[Show abstract][Hide abstract] ABSTRACT: Minor species of the Candida albicans complex may cause overestimation of the epidemiology of C. albicans, and misidentifications could mask their implication in human pathology. Authors determined the occurrence of minor species of the C. albicans complex (C. africana, C. dubliniensis and C. stellatoidea) among Yaoundé HIV-infected patients, Cameroon. Stool, vaginal discharge, urine and oropharyngeal samples were analysed by mycological diagnosis. Isolates were identified by conventional methods and mass spectrometry (MS; carried out by the matrix-assisted laser desorption–ionisation time-of-flight MS protocol). Candida albicans isolates were thereafter submitted to the PCR amplification of the Hwp1 gene. The susceptibility of isolates to antifungal drugs was tested using the Clinical and Laboratory Standards Institute M27-A3 protocol. From 115 C. albicans obtained isolates, neither C. dubliniensis nor C. stellatoidea was observed; two strains of C. africana (422PV and 448PV) were identified by PCR electrophoretic profiles at 700 bp. These two C. africana strains were vaginal isolates. The isolate 448PV was resistant to ketoconazole at the minimal inhibitory concentration of 2 μg ml−1, and showed reduced susceptibility to amphotericin B at 1 μg ml−1. This first report on C. africana occurrence in Cameroon brings clues for the understanding of the global epidemiology of this yeast as well as that of minor species of the C. albicans complex.
[Show abstract][Hide abstract] ABSTRACT: By the end of 2013, 11 million PLHIV were taking ARVs in Africa; application of the WHO recommendation to initiate treatment earlier (at CD4 count of 500 cells/mm3 or less) should further increase this number. Currently, twothirds of patients in Africa have been on treatment for less than five years, and less than 10% have received treatment for eight years or more. Given the historical perspective is in its early stages, the long-term impact of ARV therapy is still unclear. This article reviews the knowledge gained over the period marking the first ten years of implementation of the universal access strategy (2003-2013) in Africa, through a review of the literature documenting the long-term consequence of ARV treatment, focusing on medical care for adults with an emphasis on the patient-centered approach. The goal is to understand the interrelationships between biological and social factors and individual and collective aspects that affect the lives of PLHIV and determine the impacts of ARV treatment over the long term. The biomedical and social factors are addressed successively, based on the most significant results. Key knowledge on the long-term outcomes for PLHIVon ARV treatment offers vital information on the necessary conditions and adaptations for care systems needed to ensure the benefits of treatment endure over time.
Bulletin de la Societe de pathologie exotique (1990). 09/2014;
[Show abstract][Hide abstract] ABSTRACT: Vector-borne parasites of the genus Leishmania are responsible for severe human diseases. Cutaneous leishmaniasis, a common form of the disease, is most often caused by the transmission of Leishmania major to humans by female phlebotomine sandﬂies. Recently, Apes are increasingly seen as source of zoonotic diseases including malaria and rickettsiosis. To examine the possibility whether gorillas harbor Leishmania spp., we screened fecal samples from wild western lowland gorillas (Gorilla gorilla gorilla) in Cameroon for the presence of these pathogens. Of 91 wild gorilla feces samples, 12 contained Leishmania parasites and 4 contained phlebotomine sand fly vectors. The molecular identity was determined by running three different PCR tests as L. major. Next, fluorescence in situ hybridization (FISH) was performed to visualize L. major parasites in the feces of the gorillas. Both promastigote and amastigote forms of the parasite were found. This work strongly suggests that wild gorillas carry pathogenic Leishmania parasites.
[Show abstract][Hide abstract] ABSTRACT: Strain G5(T) gen. nov., sp. nov. is the type strain of Gorillibacterium massiliense, a newly proposed genus within the family Paenibacillaceae. This strain, whose genome is described here, was isolated in France from a stool sample of a wild Gorilla gorilla subsp. gorilla from Cameroon. G. massiliense is a facultatively anaerobic, Gram negative rod. Here we describe the features of this bacterium, together with the complete genome sequence and annotation. The 5,546,433 bp long genome (1 chromosome but no plasmid) contains 5,145 protein-coding and 76 RNA genes, including 69 tRNA genes.
