Contemporary epidemiological data of Rift Valley fever virus in humans, mosquitoes and other animal species in Africa: A systematic review and meta‐analysis

Abstract

Rift Valley fever (RVF) is a severe zoonotic mosquito‐borne disease that represents an important threat to human and animal health, with major public health and socioeconomic impacts. This disease is endemic throughout many African countries and the Arabian Peninsula. This systematic review with meta‐analysis was conducted to determine the RVF prevalence in humans, mosquitoes and other animal species in Africa. The review also provides contemporary data on RVF case fatality rate (CFR) in humans. In this systematic review with meta‐analysis, a comprehensive literature search was conducted on the PubMed, Embase, Web of Science and Global Index Medicus databases from January 2000 to June 2022 to identify relevant studies. Pooled CFR and prevalence estimates were calculated using the random‐effects model. Subgroup analysis and sensitivity analysis were performed, and the I2‐statistic was used to investigate a potential source of heterogeneity. A total of 205 articles were included in the final analysis. The overall RVF CFR in humans was found to be 27.5% [95% CI = 8.0–52.5]. The overall pooled prevalence was 7.8% [95% CI = 6.2–9.6] in humans and 9.3% [95% CI = 8.1–10.6] in animals, respectively. The RVF prevalence in individual mosquitoes ranged from 0.0% to 25%. Subgroup analysis showed substantial heterogeneity with respect to geographical regions and human categories. The study shows that there is a correspondingly similar prevalence of RVF in human and animals; however, human CFR is much higher than the observed prevalence. The lack of a surveillance programme and the fact that this virus has subclinical circulation in animals and humans could explain these observations. The implementation of a One Health approach for RVF surveillance and control would be of great interest for human and animal health.

Rift Valley Fever, an Emerging Viral Zoonosis Worthy of Increased Attention

“…A number of other studies have been conducted in Sub-Saharan Africa to investigate potential risk factors and the seroprevalence of the virus in these regions [22][23][24][25]. Beyond this, other studies have been conducted to try to illicit the mechanisms behind the enzootic circulation of the virus that supports its survival and spread between epizootics (epidemics) and how outbreaks occur in previously-free regions [7,[26][27][28][29].…”

“…Ebogo-Belobo JT, et al [21] and Gerken KN, et al [31], and these can be consulted for further information on prevalence and epidemiological data.…”

Exploring community-based reporting of livestock abortions for Rift Valley Fever surveillance in Uganda: A pilot study

“…Rift valley fever disease (RVF) is a zoonotic mosquito-borne viral infection caused by the Rift valley fever virus (RVFV), a member of the genus Phlebovirus and family Bunyaviridae (Sasaya et al, 2023). The disease is primarily transmitted by Aedes and culex mosquitoes and blood feeding flies (Ebogo-Belobo et al, 2023). The virus was identified in 1931 during an epidemic among sheep on a farm in the Kenyan Rift Valley (Bailey, 1988; Hartman, 2017) affecting both livestock and wildlife (Clark et al, 2018).…”

“…The virus was identified in 1931 during an epidemic among sheep on a farm in the Kenyan Rift Valley (Bailey, 1988; Hartman, 2017) affecting both livestock and wildlife (Clark et al, 2018). In humans, infection with RVFV leads to clinical outcomes ranging from a mild flu-like illness to severe haemorrhagic fevers with mortality rates of up to 27% (Ebogo-Belobo et al, 2023). The disease has the potential to disrupt countries’ livestock production due to mortalities (Ahmed et al, 2019).…”