Detection and characterization of zoonotic pathogens of free-ranging non-human primates from Zambia

Abstract

Background: Wildlife may harbor infectious pathogens that are of zoonotic concern acting as a reservoir of diseases transmissible to humans and domestic animals. This is due to human-wildlife conflicts that have become more frequent and severe over recent decades, competition for the available natural habitats and resources leading to increased human encroachment on previously wild and uninhabited areas.

Methods: A total of 88 spleen DNA samples from baboons and vervet monkeys from Zambia were tested for zoonotic pathogens using genus or species-specific PCR. The amplified products were then subjected to sequencing analysis.

Results: We detected three different pathogenic agents, including Anaplasma phagocytophilum in 12 samples (13.6%), Rickettsia spp. in 35 samples (39.8%) and Babesia spp. in 2 samples (2.3%).

Conclusion: The continuously increasing contacts between humans and primate populations raise concerns about transmission of pathogens between these groups. Therefore, increased medical and public awareness and public health surveillance support will be required to detect and control infections caused by these agents at the interface between humans and wildlife.

Figure 1

Map of Zambia showing the sampling site. NLNP: North Luangwa National Park, SLNP: South Luangwa National Park of the Luangwa valley ecosystem a Human African Trypanosomiasis (HAT) focus.

Figure 2

Phylogenetic positions of the pathogens ( R. africae : A, 426 bp, 16S rRNA; A. phagocytophilum: B, 345bp 16S rRNA and B. microti C, 238bp, 18S rRNA) detected in primates from Zambia based on 16S rRNA or 18S rRNA sequences respectively. The tree was constructed using the neighbor-joining method and ClustalW alignment, and numbers on the tree indicate 1000 bootstrap values for branch points. Accession numbers are indicated.