Prevalence study in Cameroon identifies Brucella abortus as the endemic Brucella species in livestock.

Brucellosis is a neglected zoonotic disease impacting agricultural economies, as well as animal and human health globally. In sub-Saharan Africa, brucellosis is considered endemic in many countries based on serological evidence, although the presence and distribution of specific Brucella species remain unverified due to limited bacteriological confirmation. Due to the economic importance and national/international trade routes, this cross-sectional study investigates Brucella prevalence in 4612 animals (cattle, sheep, goats, and pigs) from slaughterhouses in the Far-North, North, and West regions of Cameroon sampled between February 2021 and May 2023. The analysis includes serology (Rose Bengal Test and indirect Enzyme-Linked Immunosorbent Assay), culture, real-time PCR, and next-generation sequencing (NGS). Results show only Brucella abortus is present, primarily affecting cattle (8.3%) and goats (7.3%). NGS reveals the local B. abortus strain is related to the clade from Uganda and Sudan, indicating it is endemic to Africa, rather than introduced from outside the continent. These results confirm the presence of a genetically distinct African lineage and reinforce brucellosis as a major concern for both animal and public health. The study emphasizes the critical need for coordinated surveillance systems to support evidence-based control strategies, enhance disease monitoring, and reduce the risk of transboundary transmission.