A hundred years of rabies in Kenya and the strategy for eliminating dog-mediated rabies by 2030

Abstract

Background: Rabies causes an estimated 59,000 human deaths annually. In Kenya, rabies was first reported in a dog in 1912, with the first human case reported in 1928. Here we examine retrospective rabies data in Kenya for the period 1912 - 2017 and describe the spatial and temporal patterns of rabies occurrence in the country. Additionally, we detail Kenya's strategy for the elimination of dog-mediated human rabies by 2030. Methods: Data on submitted samples and confirmed cases in humans, domestic animals and wildlife were obtained from Kenya's Directorate of Veterinary Services. These data were associated with the geographical regions where the samples originated, and temporal and spatial trends examined. Results: Between 1912 and the mid 1970's, rabies spread across Kenya gradually, with fewer than 50 cases reported per year and less than half of the 47 counties affected. Following an outbreak in the mid 1970's, rabies spread rapidly to more than 85% of counties, with a 4 fold increase in the percent positivity of samples submitted and number of confirmed rabies cases. Since 1958, 7,584 samples from domestic animals (93%), wildlife (5%), and humans (2%) were tested. Over two-thirds of all rabies cases came from six counties, all in close proximity to veterinary diagnostic laboratories, highlighting a limitation of passive surveillance. Conclusions: Compulsory annual dog vaccinations between 1950's and the early 1970's slowed rabies spread. The rapid spread with peak rabies cases in the 1980's coincided with implementation of structural adjustment programs privatizing the veterinary sector leading to breakdown of rabies control programs. To eliminate human deaths from rabies by 2030, Kenya is implementing a 15-year step-wise strategy based on three pillars: a) mass dog vaccination, b) provision of post-exposure prophylaxis and public awareness and c) improved surveillance for rabies in dogs and humans with prompt responses to rabies outbreaks.

Keywords: Kenya; elimination; epidemiology; rabies.

Figure 1.. Trends in total submitted human and animal samples and confirmed rabies cases in Kenya from 1958 until 2017.

Figure 2.. Figure showing the proportion of human and animal samples (%) submitted for rabies testing that were positive for each year 1958–2017.

The proportion has steadily increased over time as shown by the regression line (blue). No records of samples submitted were available for the years 1995, 1996 or 1997.

Figure 3.. Trends of confirmed rabies cases by species for the period 1958 to 2017.

Figure 4.. Spatial and temporal occurrence of human and animal rabies in Kenya, 1912 – 2017.

Figure 5.. Distribution of confirmed human and animal rabies cases by counties, 1958 – 2017.

The blue dots indicate the location of the seven veterinary laboratories (one central Veterinary laboratory and six regional investigative laboratories) in the country. The online version of this figure is interactive.

Figure 6.. Stepwise Approach to Rabies Elimination (SARE) in Kenya, showing the six stages of the control strategy, associated activities and timelines.

Figure 7.. Map of Kenya showing the three zones for the implementation of rabies elimination program.

Elimination starts in pilot counties (Zone A), followed by counties neighbouring them (Zone B) and later rolled out in the rest of the counties (Zone C).