Identification of rare HIV-1 Group N, HBV AE, and HTLV-3 strains in rural South Cameroon.

Surveillance of emerging viral variants is critical to ensuring that blood screening and diagnostic tests detect all infections regardless of strain or geographic location. In this study, we conducted serological and molecular surveillance to monitor the prevalence and diversity of HIV, HBV, and HTLV in South Cameroon. The prevalence of HIV was 8.53%, HBV was 10.45%, and HTLV was 1.04% amongst study participants. Molecular characterization of 555 HIV-1 specimens identified incredible diversity, including 7 subtypes, 12 CRFs, 6 unclassified, 24 Group O and 2 Group N infections. Amongst 401 HBV sequences were found a rare HBV AE recombinant and two emerging sub-genotype A strains. In addition to HTLV-1 and HTLV-2 strains, sequencing confirmed the fifth known HTLV-3 infection to date. Continued HIV/HBV/HTLV surveillance and vigilance for newly emerging strains in South Cameroon will be essential to ensure diagnostic tests and research stay a step ahead of these rapidly evolving viruses.

[Tungiasis in Bangou (West Cameroon)]. / Étude de la tungose à Bangou (Cameroun Ouest).

Tungiasis is an ectoparasitosis caused by penetration into the skin of the sand or chigger flea, Tunga penetrans. The epidemiology in Cameroon of this disease, often associated with poverty, is unknown. Accordingly, in August 2008, we conducted a study in Bangou, in Western Cameroon, among a sample of 403 people, divided in 111 families. All data were collected and analyzed with Epi-Info 6.4 software. The prevalence in this population was 32.7%, with infestation more frequent in males (P = 0.013), mostly in children aged 1 to 5 years. The most frequent clinical features were simple inflammatory lesions (100%), infected lesions (2.27%) and necrosis (0.75%). Most patients had a moderate infestation (86.4%), lived in houses with mud floors and brick walls (OR = 2.57; 95%CI [1.67-3.96]), and had animals (dogs) in the household. The principal risk factors were sex- and age-related: boys younger than 15 years old (OR = 5.40; 95%CI [3.20-9.12]) and schoolchildren (OR = 2.57; 95%CI [1.67-3.96]). The main sequelae were toenail deformations (34%).

Impact of HIV-1infection on survival in patients with haematological malignancies in Yaoundeé, Cameroon.

The impact of HIV-1 infection on the survival of patients with haematological cancers in Yaoundeé, Cameroon, was examined. The prevalence of HIV-1 was 26.2% among 172 patients, predominantly lymphoid malignancies. At the time of analysis, 75% of patients had died giving an incidence rate of 0.05 deaths per year and a median of survival of 15 (6-27) months. However, the hazard ratio for HIV-infected patients to die was not statistically different from that of uninfected patients (1.3, 95% confidence interval: 0.9-2.0).

[Factors associated with thrombocytopenia among pregnant women in Cameroon]. / Facteurs associés aux thrombocytopénies chez les femmes enceintes au Cameroun.

To determine the factors associated with thrombocytopenia among pregnant women in Cameroon, this cross-sectional survey studied 1124 pregnant women aged 15-40 years (mean: 25.35+/-5.48) attending antenatal clinics at two hospitals in Yaoundé. Each woman underwent a thorough medical interview and clinical examination and complete blood count to diagnose anaemia and thrombocytopenia (platelets<150x10(9)/L). When thrombocytopenia was identified, a battery of other tests followed: standard coagulation screening tests, HIV screening, and thick and thin blood films to identify blood parasites. The prevalence of thrombocytopenia was 8.9% (N=100). While a prolonged bleeding time was noted in 20% of women with thrombocytopenia, the Quick test (prothrombin time) and kaolin-cephalin clotting time were normal in all of them. The major factors associated with thrombocytopenia were anaemia (29.8%), history of intermenstrual bleeding (25.7%), history of preeclampsia (23.3%), current hypertensive disorders (23.2%), malaria (22.3%), HIV infection (21.0%) and the absence of antimalaria prophylaxis (16.2%). Thrombocytopenia was not significantly associated with third-trimester bleeding (P=0.57) or with a history of postpartum haemorrhage (P=0.06).

