HANOI–People who prepare dog and cat meat for human consumption are at risk of contracting rabies, warned medical researcher Heiman Wertheim, M.D. in the March 18, 2009 edition of PLoS Medicine.
PLoS Medicine is a peer-reviewed open-accesss online scientific journal published by the Public Library of Science. With offices in San Francisco and Cambridge, England, PLoS Medicine “gives the highest priority to papers on the conditions and risk factors that cause the greatest losses in years of healthy life worldwide,” state the editors.
Wertheim and colleagues from the National Institute of Infectious & Tropical Diseases and the National Institute of Hygiene & Epidemiology in Hanoi, Vietnam, researched the association of dog meat with rabies after encountering two cases.
The first patient “had prepared and eaten a dog who was killed in a road accident; rabid dogs were known to inhabit the neighborhood. The second patient butchered and ate a cat who had been sick for a number of days,” e-mailed Wertheim to members of the International Society for Infectious Diseases.
“It is thought that infection occurred during the slaughtering [or butchering], and not by eating the meat,” Wertheim continued, “as the meals were shared by others who did not become infected.
Rabid dogs have been found in dog slaughterhouses, where workers are vaccinated as part of the national rabies control program, Wertheim explained, but people who kill dogs for personal consumption usually are not vaccinated.
“Vietnamese doctors already consider dog slaughtering a risk factor for rabies transmission, but it is important that other health care workers and policy makers, both inside and outside Vietnam, are aware of this risk factor,” Wertheim concluded.
Shamsudeen Fagbo of the Department of Tropical Veterinary Diseases at the University of Pretoria in South Africa responded to the Wertheim posting by suggesting that rabies is also contracted through killing and butchering dogs and cats in parts of Africa.
“In Nigeria,” posted Fagbo to the scientifically refereed ISID ProMed mailing list, “dog eating is very common in states such as Plateau, Akwa Ibom, Cross River, Kaduna, Kebbi and Ondo. Cat eating, though not as common as dog eating, can also be encountered, even in cosmopolitan places such as Lagos. While human consumption of bats is also common,” Fagbo added, “there seems to have been little or no local effort (as per the limited information available) to evaluate the risk of rabies transmission.
“Rabies is no doubt underreported and probably misdiagnosed in Nigeria and elsewhere in Africa,” Fagbo continued. “Cultural and religious beliefs will also contribute to the underreporting of human rabies that may arise from the consumption of infected but apparently healthy dogs and cats. The [rabies-related] Lagos bat and Mokola lyssaviruses remain under-diagnosed in the human populace.”
Fagbo pointed out that a little-noticed paper entitled “Rabies in apparently healthy dogs: histological and immunohistochemical studies,” published in 2006 in The Nigerian Postgraduate Medical Journal, identified dog-eating as a high-risk practice in restaurants near two military barracks in Maiduguri, an overwhelmingly Muslim city where eating dogs is otherwise culturally
forbidden. The researchers found evidence of rabies in the heads of 16 of 52 dogs who had been butchered. “If the observations [of authors B.B. Ajayi, J.S. Rabo JS, and S.S. Baba] are confirmed,” wrote Fagbo, “this, in their words, ‘signifies a new dimension in the epidemiology of the disease.'”
Also in 2006, rabies was linked to two human fatalities in the Philippines.
“Ressia Mae Edoria, 4, of Barangay Molobolo, Cauayan, Negros Occidental died last December of rabies and encephalitis, days after neighbors gave her dog meat” at a drinking party,” reported Margaux C. Ortiz of The Philippine Inquirer in Makati City on February 1, 2006. “Renante Edoria, the girl’s father, said his daughter suffered from high fever and exhibited symptoms of rabies shortly after eating the meat.”
Hospitalized on December 13, 2005, Ressie Edoria died a few hours later. Animal Kingdom Foundation veterinarian Winston Samaniego told Ortiz that the rabies virus may have attacked her as rapidly as it did by entering her nervous system though a tooth cavity.
“I am now appealing to everyone to stop eating dogs to avoid this kind of tragedy,” said Renante Edoria.
In June 2006, the Philippines Sun Star reported, “One man died and 23 others are under observation after eating rabid dogs in Maasin, Iloilo. Rolando Carmelita, Jr. died after he cooked and ate a rabid dog. He also fed the meal to his relatives. Not contented, they cooked and ate two more rabid dogs.”
Added Greg Salido Quimpo of Animal Kingdom Foundation, “The victim’s mother is a village councilor. She passed a resolution banning the eating of dogs.”
Malaysian Society of Parasitology & Tropical Medicine president S. Vellayan, M.D. warned in July 2008 via Marjorie Chiew of The Star of Malaysia that rabies is only one of the health hazards of eating dogs, after politicians objecting to the presence of street dogs suggested that the dog should be eaten.
“Eating stray dogs is not encouraged,” Vellayan said, “because some of them may have viruses, bacteria and parasites and can bring about parasitic problems such as cysts and tapeworm
infection. These can be transmitted from animals to humans if the meat is not cooked thoroughly. People can also be infected with tapeworms and rabies when slaughtering the infected animals with their bare hands,” Vellayan cautioned.
Vellayan suggested that rabies might be more common in dogs from northern and border states. He also cited risk of dog-eaters contracting tuberculosis, salmonellosis and leptospirosis.
“Protozoan diseases such as toxoplasmosis can be transmitted via the oral route to humans,” summarized Chiew. “In the congenital form, transplacental infection can take place in the early months of a woman’s pregnancy, resulting in abortion or stillbirth.”
Increasing recognition of eating dogs and cats as a vector for transmission of rabies may have the most significance in southern China and parts of the Philippines.
Thousands of people per year die of rabies in China, almost entirely in the regions where dogs are commonly eaten and raised for meat. So-called “meat dogs” are not vaccinated, because of the belief that vaccination would make them unfit for consumption.