[Show abstract][Hide abstract] ABSTRACT: The human immunodeficiency virus, HIV, is characterized by a tremendously high genetic diversity, leading to the currently known circulating HIV types, groups, subtypes, and recombinant forms. HIV-1 group O is one of the most diverse forms of HIV-1 and has been so far related to Cameroon or individuals originating from Cameroon. In this study, we investigated in Cameroon, the evolution of this viral group from 2006 to 2013, in terms of prevalence, genetic diversity and public health implications. Our results confirmed the predominance of HIV-1 group M (98.5%), a very low prevalence (<0.02%) for HIV-1 group N and P, and HIV-2 in this country. HIV-1 group O was found at around 0.6% (95% confidence interval: 0.4-0.8%), indicating that the frequency of this virus in Cameroon has remained stable over the last decades. However, we found an extensive high genetic diversity within this HIV-1 group, that resulted from previous steady increase on the effective number of HIV-1 group O infections through time, and the current distribution of the circulating viral strains still does not allow classification as subtypes. The frequency of dual infections with HIV-1 group M and group O was 0.8% (95% confidence interval: 0.6-1.0%), but we found no recombinant forms in co-infected patients. Natural resistance to integrase inhibitors was not identified, although we found several mutations considered as natural polymorphisms. Our study shows that infections with HIV-1 group O can be adequately managed in countries where the virus circulates, but this complex virus still represents a challenge for diagnostics and monitoring strategies.
Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 09/2015; 36. DOI:10.1016/j.meegid.2015.09.006 · 3.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
As part of its policy to shift monitoring of antiretroviral therapy (ART) to primary health care (PHC) workers, the Ministry of Health of the Democratic Republic of Congo (DRC) tested the feasibility of using dried blood spots (DBS) for viral load (VL) quantification and genotypic drug resistance testing in off-site high-throughput laboratories.
DBS samples from adults on ART were collected in 13 decentralized PHC facilities in the Nord-Kivu province and shipped during programme quarterly supervision to a reference laboratory 2,000 km away, where VL was quantified with a commercial assay (m2000rt, Abbott). A second DBS was send to a WHO-accredited laboratory for repeat VL quantification on a subset of samples with a generic assay (Biocentric) and genotypic drug resistance testing when VL>1,000 copies/ml.
Constraints arose due to an interruption in national laboratory funding rather than to technical or logistic problems. All samples were assessed by both VL assays to allow ART adjustment. Median DBS turnaround time was 37 days (IQR: 9-59). Assays performed unequally with DBS, impacting clinical decisions, quality assurance, and overall cost-effectiveness. Based on m2000rt or generic assay, 31.3% of patients were on virological failure and 14.8% presented resistance mutations versus 50.3% and 15.4% respectively.
This study confirms that current technologies involving DBS make virological monitoring of ART possible at PHC level, including in challenging environments, provided organisational issues are addressed. Adequate core funding of HIV laboratories and adapted choice of VL assays require urgent attention to control resistance to ART as coverage expands.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially.
[Show abstract][Hide abstract] ABSTRACT: Objective:
To propose two new indicators for monitoring access to antiretroviral treatment (ART) for human immunodeficiency virus (HIV); (i) the time from HIV seroconversion to ART initiation, and (ii) the time from ART eligibility to initiation, referred to as delay in ART initiation. To estimate values of these indicators in Cameroon.
We used linear regression to model the natural decline in CD4+ T-lymphocyte (CD4+ cell) numbers in HIV-infected individuals over time. The model was fitted using data from a cohort of 351 people in Côte d'Ivoire. We used the model to estimate the time from seroconversion to ART initiation and the delay in ART initiation in a representative sample of 4154 HIV-infected people who started ART in Cameroon between 2007 and 2010.
In Cameroon, the median CD4+ cell counts at ART initiation increased from 140 cells/μl (interquartile range, IQR: 66 to 210) in 2007-2009 to 163 cells/μl (IQR: 73 to 260) in 2010. The estimated average time from seroconversion to ART initiation decreased from 10.4 years (95% confidence interval, CI: 10.3 to 10.5) to 9.8 years (95% CI: 9.6 to 10.0). Delay in ART initiation increased from 3.4 years (95% CI: 3.1 to 3.7) to 5.8 years (95% CI: 5.6 to 6.2).
