Thursday, October 7, 2010

Expert pair airs lessons learned from global flu response

Lisa Schnirring Staff Writer

Oct 6, 2010 (CIDRAP News) – Two internationally known health officials yesterday gave their assessment of the global response to the 2009 H1N1 pandemic, saying good decisions were made based on what was known early in the outbreak but adding that the experience yielded several important lessons, such as the need for more flexible pandemic plans and the need to communicate more clearly about risks.

The experts are Dr Gabriel Leung, of Hong Kong's Food and Health Bureau, and Dr Angus Nicoll, of the European Center for Disease Prevention and Control in Stockholm. An essay they wrote on their pandemic observations appeared yesterday in the Public Library of Science (PLoS) Medicine. Their review covers the first 12 months of the pandemic response.

Their reflections on the world's pandemic response comes in the midst of an independent review of the World Health Organization's (WHO's) response and how the International Health Regulations (IHRs) functioned in their first major test during a public health crisis.

Though the 2009 H1N1 virus seemed to cause mild-to-moderate infections in most people, experts are still sorting out the mortality impact, Leung and Nicoll wrote. Young people were among the hardest-hit groups, and their deaths amount to more years of life lost than the deaths involving older people and those with chronic medical conditions.

Some countries turned quickly to containment strategies when the new virus emerged, using nonpharmaceutical interventions such as isolation and quarantine of people with suspected and confirmed disease, which in some ways was understandable for countries that had already grappled with the H5N1 avian influenza virus and the 2003 SARS epidemic, the authors wrote.

Though some of the measures may have delayed community transmission, it's unclear if the benefits were worth the costs, according to the authors.

Until the pandemic virus emerged, hardly any countries except Japan had used antiviral medications widely. Some struggled with whether to use the drugs for the treatment of sick patients or to prescribe them for prophylaxis. A few countries, such as England, developed innovative distribution methods.

Early evidence suggests that neuraminidase inhibitors reduced severe disease without causing adverse events, Leung and Nicoll wrote. However, they added that delayed antiviral treatment was linked to more severe complications worldwide, which points to gaps in indentifying and treating patients early.

The authors gave mixed reviews to the pandemic vaccine. Though they said it was a scientific success, it arrived too late with not enough supply to blunt the Northern Hemisphere's second pandemic wave. They noted that public health officials struggled with a difficult message when urging people to get the vaccine—that although the virus usually caused mild disease, it could sometimes be lethal, even in young and previously healthy people.

Though some critics have questioned their countries' expenditures for what may have later appeared to be excessive amounts of vaccine, the authors noted that when health officials placed their orders they didn't expect the later finding that a single dose rather than multiple doses was immunogenic in all but the youngest children.

"Hindsight always gives perfect vision and using post-hoc information to evaluate prior decisions at best confuses and often produces unfair conclusions," Leung and Nicoll wrote.

In addressing critics' charges that vaccine makers may have improperly influenced the expert advice WHO relied on in determining their recommendations and response actions, Leung and Nicoll emphasized that receiving advice is different than making decisions. Advisors' declarations of interest should be fully transparent and comprehensive and follow strict rules that can hold up to intense scrutiny, they said, and "The decision makers should also be prepared to justify their actions."

They predicted that communication about risk will remain a challenge in the months ahead because the 2009 H1N1 virus could undergo antigenic drift, given the greater number of people who are now immune through infection or vaccination.

As the lessons emerge about the pandemic response, countries will likely be retooling their pandemic plans, the authors wrote, urging the WHO to take a leadership role to coordinate the efforts. "A strong argument exists for making future plans more flexible and having extra descriptions including the many aspects of severity when a pandemic is emerging that then determine the consequential public health actions," they stated.

Their other recommendations include:

Establishing a clinical research infrastructure to help speed the collection and sharing of clinical data during the next flu pandemic or other disease outbreak
Improving surveillance systems to help gauge the true burden of flu
Developing new tools for treating severe flu infections.
Easing developing countries' access to antiviral medications and vaccines still represents a big gap, the authors wrote. "It is an indefensible fact that these vaccines started to flow to the poorer countries well after they began going to the countries with advance purchase agreements."

