Livestock Presence Influences the Seroprevalence of Crimean Congo Hemorrhagic Fever Virus on Sympatric Wildlife in Kenya

Abstract

Crimean Congo Hemorrhagic Fever (CCHF) is an emerging tick-borne zoonotic viral disease with the potential of causing public health emergencies. However, less is known about the role of wildlife and livestock in spreading the virus. Therefore, we aimed to assess how the interactions between African buffalo (Syncerus caffer) and cattle may influence the seroprevalence of CCHF across livestock-wildlife management systems in Kenya. The study included archived sera samples from buffalo and cattle from wildlife only habitats (Lake Nakuru National Park and Solio conservancy), open wildlife-livestock integrated habitats (Maasai Mara ecosystem and Meru National Park), and closed wildlife-livestock habitats (Ol Pejeta Conservancy) in Kenya. We analyzed 191 buffalo and 139 cattle sera using IDvet multispecies, double-antigen IgG enzyme-linked immunosorbent assay (ELISA). The seroprevalence toward Crimean Congo hemorrhagic fever virus (CCHFV) was significantly higher for buffalo compared to cattle (75.3% and 28.1%, respectively, p < 0.001). We obtained the highest seroprevalence among buffalo of 92.1% in closed wildlife only systems compared to 28.8% and 46.1% prevalence in closed-integrated and open-integrated systems, respectively. The regression coefficients were all negative for cattle compared to buffalo in both closed-integrated and open-integrated compared to wildlife only system. Our results show that CCHFV circulates among the diverse animal community in Kenya in spatially disconnected foci. The habitat overlap between cattle and buffalo makes cattle a ''bridge species'' or superspreader host for CCHFV and increases transmission risks to humans. The effect of animal management system on prevalence is depended on tick control on the cattle and not the animal per se. We conclude that buffalo, a host with a longer life span than livestock, is a reservoir and may serve as a sentinel population for longitudinal surveillance of CCHFV.

Exposure patterns and the risk factors of zoonotic Crimean Congo hemorrhagic fever virus amongst pastoralists, livestock and selected wild animals species at the human/livestock/wildlife interface in Isiolo County, upper eastern Kenya

“…None of the factors investigated using multivariable models were significant. A previous study by (Obanda et al, 2021) did not also find significant association between sex and CCHFV prevalence in wild animals. Similarly, (Spengler et al, 2016) did not find any association between CCHFV exposure and age in wild animals.…”

“…It is also important to note the role of livestock-wild animals interaction in the spread of CCHFV. The grazing requirements of the Bovidae species tend to overlap with domesticated livestock especially the cattle, which facilitates cross-transmission of several infectious diseases and ectoparasites (Obanda et al, 2021). In this study, the average prevalence of CCHFV in wild animals’ bovidae species was higher compared to livestock’s average seropositivity, and because of the grazing overlap, wild animals likely serve as a source of infection to cattle.…”

“…In a study that was conducted in the Maasai Mara ecosystem, Nanyuki, and the Ol Pejeta Conservancy in Kenya, a mean CCHFV seroprevalence of 31.5% in cattle, sheep, and goats was estimated (Blanco-Penedo et al, 2021). Another study that was implemented in the same year in Lake Nakuru National Park, Solio Conservancy, Maasai Mara ecosystem, Meru National Park, and Ol Pejeta Conservancy reported CCHFV seroprevalences of 75.3% and 28.1% in buffalo and cattle, respectively (Obanda et al, 2021). Similarly, a mean CCHFV seroprevalence of 5.3% (n = 1958) was reported in cattle, sheep, and goats that were sampled in western Kenya (Nyataya et al, 2020), while another study that sampled animals from slaughterhouses in Nairobi, Kiambu, and Muranga Counties reported a seroprevalence of 4.2% (n = 2330) (Sang et al, 2006).…”

Prevalence of Crimean-Congo haemorrhagic fever in livestock following a confirmed human case in Lyantonde district, Uganda

“…We report a very high CCHFV seroprevalence in both cattle and goats during an ongoing outbreak, with no interspecies statistical differences, in an area associated with a fatal human infection. A higher seroprevalence in cattle (94.0%) was noted compared with other studies previously conducted in Uganda [ 12 ] and nearby countries such as Kenya, Sudan, the Democratic Republic of the Congo, Zambia, Malawi and South Africa [ 29 – 36 ]. Similarly, a higher seroprevalence was noted in goats (89.3%) in comparison with results obtained in different regions of Africa, including Mauritania [ 37 ], Nigeria [ 38 ] and Senegal [ 39 ].…”

A systematic review of Crimean-Congo Haemorrhagic fever virus in Sub-Sahara Africa, 1969-2022

“…This could be interpreted with caution since they have carried out more serostudies for CCHFV among humans compared to other countries and they may have better and applicable diagnostic facilities thereby generating more data than other countries in the region. Evidence of the exposure of other animals such as Carmel, Buffalos and bats [12,14] signifies that there could be many more hosts yet unknown. There is need for more serological studies to provide robust information on the true burden of CCHFV among humans in Sub-Saharan Africa.…”