Superficial mycoses and HIV infection in Yaounde.

The incidence of superficial infections in patients with human immunodeficiency virus (HIV) is increasing in Yaounde. To determine the prevalence of superficial mycoses in HIV-positive subjects, a study was carried out in different hospital settings in Yaounde over a period of 18 months. Clinical observations were followed by the culture of samples on Sabouraud's glucose agar. Of the 148 HIVab-positive patients examined, 79 (44 males and 35 females) had at least one superficial mycosis (53%). The clinical presentations and the causative organisms did not differ from those found in immunocompetent individuals. The main lesions were oral candidiasis (77%), tinea corporis (21%), tinea versicolor (15%), tinea pedis (13%) and tinea inguium (12%). Trichophyton rubrum and Candida albicans were the organisms most commonly isolated. These results indicate the benefit of studying superficial mycoses for optimal management of HIV patients.

Increased HIV prevalence among individuals attending a sexually transmitted infection clinic in Yaounde, Cameroon.

Monitoring HIV prevalence among selected groups provides important data on infection trends. The present study assessed current HIV prevalence and risk correlates among 255 men and women consecutively attending a sexually transmitted infection clinic in Yaounde, Cameroon. Prevalence of 21.96% and 5.5% were found for HIV and syphilis, respectively, with a significant correlation between the two infections. Although marriage was not a significant predictor for HIV, married men were twice as likely as unmarried men to be infected; no such difference was observed for women. Inconsistent condom use was positively, but not significantly, associated with HIV. Also, age, education, and number of sex partners were not significant correlates of HIV infection. Compared to data collected in 1997, HIV prevalence in this clinic has increased nearly 6%. Our findings highlight the increasing spread of HIV infection in Cameroon and the need for additional control strategies to curb the epidemic.

HIV-1 infection in adults with haematological malignancies in Yaoundé, Cameroon.

To determine the association between haematological malignancies and the HIV-1 in Yaoundé, Cameroon, adult patients (> 16 years) followed up in the Haematology Clinics of two major hospitals were screened for the HIV between 1994 and 1999. There were nine haematological malignancies diagnosed among the 172 patients including Non Hodgkin's lymphomas (31.9%); chronic lymhocytic leukaemia (21.5%); chronic myelogeneous leukaemia (18.0%); acute myelogeneous leukaemia (9.9%); acute lymphoblastic leukaemia (7.6%) and multiple myeloma (7.0%). Burkitt's lymphoma, Hodgkin's disease and myelodysplastic syndrome were less frequently diagnosed. Forty-five of all cases (26.2%) had antibodies to the HIV-1 virus, predominantly in patients with Non-Hodgkin's lymphomas (p < 0,001, OR = 5.8, adjusted for age; CI = 2.7 - 12.4). About 19.4% and 11.8% of cases with chronic and acute myelogenous leukaemia respectively were HIV-1 positive. Although B-lineage-derived malignancies are more often associated with the HIV infection, other malignant proliferations of the haematopoietic system may not be coincidental.

Naturally occurring sequence polymorphisms within HIV type 1 group O protease.

Mutations within the protease gene associated with reduced susceptibility to protease inhibitors have been well documented for HIV-1 group M subtype B strains. In contrast, limited genotypic and phenotypic information is available for the genetically diverse HIV-1 group O strains. Preexisting resistance-associated polymorphisms have the potential to contribute to a poor virological response to antiviral drug treatment in group O-infected patients. In the present study, the protease genes of 28 protease inhibitor-naive HIV-1 group O-infected patients were analyzed to identify any naturally occurring amino acid polymorphisms associated with drug resistance. Comparison of the consensus group O protease sequence with subtype B of group M indicated that both groups have almost identical sequences in the protease active site, the flap and the substrate-binding site. Analysis of the 28 individual protease sequences revealed polymorphisms at 34% of the positions within the protease gene, but no primary mutations associated with protease inhibitor resistance. In contrast, each of the strains harbored multiple secondary or accessory mutations associated with resistance to protease inhibitors in group M viruses. Residues 10I, 15V, 36I, 41K, 62V, 63T/A/K/I, 64V, 71V, and 93L were identified in most strains. The presence of multiple natural sequence polymorphisms associated with drug resistance in the protease gene of group O viruses may contribute to a more rapid emergence of drug resistance phenotype and treatment failure in group O-infected patients.