However, they noted that the long-term solution isn't simple and includes improving surveillance, monitoring disease burden, expanding flu prevention and control efforts, and establishing seasonal flu vaccine production and use in all parts of the world.

Study explores Southern Hemisphere pandemic patterns

Lisa Schnirring Staff Writer

Oct 5, 2010 (CIDRAP News) – A review of how the first wave of the 2009 H1N1 pandemic affected Southern Hemisphere countries found many similarities with Northern Hemisphere countries, though many patients had no underlying risk factors for flu complications and pregnant women didn't seem to have severe outcomes.

The authors from Greece and from Tufts University School of Medicine in Boston based their findings on 15 studies in the medical literature that described the epidemiologic findings in the Southern Hemisphere. They published their findings today in an early online posting by Epidemiology and Infection.

Seven of the studies detailed the experience of South American countries, six covered Australia and New Zealand, and two focused on Africa.

The Southern Hemisphere experienced its first pandemic wave during the region's 2009 winter influenza season (northern summer). Some countries, such as New Zealand and Australia, recently saw or are in the midst of a second pandemic wave. Australia's health ministry said in its most recent report that flu activity is increasing, with nearly 70% of cases caused by the 2009 H1N1 virus. The rise in cases there is unusual, coming at the end of the flu season.

All but one of the studies included in the literature review contained data on the characteristics of patients with lab-confirmed 2009 H1N1 infections.

In patients whose respiratory samples were evaluated with reverse -transcript polymerase chain reaction (RT-PCR) testing, the rate of positives ranged from 31.5% to 54% in four studies from Brazil, Argentina, and Australia, though a reference laboratory in Bolivia reported a lower rate of 12.7%. The positive rate was even lower, about 8.3%, in two Brazilian studies, and a general hospital in Argentina has a 3.3% positive rate.

Hospitalization rates in confirmed cases were about 45% in Brazil and Argentina and varied from about 17% to 31% in Australia and New Zealand.

Among five studies that included data on fatality levels, rates ranged from 0.5% to 0.9%.

The majority of lab-confirmed 2009 H1N1 cases were in young and middle-aged adults, with the second highest levels of infections in older children and adolescents. Though fewer seniors were affected, the ones who were sickened were more likely to be hospitalized, to be admitted to an intensive care unit, or to die. .

Nearly 67% of patients with severe infections did not have underlying medical conditions. Common conditions in patients that did have risk factors for flu complications included, for example, chronic respiratory disease such as asthma, cardiovascular disease, renal insufficiency, and diabetes.

Studies that included information on pregnant women reported that this group accounted for between 5.4% and 8.1% of severe infections. However, they didn't find that pregnant women were substantially more likely to be hospitalized or admitted to the ICU. "In other words, pregnancy might be mostly a risk factor for acquisition of infection with pandemic A (H1N1) 2009 influenza virus, rather than for an adverse outcome, " the researchers wrote.

They noted that pregnant women were more likely to be in the age-group most affected by the virus and may often have close contact with young children, who could expose them to the virus.

The researchers found that a substantial number of obese people were sickened during the pandemic wave, a pattern that also emerged in the United States and other Northern Hemisphere countries. However, the group emphasized that their findings concerning pregnant and obese patients were just observations.

They also pointed out that most cases of pandemic flu were mild and uncomplicated and went undiagnosed. Because their review focused on lab-confirmed cases, they said, it doesn't capture the true impact and characteristics of the 2009 flu pandemic in the Southern Hemisphere.

WHO pandemic review group concludes third session

Lisa Schnirring Staff Writer

Sep 29, 2010 (CIDRAP News) – The external committee tasked with reviewing the World Health Organization's (WHO's) response to the H1N1 pandemic wrapped up its third round of live meetings in Geneva today, hearing from an array of country and organization health representatives, as well as WHO Director-General Margaret Chan, who strongly defended the organization's response.

