Incidence, risk factors, and control of Rabies in Ethiopia: A systematic review and meta-analysis

Abstract

Background: Globally, rabies is found in several geographical areas, with tens of thousands of deaths annually, mainly in developing countries. However, though Ethiopia is highly endemic for rabies, the overall risk of rabies has not yet been estimated. Hence, this systematic review and meta-analysis aimed at estimating a pooled incidence rate of human exposure to suspected rabid animals as well as the incidence rates of rabies in humans and other domestic animals.

Methods: Published articles search was systematically performed through PubMed, Scopus, Embase, and Web of Science databases to identify the available studies on rabies until October 2023. The Joanna Brigg's Institute (JBI) critical appraisal checklists were used for assessing the quality of the studies. The PRISMA 2020 guideline was followed. A qualitative synthesis was made describing the characteristics of the included studies. The quantitative synthesis was performed with a random effects model using Comprehensive Meta-Analysis (CMA) version 3.0 software. The Q statistic quantified by I2 was used to check for heterogeneity among the included studies. To explain the source of heterogeneity, subgroup analysis was performed. Egger's regression test was used to evaluate publication biases. This study is registered with PROSPERO, CRD42023468791.

Results: For this study, a total of 439 articles were retrieved; of which fifteen studies were included in the final review. The annual pooled incidence rate of human exposure to suspected rabid animals was 33.65 (95% CI: 31.82 to 35.49) per 100,000 humans. The suspected rabies deaths in humans were also estimated to be 4.57 (95% CI: 2.93 to 6.21) per one million humans annually. In both cases, considerable heterogeneities were presented across the included studies, and obvious publication biases were detected using Egger's regression test. Among animals, the highest combined estimate per 100,000 population was recorded in dogs, 120.99 (95% CI: 46.29 to 195.69), followed by equines and cattle, with pooled incidence rates of 19.57 (95% CI: -1.85 to 40.98) and 18.08 (95% CI: 1 to 35.15), respectively. It was also described that human exposure to rabid animals and human rabies deaths were more common among children.

Conclusions: The current study showed a high pooled incidence rate of human exposure to rabid animals. Significant overall incidence rates of rabies in humans and animals were also indicated. Therefore, strengthening intersectoral and transdisciplinary collaborations through one health approach are key components for rabies prevention and control.

Fig 1. PRISMA 2020 Flow diagram for literature search and selection.

Fig 2. Forest plot for the incidence rates of human exposure to suspected rabid animals [7,16,19,24,27].

Fig 3. Forest plot for subgroup analysis of incidences of human exposure by regions [7,16,19,24,27].

Fig 4. Forest plot of sensitivity analysis for incidence rates of human exposure to rabid animals [7,16,19,24,27].

Fig 5. Forest plot for the incidence rates of suspected human rabies [7,17,19,22,25,27].

Fig 6. Forest plot for sensitivity analysis of incidence rate of suspected human rabies [7,17,19,22,25,27].