Bowden R.,University of Oxford |
MacFie T.S.,University of Cambridge |
Myers S.,University of Oxford |
Myers S.,Broad Institute |
And 6 more authors.
PLoS Genetics | Year: 2012
In spite of its evolutionary significance and conservation importance, the population structure of the common chimpanzee, Pan troglodytes, is still poorly understood. An issue of particular controversy is whether the proposed fourth subspecies of chimpanzee, Pan troglodytes ellioti, from parts of Nigeria and Cameroon, is genetically distinct. Although modern high-throughput SNP genotyping has had a major impact on our understanding of human population structure and demographic history, its application to ecological, demographic, or conservation questions in non-human species has been extremely limited. Here we apply these tools to chimpanzee population structure, using ~700 autosomal SNPs derived from chimpanzee genomic data and a further ~100 SNPs from targeted re-sequencing. We demonstrate conclusively the existence of P. t. ellioti as a genetically distinct subgroup. We show that there is clear differentiation between the verus, troglodytes, and ellioti populations at the SNP and haplotype level, on a scale that is greater than that separating continental human populations. Further, we show that only a small set of SNPs (10-20) is needed to successfully assign individuals to these populations. Tellingly, use of only mitochondrial DNA variation to classify individuals is erroneous in 4 of 54 cases, reinforcing the dangers of basing demographic inference on a single locus and implying that the demographic history of the species is more complicated than that suggested analyses based solely on mtDNA. In this study we demonstrate the feasibility of developing economical and robust tests of individual chimpanzee origin as well as in-depth studies of population structure. These findings have important implications for conservation strategies and our understanding of the evolution of chimpanzees. They also act as a proof-of-principle for the use of cheap high-throughput genomic methods for ecological questions. © 2012 Bowden et al.
Njouom R.,Center Pasteur du Cameroun
BMC research notes | Year: 2014
BACKGROUND: Dog rabies is endemic in most African countries and the risk of human rabies is estimated to be high in Cameroon according to WHO estimations in 2010. This study aimed to describe the circulation rabies virus (RABV) among dogs in the southern regions of Cameroon from 2010 to 2013 in a context, where mass vaccination campaigns are launched annually in order to control rabies in domestic animals including dogs and cats.FINDINGS: From 2010 to 2013, 93 animal specimens (dogs: 91, monkey: 1, pig: 1) originating from the southern regions of Cameroon were collected and tested for rabies virus at the Centre Pasteur of Cameroon by fluorescent antibody test (FAT) and virus isolation. Of the total dog specimens, 69.2% (63/91) originated from the central part of the southern regions and 50.5% (46/91) were from the capital city Yaounde. Overall, 74.2% (66/89) of dogs' specimens that could be tested were found rabies-positive while specimens from the monkey and pig were tested negative. Overall, dog rabies was repeatedly detected in the southern regions of Cameroon especially in the nation capital, Yaounde even though low specimen submission and geographic bias did not permit major conclusions about its actual rate, geographical and over time distribution.CONCLUSIONS: The results of this study indicate that rabies is endemic in the dog population which is of public health concern. Therefore, coordinated rabies control program should be conducted to reduce the rabies incidence in dogs and in humans. In addition, proper rabies surveillance program including reporting system should be established to monitor the success of the control program in Cameroon.
Ndowa F.J.,World Health Organization |
Francis J.M.,National Institute for Medical Research |
Machiha A.,Ministry of Health and Child Welfare |
Faye-Kette H.,Institute Pasteur Of Cote Divoire |
Fonkoua M.C.,Center Pasteur du Cameroun
Sexually Transmitted Infections | Year: 2013
Many countries in Africa have weak surveillance systems for data collection of sexually transmitted infections, and hardly any programmes for gonococcal antimicrobial susceptibility assessment. The widespread adoption of the syndromic approach to the diagnosis and management of sexually transmitted infections has also meant that the collection of a genital specimen for laboratory analysis is no longer routinely done when patients present with genital complaints, and clinical staff and laboratory technicians have lost the skill to collect genital specimens and processing them for culture and antimicrobial susceptibility testing. Following reports of gonococcal antimicrobial resistance to quinolones, WHO urged countries to monitor gonococcal antimicrobial resistance in a more systematic and regular manner. Although the response in Africa has been slow to take off, a number of studies have been conducted in a few countries and plans for implementation are in place in others. However, the number of isolates studied has been small in nearly all the countries except one, and the barriers to scaling up gonococcal antimicrobial resistance surveys seem overwhelming. In spite of the studies being few and of small sample sizes, enough information can be discerned to indicate that quinolones can no longer be a medicine of choice for the treatment of gonorrhoea in Africa and the threat of antimicrobial resistance developing in Neisseria gonorrhoeae to thirdgeneration cephalosporins is real and imminent.
Pepin J.,Universite de Sherbrooke |
Lavoie M.,Universite de Sherbrooke |
Pybus O.G.,University of Oxford |
Pouillot R.,Center Pasteur du Cameroun |
And 4 more authors.
Clinical Infectious Diseases | Year: 2010
Background. In southern Cameroon, where SIVcpz, the source of human immunodeficiency virus 1 (HIV-1) group M, is prevalent among wild chimpanzees, ∼50% of some human birth cohorts have been infected with hepatitis C virus (HCV) through unclear mechanisms. Methods. To evaluate indirectly the hypothesis that medical interventions contributed to the early emergence of HIV-1, we conducted a cross-sectional study of 451 inhabitants of Ebolowa in southern Cameroon aged ≥60 years, using HCV as a marker of parenteral transmission of blood-borne viruses. We administered a questionnaire and tested serum for antibodies against HCV. Viral gene sequences were obtained from HCV-positive sera. Molecular clock analyses provided an independent source of information on epidemic history. Results. A total of 252 participants (56%) were HCV seropositive. HCV sequences were amplified and genotyped from 171 individuals. Independent risk factors for HCV seropositivity were older age, having received intravenous treatment against malaria, and having attended an ethnic school (women only), whereas having been circumcised by a traditional practitioner (men only) tended to be associated with HCV. In addition, transfusions were associated with HCV genotype 1 transmission. Molecular clock analyses of HCV genotypes 1, 2, and 4 revealed that each independently underwent exponential growth during the first half of the 20th century. Conclusions. Medical interventions (intravenous antimalarial drugs, transfusions) and to a lesser extent traditional practices (circumcision) were associated with the massive transmission of HCV among this population decades ago. This finding supports the hypothesis that medical interventions contributed to the transmission of blood-borne viruses, perhaps including SIVcpz and HIV-1, in the same region during the early 20th century. © 2010 by the Infectious Diseases Society of America. All rights reserved.
Foupouapouognigni Y.,Center Pasteur du Cameroun |
Noah D.N.,Hopital Central de Yaounde |
Sartre M.T.,Cabinet Medical de la Cathedrale |
Njouom R.,Center Pasteur du Cameroun
Journal of Clinical Microbiology | Year: 2011
Antibodies to the hepatitis delta virus (HDV) were found in 17.6% of 233 hepatitis B virus surface antigen-positive subjects in Cameroon. Phylogenetic analyses showed the presence of HDV-1, HDV-5, HDV-6, and HDV-7 genotypes. These results enrich the limited data on HDV prevalence and molecular diversity in Cameroon. Copyright © 2011, American Society for Microbiology. All Rights Reserved.