Chan, who spoke to the group yesterday during a public plenary session on the second day of its meeting, also said the WHO learned some important lessons that will position it to, for example, ease the flow of pandemic vaccine to developing countries. Her address to the group appeared yesterday on the WHO's Web site. The pandemic review committee is simultaneously reviewing how the International Health Regulations (IHRs) functioned during their first use in an international health emergency.

Dr Harvey Fineberg, the group's chairman, briefed reporters today at the conclusion of the group's 3-day meeting. He said the committee is still in an information-gathering mode and that the agenda consisted of public plenary sessions and deliberation meetings during which members met by themselves. He is president of the Institute of Medicine of the US National Academy of Sciences.

The review committee's last meeting in Geneva was in early July, and Fineberg told reporters the committee will meet again in November for deliberation sessions. He projected that the group would have a draft of a report for its own members to review by early January in time for its final plenary meeting. The members will submit a final report that includes a response from Chan in advance of the World Health Assembly next May.

Fineberg said the group heard testimony from a wide range of health and industry experts and confirmed, based on a journalist's question, that Michael T. Osterholm, PhD, MPH, addressed the group during the plenary sessions. Osterholm is director of the University of Minnesota's Center for Infectious Disease Research and Policy, publisher of CIDRAP News.

One of the largest blocks of testimony came from key people who led the WHO's response and were involved in administering the IHRs, including Chan, Fineberg said. At the committee's last meeting in July they heard from some of sharpest critics of the WHO's response, including a Council of Europe representative and the editor of the British Medical Journal.

"One of the things that was not surprising, but very revealing, was that the principals at the WHO secretariat were very eager to tell their story," he said. "They are as eager to tell their story as the critics are to tell theirs."

Chan spoke candidly about the challenges and successes she observed during the WHO's pandemic response and said the group welcomes the review and is mindful of the praise and criticisms it has received. She said the WHO is grateful for the moderate impact the pandemic had, and she said in retrospect some response measure may look excessive.

"Had the virus turned more lethal, we would be under scrutiny for having failed to protect large numbers of people," Chan said. "Vaccine supplies would have been too little, too late, with large parts of the developing world left almost entirely unprotected."

She said experts assumed that H5N1, with its more lethal severity, would cause the next pandemic, which guided preparations for a more severe pandemic than what emerged with the 2009 H1N1 virus. The phased pandemic alert approach was developed as cues to help countries increase their preparedness levels without causing public alarm. "In reality, it had the opposite effect. It dramatized the steps leading to the declaration of the pandemic and increased the build up of anxiety," Chan said.

Chan rejected charges that the WHO exaggerated the pandemic threat and said when she announced the move to alert phase 6 she reminded the world that the number of deaths were small, that she didn't expect to see them increase suddenly, and that most patients were recovering without medical care.

During a time when health officials had to make decisions in an environment of scientific uncertainty, most health officials erred on the side of caution, she said. "In this regard, the phased approach to the declaration of a pandemic was rigid and confining. In communicating the level of alarm, authorities need to be able to move down as well as up," Chan said, adding that limited vaccine capacity and long production times also hampered the flexibility of countries' pandemic responses.

She strongly rejected charges that commercial interests tainted the WHO's pandemic alert level decisions. "I can assure you: never for one moment did I see a single shred of evidence that pharmaceutical interests, as opposed to public health concerns, influenced any decisions or advice provided to WHO by its scientific advisors," Chan said in her statement.

On a positive note, Chan said some elements of the world's pandemic response worked well, including the IHRs, which she said provided a useful set of checks and balances, and the early distribution of oseltamivir stockpiles to developing countries.

"In my view, the Emergency Committee, with both experts and affected states represented, functioned well as a balanced and inclusive advisory body," she said. The emergency committee met at least nine times to advise Chan during pandemic phase and response discussions, and some critics charged that the process lacked transparency, because member names were confidential. The WHO has said the names were kept secret during the pandemic to protect members from undue influence. It revealed the member names on Aug 10 when the WHO declared that the pandemic was over.

