[Show abstract][Hide abstract] ABSTRACT: The family Arteriviridae presently includes a single genus Arterivirus. This genus includes four species as the taxonomic homes for equine arteritis virus (EAV), lactate dehydrogenase-elevating virus (LDV), porcine respiratory and reproductive syndrome virus (PRRSV), and simian hemorrhagic fever virus (SHFV), respectively. A revision of this classification is urgently needed to accommodate the recent description of eleven highly divergent simian arteriviruses in diverse African nonhuman primates, one novel arterivirus in an African forest giant pouched rat, and a novel arterivirus in common brushtails in New Zealand. In addition, the current arterivirus nomenclature is not in accordance with the most recent version of the International Code of Virus Classification and Nomenclature. Here we outline an updated, amended, and improved arterivirus taxonomy based on current data. Taxon-specific sequence cut-offs are established relying on a newly established open reading frame 1b phylogeny and pairwise sequence comparison (PASC) of coding-complete arterivirus genomes. As a result, the current genus Arterivirus is replaced by five genera: Equartevirus (for EAV), Rodartevirus (LDV + PRRSV), Simartevirus (SHFV + simian arteriviruses), Nesartevirus (for the arterivirus from forest giant pouched rats), and Dipartevirus (common brushtail arterivirus). The current species Porcine reproductive and respiratory syndrome virus is divided into two species to accommodate the clear divergence of the European and American "types" of PRRSV, both of which now receive virus status. The current species Simian hemorrhagic fever virus is divided into nine species to accommodate the twelve known simian arteriviruses. Non-Latinized binomial species names are introduced to replace all current species names to clearly differentiate them from virus names, which remain largely unchanged.
Archives of Virology 11/2015; DOI:10.1007/s00705-015-2672-z · 2.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Men who have sex with men (MSM) in Cameroon consistently face significant stigma and discrimination. The urban HIV prevalence in MSM is estimated at 35%. This study investigates the effect of stigma, discrimination and alienation on Cameroonian MSM's engagement of the HIV treatment cascade. Methods: Qualitative interviews were semi-structured using a guide. Participants in Douala, Ngaoundere, Bamenda, Bertoua and Yaoundé were asked to describe the MSM social and structural context, MSM knowledge of existing HIV-related services in public and MSM-focussed non-governmental organisation (NGO) clinics. Using a codebook, coded text was extracted from 40 transcripts with Microsoft Word Macros. These texts were analysed for recurring themes that were developed into results. Results: There were three main themes that emerged. First, among those MSM participants seeking HIV services, many commonly reported experiences of discrimination and physical violence outside the healthcare setting. Second, a few respondents used services provided by the Ministry of Health and local NGOs. However, most participants observed limited clinical and cultural competency of public clinic staff. Third, MSM declared that lack of social support and healthcare access caused them much stress. Several individuals recounted their alienation greatly discouraged them from seeking HIV prevention, treatment and care services. Conclusions: Community-level and public healthcare-related stigma impacts the mental wellbeing of Cameroonian MSM. Alienation among MSM also represents a common obstacle to the uptake of MSM-oriented HIV/AIDS services. Improving provider cultural and clinical competency among Cameroonian health care workers combined with a broader stigma-reduction intervention for Cameroonian healthcare may increase the uptake of HIV prevention, treatment and care among MSM.
Sexual Health 06/2015; 12(4). DOI:10.1071/SH15001 · 1.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Men who have sex with men (MSM) are more likely to be living with HIV than other adult men in low- and middle-income countries. MSM experience barriers to accessing HIV services including a lack of available specialized care, and community-level stigma and discrimination. This study aims to examine the uptake of HIV services at non-governmental and community-based organizations (NGOs/CBOs) to identify ways to improve coverage of HIV prevention and treatment among MSM.
