelines.

“This is not managing the media, this is not nuancing the messages, this is really getting countries and populations ready so they can handle and deal with this virus as well as possible,” he asserted.

“One of the critical issues is we do not want people to over-panic if they hear that we’re in a pandemic situation and that they understand for example that this is a moderate level [of disease],” he said in answering further questions.

Some victims previously healthy
In other comments, Fukuda said the WHO is concerned that about half of the patients who have died of the new virus did not have pre-existing health problems—an observation he has mentioned at earlier briefings.

“It’s probably fair to say approximately half of the people who have died have been previously healthy people. This is I think one of the observations that gives us the most concern,” he said. “From the outset and from reports coming from Mexico, we knew that a number of deaths had taken place among younger people who were previously healthy. This is a pattern we’ve seen with the H5N1 virus and one we’ve seen in previous pandemics.”

He added that a number of institutions and physicians are studying these cases to identify risk factors.

Fukuda also said:

* The WHO has seen no major changes in the virus in recent weeks.
* The clinical picture of cases in the southern hemisphere is much the same as in northern regions, with most cases being mild.
* The WHO and other groups are still “wrestling with” the problem of finding a name for the novel virus that is accurate and won’t stigmatize pigs or places.

See also:

WHO H1N1 influenza page

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