Elimination of rabies possible with political will, necessary funding
Elimination of rabies is possible if there is political will and necessary funding to support it, a proof-of-concept study shows.
“If you want to prevent humans from dying from rabies in Africa and Asia, you need to eliminate dog rabies,” said first author Professor Jakob Zinsstag, of the Swiss Tropical and Public Health Institute (Swiss TPH). Swiss TPH, together with collaborators in Europe and in Africa, and also with support from the Institut Pasteur in Paris, France and ETH Zurich in Basel, Switzerland, did genetic analyses of collected rabies viruses and showed that elimination of rabies is feasible. “We have shown that African teams in one of the poorest countries can eliminate human rabies through mass vaccination of dogs.”
The study was done in N'Djamena, the capital of Chad where 1.1 million people live together with approximately 30,000 dogs. In 2012 and 2013, 20,000 dogs were vaccinated each year against rabies. Hence, more than 65 percent of the city's estimated dog population were included in the intervention, which is an excellent coverage rate, said Zinsstag. “We mobilized the neighbourhood chiefs and they in turn mobilized the people and their dogs.”
The researchers conducted a mass dog vaccination exercise in Chad and determined its effect on human rabies exposure. Then, they utilized a bio-mathematical method to estimate the transmission dynamics of rabies.
This is one of the first studies to use a rigorous phylodynamic method in researching dog rabies. It is based on normative phylogenetics—examining the genetic relatedness of virus strains—with the dynamics of transmission over time. This made it possible to measure the reproductive number of rabies among the dogs after the first mass dog vaccination in 2012.
“Rabies in dogs was likely reintroduced through the import of dogs by humans from outside N'Djamena after rabies elimination had been achieved," he said. The phylogenetic analysis supports this finding; the nucleoprotein sequence of the new viruses showed a different genetic structure. The molecular method determined the results put forth by the mathematical model through an independent approach. Thus, eliminating rabies is not a technical problem, but a matter of political will and sufficient financial resources, noted Zinsstag.
Rabies is a viral disease with a high mortality rate, predominantly in Africa and Asia. The disease is transmitted predominantly through the bites of infected dogs and foxes. In West and Central Europe, rabies was eliminated approximately 20 years ago. In 1999, Switzerland was declared free of rabies after implementing a strategy that targeted foxes.