Standards in Genomic Sciences 06/2014; 9(3):807-20. · 3.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We tested 114 faecal samples from wild simian immunodeficiency virus (SIV)-positive (n = 43) and SIV-negative (n = 71) chimpanzees (Pan troglodytes troglodytes) in southeast Cameroon for the presence of gastrointestinal parasites by direct smear. We observed cysts from different protozoa (Entamoeba coli and Entamoeba histolytica / Entamoeba dispar, Endolimax nana, Iodamoeba butschlii, Chilomastix mesnili, Balantidium coli and Blastocystis cells) and trophozoites from Troglodytella abrassarti and Balantidium coli. Eggs from different helminths (strongylids, Ascaris lumbricoides, Abbreviata caucasica, Trichuris sp., Capillaria sp., Enterobius anthropopeci, Bertiella sp., Hymenolepis diminuta and an undetermined fluke) were also observed. Finally, we observed eggs that could not be properly identified and classified. We did not observe any differences between the SIV + and SIV - samples except for the unidentified eggs. The studied chimpanzees were highly parasitised by strongylid (85.1 % of prevalence), Troglodytella (43.8 %) and Blastocystis (2.9 %), and the frequency of the other parasites ranged from 0.9 to 8.8 %. These high levels of parasite infections could represent an additional burden in a population where there is a high rate of the SIV virus in circulation.
Parasitology Research 04/2014; · 2.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives
The emergence of HIV drug resistance is a crucial issue in Africa, where second-line antiretroviral therapy (ART) is limited, expensive and complex. We assessed the association between adherence patterns and resistance emergence over time, using an adherence measure that distinguishes low adherence from treatment interruptions, in rural Cameroon. Methods
We performed a cohort study among patients receiving nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART in nine district hospitals, using data from the Stratall trial (2006−2010). Genotypic mutations associated with antiretroviral drug resistance were assessed when 6-monthly HIV viral loads were > 5000 HIV-1 RNA copies/mL. ART adherence data were collected using face-to-face questionnaires. Combined indicators of early (1−3 months) and late (6 months to t − 1; t is the time point when the resistance had been detected) adherence were constructed. Multivariate logistic regression and Cox models were used to assess the association between adherence patterns and early (at 6 months) and late (after 6 months) resistance emergence, respectively. ResultsAmong 456 participants (71% women; median age 37 years), 45 developed HIV drug resistance (18 early and 27 late). Early low adherence (< 80%) and treatment interruptions (> 2 days) were associated with early resistance [adjusted odds ratio (95% confidence interval) 8.51 (1.30–55.61) and 5.25 (1.45–18.95), respectively]. Early treatment interruptions were also associated with late resistance [adjusted hazard ratio (95% confidence interval) 3.72 (1.27–10.92)]. Conclusions
The emergence of HIV drug resistance on first-line NNRTI-based regimens was associated with different patterns of adherence over time. Ensuring optimal early adherence through specific interventions, adequate management of drug stocks, and viral load monitoring is a clinical and public health priority in Africa.
[Show abstract][Hide abstract] ABSTRACT: Enteroviruses (EVs) are a genetically and antigenically diverse group of viruses infecting humans. A mostly distinct set of EV variants have additionally been documented to infect wild apes and several, primarily captive, Old World monkey (OWM) species. To investigate the prevalence and genetic characteristics of EVs infecting OWMs in the wild, faecal samples from mandrills (Mandrillus sphinx) and other species collected in remote regions of Southern Cameroon were screened for EV RNA. Remarkably high rates of EV positivity were detected in M.sphinx (100 from 102 screened), Cercocebus torquatus (7/7) and Cercopithecus cephus (2/4), with high viral loads indicative of active infection. Genetic characterisation in VP4/VP2 and VP1 regions allowed EV variants to be assigned to simian species H (EV-H), EV-J (including one or more new types) while seven matched simian EV-B variants, SA5 and EV110 (chimpanzee). Sequences from the remaining 70 formed a new genetic group distinct in VP4/2 and VP1 region from all currently recognised human or simian EV species. Complete genome sequences were obtained from three to determine their species assignment. In common with EV-J and the EV-A A13 isolate, new group sequences were chimaeric, being most closely related to EV-A in capsid genes and to EV-B in the non-structural gene region. Further recombination events created different groupings in 5' and 3' untranslated regions. While clearly a distinct EV group, the hybrid nature of new variants prevented their unambiguous classification as either members of a new species or as divergent members of EV-A using current ICTV assignment criteria.