Natural infection of wild-born mandrills (Mandrillus sphinx) with two different types of simian immunodeficiency virus.

We found a novel primate lentivirus in mandrill (Mandrillus sphinx). To clarify the evolutionary relationships and transmission patterns of human/simian immunodeficiency virus (HIV/SIV), we screened blood samples from 30 wild-born healthy Cameroonian mandrills. Five (16.7%) of them were seropositive for SIV. Three SIV strains were isolated from the five seropositive mandrills by cocultivation of their peripheral blood mononuclear cells (PBMCs) with PBMCs of rhesus macaques, a human T cell line (M8166), and/or a cynomolgus macaque T cell line (HSC-F). One of the newly isolated SIV strains was intravenously inoculated into two rhesus macaques and resulted in chronic infection. In the SIV-infected macaques at 45 weeks after inoculation, we observed a mild decline in the number of peripheral CD4(+) lymphocytes, lymphadenopathy, and blastic follicular dendritic cells with mild follicular hyperplasia in the peripheral lymph nodes. A phylogenetic analysis based on the pol sequence showed that the newly found SIVs from Cameroonian mandrills did not cluster with SIVmndGB1, which is the former representative strain of SIVmnd. The SIVmnds from Cameroon formed a new, independent lineage that branched before the root of the HIV-1/SIVcpz lineage with 996 of 1000 bootstrap replications. They clustered host specifically, and exhibited about 16.9% diversity at the level of nucleotide sequence among Cameroonian SIVmnd strains. These results indicate that the SIVmnds isolated in Cameroon are a novel type of SIVmnd and have infected Cameroonian mandrills for a long time. We therefore designated the Cameroonian SIVmnd as SIVmnd type 2 and redesignated SIVmndGB1 as SIVmnd type 1. To date, M. sphinx is the only primate species other than humans that is naturally infected with two different types of SIV.

Transfusion outcome in a resource-limited setting of Cameroon: a five-year evaluation.

OBJECTIVE: With a goal to establish strategies for improving blood safety in resource-limited conditions, the outcome of blood transfusion in a hospital setting of Cameroon was examined. METHODS: A 5-year descriptive and prospective study was conducted in which information on donor blood and recipients was obtained by direct patient observation and by examining patient notes in the various services of the hospital and records from the blood bank. RESULTS: Of 40,134 donations, 35,318 (88%) were from relatives or friends of recipients. Only 80% of all donated blood was considered safe for distribution. An average of about 20% of donated blood was rejected each year for positive human immunodeficiency virus (HIV) or hepatitis B antigen results. Other infections were not screened for. More than 50% of transfusions within the hospital were associated with an unfavorable outcome, predominantly febrile reactions and urticaria (40.1% and 19.4%, respectively). Acute intravascular hemolysis, circulatory overload, and deaths occurred in 0.01%, 0.04%, and 0.14% of cases, respectively. A case of post-transfusion HIV infection was also detected. CONCLUSIONS: Blood transfusion is still unsafe in many resource-limited communities of developing countries. However, it is possible to reduce some of these complications without sophisticated technology. Efforts to recruit more benevolent and autologous donors in the communities are essential.

The peopling of sub-Saharan Africa: the case study of Cameroon.