An Integrated Biological and Behavioral Surveillance (IBBS) survey was conducted in Yaoundé and Douala, Cameroon in 2011 using the respondent driven sampling (RDS) method to recruit and interview 239 MSM in Yaoundé and 272 MSM in Douala.
MSM in Yaoundé were statistically significantly more likely to have accessed NGO/CBO services or been reached by an outreach worker in the past 12 months if they had any STI symptoms (aOR 2.17 CI 1.02-4.59. p=0.04), or if they had a larger MSM social network (aOR 1.02 CI 1.01-1.04. p<0.01). MSM in Douala were more likely to have accessed NGO/CBO services or been reached by an outreach worker in the past 12 months if they were living with HIV (aOR 3.60 CI 1.35-9.60. p=0.01), or if they reported higher numbers of male sexual partners (aOR 1.17 CI 1.00-1.36. p=0.046). Compared to men in Douala, MSM in Yaoundé were significantly less likely to have accessed NGO/CBO services or been reached by an outreach worker in the past 12 months (aOR 0.22 CI 0 .14-0.34. p=<0.01).
With appropriate funding and resources, community-based organizations that provide care specifically for MSM can improve access to HIV prevention, treatment, and care services. Additionally, using social networks to reach MSM can connect greater numbers of the population to effective HIV interventions, which will improve health outcomes and decrease onward transmission of HIV.
PLoS ONE 04/2015; 10(4):e0122881. DOI:10.1371/journal.pone.0122881 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Female sex workers (FSWs) in Cameroon, and West Africa generally, suffer a disproportionate burden of HIV. Although violence against FSWs has been documented extensively in other parts of the world, data on violence from West African countries are lacking. The aim of this study was to qualitatively document violence and harm reduction strategies from the perspective of FSWs in Cameroon as well as to understand how experiences of violence may increase FSWs' HIV risk.
FSWs from 7 major cities in Cameroon (Douala, Yaounde, Bamenda, Bertoua, Nagoundere, Kribi, and Bafoussam) were purposively recruited. Data from 31 in-depth interviews and 7 focus groups (n = 70; with some overlapping participants from in-depth interviews) conducted with these FSWs in 6 of these 7 cities (excluding Kribi) were analyzed using a grounded theory approach.
Transcripts revealed 3 primary themes related to violence: (1) sources and types of violence, including sexual, physical, and financial violence perpetrated by clients and police, (2) harm reduction strategies, including screening clients and safe work locations, receipt of payment before sexual act, and formation of an informal security network, and (3) recommendations on structural changes to reduce violence that emphasized sex work decriminalization and increased police accountability.
As in other parts of the world, violence against FSWs is pervasive in Cameroon. Interventions targeting violence and HIV must address the forms of violence cited locally by FSWs and can build on FSWs' existing strengths and harm reduction strategies. Structural changes are needed to ensure access to justice for this population.
[Show abstract][Hide abstract] ABSTRACT: Men who have sex with men (MSM) and female sex workers (FSW) are more likely to be living with HIV and experience difficulty accessing HIV health services due to stigma and discrimination. Antiretroviral treatment and sustained viral suppression among individuals living with HIV is the last step in the continuum of HIV care, which has been shown to improve health outcomes and decrease the risk of onward transmission of HIV.
To calculate the numerator and denominator for antiretroviral therapy (ART) coverage estimates among MSM and FSW living with HIV, the Priority Locations for AIDS Control Efforts methods were modified to include individual quantitative interviews, health service assessment and mapping, and size estimation in 7 cities in Cameroon. MSM and FSW were recruited using peer referral and venue-based sampling. The numerator was calculated from interviews with MSM and FSW. Population size estimation of MSM and FSW was used to determine the denominator.
Antiretroviral coverage varied by site from 0% to 25% among HIV infected MSM and FSW. ART provision to the general population was reported at a significantly greater proportion of HIV health centers (56.5%) than ART provision to MSM and FSW populations (13.2%).
