Assessing Monkeypox Virus Prevalence in Small Mammals at the Human-Animal Interface in the Democratic Republic of the Congo

Abstract

During 2012, 2013 and 2015, we collected small mammals within 25 km of the town of Boende in Tshuapa Province, the Democratic Republic of the Congo. The prevalence of monkeypox virus (MPXV) in this area is unknown; however, cases of human infection were previously confirmed near these collection sites. Samples were collected from 353 mammals (rodents, shrews, pangolins, elephant shrews, a potamogale, and a hyrax). Some rodents and shrews were captured from houses where human monkeypox cases have recently been identified, but most were trapped in forests and agricultural areas near villages. Real-time PCR and ELISA were used to assess evidence of MPXV infection and other Orthopoxvirus (OPXV) infections in these small mammals. Seven (2.0%) of these animal samples were found to be anti-orthopoxvirus immunoglobulin G (IgG) antibody positive (six rodents: two Funisciurus spp.; one Graphiurus lorraineus; one Cricetomys emini; one Heliosciurus sp.; one Oenomys hypoxanthus, and one elephant shrew Petrodromus tetradactylus); no individuals were found positive in PCR-based assays. These results suggest that a variety of animals can be infected with OPXVs, and that epidemiology studies and educational campaigns should focus on animals that people are regularly contacting, including larger rodents used as protein sources.

Keywords: habitat analysis; human–animal interface; monkeypox; orthopoxviruses; serology; small mammals; wildlife.

Figure 1

The location of the collection sites is indicated by the orange circles in the top figure. The orange rectangle indicates the area used to extract principal component values. Bottom figures indicate the location of Tshuapa Province (left) and the 12 health zones within the province (right).

Figure 2

Vegetation types for our study area based on Verhegghen et al. (2012) [36].

Figure 3

Molecular phylogenetic analysis by Bayesian inference. Majority rules consensus tree generated with MrBayes 3.2.2. Numbers above nodes indicate Bayesian posterior probabilities. Samples with bold font were collected by this study. Letters A and B indicate lineages within the genus Funisciurus that warrant further examination, as they are at least 24% divergent from their recovered sister taxon.

Figure 4

Time series of five-year average enhanced vegetation index (EVI) values within a 1 km buffer from each of the collection localities. Bongoy, Bosenge, Inganda, and Tokumbo showed higher EVI values throughout the year than the rest of the localities.

Figure 5

Scatterplot of principle component 1 (PC1) and principle component 2 (PC2) calculated within the study area (gray) and corresponding values for the collection sites (black).