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Members of the species Enterovirus D (EV-D) remain poorly studied. The two first EV-D types (EV-D68 and EV-D70) have regularly caused outbreaks in humans since their discovery five decades ago but have been neglected until the recent occurrence of severe respiratory diseases due to EV-D68. The three other known EV-D types (EV-D94, EV-D111 and EV-D120) were discovered in the 2000s-2010s in Africa and have never been observed elsewhere. One strain of EV-D111 and all known EV-D120s were detected in stool samples of wild non-human primates, suggesting that these viruses could be zoonotic viruses. To date, EV-D111s are only known through partial genetic sequences of the few strains that have been identified so far. In an attempt to bring new pieces to the puzzle, we genetically characterized four EV-D111 strains (among the seven that have been reported until now). We observed that the EV-D111 strains from human samples and the unique simian EV-D111 strain were not phylogenetically distinct, thus suggesting a recent zoonotic transmission. We also discovered evidences of probable intertypic genetic recombination events between EV-D111s and EV-D94s. As recombination can only happen in co-infected cells, this suggests that EV-D94s and EV-D111s share common replication sites in the infected hosts. These sites could be located in the gut since the phenotypic analysis we performed showed that, contrary to EV-D68s and like EV-D94s, EV-D111s are resistant to acid pHs. We also found that EV-D111s induce strong cytopathic effects on L20B cells, a cell line routinely used to specifically detect polioviruses. An active circulation of EV-D111s among humans could then induce a high number of false-positive detection of polioviruses, which could be particularly problematic in Central Africa, where EV-D111 circulates and which is a key region for poliovirus eradication., Author summary Many examples of emergence of viruses that trigger severe diseases in humans are known. Emergence can be due to the sudden increase of the pathogenic power of a virus that had silently circulated into human populations for a long period; it can also be due to the cross-species transmission of a virus from its animal host to humans. The recent outbreaks of severe respiratory diseases due to enteroviruses D68 (EV-D68) brought to the light to potency of members of the species Enterovirus D (EV-D) to emerge as severe human pathogens. By many aspects, EV-Ds are still mysterious: their natural history and epidemiology are poorly studied and even their main hosts remain unknown. For decades, EV-Ds were believed to infect mainly humans but recent data about EV-Ds identified in sub-Saharan Africa support their zoonotic origin. In an attempt to increase our knowledge about EV-Ds, we undertook genetic and phenotypic characterization of four EV-D111 isolates, a virus type that was recently uncovered in humans and in non-human primates in Central Africa. Our results show that EV-D111s are probably enteric viruses and evolve by exchanging genetic sequences with EV-D94.

Enteroviruses (EVs) infecting African Non-Human Primates (NHP) are still poorly documented. This study was designed to characterize the genetic diversity of EVs among captive and wild NHP in Cameroon and to compare this diversity with that found in humans. Stool specimens were collected in April 2008 in NHP housed in sanctuaries in Yaounde and neighborhoods. Moreover, stool specimens collected from wild NHP from June 2006 to October 2008 in the southern rain forest of Cameroon were considered. RNAs purified directly from stool samples were screened for EVs using a sensitive RT-nested PCR targeting the VP1 capsid coding gene whose nucleotide sequence was used for molecular typing. Captive chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla) were primarily infected by EV types already reported in humans in Cameroon and elsewhere: Coxsackievirus A13 and A24, Echovirus 15 and 29, and EV-B82. Moreover EV-A119, a novel virus type recently described in humans in central and west Africa, was also found in a captive Chimpanzee. EV-A76, which is a widespread virus in humans, was identified in wild chimpanzees, thus suggesting its adaptation and parallel circulation in human and NHP populations in Cameroon. Interestingly, some EVs harbored by wild NHP were genetically distinct from all existing types and were thus assigned as new types. One chimpanzee-derived virus was tentatively assigned as EV-J121 in the EV-J species. In addition, two EVs from wild monkeys provisionally registered as EV-122 and EV-123 were found to belong to a candidate new species. Overall, this study indicates that the genetic diversity of EVs among NHP is more important than previously known and could be the source of future new emerging human viral diseases., Author Summary Enteroviruses (EVs) are among the most common viruses infecting humans. The circulation and diversity of EVs infecting humans have been extensively studied in most parts of the world but those infecting Non-Human Primates (NHP) are still poorly documented. As most African countries, Cameroon houses a wide range of Old World primates' species including apes (chimpanzees and gorillas) and at least 28 species of Old World monkeys. In this study, we investigated the diversity of EV types and species from the stool specimens obtained from captive and wild-living apes and monkeys in Cameroon. We found that captive chimpanzees and gorillas were primarily infected by EV types having a worldwide distribution in humans, thus confirming that close contacts can promote cross-species transmission of EVs between humans and NHP. We also found proposed new EV types infecting wild NHP that were genetically distinct from all known EVs. Given the potential cross-species transmission of at least some EV types and the increasing contacts between human and NHP, EVs infecting NHP could serve as a source of new emerging human viral pathogens with unpredictable symptomatology.

International audience; Conventional tests for antibody to Hepatitis C virus (HCV) and HCV RNA require considerable time before results are available, remain very expensive and are not adapted to many sub-Saharan African countries where HCV is endemic. The aim of this study was to evaluate the accuracy of an algorithm consisting of two HCV rapid tests to diagnose and predict HCV viremia in patients in Cameroon. Three hundred and twenty nine plasma samples were screened by two HCV rapid tests (ImmunoComb II HCV, PBS Orgenics and Hexagon HCV, Human). Previous evaluation of these samples for HCV antibodies (anti-HCV) by conventional third generation ELISA, considered as a reference test, indicated that 168 were anti-HCV negative and 161 positive. Among the 161 anti-HCV positive plasma, 114 (71%) were HCV RNA-positive by RT-PCR assay. The ImmunoComb II HCV test provided the more sensitive detection of anti-HCV (sensitivity: 99.4% with a 95% CI = 96-100%). Surprisingly, the second HCV rapid test, Hexagon HCV, showed a high capacity to identify non-viremic subjects amongst anti-HCV positive cases (93.6% [95% CI: 82-99%]). These results suggest an algorithm using ImmunoComb II HCV as a first test to screen anti-HCV positive subjects, and Hexagon HCV as a second test to discriminate between viremic and non-viremic HCV seropositive subjects.