The majority of MSM and FSW living with HIV and eligible for treatment in Cameroon are not connected to ART care. Additionally, ART provision for MSM and FSW at HIV health centers is insufficient. Characterizing effective strategies to reach optimal levels of engagement in the continuum of HIV care among MSM and FSW is essential for an AIDS-free generation for Cameroon.
[Show abstract][Hide abstract] ABSTRACT: HCV genotype 4 is prevalent in many African countries, yet little is known about the genotype׳s epidemic history on the continent. We present a comprehensive study of the molecular epidemiology of genotype 4. To address the deficit of data from the Democratic Republic of the Congo (DRC) we PCR amplified 60 new HCV isolates from the DRC, resulting in 33 core- and 48 NS5B-region sequences. Our data, together with genotype 4 database sequences, were analysed using Bayesian phylogenetic approaches. We find three well-supported intra-genotypic lineages and estimate that the genotype 4 common ancestor existed around 1733 (1650–1805). We show that genotype 4 originated in central Africa and that multiple lineages have been exported to north Africa since ~1850, including subtype 4a which dominates the epidemic in Egypt. We speculate on the causes of the historical intra-continental spread of genotype 4, including population movements during World War 2.
[Show abstract][Hide abstract] ABSTRACT: Background: Men who have sex with men in Cameroon consistently face significant stigma and discrimination. The urban HIV prevalence in MSM is estimated at 35% with limited provision and uptake of specific HIV care. This study investigates the effect of stigma, discrimination and alienation on Cameroonian MSM's engagement of the HIV treatment cascade.
Methods: Key informants interviews with allies, in-depth interviews with MSM, and focus groups with MSM were used. Participants in 6 cities were asked to describe the MSM social and structural context, MSM knowledge of existing HIV-related services in clinics, MSM-specific services and how to improve services.
Using a codebook, coded texts were analyzed for recurring themes that were developed into results.
Results: First, many MSM reported experiences of discrimination, bribery and physical violence outside the health care setting. In addition, they recounted instances of community-level stigma regarding same-sex practices.
Second, we investigated the MSM-specific HIV/AIDS services. Most participants observed limited clinical and cultural competency of clinic staff in addressing their needs.
Thirdly, MSM declared that there was a significant psychological toll on them due to the lack of social support and limited healthcare access. Several individuals recounted feelings of alienation and depression; their alienation greatly discouraged them from seeking HIV services.
Conclusions: Community-level and healthcare-related stigma impacts the mental well-being of Cameroonian MSM as well as the uptake of MSM-oriented HIV/AIDS services. These data suggest an MSM-sensitization, stigma-reduction intervention for Cameroonian health care and social workers. This intervention may increase the uptake of HIV services for Cameroonian MSM.
142nd APHA Annual Meeting and Exposition 2014; 11/2014
[Show abstract][Hide abstract] ABSTRACT: Despite recent declines in HIV incidence, sub-Saharan Africa remains the most heavily affected region in the global HIV/AIDS epidemic. Estimates of HIV prevalence in African military personnel are scarce and inconsistent.
We conducted a serosurvey between June and September 2007 among 4043 Armed Forces personnel of the Democratic Republic of Congo (FARDC) stationed in Kinshasa, Democratic Republic of Congo (DRC) to determine the prevalence of HIV and syphilis infections and describe associated risk behaviours. Participants provided blood for HIV and syphilis testing and responded to a demographic and risk factor questionnaire.
The prevalence of HIV was 3.8% and the prevalence of syphilis was 11.9%. Women were more likely than men to be HIV positive, (7.5% vs. 3.6% respectively, aOR: 1.66, 95% C.I: 1.21-2.28, p < 0.05). Factors significantly associated with HIV infection included gender and self-reported genital ulcers in the 12 months before date of enrollment.
The prevalence of HIV in the military appears to be higher than the general population in DRC (3.8% vs. 1.3%, respectively), with women at increased risk of infection.
