Molecular investigation of Neospora caninum in cattle in the Khomas region of Namibia

Abstract

Neosporosis is a leading cause of bovine abortions worldwide, with a substantial economic impact because of reproductive losses, costing the cattle industry billions of dollars annually. Despite the global significance of Neospora caninum, molecular studies on this protozoan parasite have yet to be conducted in cattle in Southern Africa, leaving a critical knowledge gap in countries like Namibia, where beef production is vital to the economy. This study aimed to detect latent N. caninum infections in beef cattle brain and heart muscle samples collected from abattoirs and blood samples from Neospora-seropositive animals within Namibia’s Khomas region. One hundred and ninety-nine samples were collected, comprising 110 brain samples, 75 heart muscle samples and 14 whole blood samples. Conventional polymerase chain reaction (PCR) analysis was performed using Np6 and Np21 primers targeting a ≈340 base pair (bp) segment of the Nc5 gene. All samples tested negative. These results were likely because of the low prevalence of this parasite in Namibian beef cattle, as reported in a previous serosurvey. Future studies focusing on aborted foetuses over a longer timeframe may increase the likelihood of detecting positive cases.
Contribution: This study represents the first published molecular investigation of N. caninum in beef cattle in Southern Africa. The negative results underscore the challenges of detecting N. caninum in tissues from clinically healthy cattle, particularly in a semi-arid country like Namibia, where the prevalence of the pathogen is inherently low.