Vanishing Vulture Linked to Rise in Human Anthrax

NEW DELHI, India, February 12, 2001 (ENS) - Wildlife scientists in India suspect a resurgence in anthrax among humans may be linked to the country's declining population of vultures. But government epidemiologists are not convinced.

Vultures were once common in India and were relied upon to scavenge agricultural and livestock waste traditionally dumped at the edge of towns. India does not have the resources to incinerate or process carcasses.

Scientists have been unable to pinpoint the reason for the vulture's dwindling numbers in India. (Photo courtesy Oakland Zoo)

As Devinder Sharma reported for ENS last October, India's Parsi community rely upon vultures to dispose of their dead. The Parsi religion dictates that the dead should be left on hilltops, known as towers of silence.

During the last decade though, certain species, such as the griffon vulture, have all but disappeared.

"With vultures here headed for extinction, India is losing its most efficient scavenger," said Dr. Vibhu Prakash, principal scientist with the Bombay Natural History Society, in this week's "British Medical Journal" (BMJ).

The griffon has been replaced in many areas by packs of semi-wild dogs, prompting fears of rabies and a rise in parasite infections, especially tapeworms. And in the towers of silence, the dead bodies are mounting.

A report in last August's "New Scientist" magazine quotes Jemima Parry-Jones, head of the UK's National Birds of Prey Centre in Gloucestershire, as saying bodies decaying in Bombay's Towers of Silence showed little evidence of being eaten in the last three years.

"There were bodies in every state, from fresh to extremely decomposed," she told the UK based magazine. "They [the bodies] desiccate in winter, but I dread to think what happens in the summer monsoon."

Opinions vary widely as to what is causing vultures to die out but most researchers agree a virus is to blame. A rapid expansion in India's poultry industry has prompted scientists to theorize an avian virus, novel to vultures, is the cause.

Now, the vulture's decline appears to be affecting human health, according to some scientists.

At last year's annual conference of the Association of Physicians of India in New Delhi, doctors reported that the incidence of human anthrax is rising. Wildlife scientists such as Prakash believe that the vultures' decline corresponds with the rise in anthrax.

The Parsis unique religion is marked by its tradition regarding death, which calls for bodies to be left to vultures on hilltops known as towers of silence. (Photo courtesy the Odyssey World Trek for Services and Education)

But it can occur in humans when they are exposed to infected animals or tissue from infected animals.

Inadequate vaccination and lack of cooperation from farmers means that livestock are vulnerable to infection, which is why animal anthrax remains endemic in India. Without vultures to dispose of dumped animal carcasses, anthrax is spreading to humans, according to the Association of Physicians of India.

Rapid disposal of anthrax carcasses is a key to controlling the spread of anthrax. The present human cases of anthrax in India illustrate that human scavenging is a continuing public health problem.

The association fears other zoonotic diseases - diseases and infections spread from vertebrate animals to humans - will spread, given the vulture's demise.

The BMJ reports that government epidemiologists dispute the link between a rise in anthrax cases and the disappearance of vultures. They say a more efficient disease tracking system may be responsible for the rise in the number of reported cases.

"There is no evidence that the increase has resulted from the death of vultures," Dr. Udai Rana told the BMJ. Rana is deputy director at India's National Institute of Communicable Diseases.

But documented reports of griffin vultures spotted in Pakistan and Nepal exhibiting the same symptoms of the mystery virus are fueling fears that the creature will disappear from much of its traditional terrain. Foremost among these symptoms in a drooping head.

Jemima Parry-Jones of the UK's National Birds of Prey Centre in Gloucestershire. (Photo courtesy National Birds of Prey Centre)

The Bombay Natural History Society, in conjunction with the RSPB, BirdLife International and the Indian Department of Natural Resources, held the conference at World Wide Fund for Nature's New Delhi headquarters to discuss the plight of the Indian white backed Vulture and two species of long billed Vultures.

The Indian government has so far resisted attempts to establish a captive breeding program for vultures to prevent their extinction.