FluPortal.org

[CDC / usable on your site]

The CDC’s Emerging Infections Diseases journal will publish in April a study (PDF file) examining household transmission of H1N1.

The investigators tracked patients in San Antonio, TX, (in April and May of 2009) who had lab-confirmed H1N1. They also recorded any “secondary case-patients” among housemates of the flu sufferers — i.e., people who were (presumably) sickened by their H1N1-infected housemates.

The study concludes that children (people under 18) were “disproportionately affected” by H1N1:

The highest proportion of laboratory-confirmed pandemic (H1N1) 2009 and secondary attack rates occurred in children, a finding consistent with the epidemiology of seasonal and pandemic influenza, where we know children experience higher rates of illness [...] and higher secondary attack rates [...]

It also determines that the “secondary attack rate” (contagiousness) appeared to be lower than for seasonal flu:

The secondary attack rate was 4% for laboratory-confirmed pandemic (H1N1) 2009, 9% for ILI [influenza-like illness], and 13% for ARI [acute respiratory infection]. In general, these rates are lower than for seasonal influenza and lower than anticipated for a pandemic strain [...].

You can read up on the full scope and “several limitations” of the study here (PDF file).

A study published today in the Journal of the American Medical Association suggests that vaccinating kids against H1N1 helps protect their entire community.

The researchers set out to test the idea of herd immunity and the observation that “[c]hildren and adolescents appear to play an important role in the transmission of influenza.”

The randomized, blinded study examined 46 volunteer Canadian Hutterite colonies. Roughly 80% of children aged 3 to 15 in half the colonies were given an H1N1 vaccine. Roughly 80% of those in the other colonies were given a hepatitis A vaccine.

Comparing the two populations, the study determined that vaccinating children against H1N1 “conferred 61% indirect protection against influenza among persons who did not receive the study vaccine.” The overall conclusion:

Our data suggest that a significant herd immunity effect can be achieved when the uptake of vaccine is approximately 80% in clusters in which children and adolescents aged 3 to 15 years are immunized.

The authors also propose that elderly people may benefit more from child-based herd-immunity than from being vaccinated themselves:

Although there were relatively few elderly individuals in this population, the protective effect is likely comparable with or greater than what can be achieved by direct immunization.

Helen Branswell, medical reporter for The Canadian Press, notes that children may not necessarily be the key to herd immunity:

Dr. Allison McGeer, an influenza expert at Toronto’s Mount Sinai Hospital, questioned whether the effect was due to the fact that Loeb’s team vaccinated kids, or just to the fact that they vaccinated a sizable portion of the population of the colonies randomized to get flu shots.

The New York Times piece about the study is here. The National Institute of Allergy and Infectious Diseases press release is here.

I have been thinking about systems and tools that could assist public media stations plan and launch websites in crisis scenarios. This website, FluPortal.org, is built on Wordpress, and I have been wondering whether a centrally hosted Wordpress MU installation could serve as a public media publishing platform when stations need a website up and running in a matter of hours. So I was intrigued when we came across a project using Google Sites to assist local governments to rapidly deploy websites in emergency situations.

Local governments face many of the same resource limitations that public media outlets do — namely too few web developers and IT infrastructures unable to handle large surges in traffic. The government of Santa Clara County, home to California’s Silicon Valley, ran into trouble with its website when H1N1 first emerged. The County’s website was overwhelmed by visitors searching for swine flu information and it quickly collapsed under the strain. The Social Innovation and Entrepreneurship Program at Stanford University (the school is located in the County) offered its assistance and helped the County publish its H1N1 pages on the Google Sites platform. Google Sites is basically a hosted wiki that allows users to build websites without any html or coding experience. And with Google’s redundant server infrastructure, sites hosted on the platform should be able to handle any large spikes in traffic.

The new Santa Clara County presence on Google Sites was a stable, straightforward warehouse of H1N1 information, but the default templates provided by Google made it somewhat difficult to navigate. Santa Clara officials and the Stanford team saw a need to create a custom template to meet the needs of communicating large amounts of information and improve the user experience.