International Journal of STD & AIDS 05/2014; 26(3). DOI:10.1177/0956462414533672 · 1.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Of the seven known species of human retroviruses only one, human T-cell lymphotropic virus type 4 (HTLV-4), lacks a known animal reservoir. We report the largest screening for simian T-cell lymphotropic virus (STLV-4) to date in a wide range of captive and wild non-human primate (NHP) species from Cameroon. Among the 681 wild and 426 captive NHPs examined, we detected STLV-4 infection only among gorillas by using HTLV-4-specific quantitative polymerase chain reaction. The large number of samples analyzed, the diversity of NHP species examined, the geographic distribution of infected animals relative to the known HTLV-4 case, as well as detailed phylogenetic analyses on partial and full genomes, indicate that STLV-4 is endemic to gorillas, and that rather than being an ancient virus among humans, HTLV-4 emerged from a gorilla reservoir, likely through the hunting and butchering of wild gorillas. Our findings shed further light on the importance of gorillas as keystone reservoirs for the evolution and emergence of human infectious diseases and provide a clear course for preventing HTLV-4 emergence through management of human contact with wild gorillas, the development of improved assays for HTLV-4/STLV-4 detection and the ongoing monitoring of STLV-4 among gorillas and for HTLV-4 zoonosis among individuals exposed to gorilla populations.
[Show abstract][Hide abstract] ABSTRACT: Introduction
Despite men who have sex with men (MSM) being a key population for HIV programming globally, HIV epidemiologic data on MSM in Central Africa are sparse. We measured HIV and syphilis prevalence and the factors associated with HIV infection among MSM in Cameroon.
Two hundred and seventy-two and 239 MSM aged ≥18 from Douala and Yaoundé, respectively, were recruited using respondent-driven sampling (RDS) for this cross-sectional surveillance study in 2011. Participants completed a structured questionnaire and HIV and syphilis testing. Statistical analyses, including RDS-weighted proportions, bootstrapped confidence intervals and logistic regressions, were used.
Crude and RDS-weighted HIV prevalence were 28.6% (73/255) and 25.5% (95% CI 19.1–31.9) in Douala, and 47.3% (98/207) and 44.4% (95% CI 35.7–53.2) in Yaoundé. Active syphilis prevalence in total was 0.4% (2/511). Overall, median age was 24 years, 62% (317/511) of MSM identified as bisexual and 28.6% (144/511) identified as gay. Inconsistent condom use with regular male partners (64.1%; 273/426) and casual male and female partners (48.5%; 195/402) was common, as was the inconsistent use of condom-compatible lubricants (CCLs) (26.3%; 124/472). In Douala, preferring a receptive sexual role was associated with prevalent HIV infection [adjusted odds ratio (aOR) 2.33, 95% CI 1.02–5.32]. Compared to MSM without HIV infection, MSM living with HIV were more likely to have ever accessed a health service targeting MSM in Douala (aOR 4.88, 95% CI 1.63–14.63). In Yaoundé, MSM living with HIV were more likely to use CCLs (aOR 2.44, 95% CI 1.19–4.97).
High HIV prevalence were observed and condoms and CCLs were used inconsistently indicating that MSM are a priority population for HIV prevention, treatment and care services in Douala and Yaoundé. Building the capacity of MSM community organizations and improving the delivery and scale-up of multimodal interventions for MSM that are sensitive to concerns about confidentiality and the complex individual, social, community-level and policy challenges are needed to successfully engage young MSM in the continuum of HIV care. In addition to scaling up condom and CCL access, evaluating the feasibility of novel biomedical interventions, including antiretroviral pre-exposure prophylaxis and early antiretroviral therapy for MSM living with HIV in Cameroon, is also warranted.
