Human Health Risks

Bats and Human Health

Orphaned Spectacled flying fox being raised by a trained carer

Orphaned Grey-headed flying fox with licensed carer

Juvenile Grey-headed flying being raised by a trained carer

Juvenile Grey-headed flying-foxes in rehabilitation facility

Injured flying fox waiting to be rescued

Are flying-foxes a health risk?

In a speech to Parliament in August 2011, Andrew Powell said urban bat colonies represented a significant threat to human health. A calm analysis of the facts shows that the health associated with flying-foxes is less than that posed by domestic pets, including birds, dogs and cats, and medical experts say that urban bat camps are not a health risk.

See further information on the list below at Qld Health. In a Lyssavirus Fact Sheet (also from Qld Health) authorities say "contact or exposure to bat faeces, urine or blood do not pose a risk of exposure to ABLV, nor do living, playing or walking near bat roosting areas".

Most claims about health risks are untrue

Below, we take a look at some of the health risks that the media, politicians and commentators have claimed pose a significant health risk. We demonstrate that these claims are untrue - using freely available public health information.

Australian Bat Lyssavirus

In Australia, this is the only virus known to be transmitted by flying-foxes to humans. It can only be contracted through a bite or scratch, and just one person is known to have contracted the disease from a flying-fox, although the recent tragic death of a young boy may have been been transmitted by a flying fox (health authorities have so far not divulged the source). Anyone who has contact with a flying-fox can receive treatment to prevent the disease developing. Queensland Health says: “There is no known risk of contracting ABL from bats flying overhead, contact with bat urine or faeces or from fruit they may have eaten. Living, playing or walking near bat roosting areas does not pose a risk of exposure to the virus.”

"We are a group of scientists, conservationists and wildlife carers with a common interest in the welfare and conservation of flying-foxes. More than any other group in society we have an interest in any health risks associated with flying-foxes because we work very closely with them. If bats were a direct risk to human health, we would be at greatest risk. But wildlife carers and researchers do not become ill due to working with flying-foxes. Our pets have not been affected. We urge people to take an evidence-based approach to health risks. It is safe for people to live near bat camps"
- Flying-fox Information & Conservation Network 2011

Hendra Virus

Hendra Virus is transmitted from horses to humans, not from flying-foxes. As advised by Queensland Health, the best way to prevent this disease is management of horses. Evicting flying-foxes from urban areas will not prevent them from feeding in horse paddocks. In mayy cases, dispersals have lead to the flying-foxes relocating to a more inappropriate location. By increasing stress in flying-foxes, dispersals could increase the risk of spillover of Hendra virus.

Salmonellosis

This is a bacterial infection usually contracted from infected food such as meat, eggs, milk, fruit and vegetables. There is no record of transmission from flying-foxes.

Histoplasmosis

Histoplasmosis is known to be caught from accumulated droppings, known as guano, from insectivorous, cave-dwelling bats. While it is theoretically possible, there are no records in the medical literature of histoplasmosis caused by flying-fox faeces.

Leptospirosis

Leptospirosis occurs worldwide and affects humans as well as animals. The disease is caused by bacteria from the genus Leptospira. Symptoms include fever, headache, muscle aches, vomiting, abdominal pain and rash. The incidence in Australia is about 1 per 100,000 people. It can be treated with antibiotics but if not treated, more serious symptoms can result. Death from leptispirosis is rare.

Leptospirosis is an occupational hazard for farmers, veterinarians, meat workers and others who work outdoors or with animals. Infection is through contact with water, food, or soil contaminated with urine from infected animals. Rodents are the most common source of infection, although most mammals are considered to be carriers.

Flying foxes have recently been reported as likely carriers of the disease, but there has not been any recorded incidence of flying-foxes transmitting the disease to humans.

How do bats rate as a threat?

Those who advocate protecting flying-foxes include wildlife carers, researchers or conservationists who have very close, regular contact with flying-foxes (see photos left). Many of these people regularly handle wild flying foxes. If anyone is at risk, they are. But they know that the risk of catching disease from bats is extremely low, and that measures can be taken to keep safe. After all, just one Australian is known to have become ill and died due to an encounter with a flying-fox, in 1998, from Australian bat lyssavirus, although the tragic death of a young Queensland boy in 2013 may have been been transmitted by a flying fox (health authorities have not divulged the source).

The table (above) ranks various causes of death, showing that flying-foxes are less of a risk than horses, cattle, bees, hay bales, windmills, air conditioners, car jacks and more than a dozen better known killers. Flying-foxes are safer than virtually everything else you encounter in an urban environment (just don’t touch them)! See here, here and here for more information.

The people shown in these images are trained, licensed, vaccinated wildlife rehabilitators - you should not handle wildlife for your own safety, as well as the welfare of the animal: rather, call your local wildlife rescue group (see here for contacts).

REFERENCES:References for the table can be found here. Major sources of data are:
(1) Australian Bureau of Statistics, Causes of Death, Australia (annual data available for the period 1990-2009 on the ABS website);
(2) Australian Bureau of Statistics, Year Book Australia, (annual data available for 1990-2009 on the ABS website). See http://www.abs.gov.au/
(3) National Coroners Information Service report into Deaths Involving Animals, May 2006. See www.ncis.org.au/web_pages/Broadsheet2_Animal%20related.pdf.
(4) National Coroners Information System. 2007. A sample of consumer product related deaths. Deaths reported from 01/07/2000–30/06/2007. See www.ncis.org.au/Product%20related%20fatalities%20national%20version.pdf.
(5) Pollock K, Fragar L, Morton C. 2007. Traumatic deaths in Australian agriculture – The facts. Rural Industries Research and Development Corporation and Australian Centre for Agricultural Health and Safety
(6) Franklin R, Mitchell R, Driscoll T, Fragar L. 2000. Farm-related fatalities in Australia, 1989-1992. Moree: ACAHS, NOHSC & RIRDC
All images on this page courtesy Steve Amesbury - Australian Fauna Care