The Stanford team contacted Bolt|Peters, a San Francisco design firm, to help construct custom templates to serve the emergency response needs of local governments like Santa Clara County. The results are two Google Sites templates — one for public health scenarios and another for more general emergency needs. You can read about the details and approach that went into the planning of these templates on the Bolt|Peters website.

Google Sites public health template

These templates have been made available for anyone to use on Google Sites. They could be a good option for public media outlets that need to get a site up fast when a crisis hits. It took me less than 5 minutes to launch this test site and place the FluPortal logo in the header. The templates provide a visual layout and page structure as well as plenty of pre-populated content and links that local stations can edit and customize as they see fit.

It must be said that Google Sites has a number of limitations (to name a few: limited html control and no CSS editing), but I am impressed with these emergency templates and by the ability to get a website up and running in a matter of minutes. I’m not entirely convinced that Google Sites can serve as a crisis response platform for public media at large, but the work by Bolt|Peters and the Stanford SIE team highlights important elements of crisis communication and preparedness that we should all be thinking about.

H1N1 virus [CDC / (usable on your site)]

I’ve been wondering for some time why seasonal flu is apparently being suppressed by H1N1. Much of the reporting I’ve seen notes the fact but doesn’t seem to get to the bottom of why it’s happening. Is that because doctors and public-health officials themselves aren’t sure? Are there at least plausible working theories?

This Washington Post article hints at one possible factor:

When a person is infected with one respiratory virus (such as rhinovirus, which causes colds), the chance of catching a different virus (such as flu) declines greatly. Part of the reason is that the first infection provokes what’s called “innate immunity” — a flood of interferon and other cellular hormones that defend the body in a general way without specifically targeting the invader. That protection can last weeks, breaking chains of transmission and slowing a flu epidemic.

A similar form of interference occurs between strains of flu, which is one of the reasons there’s been almost no “seasonal flu” in recent months. The strains circulating last season and still occasionally found this season — H3N2, other forms of H1N1 and influenza B — have all been outcompeted by the upstart H1N1.

In fact, even if there isn’t a third wave, the new H1N1 may well spell the end of one or more of the families of flu virus that have been circulating for decades. That’s what’s happened in previous pandemics, at least.

The H1N1 family arrived in 1918 with the Spanish flu. In the 1957 pandemic, the new virus was in the HN2 family; it drove all H1N1 strains to extinction. In 1968, the new virus was an H3N2. It spelled the end of the H2N2 family, which disappeared. H1N1 returned in 1977, apparently the result of an accidental release from a laboratory in Russia or China.

Have you seen/heard/read any good pieces about intra-flu-strain competition? It seems central to H1N1’s story arc at the moment. The questions about H1N1’s dominance — and the possible answers — could be interesting to keep in mind as you continue reporting on swine flu and seasonal flu.

The CDC has just released new numbers on H1N1 — estimates of cases, hospitalizations, and deaths from April 2009 to mid-January 2010.

This CDC chart summarizes the data:

[CDC]

Click here to find the data broken down into helpful bar graphs. Also to learn how CDC compiles its estimates.

We blogged recently about a Pittsburgh-area study that suggests roughly 63 million Americans were infected with H1N1 in 2009. This estimate — although based on a methodology completely different from the CDC’s — falls in the mid-range of the CDC estimates. (Note: the CDC numbers include data for two extra weeks in January 2010.)

[Voces de la Frontera / cc (usable on your site) / Flickr]

A study (PDF file) released in February by the Institute for Women’s Policy Research suggests that the lack of paid sick days in the private sector increased the spread of H1N1.

