[health-vn] Judging the WHO's Reaction to the H1N1 Flu Threat

[Vern Weitzel]

http://www.time.com/time/health/article/0,8599,1897547,00.html

Monday, May. 11, 2009
Judging the WHO's Reaction to the H1N1 Flu Threat

By Bryan Walsh

Few global health decisions have created quite as much commotion as that on 
April 29, when the World Health Organization (WHO), responding to the escalating 
spread of the H1N1 flu, raised its pandemic alert level for the first time to 
phase 5, meaning that a full pandemic was considered imminent. As of May 11, the 
WHO has reported more than 4,600 cases in 30 countries — including 2,600 cases 
in nearly every state in the U.S., according to the Centers for Disease Control 
and Prevention (CDC) — and the threat level remains at phase 5.

But over the past two weeks, fears over H1N1 have cooled considerably, as the 
virus has failed to spread easily outside North America and the number of deaths 
from the disease has remained low, leaving the WHO fending off critics who 
questioned whether the international agency overreacted. "We know that we are 
seeing things change on an almost daily basis," said Keiji Fukuda, the WHO's 
interim director for health, safety and the environment. "It is still a 
confusing situation." (See pictures as the swine flu hit Mexico.)

Now new research suggests that the WHO acted wisely in raising the pandemic 
alarm — and that the threat of H1N1 may not have passed. In a study released May 
11 in the journal Science, researchers from Imperial College London, along with 
WHO staff and Mexican scientists, conclude that H1N1 is transmitted considerably 
easier than the regular seasonal flu and is about as deadly as the 1957 Asian 
flu, which killed about 2 million people worldwide. A World Bank study last year 
found that a pandemic of similar severity today might kill 14.2 million people 
around the world, and cut 2% from the global economy.

The authors of the Science paper based their findings on early data from the 
H1N1 outbreak, estimating that about 23,000 people had been infected in Mexico 
by late April, with a fatality rate of about 0.4%. Those numbers come with a 
wide margin for error on either side, and there are still holes in the 
epidemiology that need to be filled, but the consensus is that the WHO's 
handling of H1N1 was reasonable. "Our research indicates that the WHO was 
justified in its actions in the early days," says Christophe Fraser, an 
epidemiologist at Imperial College and the lead author of the paper. "There was 
no overreaction there."

The Science study also indicates that young people — those who are generally the 
most resistant to the seasonal flu — are especially vulnerable to H1N1. It's 
still not clear why that is. It could be that older people are more likely to 
have contracted a virus similar to H1N1 in the past, which might give them some 
immunity. Or it may be that young people simply encountered H1N1 more often in 
the early days of the outbreak. The only thing that's clear is that young people 
are contracting it and they are getting sick. In the small Mexican town of La 
Gloria, where the virus appears to have originated in early February, H1N1 
infected over 61% of the under-15-year-olds in the community. That's worrying 
because the 1918 Spanish flu, which killed up to 50 million people, was 
particularly virulent in the young.

As epidemiologists begin to crunch the data on H1N1, we should have a better 
idea of how it spreads — and how dangerous it might be. New studies published 
recently in the New England Journal of Medicine indicate that older people in 
the U.S. also appear to have escaped the virus — just 5% of U.S. patients with 
confirmed cases of H1N1 are 51 or older. Still, since health officials have so 
far focused mostly on outbreaks in schools, it's possible they are simply 
missing older cases. "This is an evolving outbreak and we're still learning how 
this virus works," said Fatima Dawood, a CDC epidemiologist.

One major question is what impact the virus will have in the next flu season, 
when the conditions could be ripe for the disease to spread rapidly. Another 
concern is what will happen in developing countries that haven't yet had to deal 
with H1N1. Rich countries like the U.S. can afford to spend millions on 
antivirals like Tamiflu, but in poorer nations, especially in those parts of 
sub-Saharan Africa where rampant HIV makes the population more vulnerable to 
secondary infections like flu, H1N1 will likely take a far greater toll. Indeed, 
health officials said last week that early evidence suggests underlying 
conditions — including asthma, heart disease, diabetes and tuberculosis — could 
make H1N1 patients more likely to land in the hospital or die. "That's the big 
uncertainty," says Fraser.

It's those uncertainties that keep the WHO on edge, even after most of the world 
has moved on from H1N1. The agency is looking to develop a new pandemic alert 
system that would reflect the potential severity of a new virus — as opposed to 
the current system, which registers only the transmissibility of a new virus, 
not how deadly it might be. That would be a good idea, although in the early 
days of a potential pandemic, there may not be time to wait and see how virulent 
a new pathogen is before alerting the world that it needs to respond.

"If countries had not been thinking about what to do in this kind of situation, 
the fact is we would have had much more confusion," said the WHO's Fukuda. "The 
key to being better off is to be as prepared as possible."