SWINE FLU BREAKING NEWS 2: Global case update, eyeing phase 6, probable cases, southern hemisphere viruses, WHO gathers clinical experts

May 4, 2009

The World Health Organization (WHO) reported 1,085 confirmed cases of influenza A/H1N1 (swine flu) and 26 deaths in 21 countries as of 18:00 GMT (noon US EST) today, up from 985 cases in 20 countries reported earlier in the day. Mexico has reported 590 confirmed cases and 25 deaths. The WHO's latest total reflects today's updated US numbers from the Centers for Disease Control and Prevention (CDC), which stand at 286 cases and 1 death. [WHO update 14]

At a WHO media briefing today, Keiji Fukuda, MD, the WHO's assistant director-general for health security, emphasized that the rationale for any future move to pandemic alert phase 6 wouldn't be based on disease severity, but rather on sustained outbreaks in more than one WHO region. On Apr 29 the WHO raised the pandemic alert to its current level, phase 5, which signifies sustained community outbreaks in two or more countries within one WHO region.

The CDC will begin reporting "probable" cases of flu in addition to confirmed cases to give a better sense of the size of the US epidemic, acting director Dr. Richard Besser said Monday. In addition to the 286 confirmed cases, there are more than 700 probable cases in the United States.

The CDC will work with international health authorities to monitor the southern hemisphere's flu season, beginning shortly, to see how the novel H1N1 strain behaves in competition with other flu viruses. "That will tell us a lot about whether the virus is changing and what measures we might want to take in the fall," Besser said.

Tomorrow the WHO will host its second scientific teleconference to address clinical issues surrounding patients who have influenza A/H1N1 (swine flu) infections, the WHO's Fukuda said today at a media briefing. The conference will allow scientists to share information on crucial topics such as disease severity. The topic of the first teleconference, held on Apr 29, was the influenza situation in Mexico.