Jun 2, 2009 (CIDRAP News) – The global novel H1N1 influenza situation is drawing closer to the status of a true pandemic but is not there yet, the World Health Organization's (WHO's) lead spokesman on the issue said today.
"Globally we believe we're in phase 5 but are getting closer to phase 6," said Dr. Keiji Fukuda, the WHO assistant director-general for health security and the environment, referring to the WHO's pandemic alert phases.
By the WHO definition, phase 5 means a novel virus is causing sustained community outbreaks in more than one country within one WHO region, in this case the Americas. Phase 6 signals a full pandemic, defined as a novel virus spreading widely in more than one global region. The phases as currently defined do not say anything about the severity of the disease, only its geographic extent.
Speaking at a news briefing, Fukuda also said the WHO will come up with ways to describe the severity of the epidemic and provide related guidance so that governments will have more information on how to respond to the situation.
Last week, after a number of countries voiced concern that a pandemic declaration would cause undue alarm and disruption in the context of a generally mild disease, Fukuda said the WHO would consider modifying its phase definitions. Today, in the wake of a teleconference with experts yesterday, he signaled that the WHO will stick with the current definitions, but promised the agency would supplement them by finding a way to describe the severity of the disease threat.
Fukuda said several countries outside North America, including the United Kingdom, Spain, Japan, Chile, and Australia, seem to be moving from having limited H1N1 outbreaks related to travelers and institutions to having widespread community transmission.
"However, we still are waiting for evidence of really widespread community activity in these countries, so I think it's fair to say that they are in transition and are not quite there yet," he said.
He contrasted those countries with the United States, Mexico, and Canada, where the virus is widespread, and most other countries, where cases are limited and mostly linked to travel or to institutional outbreaks.
As of today, the WHO has confirmations of 18,365 novel H1N1 cases in 64 countries, with 117 deaths, Fukuda reported. He said the WHO now plans to update its online H1N1 case count on Monday, Wednesday, and Friday, instead of 5 days a week.
Offering a kind of one-word descriptor that the WHO has generally avoided, he said, "It's probably fair to call the situation moderate right now. We have some hesitation in calling it mild, for a couple of reasons."
One reason is that while the number of serious and fatal cases appears relatively low, the WHO doesn't know the true proportion of severe cases, he said. Another reason is that the infection can be fatal in some people, including those with underlying medical problems, pregnant women, and even some who were previously healthy.
Creating a severity scale
The WHO's decision to assess severity but not change the pandemic phase definitions comes out of a series of telephone consultations yesterday with about 30 experts from 23 countries, Fukuda reported.
He said the discussions were fruitful and produced consensus in a number of areas: "The experts urged WHO to continue to use geographic spread as the basis for moving to phase 6, but also said WHO should modify this movement with an assessment of severity, and WHO should provide more tailored guidance to countries, responding to the severity."
Much of the discussion focused on how to assess severity, which has to do not only with the virulence of the virus but also with the vulnerability and resilience of populations, which are likely to vary from country to country, he said.
The WHO may come up with something like a 3-point severity scale, Fukuda said. The agency hopes to develop a general severity assessment that will be useful to all countries but link it with detailed guidance to help local authorities assess their own situation and respond appropriately.
"One of the things we hope to do is reduce some of the more drastic actions that may be uncalled for, but also provide guidance to countries regarding what steps they can take," he added. He cited embargoes on pork and the slaughter of pigs, measures used by some countries in the early stages of the epidemic, as examples of uncalled-for actions.
In other comments, Fukuda said the novel virus seems to be behaving pretty much the same in the southern hemisphere as it has in the northern hemisphere. In Chile and Australia, for example, most cases have been mild, but some severe cases with respiratory failure have occurred, just as in North America.
"Overall, what we're seeing in the first few countries in the southern hemisphere is similar to what we're seeing in the northern hemisphere," he said.
He also reported that most of the flu viruses identified recently in Chile have been the novel H1N1 rather than the seasonal flu viruses that normally show up at this time of year.
May 26 CIDRAP News story "WHO may redefine pandemic alert phases"