Improving systematic rabies surveillance in Cameroon: A pilot initiative and results for 2014-2016

Canine rabies is endemic in Cameroon, but human rabies exposures and cases are likely underreported because of inadequate surveillance. In 2014, the surveillance network in the West region of Cameroon was reinforced by introducing a new anti-rabies center, a framework for data collection and evaluation, provisions for sample collecting and laboratory confirmation, and training for health professionals. The objective of this observational cohort study was to describe the incidence and characteristics of reported exposures and human and animal rabies cases following this reinforcement of the existing rabies surveillance system. The surveillance network consisted of local, regional, and national health and veterinary authorities in 11 of the 20 West region districts, and was completely integrated within the existing national rabies surveillance network. Animal exposures and suspected rabies exposures, the suspected rabid animals involved, and laboratory confirmation of human and animal rabies cases were recorded in a centralized information database. Between January 2014 and June 2016, the network recorded 1340 animal exposure cases for an overall incidence rate of 38.2 animal exposures per 100,000 people, four confirmed rabies-positive animals, and one confirmed human rabies case out of four clinically suspected cases. In contrast, 62 animal exposures and an overall incidence rate of 6.1 exposures per 100,000 people were reported for the West region districts not participating in the reinforced surveillance. Of the 925 animal exposure victims for whom a detailed case report form was completed, 703 were considered to be at risk of rabies and only 428 (61%) of these received any post-exposure prophylaxis in the form of rabies vaccine. Obstacles encountered within the network included low rates of animal sample submission and animal follow-up by veterinarians. Reinforced rabies surveillance in the West region of Cameroon has provided the most accurate estimate of the region's disease and exposure burdens to date, and indicates that animal exposures are substantially underreported. The reinforced network also signaled that greater access to post-exposure prophylaxis is needed. Integration of regions not covered by the surveillance network and efforts to improve engagement of veterinary services will be needed to reveal the true burden of rabies in Cameroon.