Some of the study’s interesting findings:

• “The vast majority of public sector employees receive paid sick days, but two of five private sector employees have no access to paid sick days.”
• “[E]mployees who attended work while infected with H1N1 are estimated to have caused the infection of as many as 7 million co-workers.”
• “The data suggest that more than 90 percent of public sector employees, but only 66 percent of private sector employees, took time away from work when infected with H1N1 [...] implying that many more private sector employees felt that it was necessary to attend work while ill.”
• “[T]he drop in absence rates between October and November was twice as steep in the public sector as it was in the private sector, suggesting that contagion was less common in the public sector.”

The study goes on to propose that “similar patterns of absence” might be “found among children and students” depending on whether their parents “have access to paid sick days to care for family members.”

(Our usual disclaimer: we can’t vouch for the study’s methodology or results; we offer it up as something you might be interested in reporting on.)

[Update 4 March 2010: This is an issue that public-health experts have worried about throughout the H1N1 pandemic. New York Times article from November 2009 here and WNYC report from September 2009 here.]

When the World Economic Forum convened its annual meeting of high-powered business leaders this winter, it offered a panel examining the pandemic vulnerability of companies dependent on the global economy.

Here’s one statistic it cited to make people sit up and take notice. (It’s not clear whether the numbers refer specifically to H1N1 or to any pandemic.)

[A]lthough 60% of CEOs believe the threat of a pandemic is real, only 22% have an emergency plan and only 27% are working on developing one.

Among the key points it raised:

The interconnected nature of the global economy is likely to result in unexpected effects from a pandemic. A company may find that a disease halfway around the world stops it from receiving critical parts or materials needed for its own manufacturing.

To stress the importance of desigining a pandemic plan ahead of time, the panel cited examples of two Mexican companies navigating H1N1’s first wave. The first company weathered it well because it had a pandemic plan in place. The second one had “to suspend operations for nearly a month and ran a significant loss” because it apparently had no pre-existing plan. The panel emphasized that it’s virtually impossible to design an effective plan once a flu pandemic is already underway:

[O]nce a pandemic starts, the flood of conflicting and often misleading information is likely to dramatically increase the difficulty of making executive decisions and communicating them to employees. As a result, it is crucial to have a contingency plan already in place.

The full summary of the “Prepared for a Pandemic?” panel is here. To read our post highlighting what companies can do to prepare for pandemics — what steps they can take to ensure “business continuity” — click here.

[Disclaimer: We're featuring the following study and estimate as interesting food for thought. We can't vouch for their accuracy; you would need to do your own reporting to evaluate that.]

Two different assessments of U.S. immunity to H1N1 have emerged recently. The first suggests the number of Americans infected by swine flu in 2009 (roughly 63 million). The second estimates the number of Americans who currently have immunity to H1N1 (somewhere roughly between 150 and 165 million).

Ted Ross [U. of Pittsburgh]

Assessment #1: A new study published in PLoS Currents: Influenza estimates the number of Americans who were infected with H1N1 in 2009. (Read our post about PLoS — the Public Library of Science — here.) The lead author is Ted Ross, an associate professor of microbiology and molecular genetics at the University of Pittsburgh.

The study looks at levels of antibodies to 2009 H1N1 in Pittsburgh-area residents. (Infection with a virus stimulates antibody production, which then confers immunity.) It examines blood from “846 persons that ranged in age from 1 month to 90 years of age.” The samples were taken from “hospital and clinic patients in mid-November and early December 2009.”

It’s possible that some people with antibodies to 2009 H1N1 got them from the vaccine rather than infection with the virus — but “the timing of the sampling relative to vaccine availability in Pittsburgh suggests that these samples are likely from a largely unvaccinated population during the peak of the second pandemic wave.” In other words: the data probably approximate the number of people actually infected by H1N1 in 2009.

Here’s the study conclusion in a nutshell:

21% of persons in the Pittsburgh area had become infected and developed immunity. Extrapolating to the entire US population, we estimate that at least 63 million persons became infected in 2009. As was observed among clinical cases, this sero-epidemiological study revealed highest infection rates among school-age children.

