New cases of bird flu underscore dangers of a global pandemic

The appearance of new cases of the bird flu virus HIN5 among poultry and humans in Asia has prompted urgent warnings about the potentially catastrophic consequences of a deadly worldwide pandemic. At present, the virus is transmitted to humans via infected birds. With the virus entrenched in parts of Asia, what concerns scientists and health workers is the possibility that a mutant strain will emerge that can spread directly from human to human.

In late February, Dr Julie Gerberding, director of the US Centres for Disease Control and Prevention, told a convention of the Association for the Advancement of Science: “Our assessment is that this is a very high threat. Each time we see a new H1 antigen emerge, we experience a pandemic of influenza.” She explained that a similar influenza virus killed an estimated 20-40 million people in 1918-1919.

World Health Organisation (WHO) director general Lee Jong-wook told the Financial Times in early March: “Nobody knows how bad it will be. But there is no disagreement that this is just a matter of time. We can’t be optimistic.” WHO estimates that a pandemic could kill 8 million people and put another 30 million people in hospital. Other virologists put the figures even higher.

British newspapers last week reported the comments of a senior government official to a security conference in London, warning that the number of deaths from an influenza epidemic in the United Kingdom alone could reach 750,000. Up to a quarter of the workforce could be absent through sickness. Professor Hugh Pennington, president of the British Society for General Microbiology, said the death rate could be even higher—up to two million.

At this stage, a mutant strain has not emerged. The deaths have been limited to relatively small numbers of people in South East Asia—Vietnam, Thailand and Cambodia. But as Dr Shigeru Omi, a senior WHO official, warned at a conference last month in Vietnam, the longer the virus circulates among animals, the greater the risk for humans and the potential for a pandemic. North Korea is the latest country to report the disease in its bird population.

Vietnam’s death toll from bird flu reached 35 last Friday when a 17-year-old woman from Nam Dinh province succumbed to the disease. Authorities also confirmed that a 40-year-old woman from Quang Ninh near the border with China had contracted the virus.

Two people have died in Cambodia, the most recent on March 22 in the southern province of Kampot. A third person, who had close contact with the latest victim, also has the disease. Another 12 people have died in Thailand, bringing the overall deaths to 49 since 2003.

The fatality rate from the disease—the ratio of deaths to the number of cases—currently stands at 70 percent. Health authorities suggest, however, that the actual rate may not be so high as a number of less virulent cases could have gone unreported.

Health investigators have been concerned to identify quickly any possible cases of human-to-human transmission of the disease. One case in Vietnam early this year involved two brothers.

The elder brother died after eating raw duck blood porridge at the funeral of his son. He was hospitalised on December 31 and died on January 9, but was not initially diagnosed with bird flu. His younger brother, who looked after him in hospital, also became ill and tested positive for the disease. Doctors retested the dead brother and found he had contracted the virus, but eventually ruled out human-to-human transmission. The younger brother survived.

WHO officials are also investigating the case of Cambodian woman Tit Sakhan who died on January 30. Her younger brother died nine days earlier and two other family members are sick. Tit Sakhan was only diagnosed with the disease because she crossed into Vietnam to seek medical attention. Compared to Vietnam, Cambodia’s health system is even more rudimentary.

An article in the Washington Post this month highlighted the limited character of preventative efforts in Cambodia. Surveillance for the bird flu virus consists of a network of informants connected via cell phone to an office in Phnom Penh. Cambodia is seeking $10,000 in international assistance to pay for prepaid phone cards. Overall annual per capita spending on health care, amounts to just $US3.

Poor communications and the lack of trained medical personnel and equipment are hampering control of the disease in all three countries. More fundamentally, however, lack of education, endemic poverty and economic backwardness are creating the conditions for new cases of bird flu. Many small farmers are reliant on raising fowl to survive and live in close proximity to their birds thus increasing the chances of contracting the disease from sick birds.

In Vietnam, the virus has spread to poultry in almost half of the country’s 64 provinces. Since December, 800,000 birds have been culled in an effort to eradicate bird flu. Some 40 million of Vietnam’s 258 million chicken and ducks have been slaughtered since the disease emerged in late 2003. Around 80 percent of poultry producers are small-scale farmers who raise a few dozen birds to eat or sell.

Most fatal cases in Vietnam have been in the Mekong Delta. Authorities in Ho Chi Minh City have ordered the slaughter of all fowl in the city. But there is reportedly a thriving black market in live chickens, which still can be bought in the city for $2.50 each and a 60-cent finder’s fee.

While South East Asia would bear the immediate blunt of any pandemic, these countries are least able to cope with such an outbreak. Wealthier countries like Australia, the UK and the US are building stockpiles of anti-viral drugs that have proven effective in limiting the impact of flu viruses. Britain has ordered 14.6 million doses of the drug oseltamivir.

Poorer countries cannot afford to stockpile these expensive drugs. Oseltamivir, for instance, costs $US120 for a six-week course. At a WHO meeting in January on bird flu, a Thai delegate, Dr Viroj Tangcharoensathien, suggested that drug patents be set aside in the case of a pandemic to enable the production of cheap anti-virals in the affected countries. US and French delegates immediately rejected the idea declaring that it could lead to smuggling and profiteering.

Research is also underway into the development of a vaccine. Three potential vaccines are already undergoing clinical trials. The value of a vaccine in combatting a mutant virus that is yet to emerge is unknown, but researchers hope that it could at least attenuate the disease. Thailand and Vietnam provided samples of the human H5N1 virus to help develop a vaccine and are asking for assistance to inoculate their populations but have received no guarantees.

At a regional conference in Vietnam in late February, UN Food and Agriculture Organisation (FAO) official Samuel Jutzi expressed concern at the lack of financial support for preventing bird flu. “I perceive an alarming lack of commitment among the donors and also among the affected countries,” he declared. Last year donor countries gave $18 million dollars but Jutzi estimated that $300 million was needed.

In late January, the FAO warned that the Asian tsunami may have compounded the dangers of bird flu. The organisation pointed out that the devastation may lead to a large-scale movement of poultry into affected areas under conditions where any ability to monitor outbreaks of the disease has been destroyed. It noted that one of the worst affected areas—the Indonesian province of Aceh—was along the route of migratory birds that have been identified as possible carriers of the virus.

Writing in the International Herald Tribune, Dr Hans Troedsson, WHO representative in Vietnam, and FAO official Dr Anton Rychener drew a parallel with the December 26 Asian tsunami. “For the tsunami, the world had no warning. For the avian influenza, the world is constantly being alerted about the danger. Let us all heed the warning,” the authors pleaded.

What is common to the tsunami disaster and the danger of a bird flu pandemic is that the risks are known, preventive and curative methods either exist or are being developed, and yet the major powers treat the fate of millions of people in countries like Vietnam with complete indifference. In the event of an outbreak, it inevitably will be the poor of South East Asia and other countries, including the US and Europe, who will be the hardest hit.