A survey of animal-bite injuries in humans and the economic burden of rabies in Machakos county, Kenya

Abstract

This thesis describes a survey of a retrospective and prospective study conducted in Machakos County and the epidemiology of animal-bites in humans in Machakos, Kenya. The objectives of the study were: 1) to characterize animal-bite injuries in humans in Machakos County; 2) to estimate the burden of rabies in Machakos County; and 3) to test the application of ‘One Health’ Approach in the control of rabies in the County. Cases of animal-bites in humans that were reported at the two main district hospitals in the county, namely, Machakos (Level 5) and Kangundo (Level 4) were reviewed. Retrospective data on animal-bites were collected from records kept at the Machakos and Kangundo district veterinary offices and the corresponding district hospitals (2009-2012). Detailed data on animal-bites were collected prospectively for three months (May-July, 2013) at the district veterinary offices and the two hospitals. During 2009-2012, a total of 2636 cases of human bites by animals were reported at the hospitals. Dog bites accounted for the majority (95%; 2505/2636) of the cases. During the same period, only a quarter (25%; 748/2636) of bites cases was reported to the veterinary offices (95%; 710/748 by dogs). From (May –July, 2013), 121 cases were reported at the two hospitals and none at the veterinary offices. Approximately a half (49.5%; 60/121) of the bites was caused by unknown unvaccinated dogs against rabies and 50.5% by dogs of unknown vaccinated status. Some cases came from distant villages in the county including Masinga, Matuu and Ikombe. Data on cases of animal-bites in humans reported to the two hospitals and district veterinary offices were also collected to assess the flow of information between the two ministries responsible for rabies control activities. A huge proportion (88%; 106/121) of the bites victims were not given anti-rabies vaccine sourced from the hospitals and had to purchase it from xiv private pharmacies at a price of Ksh 900 per dose. Thirty eight percent (46/121) of the bite cases received only a three-dose vaccination regimen of 1ml of vaccine on days (0, 3, 7), while 27% received a 5-dose regimen of 1ml of vaccine on days (0, 3, 7, 14, 28). Data were entered and cleaned in MS Excel®. Summary statistics including graphs (bars and pie charts), frequency tables and means were generated using the spreadsheets. Data were then exported to Genstat (15th Edition SP1 Version) for statistical analysis. Chi square statistics was used to determine association between categorical variables in the dataset and the type of animal bite. ANOVA statistics were used to determine mean differences across groups. A p value of < 5% was considered significant. A GIS Programme called GIS Map Info Professional was used to plot graphs showing locations and bites incidences within Machakos County. In conclusion, this study revealed that the incidence of animal-bites in humans, and therefore the risk of rabies, is high in Machakos County and that the domestic dog is the most important species. Control of rabies is often seen as the responsibility of veterinary authorities, but demonstration of the public health importance of rabies and the benefits of disease control to the public health authorities will encourage involvement of the health sector in control efforts. In Machakos, the integration of hospitals, medical and veterinary sectors is likely to be crucial for effective disease control, as shown by the success of recent rabies control strategies. Rabies control targeted at vaccinating the domestic dog should stepped up and closer collaboration between the medical and veterinary personnel should be enhanced in line with the ‘One Health’ approach if the control of this ancient and most dreadful of human infections is to be successful. Key words: Animal-bites; Rabies; Machakos; “One Health; Control.