In response to journalists' questions, Fineberg said several times that the role of the committee isn't to assign blame, but to identify ways that the WHO can improve its pandemic response.

He said the review committee is hearing a lot about the challenge of decision making under conditions of great uncertainty and that some response measures, such as the vaccine donation process, are very complex.

"Everyone came at this from their own perspective, but few had a vision of the whole. Each told an important side of the story," Fineberg said. "Our job is making a coherent whole out of these perspectives."

Tuesday, June 15, 2010

Pandemic (H1N1) 2009 - update 104

WHO's Weekly update

11 June 2010 -- As of 6 June, worldwide more than 214 countries and overseas territories or communities have reported laboratory confirmed cases of pandemic influenza H1N1 2009, including over 18156 deaths.

WHO is actively monitoring the progress of the pandemic through frequent consultations with the WHO Regional Offices and Member States and through monitoring of multiple sources of information.

Situation update:
Active but declining transmission of pandemic influenza virus persists in limited areas of the tropics, particularly in Southeast Asia and the Caribbean. As countries of the temperate southern hemisphere enter winter, only sporadic influenza activity has been detected so far, except in Chile and Uruguay, both of which have recently reported small numbers of pandemic influenza virus detections. Although seasonal influenza B viruses have been the predominant type of influenza virus circulating worldwide since the end of February 2010, there have been increasing but low level detections of seasonal influenza H3N2 viruses, particularly in South America and in East Africa.

In the tropics of the Americas, overall pandemic influenza activity is low, however, both seasonal influenza H3N2 and type B viruses are actively circulating in parts of tropical South America. Active but declining transmission of pandemic influenza virus continues to be detected primarily in Cuba. Since early 2010, pandemic influenza virus has circulated at low levels in Costa Rica. Sporadic detections of pandemic influenza virus continue to be reported in Brazil. During the most recent reporting week (last week of May 2010), both Brazil and Venezuela reported regional spread of influenza activity associated with an increasing trend of respiratory diseases. In Venezuela, recent influenza activity (which began during early May 2010) has been predominantly due to circulating seasonal influenza A viruses. In Bolivia, circulation of seasonal influenza viruses, predominantly type B, was observed between March and May 2010 and now appears to be subsiding.

In Asia overall pandemic influenza virus transmission remains low, except in parts of tropical South and Southeast Asia, particularly Singapore, Malaysia, and Bangladesh. In Singapore, overall levels of ARI remained slightly below the epidemic threshold and the proportion of respiratory samples testing positive for pandemic influenza virus increased slightly to 34%. In Malaysia, limited data suggests that pandemic influenza virus transmission has begun to decline since plateauing during May 2010. In Bangladesh, there has been stable persistent low level co-circulation of pandemic and seasonal influenza B viruses since March 2010. Sporadic detections of pandemic influenza virus continued to be reported across other parts of Asia. In East Asia, overall influenza activity remains low, however, seasonal influenza B viruses continue to circulate at low and declining levels.

In Sub-Saharan Africa, pandemic influenza virus continued to circulate at low levels in parts of West Africa, most notably in Ghana. During the most recent reporting week, 13% of all respiratory samples tested positive for pandemic influenza virus in Ghana. Small but significant numbers of seasonal H3N2 viruses have been detected in Kenya and Tanzania since late May 2010.

Overall, in the temperate regions of the northern hemisphere, pandemic influenza viruses have been detected only sporadically during the past month. In the temperate southern hemisphere, only two countries, Chile and Uruguay, have recently reported small numbers of pandemic influenza virus detections. In Chile, there was low level geographically limited circulation of pandemic influenza virus during May 2010; 3.4% of respiratory samples tested positive for pandemic influenza virus during the last week of May 2010. Of note, in Uruguay, 11 (44%) of 25 samples tested positive for pandemic influenza during the most recent reporting week (the last week of May 2010); however, the corresponding intensity of respiratory diseases in the population is not yet known. Other respiratory viruses, most notably RSV, are known to be circulating in Chile and Argentina. There have been no recent detections of pandemic influenza virus in South Africa. In New Zealand and Australia, overall levels of ILI remain low; only sporadic detections of seasonal and pandemic influenza viruses have been recently reported in Australia.