This study analyzes the distribution of ten protein genetic polymorphisms in eighteen populations from the most densely inhabited areas of Cameroon. The languages spoken belong to three different linguistic families [Afro-Asiatic (AA), Nilo-Saharan (NS) and Niger-Kordofanian (NK)]. The analysis of variation of allele frequencies indicates that the level of genetic interpopulation differentiation is rather low (F(st) = 0.011 +/- 0.006) but statistically significant (p < 0.001). This result is not unexpected because of the relatively small geographic area covered by our survey. This value is also significantly lower than the one estimated for other groups of African populations. Among the factors responsible for this, we discuss the possible role of gene flow. There is a considerable genetic differentiation among the AA populations of north Cameroon as is to be expected because they all originated from the first agriculturists of the farming "savanna complex." The Podowko and Uldeme are considerably different from all the other AA groups, probably due to the combined effect of genetic drift and isolation. In the case of the Wandala and Massa, our analyses suggest that genetic admixture with allogeneous groups (especially with the Kanuri) played an important role in determining their genetic differentiation from other AA speaking groups. The Bantu speaking populations (Bakaka, Bamileke Bassa and Ewondo, NK family, Benué Congo subfamily) settled in western and southern Cameroon are more tightly clustered than AA speaking groups. This result shows that the linguistic affinity among these four populations coincides with a substantial genetic similarity despite their different origin. Finally, the Fulbe are genetically distinct from all the populations that belong to their same linguistic phylum (NK), and closer to the neighboring Fali and Tupuri, eastern Adamawa speaking groups of north Cameroon.

HIV type 1 genetic variability in the northern part of Cameroon.

In 1995, 53 blood samples from Muslim patients with AIDS, or who were thought to have AIDS, were collected in the main hospitals of Adamaoua Province, in the northern part of Cameroon. The variable env C2V3 region of HIV-1 was amplified by nested PCR and phylogenetically analyzed. The results indicated that of 15 amplified samples, 1 belonged to HIV-1 group O, 1 to HIV-1 subtype D, 1 to subtype G, 2 to subtype H, and 10 to subtype A. Furthermore, the northern Cameroonian subtype A could be divided into at least two subclusters as shown by the env tree as well as by two remarkably conserved hexameric amino acid sequences in the apex of V3 (GPGQAF in one subcluster and GPGQTF in the other). This distinction suggests that the HIV-1 subtype A circulating in northern Cameroon evolved from two main sources. More recently, three HIV-1 strains from Nigeria (IBNG) and Djibouti (DJ263 and DJ264), previously reported on the basis of their env C2V3 sequences as subtype A, were found to have a similar A/G mosaic structure alongside their full-length sequence and were tentatively designated as members of a new subtype called "IBNG." Interestingly, within the northern Cameroonian subtype A described, the isolates of the second subcluster clustered distinctly with these A/G mosaic strains, strongly suggesting that they may be members of the IBNG subtype.

Coreceptor requirements of primary HIV type 1 group O isolates from Cameroon.

HIV-1 group O has its epicenter in Cameroon and neighboring countries and is responsible for 3 to 5% of all HIV infections in this region. It is believed that HIV-1 group O was introduced into the human population by a separate cross-species transmission, occurring independently of the HIV-1 (group M and group N) and HIV-2 transmissions. We have studied the coreceptor requirements of 12 primary HIV-1 O-type isolates from individuals with different clinical symptoms. Only 2 of these 12 viruses showed a syncytium-inducing phenotype after infection of primary peripheral blood mononuclear cells (PBMCs) and were infectious for the T cell line C8166. These isolates used CXCR4 as a coreceptor for entry, whereas the remaining isolates used only CCR5 efficiently. One isolate was able to use BOB and CCR8 as coreceptors in addition to CXCR4. All group O isolates tested were efficiently inhibited by SDF-1 or RANTES, the natural ligands of CXCR4 and CCR5, respectively. These results indicate that CXCR4 and CCR5 are the principal coreceptors for HIV-1 O-type viruses. Most of the HIV-1 group O isolates studied were derived from patients at later stages of the disease. Although HIV-1 group O and group M infections do not differ in their pathogenesis, the studied isolates did not evolve to use a broad range of coreceptors as described for HIV-1 group M and HIV-2.

Genetic diversity of HIV-1 group M from Cameroon and Republic of Congo.

