10 November 2011 - FAO has published a forward-thinking manual on bats and their role in emerging infectious diseases in animals and humans, while underlining their important role in maintaining the delicate balance in ecosystems that support human, plant and animal life.
“Investigating the Role of Bats in Emerging Zoonoses: Balancing Ecology, Conservation and Public Health Interest” is a manual meant to be used by epidemiologists, wildlife officials, farmers, livestock veterinarians, zoologists, and any number of different professionals who might be coming into increased contact with bats. It is a hands-on reference to their history, biology, monitoring and handling them, especially amid growing evidence they can be a route for introduction of emerging diseases in livestock and humans.
“Bats are much maligned in many cultures,” said Scott Newman, Wildlife Coordinator of the FAO’s EMPRES Animal Health programme and one of the manual’s co-authors. “While it’s true they can be reservoirs for disease – carrying them while remaining unaffected themselves – they also support our ecosystems as pollinators and natural pest controllers. Essentially they help agriculture and save farmers millions of dollars in pesticides,” he said.
But as livestock and human populations expand and encroach on wildlife habitat, their increasing closeness has also given rise to increased risks.
For example, the Nipah virus, which emerged from bats, began sickening large numbers of pigs in Malaysia in 1998. Humans who had had close contact with pigs, mostly farmers, were also sickened. The virus, which killed 105 people, had a 40 percent mortality rate in humans.
The virus devastated Malaysia’s multi-billion dollar pork industry. Of a total pig population of some 2.4 million animals, about 1.1 million pigs had to be culled to bring the disease outbreak under control.
Leading up to the outbreak, pig production had been intensifying, with resulting regional deforestation and lost habitat. As a result, bats and pigs came into greater contact, with bats feeding from fruit trees overhanging pig’s feeding troughs, and contaminating them with saliva and excrement.
"We have an agreement with the Zoological Society of London, with specialists who have been hired to create a database of Old World fruit bat populations and their roosts especially in Africa and Southeast Asia,” Newman said. “Old World fruit bats pollinate bananas, for example, which are of global importance, but it’s especially local varieties of banana that can provide people with up to about a quarter of their daily calorie intake, in countries such as Gabon, Cameroon, Uganda and Rwanda.”
The “bat manual” is a concrete example of tackling complex animal and human diseases through a “One Health” approach, taking into account the interconnectedness of the world’s health across the animal-human-ecosystems interfaces.
“Investigating the Role of Bats in Emerging Zoonoses: Balancing Ecology, Conservation and Public Health Interest” benefited from the financial support of the Australian Government’s Department of Agriculture, Fisheries and Forestry and the FAO’s Animal Production and Health Commission for Asia and the Pacific. See the right-hand links to partners who contributed in-kind knowledge and expertise.