Global surveys on rabies in progress

At the recent Rabies in the Americas (RITA) meeting in Puerto Rico, updates on the progress of two ongoing research surveys were presented: one on the availability of rabies biologicals for travelers and another on the reassessment of the global burden of rabies.

Dr Emily Jentes, of the Traveller's Health Branch of the US's Centers for Disease Control and Prevention, presented preliminary results of a short web based survey designed to assess the global availability of human rabies vaccine (RV) and anti-Rabies ImmunoGlobulins (RIG) to travellers. The results from 300 respondents based in travel medicine and other rabies clinics worldwide were analysed. These provided data from 58 countries, most commonly North America (47%), Western Europe (16%), Australia/Pacific (10%), East Asia (5%), and Southern Africa (4%). Most clinics administered post exposure prophylaxis (PEP) very rarely in 2010 (median of 2 patients), but some treated more than 30,000.

Overall, 44% of the respondents stated that patients with animal exposures seldom or never presented with adequately cleansed wounds. RIG was always accessible for 58% of respondents in North America, 64% in Western Europe, 68% in Australia/Pacific, and 38% in East Asia. RV was always accessible for 72% of respondents in North America, 79% in Western Europe, 100% in Australia/Pacific, and 92% in East Asia. Across all regions, about a third of respondents felt that the cost of both RV and RIG was too high. More in depth regional analyses will be conducted next and the final results will be published.

The second study was presented by Dr Katie Hampson of the University of Glasgow, UK at the Partners for Rabies Control (PRP) meeting just prior to RITA. This is a large survey using several data sources to reassess the global burden of rabies. Online surveys ask Veterinary, Public Health and Laboratory experts connected with rabies work in their countries for detailed information such as the numbers of reported human and animal cases, how much under-reporting they think may be occurring, the number of people seeking PEP each year, how far patients have to travel for PEP and how often it is available to them, the number of dogs vaccinated each year, the percentage of dogs and other animals that are vaccinated. In an effort to assess the economic impact of rabies and rabies control, questions about the costs of animal vaccination programmes and PEP provision are also included.

Data from international databases is being used for human population estimates and other relevant published data are also being used. The data are being used to set the parameters of a probability model which estimates both the burden of disease in terms of numbers of human deaths and the years of life lost due to the disease and also through a linked economic model, the economic impacts such as livestock losses and the cost to PEP provision and animal vaccination programmes. A cluster-based approach is being used, grouping together countries within regions where rabies epidemiology and development indices are similar. This approach should allow gaps in the data to be filled as accurately as possible with estimates based on the rabies burden in similar countries.

Data collection, validation and analysis is ongoing, and several significant gaps in the available information were pointed out. However, very preliminary results suggest that the current burden of rabies is around 70,000 human deaths per year, with an worldwide economic impact of about $4 billion each year. Further critical validation of these data are necessary and input from country public health experts is welcome. Please contact [email protected]

Summarised from the abstracts and presentations by Louise Taylor of GARC. There is more information about the reassessment of the global burden of rabies on the PRP section of the GARC website.