We analyzed 57 HIV-1 isolates from Cameroon and the Republic of Congo, with respect to the env C2V3 and/or the pol integrase regions. The results indicated that the topology of the pol tree correlated well with that of the env tree for four clusters of subtype D, F G and H, suggesting that these trees reflect the true evolution of the overall genome structures of these subtypes. However, of 22 Cameroonian isolates that were classified as subtype A based on env, 20 of them diverged in their pol sequence into two lineages that were completely different from the prototypical subtype A, tentatively designated as subtypes A1 and A2. The subtype A1 isolates (6 out of 22) were related in their env C2V3 regions with prototypical subtype A strain, but in their pol regions, they formed an independent cluster that diverged from known HIV-1 subtypes so far reported (except for subtypes I and J). The subtype A2 isolates (14 out of 22), which represent the major epidemic type of HIV-1 in Cameroon, clustered distinctly in both the env and pol trees with the recently described A/G mosaic strains from Nigeria and Djibouti. These two lineages were not spreading in the neighboring Republic of Congo.

Various types of HIV mixed infections in Cameroon.

In order to assess the incidence of HIV mixed infection as well as to clarify the molecular epidemiology of HIV in central Africa, we investigated 43 HIVs obtained from 211 Cameroonian AC, ARC, and AIDS patients in 1994 and 1995. Part of the pol region and part of the env region were phylogenetically analyzed. The genotypes observed were varied: of 43 specimens, 28 (65%) were subtype A, 1 (2%) was subtype B, 2 (5%) were subtype D, 3 (7%) were subtype F, and 2 (5%) were group O. Of the remaining 7 specimens, 3 were mixed infections with HIV-1 subtypes A and C, HIV-1 subtypes C and F, and HIV-2 subtype A and HIV-1 subtype A; 1 was a mixed infection with HIV-1 subtypes A and D and the highly divergent group O (triple infection); another 3 appeared to consist of mosaic genomes (A/G, A/E, and B/A recombinant). These data show that various types of mixed infection, such as between different subtypes of HIV-1 group M, between HIV-1 and HIV-2, and even between HIV-1 groups O and M, were confirmed at a rather high frequency (approximately 10%). The mixed infection is particularly significant where there is a greater variety of HIV-1 subtypes circulating, since it results in new genetic diversity generated by intersubtype recombination.

African origin of GB virus C/hepatitis G virus.

Ninety-four GB virus C/hepatitis G virus (GBV-C/ HGV) RNA-positive serum samples were obtained from all over the world. We found that all 15 GBV-C/HGV isolates from the Pygmies and the Bantu in the Central African region had a 12-amino acid indel (i.e. insertion or deletion) in the non-structural protein (NS) 5A region. Phylogenetic analyses of the NS5A region, using GBV-A as an outgroup, showed that these 15 isolates had diverged from the common ancestor much earlier than the remaining isolates, indicating an African origin of GBV-C/HGV.

Diversity of the immunodominant epitope of gp41 of HIV-1 subtype O and its validity for antibody detection.

The immunodominant regions of the gp41 from 13 HIV-1 subtype O strains from Cameroon, 11 from France and one from Germany were sequenced. The amino acid sequences were compared to those of the 3 published HIV-1 subtype O isolates, ANT70, MVP-5180 and VAU. All HIV-1 subtype O isolates had a very conserved amino acid sequence in this region and showed a subtype O specific structure. Within the cysteine loop there was a positive charge of two basic amino acids, arginine and lysine. Only two strains (CM.6778 and CM.8161) showed an acidic amino acid in this loop. None of the isolates showed the same amino acid sequence in this immunodominant region. A 25 residue peptide from the immunodominant domain of gp41 of the MVP-5180 strain was synthesized, cycled to form the cysteine-loop and coated to microtiter plates. Antibody binding was detected by indirect ELISA using an enzyme labeled anti-human IgG. Out of 111 anti-HIV-1 positive specimens, collected mainly from Cameroonian HIV infected patients, only 10 were not reactive in this assay. The 42 anti-HIV-1 subtype O positive specimens gave all a reaction above cut off. Despite the diversity found in the amino acid sequences within the 25 isolates a peptide-based indirect ELISA representing the immunodominant epitope of the strain MVP-5180 successfully detected all the anti-HIV-O sera so far tested, pointing to the importance of adding such a peptide for correct identification of HIV-1 subtype O infected patients, while some assays without HIV-O specific antigens partially fail to detect all anti-HIV-O specimens.