Is swine flu pandemic?
01 05 09 - 13:05
Will pandemic be mild, or kill millions?
By Laura MacInnis - Analysis
GENEVA (Reuters) - Swine flu will carry the name "pandemic" even if the new virus turns out to cause mainly mild symptoms as it sweeps the world, raising questions about how serious the global alert actually is.
Although it has been deadly in the disease epicenter, Mexico, and caused the death of one Mexican infant in the United States, in other countries people infected with swine flu have fared well, with diarrhea the biggest complaint.
The World Health Organization is expected to move quickly to designate a full pandemic -- at level 6 of its 6-point scale -- within days to reflect the continuing spread of swine flu among people who have not been to Mexico, including in Europe.
Margaret Chan, the WHO's director-general, on Wednesday night raised the world flu alert level from 4 to 5 and said: "It is really all of humanity that is under threat during a pandemic."
Echoing other infectious disease experts, and drawing on her experience fighting SARS and bird flu outbreaks as health director of Hong Kong, she said viruses such as the H1N1 swine strain needed to be closely watched in case they worsen.
"We learn from previous pandemics. Pandemic virus is precarious, unpredictable, and will take us by surprise," she told reporters at the WHO's headquarters.
PATIENTS RECOVERING WITHOUT DRUGS
But Chan acknowledged that the disease may well cause more discomfort than death, noting that many patients infected in the United States have recovered on their own and without medicine.
"It is possible that the full clinical spectrum of this disease goes from mild illness to severe disease. We need to continue to monitor the evolution of the situation to get the specific information and data we need to answer this," she said.
"There may be a possibility that the virus will die out and stop, and that would be the best for us. But it can turn the other way."
Several theories are circulating about why swine flu has killed as many as 176 people in Mexico while having mild and more manageable effects elsewhere.
Some experts speculate that the Mexican victims did not receive appropriate medical care or suffered other health complications that made them vulnerable to the flu.
For the time being, the WHO's own guidance to people who suspect they have been infected with swine flu is essentially the same as advice for seasonal flu care.
Its website's "frequently asked questions" about the virus tell people who have a high fever, cough or sore throat to rest and take plenty of fluids, wash hands frequently, and avoid work, school or crowds as much as possible. (www.who.int/csr/disease/swineflu/faq/en/index.html#q11)
MILD OR SEVERE PANDEMIC?
Keiji Fukuda, the WHO's acting assistant director-general, said that swine flu appeared very similar to normal seasonal flu, a disease that is rarely fatal for healthy adults but can kill the elderly and infirm.
Between 3 and 5 million people experience severe illness due to regular, seasonal flu around the world each year, and between 250,000 and 500,000 die as a result.
Fukuda said it was not yet clear whether swine flu would turn into a mild or severe pandemic, raising the possibility that the virus could have more serious effects as it continues to permeate new communities or as climate conditions change.
There were three pandemic flu outbreaks in the 20th century -- in 1918, 1957 and 1968 -- known respectively as Spanish, Asian, and Hong Kong influenza. An estimated 50 million people died in the first outbreak, about 2 million in the second and between 1 and 3 million in the third.
"In the 1918 pandemic, the first wave was mild, but by fall, the second wave killed many people. So whichever way this virus swings, we can't possibly know," said Guan Yi, a microbiologist at the University of Hong Kong.
"At this point, chances are it will be mild, but we can't rule out it will turn virulent. And even if it turns milder, it can still kill, depending on the kind of person it infects."
Health experts fear swine flu could be especially dangerous for the old and infirm, especially those with immune-system suppressing diseases such as HIV/AIDS.
Its spread to poor countries that lack medical staff, drug stockpiles, and diagnostic tests -- and where tropical and other diseases are also prevalent -- is another serious concern.
Guan Yi said that if it spread to Egypt or Indonesia, where H5N1 bird flu is endemic, it might combine with that virus.
"It could turn into a very powerful H5N1 that is very transmissible among people. Then we will be in trouble, it will be a tragedy."