Serological evidence of Crimean-Congo haemorrhagic fever in domestic animals from eight regions of Namibia.

Abstract

Crimean-Congo haemorrhagic fever (CCHF) is a viral zoonotic disease endemic to regions of Africa, the Balkans, the Middle East, and Asia, with increasing reports of cases in southern Europe. Human transmission occurs primarily through the bite of infected ticks and by body fluids from infected human. Crimean-Congo haemorrhagic fever virus (CCHFV) affects a broad host range, including both domestic and wild vertebrates. Recent studies have suggested a potential susceptibility of companion animals, posing an additional threat to public health. In the present study, the presence of CCHFV antibodies was evaluated by screening 374 dog and 238 cat serum samples collected from eight Namibian regions using a commercial enzyme-linked immunosorbent assay. Overall, dogs (11.50%) showed significantly higher odds of seropositivity (OR = 7.60; 95% CI = 3.02 - 25.51; p-value < 0.001) compared to cats (1.68%). Most of the positive dogs and all positive cats originated from the Kunene and Hardap regions. No other factors were found to affect seroprevalence. The limited development of farming systems in these regions, combined with the higher roaming activity of dogs, may suggest a greater exposure risk to wild animals or infected ticks. Tick species of the genus Hyalomma are not commonly reported to infest dogs in Namibia, and other tick species may also be involved in transmission. The detection of CCHFV antibodies in dogs and cats in Namibia should be considered by public health authorities as a potential threat, warranting further investigation to identify infection sources and risk factors. While the level and duration of viremia in companion animals, as well as their actual infectivity, remain unknown, efforts should focus on reducing contact between domestic pets, livestock, and wild animals, as well as regular prophylactic tick treatment of pets to prevent or minimise tick infestations.