WHO defends pandemic actions, says rules need tightening

Jun 10, 2010 (CIDRAP News) – The World Health Organization (WHO) replied at greater length today to recent criticism of the way it used science advisors in pandemic planning, defending its response to the H1N1 flu pandemic but allowing that its policies concerning transparency and relations with the pharmaceutical industry need strengthening.

Today's WHO statement largely reiterates points made by WHO Director-General Margaret Chan in a Jun 8 letter, but it offers more details and goes a step further by expressing regret that the agency did not list the industry connections of WHO advisors who helped develop pandemic guidance published in 2004 on the use of vaccines and antivirals.

The new statement was issued in response to an article and editorial published Jun 3 in BMJ (formerly the British Medical Journal) and a report by a committee of the Parliamentary Assembly of the Council of Europe (PACE), a human rights organization. The reports and editorial raised questions about possible conflicts of interest among the WHO's pandemic advisors because they had done paid work for pharmaceutical companies. The PACE committee report went further, branding the WHO's pandemic response an "unjustified scare" that led to wasteful spending.

Concerning potential conflicts of interest, the WHO notes that many leading experts who advise the agency have ties with industry, such as research funding, consulting work, and participation in industry-sponsored conferences. To guard against biased advice, the WHO requires expert advisors to declare their interests, and it assesses those interests to decide if any action is required, the statement says.

It adds, "The publication of summaries of relevant interests following meetings is inconsistent and needs to be made routine. WHO further acknowledges that safeguards surrounding engagement with industry need to be tightened, and is doing so."

The BMJ critique focused heavily on the 2004 pandemic guidance, stating that the industry connections of three scientists who helped write the guidance were not listed in the document. The guidance was based on a meeting held in 2002.

"In line with WHO policy, all experts who participated in this meeting were required to submit a declaration of interest form and all such forms were duly reviewed by WHO," today's statement says. "However, a summary of relevant interests was not issued together with the publication. WHO regrets this oversight.

"Since that time, a number of administrative and legal changes have been implemented to strengthen procedures for addressing potential conflicts of interest that might influence the advice provided to WHO. WHO is committed to tightening these procedures further and ensuring their more consistent application."

The BMJ critique also dwelt on the WHO's withholding of the names of members of the Emergency Committee it established last year to advise on its response to the pandemic. The article implied that the panel members may have conflicts of interest that slant their advice.

The WHO has said it has withheld the names to protect the members from commercial or political pressures. Today's statement provides more background on this rationale.

Whether to release the names was debated when the committee was set up under the International Health Regulations, the WHO said. The names of members of other advisory groups are released after their meetings. However, the SARS (severe acute respiratory syndrome) epidemic in 2003 showed that public health emergencies can cause considerable economic and social disruption, suggesting that "experts could well be lobbied or pressured for commercial or political reasons."

After considering the issues, the WHO decided to follow its usual practice of disclosing the names of experts after completion of the advisory group's work. But the committee has held a number of meetings over more than a year, rather than a single meeting like most advisory groups, so the release of names has been delayed.

The names of members and summaries of their declarations of interest will be issued after the pandemic is declared over, the WHO said. Meanwhile, "Procedures for revealing names of member of future Emergency Committees are under review."

Other points in today's statement, which is presented in a question-and-answer format, deal more with the substance of the WHO's pandemic guidance and decisions.

For example, the statement summarizes how the H1N1 virus differed from seasonal flu and met the criteria for a pandemic: it was genetically unique, it circulated in summer, it hit younger people, it crowded out other flu viruses, and antibodies to seasonal H1N1 flu did not protect people.

