An epidemiological description of rabies outbreaks in Zambia from 2013 to 2023

Abstract

AbstractBackgroundIn Zambia, a dog bite is the most common rabies exposure. There is limited information on rabies outbreaks in jackals in Zambia. We investigated all rabies cases in Zambia and narrowed down on jackal bites in Mungwi district to determine a temporal trend and buffer zones for rabies.MethodsThe risk of exposure included all humans and animals bitten by jackals, data were collected by interviewing jackal bite victims and collecting brain specimen samples from animals. Risk of spread was determined by estimating the distance jackals strayed into human population and the Rabies Vaccination Coverage (RVC) in the district. The RVC was determined by dividing vaccinated dogs by dog population. The incidence rate (IR) and a Sen’s slope was used to determine a trend of RVC and the rabies cases in Zambia. QGIS was used to produce a heatmap and rabies risk zones. Direct Fluorescent Antibody technique was used to test for rabies.ResultsZambia had recorded a total of 224 rabies cases with a mean (SD) of 22.4 (16) rabies cases and a positivity rate of 65.4% (25.7) per year from 2013 to 2022. Lusaka and Copperbelt provinces recorded the highest rabies cases. The rabies incidence rate was 2.3 rabies cases per 10,000 dogs in Zambia. The cases had reduced from 2013 to 2021 with a Sen’s slope of -0.74 (p = 0.02). At least 227 animal bites were recorded (two jackals and 225 dog bites) in Mungwi District. 94% (213) of the victims needed Post Exposure Prophylaxis. The victim’s median age was 20 (Interquartile range=12-38) years. The accumulative RVC from 2018-2022 (611/7777), was 0.11 (95% CI: −0.4-0.7, p=0.46) annual slope increase with 1.60% mean (Standard deviation = 0.34). One rabies heatmap and three risk-level zones (low, medium and high) were produced, and two jackals and one goat specimens were positive.ConclusionsA risk-based surveillance and enhanced vaccination of dogs in high-risk areas through a one health approach is critical for rabies control in Zambia.