Journal of the International AIDS Society 12/2013; 16(4(Suppl 3)-4 Suppl 3):18752. DOI:10.7448/IAS.16.4.18752 · 5.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The prevalence and genetic diversity of hepatitis C virus (HCV) and human pegivirus (HPgV) in many regions of sub-Saharan Africa is poorly characterized, including in the Democratic Republic of Congo - the largest country in the region and one of the most populous. To address this situation we conducted a molecular epidemiological survey of HCV and HPgV (previously named GB Virus C or hepatitis G virus) in samples collected in 2007 from 299 males from the DRC, whose ages ranged from 21 to 71years old. Samples were tested for the presence of HCV antibodies by ELISA reactive samples were subsequently tested for HCV RNA using RT-PCR in which both the HCV Core and NS5B genome regions were amplified. Remaining samples were tested for HPgV RNA and the HPgV NS3 genome region of positive samples was amplified. For HCV, 13.7% of the samples were seropositive (41/299) but only 3.7% were viremic (11/299). HPgV RNA was found in 12.7% (33/259) of samples. HCV viremia was strongly associated with age; the percentage of samples that contained detectable HCV RNA was ∼0.5% in those younger than 50 and 13% in those older than 50. Our study represents the first systematic survey of HCV genetic diversity in the DRC. HCV sequences obtained belonged to diverse lineages of genotype 4, including subtypes 4c, 4k, 4l and 4r, plus one unclassified lineage that may constitute a new subtype. These data suggest that HCV in the DRC exhibits an age 'cohort effect', as has been recently reported in neighbouring countries, and are consistent with the hypothesis that HCV transmission rates were higher in the mid-twentieth century, possibly as a result of parenteral, iatrogenic, or other unidentified factors. Different HCV subtypes were associated with individuals of different ages, implying that HCV infection in the DRC may have arisen through multiple separate HCV epidemics with different causes.
Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 02/2013; 19. DOI:10.1016/j.meegid.2013.01.021 · 3.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Zoonotic transmission of simian retroviruses in Central Africa is ongoing and can result in pandemic human infection. While simian foamy virus (SFV) infection was reported in primate hunters in Cameroon and Gabon, little is known about the distribution of SFV in Africa and whether human-to-human transmission and disease occur. We screened 3,334 plasmas from persons living in rural villages in central Democratic Republic of Congo (DRC) using SFV-specific EIA and Western blot (WB) tests. PCR amplification of SFV polymerase sequences from DNA extracted from buffy coats was used to measure proviral loads. Phylogenetic analysis was used to define the NHP species origin of SFV. Participants completed questionnaires to capture NHP exposure information.
Sixteen (0.5%) samples were WB-positive; 12 of 16 were from women (75%, 95% confidence limits 47.6%, 92.7%). Sequence analysis detected SFV in three women originating from Angolan colobus or red-tailed monkeys; both monkeys are hunted frequently in DRC. NHP exposure varied and infected women lived in distant villages suggesting a wide and potentially diverse distribution of SFV infections across DRC. Plasmas from 22 contacts of 8 WB-positive participants were all WB negative suggesting no secondary viral transmission. Proviral loads in the three women ranged from 14 – 1,755 copies/105 cells.
Our study documents SFV infection in rural DRC for the first time and identifies infections with novel SFV variants from Colobus and red-tailed monkeys. Unlike previous studies, women were not at lower risk for SFV infection in our population, providing opportunities for spread of SFV both horizontally and vertically. However, limited testing of close contacts of WB-positive persons did not identify human-to-human transmission. Combined with the broad behavioral risk and distribution of NHPs across DRC, our results suggest that SFV infection may have a wider geographic distribution within DRC. These results also reinforce the potential for an increased SFV prevalence throughout the forested regions of Africa where humans and simians co-exist. Our finding of endemic foci of SFV infection in DRC will facilitate longitudinal studies to determine the potential for person-to-person transmissibility and pathogenicity of these zoonotic retroviral infections.