The estimated time to initiate ART and the delay in ART initiation indicate that progress in Cameroon is insufficient. These indicators should help monitor whether public health interventions to accelerate ART initiation are successful.
Bulletin of the World Health Organisation 08/2015; 93(8):521-528. DOI:10.2471/BLT.14.147892 · 5.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: WHO recommends ritonavir-boosted protease inhibitor with two nucleoside reverse transcriptase inhibitors in HIV-infected patients failing non-nucleoside reverse transcriptase inhibitor-based first-line treatment. Here, we aimed to provide more evidence for the choice of nucleoside reverse transcriptase inhibitor and boosted protease inhibitor.
ANRS 12169 is a 48-week, randomized, open-label, non-inferiority trial in three African cities, comparing efficacy and safety of three second-line regimens.
Patients failing non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy with confirmed plasma HIV-1 viral load above 1000 copies/ml were randomly assigned to tenofovir/emtricitabine + lopinavir/ritonavir (control group as per WHO recommendations), abacavir + didanosine + lopinavir/ritonavir (ABC/ddI group) or tenofovir/emtricitabine + darunavir/ritonavir (DRV group) regimens. The primary endpoint was the proportion of patients with plasma vral load below 50 copies/ml at week 48 in the modified intention-to-treat population. Non-inferiority was pre-specified with a 15% margin.
Of the 454 randomized patients, 451 were included in the analysis. Globally, 294 (65.2%) and 375 (83.2%) patients had viral load below 50 and 200 copies/ml, respectively, at week 48. The primary endpoint was achieved in 105 (69.1%) control group patients versus 92 (63.4%) in the ABC/ddI (difference 5.6%, 95% confidence interval -5.1 to 16.4) and 97 (63.0%) in the DRV (difference 6.1%, 95% confidence interval -4.5 to 16.7) groups (non-inferiority not shown). Overall, less number of patients with baseline viral load at least 100 000 copies/ml (n = 122) had a viral load below 50 copies/ml at week 48 (37.7 versus 75.4%; P < 0.001).
The three second-line regimens obtained similar and satisfactory virologic control and confirmed the WHO recommendation (TDF/FTC/LPVr) as a valid option. However, the suboptimal response for patients with high viral load warrants research for improved strategies.
AIDS (London, England) 07/2015; 29(12):1473-81. DOI:10.1097/QAD.0000000000000709 · 5.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ebola virus disease is a complex zoonosis and each outbreak is the result of independent zoonotic events. In certain outbreaks, even more than one cross-species transmission was involved. Today it is believed that human infection with Ebola Virus (EBV) can result from exposure to infected blood during hunting and butchering of infected animals for food or via contact with fruit contaminated with EBV by faeces or saliva from bats. Viral RNA from Zaire EBV has been identified in three fruit bat species from Gabon (Epomops franqueti, Hypsignathus monstrosus, and Myonycteris torquata). Other studies across Africa (Ghana, Gabon, Congo and Zambia) documented EBV antibodies in additional fruit and insect bat species (Eidolon helvum, Epomophorus gambianus, Micropteropus pusillus, Mops condylurus, Rousettus aegyptiacus, and Rousettus leschenaultii). Bats are at the origin of two EBV outbreaks; as bushmeat in the 2008 EBV outbreak in Luebo (DRC) and the index case (a 2-year-old boy in Meliandou) from the actual epidemic in Guinea, may have been infected by playing in a hollow tree housing a colony of insectivorous free-tailed bats (Mops condylurus). However, at least 8 of the 25 outbreaks have been related to contact with NHP (non-human primates), mainly apes. For the other EBV outbreaks, the zoonotic source is unknown. Since significant mortality related to EBV has been reported in wild gorillas (Gorilla gorilla) and chimpanzees (Pan troglodytes) in Gabon and Congo and also in chimpanzees from the Tai forest in Ivory Coast, apes are likely dead-end hosts for the virus and not reservoir species, but they play a role as amplifying host. EBV antibodies have also been observed in several wild-captured but captive non-human primate (NHP) species (chimpanzees, gorillas, mandrills, drills, baboons and Cercopithecus species) from Cameroon and Gabon, suggesting that EBV could be more widespread among NHP and that non-lethal or asymptomatic infections could occur in certain NHPs. Today, many questions still remain on the animal reservoir: how is EBV maintained and transmitted among bats and across the African continent, for example the Zaire EBV strain identified in the actual outbreak in West Africa diverged from Central African strains 10 years ago; how is the virus transmitted between different animal species; what is the role of reservoir and/or amplifying hosts in human outbreaks; to what extend are other Ebola viruses (Tai, Bundinguyo, Sudan, Reston,) present in animals; to what extend other unrecognized outbreaks occurred in humans.