Ian York [Michigan State University]

Assessment #2: Ian York, an assistant professor of microbiology and molecular genetics at Michigan State University, recently offered his best educated guess of the number of Americans now immune to H1N1 (on his blog Mystery Rays from Outer Space). As he puts it, there are three ways in which someone could have acquired immunity:

They could have been exposed to a related virus, some time in the past, and have developed a long-term immunity. They could have been infected with [H1N1], somewhere in the first or second wave. Or, of course, they could have been vaccinated.

He collects the available data for each of those categories — emphasizing that “[t]hey’re more or less approximate” — and concludes that:

• Over half the US population as a whole is now immune to the new [H1N1].
• As many as three-quarters of the elderly and two-thirds of the children — the most important populations as far as flu is concerned — may be immune.
• Between a third and about half of this immunity was due to vaccination.

To find York’s full table of high and low estimates — broken down by age group — click here.

Why is it useful to know what percentage of the population may have immunity to H1N1? As the PLoS study puts it, it “provides valuable information about the likelihood of a possible third wave and may be useful in decision-making about immunization strategies.” Or as York writes, the “level of immunity” that he calculated “is probably enough to impact virus transmission drastically.”

The Harvard School of Public Health (HSPH) recently hosted a talk evaluating how well journalists and health officials communicated H1N1 information to the public.

Dr. K “Vish” Viswanath
[Viswanath Lab]

One of the speakers, Dr. K “Vish” Viswanath, runs a lab at HSPH dedicated to researching health communication. Viswanath highlighted some particularly difficult aspects of transmitting the H1N1 story:

• Health journalists have to straddle two cultures: the world of medical complexities and uncertainties; and the world of deadlines and commercial pressures.
• “More information does not necessarily mean more communication”: even if scientists and journalists do an exemplary job during a health crisis, the internet makes it impossible to control the spread of misunderstandings and misinformation.

One interesting positive lesson: Viswanath noted that whether or not the subtleties of the H1N1 story were getting through to the public, people seemed to be following recommended behaviour — if it was easy to follow. He tracked sales of hand sanitizer during the pandemic, for example, and saw that they went up significantly:

[Dr. Viswanath, screenshot from lecture on H1N1 communication]

Finally, Viswanath made one more very important point: different social groups — whether based on “class, race, ethnicity, or language” — differ widely in their access to information and where they go to look for it. This “communication inequality” is hugely significant during a public-health crisis.

Not everyone, for example, has equal access to online information — or the skills to learn from it or act on it. As he put it, while “it’s exciting to see social media being exploited [...] not everybody uses the internet.” If media and public-health departments rely too much on the web, he says, this can actually widen disparities in access to reliable information. In a survey done in April 2009, only 19% of people reported getting “the most information” about H1N1 online. The lesson here: local and ethnic news sources in traditional media — whether broadcast or paper — remain critical; it’s not just all about Twitter and Facebook.

I asked Viswanath whether he feels there’s a dearth of experienced health reporters (see this post). He said yes, that because of cuts in journalism, reporters are covering multiple beats and not necessarily able to stay on the health beat over the course of their careers. He hasn’t had a chance, however, to study this in relation to the H1N1 story specifically.

You can learn lots more from Dr. Viswanath in this video of the talk.

Today WHO recommended that next winter’s seasonal-flu vaccine include H1N1. Keiji Fukuda, WHO’s resident pandemic-flu expert, apparently cautioned in a press conference, however, that “[t]he inclusion of the H1N1 pandemic virus in the influenza vaccine does not signal that the pandemic is over.” WHO will meet next week to determine whether the pandemic is waning.

Here are the three viruses WHO recommended for the 2010/11 vaccine:

– an A/California/7/2009 (H1N1)-like virus;
– an A/Perth/16/2009 (H3N2)-like virus;*
– a B/Brisbane/60/2008-like virus.

* A/Wisconsin/15/2009 is an A/Perth/16/2009 (H3N2)-like virus and is a 2010 southern hemisphere vaccine virus.

Click here for a link to a PDF of the full report.