Meta-analysis of canine cryptosporidiosis in Africa and prevalence of clinical infection in Oyo, Ogun, and Kwara states, Nigeria.

Abstract

Cryptosporidium infection is a significant parasitic disease affecting both humans and animals worldwide. However, there is limited data on its prevalence in canine populations across Africa. This study was carried out between December 2021 and August 2022 to assess the burden of Cryptosporidium infection in dogs on the continent through a meta-analysis and a targeted survey of dogs presented at veterinary clinics in Nigeria. A systematic review and meta-analysis were conducted using available studies on Cryptosporidium prevalence in dogs from African countries to determine the pooled prevalence. Additionally, a survey was carried out to determine the prevalence of Cryptosporidium oocysts in 309 dogs presented at veterinary clinics across several Nigerian states using microscopy and the presence of Cryptosporidium DNA was confirmed using the nested PCR methods. Data suitable for meta-analysis were found from only three African countries - Nigeria, Zambia, and Mozambique - highlighting a significant research gap across the continent. The pooled estimates of Cryptosporidium infection in Africa was 13.7% (95% CI: 7.7, 22.9), with country-specific rates of 22% in Nigeria, 5.9% in Zambia, and 6.4% in Mozambique. The survey conducted in Nigeria revealed a low prevalence of Cryptosporidium oocysts (6.7%) in dogs presented at clinics, while PCR confirmed the presence of Cryptosporidium DNA in positive samples. The findings highlight the significance of Cryptosporidium as a health concern in African canine populations, with prevalence rates comparable to global figures. The low prevalence observed in clinical settings indicates that routine screening should still be prioritized to ensure early detection and treatment, given the potential zoonotic risk posed by C. canis (the dominant species in dogs). Further research is needed to address the geographic and diagnostic gaps identified and to explore the clinical and public health implications of Cryptosporidium infection in dogs across Africa.