Epidemiology and surveillance of human animal-bite injuries and rabies post-exposure prophylaxis, in selected counties in Kenya, 2011–2016

Human animal-bite injuries are a serious public health problem due to associated risk for rabies virus exposure. Animal-bite injuries especially dog bites are useful indicators for assessing the risk of rabies virus transmission and need for rabies post exposure prophylaxis (PEP). Understanding the epidemiology and surveillance of animal bites and rabies post-exposure prophylaxis is critical in implementing Kenya’s national rabies elimination strategy. We aimed to describe the incidence of human animal-bite injuries, patient/biting animal characteristics, uptake of rabies PEP and factors associated with animal bite incidents.

We reviewed animal bite records from outpatient and anti-rabies vaccine (ARV) registers of 17 health facilities from five counties. An animal bite was defined as an entry of an animal bite of the class mammal including humans in registers in a person of any age from January 2011 to December 2016. We collected demographic and information on PEP uptake. We calculated descriptive statistics, odds ratios (OR) and 95% confidence interval (CI) to examine factors associated with being an animal bite case-patient. We also calculated incidence of animal bites using health facility catchment population for year 2016 as the denominator.

We analyzed 7307 records. The median age was 22 years (IQR = 31 years); there were 4019 (55%) male and age < 15 years were 2607 (37%). Dogs accounted for 6720 (93%) of bites of which 78% were owned free-roaming dogs. Of the 5674 (88%) cases that received rabies PEP, 2247 (40%) got at least three-doses. The median time from bite to seeking medical care was 2 days (IQR = 4 days). Being bitten on the head/face (OR = 5.8; CI: 3.3–10.2); being bitten by owned free-roaming dog (OR = 1.7; CI: 1.5–1.9) and being male (OR = 1.4; CI: 1.3–1.5) were significantly associated with being an animal-bite case-patient. Being male, being bitten on head/face and being bitten by owned free-roaming dog remained independently associated with being an animal bite case-patient at multivariable logistic regression. Bite-incidence was 289 bites /100,000 persons among all counties.

Preventing dog bites would most effectively reduce bite injuries by improving public health education among children below 15 years, encouraging early PEP initiation and completion, development and implementation of responsible dog ownership and animal behaviour educational programmes as well as improving human and veterinary health linkages.