This study is the first large scale investigation of the frequency of infection and diversity of enteroviruses (EVs) infecting monkeys (primarily mandrills) in the wild. Findings demonstrate extremely high frequencies of active infection (95%) among mandrills and other Old World monkey species inhabiting remote regions of Cameroon without human contact. EV variants detected were distinct from those infecting human populations, comprising members of enterovirus species B, J and H and a large novel group of viruses that potentially represent a candidate new EV species. The viral sequences obtained contribute substantially to our growing understanding of the genetic diversity of EVs and the existence of inter-species chimaerism that characterises the novel variants in the current study, as well as in previously characterised species A and J viruses infecting monkeys. The latter findings will contribute to future development of consensus criteria for species assignments in enteroviruses and other picornavirus genera.
[Show abstract][Hide abstract] ABSTRACT: Plasmodium vivax is the leading cause of human malaria in Asia and Latin America but is absent from most of central Africa due to the near fixation of a mutation that inhibits the expression of its receptor, the Duffy antigen, on human erythrocytes. The emergence of this protective allele is not understood because P. vivax is believed to have originated in Asia. Here we show, using a non-invasive approach, that wild chimpanzees and gorillas throughout central Africa are endemically infected with parasites that are closely related to human P. vivax. Sequence analyses reveal that ape parasites lack host specificity and are much more diverse than human parasites, which form a monophyletic lineage within the ape parasite radiation. These findings indicate that human P. vivax is of African origin and likely selected for the Duffy-negative mutation. All extant human P. vivax parasites are derived from a single ancestor that escaped out of Africa.
[Show abstract][Hide abstract] ABSTRACT: Dried blood spots (DBS) can be used in developing countries to alleviate the logistic constraints of using blood plasma specimens for viral load (VL) and HIV drug resistance (HIVDR) testing, but they should be assessed under field conditions. Between 2009 and 2011, we collected paired plasma-DBS samples from treatment-experienced HIV-1-infected adults in Burkina Faso, Cameroon, Senegal, Togo, Thailand, and Vietnam. The DBS were stored at an ambient temperature for 2 to 4 weeks and subsequently at -20°C before testing. VL testing was performed on the plasma samples and DBS using locally available methods: the Abbott m2000rt HIV-1 test, generic G2 real-time PCR, or the NucliSENS EasyQ version 1.2 test. In the case of virological failure (VF), i.e., a plasma VL of ≥1,000 copies/ml, HIVDR genotyping was performed on paired plasma-DBS samples. Overall, we compared 382 plasma-DBS sample pairs for DBS VL testing accuracy. The sensitivities of the different assays in different laboratories for detecting VF using DBS varied from 75% to 100% for the m2000rt test in labs B, C, and D, 91% to 93% for generic G2 real-time PCR in labs A and F, and 85% for the NucliSENS test in lab E. The specificities varied from 82% to 97% for the m2000rt and NucliSENS tests and reached only 60% for the generic G2 test. The NucliSENS test showed good agreement between plasma and DBS VL but underestimated the DBS VL. The lowest agreement was observed for the generic G2 test. Genotyping was successful for 96/124 (77%) DBS tested, and 75/96 (78%) plasma-DBS pairs had identical HIVDR mutations. Significant discrepancies in resistance interpretations were observed in 9 cases, 6 of which were from the same laboratory. DBS can be successfully used as an alternative to blood plasma samples for routine VL and HIVDR monitoring in African and Asian settings. However, the selection of an adequate VL measurement method and the definition of the VF threshold should be considered, and laboratory performance should be monitored.
