Serological Evidence of Potential Marburg Virus Circulation in Livestock and Dogs in Ghana

Abstract

Marburg virus disease (MVD) is a zoonotic hemorrhagic disease with an estimated case fatality rate of up to 88%. Ghana recorded its first human MVD outbreak in June 2022 and although the outbreak was quickly brought under control, the transmission dynamics of the disease remained unclear. We assessed the presence of Marburg virus (MARV) antibodies in livestock and dogs and identified associated risk factors that increased the risk of these animals being exposed to MARV in five regions of Ghana. Sera collected from 3113 livestock and dogs in 2 climatic seasons (rainy and dry seasons) were tested for MARV antibodies using an indirect ELISA test. The samples were further tested using dot blotting to substantiate the presence of antibodies against MARV glycoprotein (GP). Overall, MARV antibodies were detected in 20.6% of the animals. The species-specific prevalence was 28.7% in cattle, 21.8% in sheep, 19.5% in goats, 15.3% in dogs and 11.2% in pigs. The seropositivity was higher in the rainy season [RR 1.5; 95% CI 1.3-1.8] and in older animals [RR = 2.6; 95% CI 1.9-3.4]. The findings underscore the importance of regular surveillance using the one health approach and future studies into the role of livestock and dogs as potential intermediaries in the circulation of MARV.

Keywords: Ghana; MARV; Marburg exposure; Marburg virus antibodies; emerging zoonosis; livestock.

Figure 4

A diagrammatic depiction of the interaction between domestic animals and wildlife which may have led to exposure to MARV. The hunters go to the forest with hunting dogs to capture rodents and other wildlife. The dogs may also pick up dead bats or fruits partially eaten by bats on the forest bed. The domestic animals interact with wildlife as they stray into forests to pasture [46]. These animals may be exposed to MARV and other filoviruses through the consumption of fruit that has been partially eaten by bats [39] and direct interaction with bats. Illustration by Kweku Aboagye, Ghana.

Figure 1

(A) picture showing the entrance of a study site, Ve-Golokauti depicting the importance of hunting to its inhabitants. (B) shows a residence in the forests of Kwaman depicting the closeness of human settlements to the forests.

Figure 2

Map of Ghana showing the study locations with prevalence of MARV GP-specific antibodies, 2023. (A–C) The locations of the study site in relation to known habitats of Rousettus aegyptiacus in Ghana [24]. Gelenkong is a community adjacent to the Mole National Park which has a dense population of wildlife including fruit bats, ungulates, and non-human primates. Fomena, Kwaman and Bogoso have dense forest and cave systems. They have high mineral deposits which attracts miners from neighboring regions and countries. The index case of MVD in Ghana was recorded in the Bogoso and Fomena enclave [17,27]. Buoyem and Tanoboase are part of the Mampong range while Ve Golokwati is located along the Akuapim–Togo range. The Akwapim–Togo range has intricate cave systems and extensive forests home to several species of fruit bats including the Rousettus aegyptiacus. Generally, the forests serve as pasture for livestock and hunting grounds for hunters who send hunting dogs to capture wildlife. In Ve Golokwati, the dogs in the community serve as hunting dogs irrespective of their original purposes. The dogs may also be borrowed by other hunters for hunting purposes.

Figure 3

Distribution of anti-Marburg glycoprotein IgG levels in cattle, dogs, goats, pigs, and sheep. Antibody distributions are shown as boxplots underlaid with dots representing individual samples. Boxplots are represented as lower quartile, median, and upper quartile; whiskers are 1.5 times the interquartile range. The red dashed lines represent the seropositive cut-off point for each species. The seropositive cut-offs are as follows: cattle (81.21), dogs (39.43), goats (138.99), pigs (141.93), and sheep (138.99). Seropositive samples are samples with anti-Marburg glycoprotein IgG levels greater than the seropositive cut-off.