[Show abstract][Hide abstract] ABSTRACT: HIV-1, the cause of AIDS, is composed of four phylogenetic lineages, groups M, N, O, and P, each of which resulted from an independent cross-species transmission event of simian immunodeficiency viruses (SIVs) infecting African apes. Although groups M and N have been traced to geographically distinct chimpanzee communities in southern Cameroon, the reservoirs of groups O and P remain unknown. Here, we screened fecal samples from western lowland (n = 2,611), eastern lowland (n = 103), and mountain (n = 218) gorillas for gorilla SIV (SIVgor) antibodies and nucleic acids. Despite testing wild troops throughout southern Cameroon (n = 14), northern Gabon (n = 16), the Democratic Republic of Congo (n = 2), and Uganda (n = 1), SIVgor was identified at only four sites in southern Cameroon, with prevalences ranging from 0.8–22%. Amplification of partial and full-length SIVgor sequences revealed extensive genetic diversity, but all SIVgor strains were derived from a single lineage within the chimpanzee SIV (SIVcpz) radiation. Two fully sequenced gorilla viruses from southwestern Cameroon were very closely related to, and likely represent the source population of, HIV-1 group P. Most of the genome of a third SIVgor strain, from central Cameroon, was very closely related to HIV-1 group O, again pointing to gorillas as the immediate source. Functional analyses identified the cytidine deaminase APOBEC3G as a barrier for chimpanzee-to-gorilla, but not gorilla-to-human, virus transmission. These data indicate that HIV-1 group O, which spreads epidemically in west central Africa and is estimated to have infected around 100,000 people, originated by cross-species transmission from western lowland gorillas.
Proceedings of the National Academy of Sciences 03/2015; 112(11). DOI:10.1073/pnas.1502022112 · 9.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Evidence of gender differences in antiretroviral treatment (ART) outcomes in sub-Saharan Africa is conflicting. Our objective was to assess gender differences in (1) adherence to ART and (2) virologic failure, immune reconstitution, mortality, and disease progression adjusting for adherence.
Cohort study among 459 ART-naive patients followed up 24 months after initiation in 2006-2010 in 9 rural district hospitals. Adherence to ART was assessed using (1) a validated tool based on multiple patient self-reports and (2) antiretroviral plasma concentrations. The associations between gender and the outcomes were assessed using multivariate mixed models or accelerated time failure models.
One hundred thirty-five patients (29.4%) were men. At baseline, men were older, had higher body mass index and hemoglobin level, and received more frequently efavirenz than women. Gender was not associated with self-reported adherence (P = 0.872, 0.169, and 0.867 for moderate adherence, low adherence, and treatment interruption, respectively) or with antiretroviral plasma concentrations (P = 0.549 for nevirapine/efavirenz). In contrast, male gender was associated with virologic failure [odds ratio: 2.18, 95% confidence interval (CI): 1.31 to 3.62, P = 0.003], lower immunologic reconstitution (coefficient: -58.7 at month 24, 95% CI: -100.8 to -16.6, P = 0.006), and faster progression to death (time ratio: 0.30, 95% CI: 0.12 to 0.78, P = 0.014) and/or to World Health Organization stage 4 event (time ratio: 0.27, 95% CI: 0.09 to 0.79, P = 0.017).
Our study provides important evidence that African men are more vulnerable to ART failure than women and that the male vulnerability extends beyond adherence issues. Additional studies are needed to determine the causes for this vulnerability to optimize HIV care. However, personalized adherence support remains crucial.