The WHO rejects the critics' assertion that it removed severity from its definition of a pandemic. In particular, it addresses a 2003 WHO document—often cited by critics—stating that a flu pandemic causes "enormous numbers of deaths and illnesses."

"At the time, this was considered a likely scenario should the highly lethal H5N1 avian influenza virus develop an ability to spread readily among humans, but it was never a formal definition," the statement says.

The WHO also repeated Chan's flat rejection of the allegation that it declared a pandemic to boost the earnings of drug companies, saying no evidence for this has been found.

The statement also defends the agency's guidance on use of antivirals during the pandemic.


Study raises questions about age-group impact of H1N1

Jun 14, 2010 (CIDRAP News) – A study by French researchers suggests that the H1N1 influenza pandemic may not have differed from seasonal influenza epidemics in its effects on different age-groups quite so much as has been supposed.

The general understanding is that H1N1 has disproportionately affected children and young adults, leaving elderly people relatively unscathed. The new study agrees that the younger groups have borne a much larger share of pandemic deaths than they do in seasonal flu, but it suggests that the age distribution of total cases is much the same as in past seasonal flu epidemics.

"The age distribution of influenza-like illness was similar between the 2009 H1N1 pandemic and seasonal epidemics whereas the proportion of under-60s among influenza deaths was markedly higher during the 2009 pandemic (peak<20 years) than during the seasonal epidemics," says the report by Magall Lamaitre and Fabrice Carrat. It was published online last week by BMC Infectious Diseases.

The US Centers for Disease Control and Prevention (CDC) has estimated that about 90% of all pandemic H1N1 cases were in people younger than 65 and that 32% were in children (under 18). The BMC study implies that this disproportionate burden of illness in young people is not much different from what happens in seasonal flu.

The French researchers compared the age distribution of cases and deaths during two different seasonal flu epidemics in the United States and France with the age distribution of pandemic H1N1 cases and deaths in the two countries.

For the seasonal epidemics, the researchers chose the H1N1 epidemics of 1978-79 in the United States and 1998-89 in France and the H3N2 epidemics of 1989-90 in both countries.

They used influenza-like illness (ILI) as the indicator of cases (morbidity), gathering data from published studies, the CDC, and France's Sentinel flu surveillance system. The age distributions of flu-related deaths were obtained from national death registries.

To assess the relative burden of illness and deaths on different age-groups, the investigators calculated a relative illness ratio (RIR) and a relative mortality ratio (RMR). The RIR is the percentage of sick people in a given age-group divided by the percentage of the total population belonging to that age-group. Similarly, the RMR is the percentage of total flu deaths in a given age-group divided by the percentage of total all-cause deaths in that age-group. Any ratio greater than 1 signals a disproportionate burden.

Overall, the age profile of the 2009 pandemic resembled that of the seasonal epidemics, the researchers found. The highest illness burdens (RIR values) in the pandemic were in 5- to 9-year-olds in France (RIR, 2.97) and in 0- to 4-year-olds in the United States (RIR, 3.49).

The 5- to 9-year-old group had the highest illness burdens in both seasonal epidemics in France (H1N1, 2.15; H3N2, 1.77). In the US seasonal epidemics, the highest illness ratio in the 1978-79 H1N1 outbreak fell on 10- to 14-year-olds (2.99) and, in the 1989-90 H3N2 epidemic, on 5- to 24-year-olds (1.84). All the RIRs for those 35 and older were lower than 1.

In contrast to the morbidity pattern, the age pattern for deaths differed sharply between the pandemic and the seasonal epidemics, the researchers found. In the pandemic, RMRs for those under 60 were all higher than 1, with peak ratios in those under age 20. In the United States the hardest hit age-group was 5- to 24-year-olds (RMR, 38.66), while 5- to 9-year-olds were hardest hit in France (RMR, 37.39).