Journal of clinical microbiology 02/2014; 52(2):578-86. · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The consumption of insects by apes has previously been reported based on direct observations and/or trail signs in feces. However, DNA-based diet analyses may have the potential to reveal trophic links for these wild species. Herein, we analyzed the insect-diet diversity of 9 feces obtained from three species of African great apes, gorilla (Gorilla gorilla gorilla), chimpanzee (Pan troglodytes) and bonobo (Pan paniscus), using two mitochondrial amplifications for arthropods. A total of 1056 clones were sequenced for Cyt-b and COI gene libraries, which contained 50 and 56 operational taxonomic units (OTUs), respectively. BLAST research revealed that the OTUs belonged to 32 families from 5 orders (Diptera, Isoptera, Lepidoptera, Coleoptera, and Orthoptera). While ants were not detected by this method, the consumption of flies, beetles, moths, mosquitoes and termites was evident in these samples. Our findings indicate that molecular techniques can be used to analyze insect food items in wild animals.
[Show abstract][Hide abstract] ABSTRACT: HIV infection is an emerging problem in Laos. We conducted the first prospective study on intestinal parasites, including opportunistic protozoa, in newly diagnosed HIV infected patients, with or without diarrhea. The aims were to describe the spectrum of infections, to determine their prevalence and to assess their associations with diarrhea, CD4 cell count, place of residence and living conditions.
One to three stool samples over consecutive days were obtained from 137 patients. The Kato thick smear method, formalin-ethyl concentration and specific stains for coccidia and microsporidia diagnosis were performed on 260 stool samples. Baseline characteristics regarding relevant demographics, place of residence and living conditions, clinical features including diarrhea, were collected using a standardized questionnaire.
The 137 patients were young (median age: 36 years) and severely immunocompromised (83.9% at WHO stage 3 or 4, median CD4 cell count: 41/mm3). Diarrhea was present in 43.0% of patients. Parasite infection was found in 78.8% of patients, infection with at least two species in 49.6%. Prevalence rates of protozoan and helminth infections were similar (54.7% and 58.4% respectively). Blastocystis sp. was the most frequent protozoa (26.3%). Cryptosporidium sp., Cytoisospora belli and microsporidia, found at low prevalence rates (6.6%, 4.4%, 2.9%, respectively), were described for the first time in Laos. Cryptosporidium sp. was associated with persistent diarrhea. Strongyloides stercoralis was the most prevalent helminth following Opisthorchis viverrini (20.4% and 47.5% respectively). The most immunocompromised patients, as assessed by a CD4 count ≤ 50 cells/mm3, were more likely to be infected with intestinal parasites.
HIV infection was mainly diagnosed at an advanced stage of immunosuppression in Lao patients. Intestinal parasite infections were highly prevalent regardless of their diarrheal status. Opportunistic infections were reported. Improving the laboratory diagnosis of intestinal parasite infections and the knowledge on their local risk factors is warranted.
PLoS ONE 01/2014; 9(3):e91452. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although gorillas regarded as the largest extant species of primates and have a close phylogenetic relationship with humans, eukaryotic communities have not been previously studied in these populations. Herein, 35 eukaryotic primer sets targeting the 18S rRNA gene, internal transcribed spacer gene and other specific genes were used firstly to explore the eukaryotes in a fecal sample from a wild western lowland gorilla (Gorilla gorilla gorilla). Then specific real-time PCRs were achieved in additional 48 fecal samples from 21 individual gorillas to investigate the presence of human eukaryotic pathogens. In total, 1,572 clones were obtained and sequenced from the 15 cloning libraries, resulting in the retrieval of 87 eukaryotic species, including 52 fungi, 10 protozoa, 4 nematodes and 21 plant species, of which 52, 5, 2 and 21 species, respectively, have never before been described in gorillas. We also reported the occurrence of pathogenic fungi and parasites (i.e. Oesophagostomum bifurcum (86%), Necator americanus (43%), Candida tropicalis (81%) and other pathogenic fungi were identified). In conclusion, molecular techniques using multiple primer sets may offer an effective tool to study complex eukaryotic communities and to identify potential pathogens in the gastrointestinal tracts of primates.
