The Human Hand Behind Avian Flu

For the first time since the avian flu reemerged in Asia, the virus is believed to have passed to a third human victim after jumping to first one individual, then another, reports the New York Times. The “double jump” that led to the death of an Indonesian man on May 22 does not mean the disease has mutated into a strain that can cause a pandemic, however, because all of the victims were in close family contact, according to the World Health Organization (WHO).

The WHO reports that there are now 218 confirmed human cases of avian influenza worldwide, and the virus has caused 124 deaths on three continents. H5N1, the most lethal strain so far, has spread rapidly since it was first discovered in humans in Hong Kong in 1997, giving rise to a multitude of theories on both how this spread occurred and what the potential global effects will be.

Despite the unknowns, one thing seems clear: avian flu and other emerging animal diseases are more closely linked to human activities, and in particular large-scale ecosystem alterations, than was previously believed. In mid-April, the United Nations Environment Programme (UNEP) reported that the loss of wetlands may be contributing to the flu’s spread as migrating wild birds water instead at farm ponds and paddy fields, where they come into closer contact with domestic fowl and ultimately people. “[T]he link between a healthy environment and disease prevention is no marginal topic, but an important component in public health policy, particularly in a globalized world,” noted Shafqat Kakakhel, UNEP’s deputy executive director.

Researchers are also highlighting the connections between the spread of avian flu and industrial farming practices. “Factory farming may not be the direct cause of the most recent outbreak of avian flu,” writes Worldwatch agriculture expert Danielle Nierenberg, “but it is likely one of the many factors that has led to the disease's rapid spread and virulence.” Besides being highly inefficient users of water, energy, and other resources, factory farms, where animals are often packed together tightly under poor hygienic conditions, are ripe grounds for spreading disease, Nierenberg says.

Yet some skeptics wonder whether the potential for an avian flu pandemic is great enough to warrant all the media hype. In a March 28 New York Times article, Jeremy Farrar, director of the Oxford University Clinical Research Unit at the Hospital for Tropical Disease in Ho Chi Minh City, Vietnam, and a physician with frontline experience with the disease, downplays the risk of widespread epidemic. While he agrees that more funding for medical facilities in developing countries would reduce the risk of transmission, he says the fact that the disease is not yet pandemic in Asia, where people have retained close proximity to their poultry, suggests it is not as transmittable as is believed.

Other experts are less optimistic. David Nabarro, chief avian flu coordinator for the United Nations, has predicted anywhere between 5 million and 150 million deaths from the virus, though he admits no one can really know how many people will be affected. Regardless, he says, humans are ill-prepared for the potential spread of diseases from animals to humans. “Pathogens from the animal kingdom are something against which we are appallingly badly protected, and our investment in pandemic insurance is minute,” Nabarro told the New York Times.

This story was produced by Eye on Earth, a joint project of the Worldwatch Institute and the blue moon fund. View the complete archive of Eye on Earth stories, or contact Staff Writer Alana Herro at aherro [AT] worldwatch [DOT] org with your questions, comments, and story ideas.