|
Monday, June 20, 2005
Dumaguing: Bird flu a real health threat
By Dr. Victor Dumaguing
IT IS GETTING real and imminent! World Health Organization (WHO) scientists and health experts are calling for stepped-up surveillance of avian influenza in Southeast Asia and that includes the Philippines, after reports surfacing from northern Vietnam suggest that the deadly virus may be evolving into something more easily transmitted to humans.
At this juncture, we would like to remind our readers that while meningococcemia is a bacterial infection, bird flu is a viral infection like the equally-dreaded Sars.
While stressing that there is no proof as yet of human-to-human transmission of the so-called H5N1 strain of the virus, scientists who met five weeks ago in Manila concluded there are numerous signs that the virus is undergoing an evolutionary change. "If action is delayed until there is unmistakable evidence that the virus has become sufficiently transmissible among people to allow a pandemic to develop, then it most likely be too late to implement effective focal, national or regional response," - a warning statement from the Manila WHO summit.
A WHO team that assessed the Vietnam bird flu cases last April was alarmed that it called for an urgent review of the situation. A report was synthesized from the two-day Manila summit and was circularized to many health agencies.
The report strongly recommends "immediate steps" to improve monitoring and urged nations "to move ahead as quickly as possible" on pandemic preparedness plans. It urged the WHO to make experimental vaccines for bird flu available to affected Asian countries and said antiviral drugs should be stockpiled. At the moment, the Roche drug Tamiflu is being considered but the present supply may not be enough, if indeed a pandemic may occur.
Bird flu has infected at least 92 humans since December 2003, killing 52 of them. It is the high probability that the lethal virus be readily passed among humans that worry health experts. In Northern Vietnam, reports suggest that the virus is behaving differently than it has in the south or in other parts of Southeast Asia. This year, there have been eight clusters of cases in the north and only two in South Vietnam. People of all ages have come down with bird flu in the north while no one over the age of 40 was stricken in the south. "These changes" warm WHO experts, "were all consistent with avian virus possibly adapting to a human host." The Spanish flu of 1918, which killed at least 20 million people, was fatal to just 2.7% of those it infected. This is the paradox about a milder form of bird flu being more dangerous because many people would catch it. In Northern Vietnam, the death rate among 47 patients who contracted the bird flu was 34% while the death rate in the south was 63 percent among 24 cases.
Microbiologists have also discovered that the surface proteins on viruses found in Northern Vietnam are slightly different from the ones in the south. One strain isolated this year is "anti-genetically distinct" from the strain being used as a basis for making an experimental vaccine. "The greater age spread, the genetic divergence from north to south and the molecular changes are all things that people have to been concerned about" said Dr. George Rutherford, director of the Institute for Global Health. However, Rutherford was quick to emphasize that "no scientists can be sure whether what is being observed is the birth of a pandemic of simply the normal behavior of avian flu strain that has never been observed so closely.
That notwithstanding, Dr. Larry Drew, director of the Virology Laboratory of the University of California in San Francisco, said the latest WHO findings underscore the need for pandemic planning. This report may help to convince the necessary people that the threat is imminent," he said. "Vaccine development has to accelerate... the most achievable goal is to rapidly build a worldwide stockpile of antiviral drug."
As I've written in past issues, there is no recorded case of bird flu yet in the Philippines but the absence of case does not translate to a unique resistance of the Filipinos to the virus. There may be a vast sea that separates the Philippines from affected countries like Vietnam and Thailand, but then remember that the virus can be carried by migratory birds seeking warmer climes in our lands during the winter. On top of that, let us not forget that air travel has made the world become smaller. Now, do you get the whole picture?
(June 20, 2005 issue)
Write letter to the editor.Click here.
Join the Sun.Star message board.Click here. |
|
[return to top]
[home]
[network page]
|
LOCAL NEWS
BUSINESS
OPINION
SPORTS
LIFESTYLE
FEATURE
|