[Show abstract][Hide abstract] ABSTRACT: The Simian Immunodeficiency Virus (SIV) mus/mon/gsn lineage is a descendant of one of the precursor viruses to the HIV-1/SIVcpz/gor viral lineage. SIVmus and SIVgsn were sequenced from mustached and greater spot nosed monkeys in Cameroon and SIVmon from mona monkeys in Cameroon and Nigeria. In order to further document the genetic diversity of SIVmus, we analyzed two full-length genomes of new strains identified in Gabon. The whole genomes obtained showed the expected reading frames for gag, pol, vif, vpr, tat, rev, env, nef, and also for a vpu gene. Analyses showed that the Gabonese SIVmus strains were closely related and formed a monophyletic clade within the SIVmus/mon/gsn lineage. Nonetheless, within this lineage, the position of both new SIVmus differed according to the gene analyzed. In pol and nef gene, phylogenetic topologies suggested different evolutions for each of the two new SIVmus strains whereas in the other nucleic fragments studied, their positions fluctuated between SIVmon, SIVmus-1, and SIVgsn. In addition, in C1 domain of env, we identified an insertion of seven amino acids characteristic for the SIVmus/mon/gsn and HIV‑1/SIVcpz/SIVgor lineages. Our results show a high genetic diversity of SIVmus in mustached monkeys and suggest cross-species transmission events and recombination within SIVmus/mon/gsn lineage. Additionally, in Central Africa, hunters continue to be exposed to these simian viruses, and this represents a potential threat to humans.
[Show abstract][Hide abstract] ABSTRACT: A total of 139 stool samples from wild chimpanzees, gorillas and bonobos in Cameroon and Democratic Republic of Congo (DRC) were screened for enteroviruses (EVs) by RT-PCR. EV RNA was detected in 10% of samples, comprising 8 from 58 sampled chimpanzees (13.8%), 1/40 bonobos (2.5%) and 5/40 gorillas (12.2%). Three chimpanzee variants grouped with human isolate EV-A89 while four (4 chimpanzee, 1 gorilla) represented a newly identified type, EV-A119. These species A virus types overlapped with those circulating in human populations in the same area. The remaining six strains comprised a new species D type, EV-D120, infecting one chimpanzee and 4 gorillas, and a single EV variant infecting a bonobo that was remarkably divergent from other EVs and potentially constitutes a new enterovirus species. The study demonstrates both the circulation of genetically divergent EV variants in apes and monkeys as well as those shared with local human populations.
Journal of General Virology 11/2013; · 3.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background. The limited access to virological monitoring in developing countries is a major weakness of the current antiretroviral treatment (ART) strategy in these settings. We conducted a large cross-sectional study in Burkina-Faso, Cameroon, Cote d'Ivoire, Senegal, Togo, Thailand and Vietnam to assess virological failure (VF) and drug resistance mutations (DRMs) after 12 or 24 months of ART. Methods. Between 2009 and 2011, we recruited adult-patients attending ART centers for their medical visit at month 12±2 (M12) or 24±2 (M24). Demographic and clinical data were collected on site, and viral load (VL) was performed. Samples with VL≥1000 copies/ml, considered as the failure threshold, were genotyped for drug resistance assessment. Results. Overall, 3935 patients were recruited, 2060 at month 12 and 1875 at month 24 since starting ART. Median ages varied from 32 to 42 years. Median CD4 values at ART initiation were low, 99 to 172 cells/μl. Main ART regimens included stavudine/zidovudine plus lamivudine plus nevirapine/efavirenz. Overall, VF frequency was 11.1% for M12 and 12.4% for M24 patients, and 71.0% to 86.1% of these patients selected drug resistant virus. Across sites, VF varied from 2.9% to 20.6% in M12 and 3.7% to 26.0% in M24 patients. Predominant DRMs were associated with ART regimens, but several patients accumulated DRMs to drugs not received as abacavir, didanosine, tenofovir, etravirine and rilpivirine. Conclusions. Our findings show heterogeneous virological failure and illustrate that in addition to routine access to VL, good ART-programme management is even more critical to improve treatment outcome in resource-limited countries.