[Show abstract][Hide abstract] ABSTRACT: Hepatitis B virus (HBV) infections are widely distributed in humans, infecting approximately one third of the world's population. HBV variants have also been detected and genetically characterised from Old World apes; Gorilla gorilla (gorilla), Pan troglodytes (chimpanzee), Pongo pygmaeus (orang-utan), Nomascus nastusus and Hylobates pileatus (gibbons) and from the New World monkey, Lagothrix lagotricha (woolly monkey). To investigate species-specificity and potential for cross species transmission of HBV between sympatric species of apes (such as gorillas and chimpanzees in Central Africa) or between humans and chimpanzees or gorillas, variants of HBV infecting captive wild-born non-human primates were genetically characterised. 9 of 62 chimpanzees (11.3%) and two from 11 gorillas (18%) were HBV-infected (15% combined frequency), while other Old world monkey species were negative. Complete genome sequences were obtained from six of the infected chimpanzee and both gorillas; those from P. t .ellioti grouped with previously characterised variants from this subspecies. However, variants recovered from P. t. troglodytes HBV variants also grouped within this clade, indicative of transmission between sub-species, forming a paraphyletic clade. The two gorilla viruses were phylogenetically distinct from chimpanzee and human variants although one showed evidence for a recombination event with a P.t.e.-derived HBV variant in the partial X and core gene region. Both of these observations provide evidence for circulation of HBV between different species and sub-species of non-human primates, a conclusion that differs from the hypothesis if of strict host specificity of HBV genotypes.
PLoS ONE 03/2012; 7(3):e33430. DOI:10.1371/journal.pone.0033430 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hunting and butchering of wildlife in Central Africa are known risk factors for a variety of human diseases, including HIV/AIDS. Due to the high incidence of human exposure to body fluids of non-human primates, the significant prevalence of simian immunodeficiency virus (SIV) in non-human primates, and hunting/butchering associated cross-species transmission of other retroviruses in Central Africa, it is possible that SIV is actively transmitted to humans from primate species other than mangabeys, chimpanzees, and/or gorillas. We evaluated SIV transmission to humans by screening 2,436 individuals that hunt and butcher non-human primates, a population in which simian foamy virus and simian T-lymphotropic virus were previously detected. We identified 23 individuals with high seroreactivity to SIV. Nucleic acid sequences of SIV genes could not be detected, suggesting that SIV infection in humans could occur at a lower frequency than infections with other retroviruses, including simian foamy virus and simian T-lymphotropic virus. Additional studies on human populations at risk for non-human primate zoonosis are necessary to determine whether these results are due to viral/host characteristics or are indicative of low SIV prevalence in primate species consumed as bushmeat as compared to other retroviruses in Cameroon.
[Show abstract][Hide abstract] ABSTRACT: To estimate population exposure of apes and Old World monkeys in Africa to enteroviruses (EVs), we conducted a seroepidemiologic study of serotype-specific neutralizing antibodies against 3 EV types. Detection of species A, B, and D EVs infecting wild chimpanzees demonstrates their potential widespread circulation in primates.
[Show abstract][Hide abstract] ABSTRACT: Between January 2010 and February of 2011, surveillance was conducted among patients with influenza-like illness (ILI). 1,837 patients of all ages presenting with ILI at 37 clinics and hospitals in 3 regions of Cameroon (Center, South and East) were included. Demographic information and symptoms were recorded for each patient. Participants provided either a nasopharyngeal or throat swab which was screened by real-time PCR for influenza viruses prior to virus isolation. Data was analyzed using STATA 11. As of February 2011, 98.2% of the samples have been tested. 17.8% were positive for influenza. 9.8% were Influenza B. H1N1 and H3N2 accounted for 5.7% and 2.4% of samples tested, respectively. 89.4% of influenza samples collected between March September 2010 were Influenza B. 92.7% of flu samples collected between October 2010 January 2011 were Influenza A viruses. Between November 2010 January 2011, H1N1 accounted for 84.6% of the influenza positive samples for the 3 month period. 61.2% of influenza positives for September and October of 2010 were H3N2. Influenza B patients reported 27.3% more acute symptoms as compared to H3N2 patients and 16.7% more acute symptoms than H1N1 patients. This study points to seasonal trends of influenza by subtype in Cameroon. Continued surveillance is necessary to determine if this trend is observed annually, and surveillance should be expanded to include more regions of Cameroon. Some patients reported receiving influenza vaccine and presenting with ILI shortly thereafter. Research into the efficacy of the vaccine and subtypes circulating in Cameroon is imperative.
