Rabies infections highlight dangers of processing dog meat

In research published today in the open access journal PLoS Medicine, Dr Heiman Wertheim and colleagues from the National Institute of Infectious and Tropical Diseases and the National Institute of Hygiene and Epidemiology in Hanoi, Viet Nam, report on two patients admitted to hospital showing signs of rabies infection. Neither patient was thought to have been bitten by a rabid animal in the preceding months.

Rabies is a very serious – and in nearly all cases fatal – disease. It is estimated to kill over 30,000 people each year in Asia, and the number of cases in China and Viet Nam is increasing. Symptoms include agitation, severe spasms, fever, fear of water and inability to drink liquids, and eventually death. Humans are usually infected after being bitten by an infected animal such as a dog or bat.

When the researchers investigated whether the patients had come into contact with infected animals in the preceding months, they found that both had been involved in preparing and eating animals which may have been infected. In the first patient's case, he had prepared and eaten a dog that had been killed in a road traffic accident; rabid dogs were known to inhabit the neighbourhood. The second patient had butchered and eaten a cat that had been sick for a number of days.

In both cases seen by Dr Wertheim and colleagues, it is thought that infection occurred during the slaughtering, and not by eating the meat as the meal was shared by others who did not become infected. In Asia, it is believed that eating dog meat enhances health and longevity. It is eaten throughout the year in the second half of the lunar month, particularly in the winter months, when it is believed to increase body heat.

In Viet Nam, dogs with rabies have been detected in dog slaughterhouses and workers at dog slaughterhouses are vaccinated against rabies as part of the national programme for rabies control and prevention. However, the private slaughter of dogs is relatively common in the country.

“We need to alert both the general public and clinicians about the risks around butchering and handling meat,” says Dr Wertheim. “People should not handle animals that may be infected with rabies. Rabies can be prevented with a vaccine and people exposed to rabies can be helped with post-exposure prophylaxis, but this needs to be administered as quickly as possible following the exposure. Once a person shows symptoms, the disease is almost invariably fatal.

“Vietnamese doctors already consider dog slaughtering to be a risk factor for rabies transmission, but it is important that other health care workers and policy makers, both in- and outside Vietnam, are aware of this risk factor.”