[Show abstract][Hide abstract] ABSTRACT: Circulating and unique recombinant HIV-1 strains continue to be identified and their number increases over time, suggesting that co-infection with multiple HIV-1 is frequent. In this study we analysed to what extent dual infections with different HIV-1 variants occur in a population group with high risk behaviour, high HIV-1 prevalence and in an area where multiple HIV-1 subtypes and Circulating Recombinant Forms (CRFs) co-circulate. We studied 69 MSM with our recently developed multi-region hybridization assay (MHA), based on fluorescent probe detection for eight common variants circulating in West and West Central Africa. At least 11 (15.9%) of the 69 patients were simultaneously infected with two different HIV-1 subtypes and/or CRFs. Among the 29 samples identified as subtype C by MHA in gag, 15 (57.7%) reacted with both C1 and C2 probes. Sequence analysis suggests that the majority of the samples reactive with C1 and C2 probes are most likely infected with two different subtype C clades. Single genome amplification and DNA dilutions confirmed dual infection with subtype D and C for MSM1193, triple infection with two different C subtype strains and one CRF02_AG strain in MSM1157 and showed that MSM3017 is at least co-infected with CRF06_cpx and CRF02_AG and another strain that could not be classified. Comparison of all subtype C sequences from the MSM population and from the general population from this and previous studies confirmed the intermixing of HIV-1 variants between low-risk women and high-risk men as shown by the intermixing of subtype C variants from MSM1157 and a female patient (02SN-HALD478). Comparison of dual infection rates between the general population and MSM in Senegal, show also clearly the importance of high HIV prevalence and high risk behaviour in dual infections and subsequent intermixing of HIV-1 variants which can lead to emergence and spread of new recombinants (CRFs).
Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 09/2013; · 3.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of the present study was to determine appropriate tenofovir-based regimens meriting evaluation in large-scale randomized trials among sub-Saharan African patients.
Randomized, open-label, 96-week, prospective pilot study evaluating four first-line regimens: tenofovir/emtricitabine/nevirapine (Group 1), tenofovir/lopinavir/ritonavir (Group 2), tenofovir/emtricitabine/zidovudine (Group 3) and tenofovir/emtricitabine/efavirenz (Group 4) in antiretroviral-naïve, HIV-1-infected patients in Senegal and Cameroon. The primary endpoint was defined as an HIV-1-RNA viral load <50 copies/mL (study detection limit) at week 16 in at least 50% of patients using intention-to-treat analysis.
At baseline, 119 patients included were 34% male, had a median plasma viral load of 5.4 log10 copies/mL and median CD4 cell count of 200/mm(3) (range=53-358). Primary endpoint was achieved for groups 1, 3, and 4 (58%, n=31; 62%, n=29; 53%, n=30, respectively), but not for Group 2 (38%, n=29). At week 96, undetectable HIV-1-RNA had been achieved in 74% of patients in Group 1, 38% Group 2, 72% Group 3 and 73% Group 4. Patients with detectable HIV-RNA at week 16 were more likely to have baseline HIV-1-RNA ≥100 000 copies/mL (adjusted OR=5.56; 95% CI:1.72-16.67). HIV-mutations associated with protease inhibitor resistance emerged in three patients, all of whom were in Group 2. Anemia occurred in two Group 3 patients and was the only serious treatment-related adverse event.
Three efficient and safe tenofovir-based, triple regimens were identified; the two-drug regimen (tenofovir/lopinavir/r) did not achieve protocol-defined virologic threshold of efficacy.