In three of the four seasonal epidemics, the highest RMRs were in those 65 and older, the report says. The exception was the 1978-79 H1N1 epidemic in the United States, in which the 5- to-24-year-old age-group had the highest relative mortality (RMR, 3.91). As the authors note, the H1N1 virus re-emerged in 1977 after a 20-year absence, leaving young people at the time relatively unprotected.

The researchers say their morbidity findings suggest that "the age distribution of risk of infection did not differ" between the pandemic and the seasonal epidemics. They add that previous studies have shown that school-age children are most susceptible to contracting seasonal flu and that studies of the 1918, 1957, and 1968 pandemics showed an age distribution of cases similar to that of seasonal flu epidemics.

As for mortality findings, the authors write that while mortality was highest in children and younger adults, it decreased with age between 20 and 60. "Prior exposure to seasonal influenza viruses thus seems to protect against the 2009 H1N1 virus," they add. They further comment, as have others, that the relatively low mortality in elderly people suggests they have immunity related to their exposure to H1N1 viruses that circulated before 1957.

Cecile Viboud, PhD, a staff scientist in the division of international epidemiology and population studies at the National Institutes of Health's Fogarty International Center, observed that the finding of a shift in the mortality burden to younger people in the H1N1 pandemic has been detected in several other studies and also has been described in the previous three pandemics.

However, "the authors do not find evidence of an age shift in the distribution of influenza cases" in the 2009 pandemic, "which is perhaps a little surprising," Viboud told CIDRAP News by e-mail.

She said the study may lack the statistical power to detect changes in the age distribution of cases in pandemics. This is "mostly because they only have two seasonal epidemics to compare with, and also because the morbidity data come from several different studies with likely large variations in sampling and testing practices."

Viboud added that at least two previous studies "have noted a change in the age distribution of cases in [past] pandemics, with proportionally more children being sick than expected. Also, we know that seasonal A/H1N1 epidemics tend to cause illness in younger individuals than H3N2 epidemics, which is not obvious from their [Lamaitre and Carrat's] data, and suggests that the study may be underpowered."

She said another possible problem with the study is its use of data on deaths specifically coded as influenza, which underestimate the true flu burden and may introduce age-related biases in coding. She added that she looks forward to further studies on the age distribution of cases and deaths as more data on the 2009 pandemic become available.


Tuesday, June 8, 2010

Studies Needed to Address Public Health Challenges of the 2009 H1N1 Influenza Pandemic: Insights from Modeling

In light of the 2009 influenza pandemic and potential future pandemics, Maria Van Kerkhove and colleagues anticipate six public health challenges and the data needed to support sound public health decision making in the June edition of PLoS Medicine. Summary points from the group’s paper include the following:
  • As the global epidemiology of the pandemic (H1N1) 2009 influenza (H1N1pdm) virus strain unfolds into 2010, substantial policy challenges will continue to present themselves for the next 12 to 18 months.
  • Here, we anticipate six public health challenges and identify data that are required for public health decision making: Measuring age-specific immunity to infection; accurately quantifying severity; improving treatment outcomes for severe cases; quantifying the effectiveness of interventions; capturing the full impact of the pandemic on mortality; and rapidly identifying and responding to antigenic variants.
  • Representative serological surveys stand out as a critical source of data with which to reduce uncertainty around policy choices for both pharmaceutical and nonpharmaceutical interventions after the initial wave has passed.
  • Continuing to monitor the time course of incidence of severe H1N1pdm cases will give a clear picture of variability in underlying transmissibility of the virus during population-wide changes in behavior such as school vacations and other nonpharmaceutical interventions.

    The entire article is worth reading, and can be viewed by clicking on the hyperlink below.

    Article: Van Kerkhove MD, Asikainen T, Becker NG, Bjorge S, Desenclos J-C, et al. (2010) Studies Needed to Address Public Health Challenges of the 2009 H1N1 Influenza Pandemic: Insights from Modeling. PLoS Med 7(6): e1000275. doi:10.1371/journal.pmed.1000275