Swine flu: WHO moves to Stage 5 alert
NEW YORK — The human swine flu outbreak is evolving so quickly that the World Health Organization raised the pandemic alert level late Wednesday from 4 to 5 — just one step from acknowledging a full-scale global epidemic.
The designation means the WHO is aware of sustained human-to-humantransmission in at least two countries.
“It is clear that the virus is spreading, and we don’t see any evidence of this slowing down,” said Dr. Keiji Fukuda of the WHO, earlier in the day. “It is possible, always theoretically possible, that this epidemic could suddenly stop for unknown reasons, although this is probably unlikely at this point.”
The WHO had received notice of 114 cases of human swine flu from seven countries. Officially, eight people have died — seven in Mexico and one in the U.S. The death in the U.S., reported Wednesday, was of a 23-month-old child in Texas.
These laboratory-confirmed numbers are smaller than other numbers that have been reported because there is often a short delay in reporting to the WHO and press reports often include suspected or probable cases as well as confirmed cases. For example, at the same time Fukuda was speaking with reporters, the U.S. Centers for Disease Control reported that American cases had risen from 64 to 91.
Even if the current outbreak turns out to be a mild one, that is no cause for anyone to relax their guard, said Fukuda.
“The worst pandemic of the last century started out mild in the spring time,” he said. “It was fairly quiet during the summer and in the autumn, when it really exploded — this was in 1918 — it was a much more severe form.”
Perhaps one of the biggest lessons from the 1918 pandemic is that withholding information out of fear of causing a panic is actually counterproductive, according to John Barry who wrote "The Great Influenza", a best-selling account of the pandemic.
Barry writes that newspapers refused to print warnings from doctors in Philadelphia that a planned parade through the streets of the city could accelerate the spread of flu. The parade went on as planned and Philadephia’s death toll turned out higher than in other cities of comparable size.
Another important lesson from 1918 concerns the role of secondary infections — like bacterial pneumonia — in determining whether people lived or died. Many who were weakened by the viral infection then succumbed to a bacterial infection of the lungs. Of course, back then, there were no antibiotics to treat bacterial pneumonia.
Flu researchers like to joke, “If you’ve seen one influenza pandemic … then you’ve seen one influenza pandemic.” By that they mean that influenza is an incredibly unpredictable virus, and knowing how previous flu strains have behaved helps little in predicting what will happen with the current outbreak of human swine flu.
Even if the current outbreak proves no more than a “dress rehearsal” for some later pandemic, the experience gained could save lives in the future.
Health officials will now be paying particularly close attention to what happens in New York City, where four schools have now closed due to confirmed or suspected cases of swine flu. That’s because the next step on the road to pandemic is the sustained transmission of flu out into the community — beyond the first few people who fell ill and their friends and family.
New York City has the public health infrastructure to quickly assess whether sustained transmission is occurring. Its population density means transmission can be more easily spotted.
So far, the biggest outbreak in New York City was at one school where 75 students reported sick last Thursday and 150 were out sick on Friday, before the school was closed. Those kinds of numbers have not yet been seen in other schools or institutions in New York City, although two people — a 19-month-old infant and an adult woman — with no link to the school have also tested positive for the human swine flu.
The next question will then be — is this virus more deadly than the usual seasonal flu or about the same? No one can answer that question for now.
For more GlobalPost dispatches on the swine flu: