CANCUN, Mexico — World health experts warned Thursday that the global swine flu outbreak that so far has sickened nearly 4,000 Texans and killed 17 is all but certain to worsen in the coming months.
“We are really at the start of a global phenomenon,” said Keiji Fukuda, assistant director general of the World Health Organization. “This is a very humbling virus.”
Hundreds of specialists from 40 countries meeting at a posh beach side resort in this tourist mecca were plotting strategies for what many dread could become an outbreak rivaling a 1918 flu pandemic that killed tens of millions of people.
Health officials in the United States, Mexico and Canada fear that a strengthened virus will return north with the winter cold. And the United Kingdom’s health minister warned this week that the flu could strike as many as 100,000 Britons a day by the end of August.
“We need to plan for the most extreme scenarios as well as for the likely scenarios,” said Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention. “Influenza is perhaps the most unpredictable of infectious diseases.”
This swine flu strain — which scientists call A-H1N1 — was first noticed in late April in Mexico City. The virus was later traced to cases in early March, one of them fatal, in the Mexican states of Veracruz and Oaxaca as well as two near San Diego, Calif.
In just three months the virus has zipped around the world, sickening at least 80,000 and killing 327 in 121 countries. It now stalks the southern hemisphere, where winter flu season rages.
“Watching how quickly H1N1 spread globally was quite disconcerting,” said Canada’s Health Minister Leona Aglukkaq. “It is so important for countries to have a plan in place to be able to respond.”
The WHO declared a pandemic last month. Vaccines are being developed, and it is being effectively treated with anti-viral medicines.
“It really makes sense that the origin was Mexico,” said Nancy Cox, the CDC’s leading flu expert. “We don’t know how long it circulated in humans before it was detected.”
Unlike seasonal flu, which kills tens of thousands of toddlers and the elderly each year, H1N1 has mostly sickened young adults and been deadliest in older children and teens. Experts worry that it could mutate into strains for which most people have no immunity.