Ph.D.
Project Summary: Despite the fact that human enteroviruses (EVs) are worldwide distributed and are involved in a wide range of epidemic diseases, they are rarely considered in developing countries, sub-Saharan Africa in particular. Our study aimed to i) describe the genetic diversity of human and simian EVs circulating in Cameroon, ii) evaluate the capacities of genetic exchanges between these EVs, and iii)
assess the potential of cross-species transmission of EVs between humans and non human primates.
The genetic diversity of human EVs, including polioviruses (PVs), circulating in Cameroon was
investigated in acute flaccid paralysis patients throughout the entire territory as well as in healthy children from the far northern region of the country. The results showed a high frequency combined with a high genetic diversity of human EVs in Cameroon. The frequency of EVs belonging to the Human Enterovirus C species (HEV-C) was as high as 56.5% of the identified isolates. Apart from
worldwide distributed types, several African specific types and variants were identified.
The investigation of genetic exchanges between HEV-C, including vaccine PVs, confirmed the fact that frequent recombination in the non structural regions of the genome contribute to their genetic diversity. PVs in particular co-circulate and exchange the sequences of their non structural regions
with CVA-13, -17 and -20. The co-circulation of PVs and diverse HEV-C may be a major viral factor that could favor the emergence of pathogenic recombinant vaccine-derived PVs (VDPVs).
In the other hand, simian specific EVs as well as EVs previously known human EVs were
identified in the stools of captive and wild non human primates (NHP). Four novel types of simian EVs in particular were identified. The results confirmed that cross-species transmission of at least some EV
types, including some coxsackievirus A of the species HEV-C can happen naturally and could play a role in the emergence of new EV types from humans to NHP and vice-versa.
