Eliminating dog-transmitted rabies
Global health organizations hope to eliminate rabies transmission from dogs to humans in the Americas within the next two years.
The World Health Organization and the Pan American Health Organization, which serves as a regional office for the WHO, hope to accomplish that goal by the end of 2015.
Dr. Victor J. del Rio Vilas, zoonosis coordinator in Panaftosa, a scientific section of the PAHO, said the rabies case load has declined, but rabies remains a neglected disease and a “morally unacceptable” presence in the current level of global development.
The 2013 report of the WHO Expert Consultation on Rabies indicates canine rabies control programs reduced dog-transmitted cases of human rabies in Latin America and the Caribbean from 250 in 1990 to fewer than 10 in 2010. Dr. del Rio said in early November that his organization had received nine reports of humans infected with rabies in Latin America and the Caribbean during 2013, and not all those infections were transmitted by dogs.
People in the Western Hemisphere now contract rabies from bats more often than they do from dogs, he said.
But the WHO report also indicated that official reports likely underestimate the magnitude of rabies problems, particularly in Haiti but also in Bolivia, Cuba, the Dominican Republic, El Salvador, Guatemala, Honduras, and parts of Brazil, Mexico, and Peru.
“In these countries, human deaths from rabies are either still occurring or are at risk of occurring,” the report states.
Dr. del Rio said Haiti remains a priority country for rabies control, along with the Dominican Republic and parts of Bolivia, Brazil, and Peru.
In August, the PAHO hosted a meeting in Lima, Peru, for directors of national rabies control programs in the Americas.
Dr. del Rio said it is common that, with a disease control program or other public program, reducing a problem can lead to a perception that the program is no longer a priority, and this type of perception is a risk to current rabies control efforts. Yet, he said figures provided during the meeting in August indicated governments had been maintaining their budget levels related to rabies.
About 95 percent of human deaths from rabies occur in Asia and Africa, with more of those deaths occurring in Asia, according to the WHO. Dogs are the sources of most of those infections.
The report states that the rabies virus disproportionately affects people in rural areas, particularly children.
Dr. Charles E. Rupprecht, research director of the Global Alliance for Rabies Control, said it is “unconscionable” that children die of rabies transmitted by dogs in the 21st century. Success in eliminating such deaths depends on establishing or maintaining the perception that rabies is a priority, he said.
“Inarguably, the Americas, as a region, have made huge progress compared to any other region of the world,” he said. “And the progress that has been made over the past 20-plus years in the Americas serves as a model that we can do this, that it’s not just something that can be done in developed countries.”
Dr. Rupprecht, who is a professor of epidemiology and public health at the Ross University School of Veterinary Medicine and former chief of the Centers for Disease Control and Prevention’s rabies program, said he typically would expect two years without rabies transmission from dogs to humans, verified through laboratory-based surveillance that meets international standards, to ensure transmission has been eliminated. He said people in the Americas are at risk if the region not only fails to reach its goal—a possibility, since elimination requires more intense scrutiny when closer to the goal—but also backslides.
Such a reversal could occur through not only existing canine-associated rabies variants but also variants that could spill over from wild species and adapt for dog-to-dog transmission.
Dr. del Rio said PAHO member countries are working to define success in the campaign to eliminate human deaths from dog-transmitted rabies. National rabies program managers agreed in August to create a working group on rabies-free declaration, and the group will define when and how such a declaration could be made.
Dr. Rupprecht said the world has the diagnostic ability, inexpensive vaccines, and epidemiologic knowledge to prevent, control, and eliminate human infections with rabies. He said the same tools were successfully used to eliminate rinderpest, the second disease wiped out by humans, following smallpox. The rinderpest virus killed hundreds of millions of cloven-hoofed animals, and it was declared eradicated in May 2011.