139st APHA Annual Meeting and Exposition 2011; 11/2011
[Show abstract][Hide abstract] ABSTRACT: African tick-bite fever is an emerging infectious disease caused by the spotted fever group Rickettsia, Rickettsia africae, and is transmitted by ticks of the genus Amblyomma. To determine the seroprevalence of exposure to R. africae and risk factors associated with infection, we conducted a cross-sectional study of persons in seven rural villages in distinct ecological habitats of Cameroon. We examined 903 plasma samples by using an indirect immunofluorescence assay for antibodies to R. africae and analyzed demographic and occupational data collected from questionnaires. Of the 903 persons tested, 243 (26.9%) had IgG/IgM/IgA reactive with R. africae. Persons from four of the seven village sites were significantly more likely to be seropositive (P < 0.05), and lowland forest sites tended to have higher seroprevalences. These results suggest that African tick-bite fever is common in adults in rural areas of Cameroon and that ecological factors may play a role in the acquisition of R. africae infection.
The American journal of tropical medicine and hygiene 04/2011; 84(4):608-13. DOI:10.4269/ajtmh.2011.10-0191 · 2.70 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Data on the evolution of natural SIV infection in chimpanzees (SIVcpz) and on the impact of SIV on local ape populations are only available for Eastern African chimpanzee subspecies (Pan troglodytes schweinfurthii), and no data exist for Central chimpanzees (Pan troglodytes troglodytes), the natural reservoir of the ancestors of HIV-1 in humans. Here, we report a case of naturally-acquired SIVcpz infection in a P.t.troglodytes chimpanzee with clinical and biological data and analysis of viral evolution over the course of infection.
A male chimpanzee (Cam155), 1.5 years, was seized in southern Cameroon in November 2003 and screened SIV positive during quarantine. Clinical follow-up and biological analyses have been performed for 7 years and showed a significant decline of CD4 counts (1,380 cells/mm³ in 2004 vs 287 in 2009), a severe thrombocytopenia (130,000 cells/mm³ in 2004 vs 5,000 cells/mm³ in 2009), a weight loss of 21.8% from August 2009 to January 2010 (16 to 12.5 kg) and frequent periods of infections with diverse pathogens.DNA from PBMC, leftover from clinical follow-up samples collected in 2004 and 2009, was used to amplify overlapping fragments and sequence two full-length SIVcpzPtt-Cam155 genomes. SIVcpzPtt-Cam155 was phylogenetically related to other SIVcpzPtt from Cameroon (SIVcpzPtt-Cam13) and Gabon (SIVcpzPtt-Gab1). Ten molecular clones 5 years apart, spanning the V1V4 gp120 env region (1,100 bp), were obtained. Analyses of the env region showed positive selection (dN-dS >0), intra-host length variation and extensive amino acid diversity between clones, greater in 2009. Over 5 years, N-glycosylation site frequency significantly increased (p < 0.0001).
Here, we describe for the first time the clinical history and viral evolution of a naturally SIV infected P.t.troglodytes chimpanzee. The findings show an increasing viral diversity over time and suggest clinical progression to an AIDS-like disease, showing that SIVcpz can be pathogenic in its host, as previously described in P.t.schweinfurthii. Although studying the impact of SIV infection in wild apes is difficult, efforts should be made to better characterize the pathogenicity of the ancestors of HIV-1 in their natural host and to find out whether SIV infection also plays a role in ape population decline.