Vaccination may significantly reduce rabies deaths in India

Vaccinating stray dogs may be a cost-effective way to reduce deaths due to rabies in India by 90 per cent, according to a new study of the disease that kills an estimated 20,000 people in the country every year.

Nearly all of the deaths occur after victims are bitten by rabid dogs. Most of the victims are children. For years, experts have debated the best strategy to reduce this burden.

The study led by a scientists at the University of Maryland in the US found that over the course of five years, vaccinating 200,000 stray dogs a year would reduce rabies incidence by 90 per cent.

Researchers estimated this strategy would cost about USD 1.27 million annually.
"We wanted to evaluate the cost-effectiveness of different rabies control strategies," said Meagan C Fitzpatrick, a post-doctoral fellow at the university's Centre for Vaccine Development (CVD).

"Our goal was to maximise the impact of vaccination and/or sterilisation on human health outcomes in the real world, where policymakers operate within cost constraints," said Fitzpatrick.

The research, which included scientists from the Public Health Foundation of India, the Harvard School of Public Health in the US and the London School of Hygiene and Tropical Medicine, focused on the state of Tamil Nadu.

India accounts for more than a third of the world's rabies deaths. Stray dogs are common and comprise about 42 per cent of the total canine population in Tamil Nadu.

Researchers examined a range of strategies aimed at stray dogs, including vaccination as well as combined vaccination and sterilisation.

They also looked at different numbers of dogs captured and treated per day, to identify the most efficient scale for the programme.

The ten-year cumulative cost of these programmes ranged from USD 12-72 million. Indian decision-makers face competing health priorities, and as a result, reducing rabies must be cost-effective, researchers said.

Researchers used a measurement called Disability-Adjusted Life Year (DALY) to compare the efficiency of each approach. A DALY is defined as a lost year of healthy life.

Fitzpatrick measured how many DALYs each strategy would save, allowing her to compare costs. Based on this approach, a strategy of vaccination without sterilisation was the most efficient way to reduce death from rabies.

Rabies is a viral disease of mammals that is usually transmitted via the bite of a rabid animal. In the US, most rabies cases involve wild animals such as raccoons, skunks, bats and foxes.

The rabies virus attacks the central nervous system, eventually causing disease in the brain and death.

The study was published in the journal PNAS.