Wildlife in Cameroon harbor diverse coronaviruses, including many closely related to human coronavirus 229E.

Zoonotic spillover of animal viruses into human populations is a continuous and increasing public health risk. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) highlights the global impact of emergence. Considering the history and diversity of coronaviruses (CoVs), especially in bats, SARS-CoV-2 will likely not be the last to spillover from animals into human populations. We sampled and tested wildlife in the Central African country Cameroon to determine which CoVs are circulating and how they relate to previously detected human and animal CoVs. We collected animal and ecological data at sampling locations and used family-level consensus PCR combined with amplicon sequencing for virus detection. Between 2003 and 2018, samples were collected from 6,580 animals of several different orders. CoV RNA was detected in 175 bats, a civet, and a shrew. The CoV RNAs detected in the bats represented 17 different genetic clusters, coinciding with alpha (n = 8) and beta (n = 9) CoVs. Sequences resembling human CoV-229E (HCoV-229E) were found in 40 Hipposideridae bats. Phylogenetic analyses place the human-derived HCoV-229E isolates closest to those from camels in terms of the S and N genes but closest to isolates from bats for the envelope, membrane, and RNA-dependent RNA polymerase genes. The CoV RNA positivity rate in bats varied significantly (P < 0.001) between the wet (8.2 per cent) and dry seasons (4.5 per cent). Most sampled species accordingly had a wet season high and dry season low, while for some the opposite was found. Eight of the suspected CoV species of which we detected RNA appear to be entirely novel CoV species, which suggests that CoV diversity in African wildlife is still rather poorly understood. The detection of multiple different variants of HCoV-229E-like viruses supports the bat reservoir hypothesis for this virus, with the phylogenetic results casting some doubt on camels as an intermediate host. The findings also support the previously proposed influence of ecological factors on CoV circulation, indicating a high level of underlying complexity to the viral ecology. These results indicate the importance of investing in surveillance activities among wild animals to detect all potential threats as well as sentinel surveillance among exposed humans to determine emerging threats.

Market characteristics and zoonotic disease risk perception in Cameroon bushmeat markets.

Behavioral practices are one of the key factors facilitating zoonotic disease transmission, especially in individuals who have frequent contact with wild animals, yet practices of those who work and live in high-risk animal-human interfaces, such as wild animal 'bushmeat' markets in the Congo Basin are not well documented in the social, health and medical sciences. This region, where hunting, butchering, and consumption of wild animal meat is frequent, represents a hotspot for disease emergence, and has experienced zoonotic disease spillover events, traced back to close human-animal contact with bats and non-human primates. Using a One Health approach, we conducted wildlife surveillance, human behavioral research, and concurrent human and animal biological sampling to identify and characterize factors associated with zoonotic disease emergence and transmission. Research was conducted through the USAID Emerging Pandemic Threats program between 2010 and 2019 including qualitative studies of bushmeat markets, with selected study sites prioritized based on proximity to bushmeat markets. Sites included two hospitals where we conducted surveillance of individuals with syndromes of acute febrile illness, community sites where we enrolled actors of the animal value chain (ie. hunters, middlemen, transporters), and bushmeat markets, where we enrolled bushmeat vendors, butchers, market managers, cleaners, and shoppers. Mixed methods research was undertaken at these sites and included investigation of bushmeat market dynamics through observational research, focus group discussions, quantitative questionnaires, and interviews. Participants were asked about their risk perception of zoonotic disease transmission and specific activities related to bushmeat trade, local market conditions, and regulations on bushmeat trade in Cameroon. Risks associated with blood contact and animal infection were not well understood by most market actors. As bushmeat markets are an important disease interface, as seen with CoVID19, risk mitigation measures in markets and bushmeat alternative strategies are discussed.