HEALTH-ASIA: Bird Flu, Fearsome but Fickle

By Marwaan Macan-Markar Reprint | | Print |

Marwaan Macan-Markar

BANGKOK, Oct 27 2005 (IPS) - Despite the doomsday scenarios being painted in sections of the media, now that Europe has detected its first signs of bird flu, the virus concerned has left only a small signature in Asia, during a career that began in January 2004.

After two winters, and with a third cold season approaching, the H5N1 strain of the bird flu virus has still not mutated into a strain capable of being transmitted among humans-much less trigger a global pandemic, observe public health experts in South-east Asia.

”The virus has been changing in the normal way we expect it to, but it has not mutated into a critical level that could be worrying,” says Dr. Supamit Chunsuttiwat, senior medical officer at the department of disease control in Thailand’s public health ministry.

”We have no evidence to suggest that the (H5N1 strain of the) virus that has been detected in Thailand has mutated to one that could cause a pandemic,” he added during an interview.

That diagnosis comes after Thailand was shaken by a bird flu-related death last week, the first such fatality in the country this year. The death of Bang-orn Benpad, 48, due to infection with H5N1 avian influenza brought to 13 the number of fatalities here out of 19 cases detected since the beginning of 2004.

The latest victim from the Kanchanaburi province, west of Bangkok, had shown up with flu symptoms on Oct. 13 and was hospitalised four days later. But he only survived for two more days, dying on Oct. 19.

His death was linked to close contact he had had with infected poultry, including slaughtering diseased chickens, according to reports from the public health ministry.

This week, Thai health authorities confirmed that the seven-year-old son of Bang-orn had developed symptoms of the same killer flu and has been hospitalised. Along with him are three other patients being treated and under observation for a possible bird flu-related illness in the same area.

In neighbouring Indonesia, too, new cases of human infections with H5N1 have been reported in recent weeks. The youngest among them was a four-year-old boy from the island of Sumatra. He had shown flu symptoms on Oct. 4 but responded well to treatment and was discharged from hospital, fully recovered.

Not so fortunate was a 23-year-old man from the island of Java, who was admitted to hospital on Sep. 28 and who died two days later.

Thailand and Indonesia, along with Cambodia and Vietnam, are the only countries in the world that have seen human fatalities due to the H5N1 strain of the virus that began spreading through the region’s poultry population since an outbreak in the winter of 2003. To date, 62 people have died out of 121 cases.

Vietnam remains the worst hit, with 41 deaths out of 91 cases, followed by Thailand, then Indonesia, with four deaths from seven cases, and Cambodia, with four deaths from four cases.

Yet, in neither locality, dubbed in some quarters as the ”ground zero” for the next global pandemic triggered by the H5N1 strain of bird flu, has the virus triggered alarm bells since making its presence felt for nearly two years.

”It still remains a very fickle virus,” Peter Cordingly, spokesman for the World Health Organisation’s (WHO) Western Pacific regional office, told IPS.

But that is little reason for public health authorities to be less vigilant, he added, given the threats posed by this particular strain of the H5N1 virus. For one, it contains a combination of proteins that could contribute to rapid mutation into a flu virus that could result in a deadly contagion, say researchers.

Viruses caused by ”A strains of the influenza virus”, of which the H5N1 strain is one, have characteristics of great public health concern that require constant vigilance, states the Geneva-based global health agency. ”Influenza A viruses, including subtypes from different species, can swap or ‘reassort’ genetic materials and merge.”

The outcome could be a ”novel subtype (of virus) different from both parent viruses,” it adds. ”For this to happen, the novel subtype needs to have genes from human influenza that make it readily transmissible from person to person for a sustainable period.”

And what makes people vulnerable in the face of such virus mutations is the lack of immunity to such new subtypes of virus, compounding an already prevailing worry that humans lack the immunity to fight infections caused by the H5N1 strain of the avian flu virus.

It was a virus with somewhat similar properties and also one that crossed over to humans from birds that was behind the flu pandemic of 1918, which killed close to 50 million people.

”Of the 15 avian influenza subtypes, H5N1 is of particular concern for several reasons,” states the WHO. ”H5N1 mutates rapidly and has a documented propensity to acquire genes from viruses infecting other animal species.”

But for now, after infecting poultry for nearly two years in the region, resulting in tens of millions of chickens dying from the virus or being culled, the H5N1 virus continues to remain only a threat due to the pace of its mutation – ”fickle” but not strong and fast enough to trigger deaths of doomsday proportions.