[Show abstract][Hide abstract] ABSTRACT: Simian immunodeficiency virus (SIV) infects many primate species. Chimpanzees (Pan troglodytes) can develop an immune disease similar to human acquired immunodeficiency syndrome (AIDS). Immunosuppressed patients often suffer from opportunistic diseases such as microsporidiosis and cryptosporidiosis. We report on the occurrence of infections with microsporidia and Cryptosporidium spp. in wild-living chimpanzees, gorillas (Gorilla gorilla gorilla), bonobos (Pan paniscus), and four monkey species from the Cercopithecinae subfamily (Cercocebus agilis, Cercopithecus cephus, Cercopithecus nictitans, and Lophocebus albigena) and assess whether these infections may be good indicators of SIV-related immunosuppression. We analyzed 399 fecal samples collected in Cameroon and Democratic Republic of Congo for the presence of cross-reactive HIV antibodies using a line immunoassay (INNO-LIA®). We amplified via polymerase chain reaction (PCR) a 200–500 bp DNA fragment for the genus Encephalitozoon and the genus Enterocytozoon respectively (microsporidia), and an 820 bp DNA fragment of various Cryptosporidium species. Twenty-nine percent (45/155) of the chimpanzees samples analyzed were SIV+, whereas samples from the other primate species were SIV–. Phylogenetic analyses showed that 11 fecal samples [one SIV+, four SIV– chimpanzees, three gorillas, a bonobo, an agile mangabey (Cercocebus agilis), and a moustached monkey (Cercopithecus cephus)] are infected with microsporidia. DNA sequences of amplicons derived from eight fecal samples clustered together with Encephalitozoon hellem and three branched close to E. intestinalis. We also amplified Cryptosporidium spp. in two SIV+ chimpanzee samples and in two gorilla samples. We found no significant association between SIV infection status in chimpanzees and the presence of microsporidia or Cryptosporidium, suggesting that detection of microsporidia and Cryptosporidium is not a reliable marker for immunosuppressive status in SIV-infected primates.
International Journal of Primatology 02/2015; 36(2). DOI:10.1007/s10764-015-9820-x · 1.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Wild apes are considered to be the most serious reservoir and source of zoonoses. However, little data are available about the gut microbiota and pathogenic bacteria in gorillas. For this propose, a total of 48 fecal samples obtained from 21 Gorilla gorilla gorilla individuals (as revealed via microsatellite analysis) were screened for human bacterial pathogens using culturomics and molecular techniques. By applying culturomics to one index gorilla and using specific media supplemented by plants, we tested 12,800 colonies and identified 147 different bacterial species, including 5 new species. Many opportunistic pathogens were isolated, including 8 frequently associated with human diseases; Mycobacterium bolletii, Proteus mirabilis, Acinetobacter baumannii, Klebsiella pneumoniae, Serratia marcescens, Escherichia coli, Staphylococcus aureus and Clostridium botulinum. The genus Treponema accounted for 27.4% of the total reads identified at the genus level via 454 pyrosequencing. Using specific real-time PCR on 48 gorilla fecal samples, in addition to classical human pathogens, we also observed the fastidious bacteria Bartonella spp. Borrelia spp., Coxiella burnetii and Tropheryma whipplei in the gorilla population. We estimated that the prevalence of these pathogens vary between 4.76% and 85.7%. Therefore, gorillas share many bacterial pathogens with humans suggesting that they could be a reservoir for their emergence.
[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: 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: 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 Société de pathologie exotique 09/2014; 107(4). DOI:10.1007/s13149-014-0392-3
[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 sand ﬂies. Apes are increasingly being seen as a source of zoonotic diseases, including
malaria and rickettsiosis. To examine whether gorillas harbor Leishmania species, we screened fecal samples from wild western lowland gorillas (Gorilla gorilla gorilla) in Cameroon for the presence of these pathogens. Of 91 wild gorilla fecal samples, 12 contained Leishmania parasites, and 4 contained phlebotomine sand fly vectors. The molecular identity was determined by running 3 different polymerase
chain reaction tests for detection of L. major. Next, fluorescence in situ hybridization was performed to visualize L. major parasites in fecal samples from the gorillas. Both promastigote and amastigote forms of the parasite were found. This work
strongly suggests that wild gorillas carry pathogenic Leishmania parasites.
The Journal of Infectious Diseases 07/2014; 211(2). DOI:10.1093/infdis/jiu380 · 6.00 Impact Factor
[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.