Transmission of hepatitis C virus among spouses in Cameroon and the Central African Republic.

Heterosexual transmission of hepatitis C virus (HCV) is uncommon, with few studies undertaken in Central Africa. To determine the frequency of inter-spouse HCV transmission, cross-sectional studies of elderly individuals in Ebolowa, Cameroon and Nola, Central African Republic, in which, respectively, 24 and 83 long-term couples had been identified, were examined further. Blood samples were tested for antibody to HCV. Anti-HCV positive samples were genotyped by phylogenetic analysis of a fragment of the NS5B gene. In Nola, 4 out of 9 (44.4%) wives of anti-HCV positive husbands and 1 out of 74 (1.4%) wives of anti-HCV negative husbands were anti-HCV positive (P < 0.001); in Ebolowa, the corresponding proportions were 10 out of 15 (66.7%) and 3 out of 9 (33.3%) (P = 0.21). After adjustment for age and site-specific risk factors of HCV infection, HCV seropositivity of the wives remained associated with their husbands' HCV serostatus, significantly so in Nola (P = 0.003) and marginally in Ebolowa (P = 0.06). In 7 out of 14 concordant seropositive couples, the genotype could be determined in both spouses. Four couples were infected with different genotypes, while three were infected with the same genotype. Thus, serological concordance between the spouses was related to a combination of infections acquired independently and inter-spouse transmission. It could not be determined whether inter-spouse transmission occurred sexually, through blood-blood contact, or otherwise. Inter-spouse transmission may have contributed to the high prevalence among elderly populations of Central Africa since some patients infected during healthcare subsequently transmitted the virus to their spouse.

Iatrogenic transmission of human T cell lymphotropic virus type 1 and hepatitis C virus through parenteral treatment and chemoprophylaxis of sleeping sickness in colonial Equatorial Africa.

BACKGROUND: The simultaneous emergence of human immunodeficiency virus (HIV)-1 group M and HIV-2 into human populations, circa 1921-1940, is attributed to urbanization and changes in sexual behavior. We hypothesized that the initial dissemination of HIV-1, before sexual transmission predominated, was facilitated by the administration, via reusable syringes and needles, of parenteral drugs against tropical diseases. As proxies for highly lethal HIV-1, we investigated risk factors for hepatitis C virus (HCV) and human T cell lymphotropic virus 1 (HTLV-1) infections, blood-borne viruses compatible with prolonged survival, in an area known in 1936-1950 as the most virulent focus of African trypanosomiasis. METHODS: Cross-sectional survey of individuals 55 years and older in Mbimou land and Nola, Central African Republic. Dried blood spots were used for HCV and HTLV-1 serologic testing and nucleic acid detection. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were measured by logistic regression. RESULTS: The only risk factor for HCV genotype 4 infection was treatment of trypanosomiasis before 1951 (OR, 3.13; 95% CI, 1.38-7.09). HTLV-1 infection was associated with having received 2 injections of pentamidine for trypanosomiasis chemoprophylaxis (adjusted OR, 2.03; 95% CI, 1.01-4.06) and with transfusions (adjusted OR, 2.82; 95% CI, 1.04-7.67). From historical data, we predicted that 59% of Mbimous 65 years and older would report treatment for trypanosomiasis before 1951; only 11% did so. CONCLUSIONS: Treatment of trypanosomiasis before 1951 may have caused iatrogenic HCV transmission. Population-wide half-yearly intramuscular pentamidine for trypanosomiasis chemoprophylaxis in 1947-1953 may have caused iatrogenic HTLV-1 transmission. These and other interventions against tropical diseases could have iatrogenically transmitted SIV(cpz), jump-starting the HIV-1 epidemic. The excess mortality among patients with trypanosomiasis treated before 1951 supports this hypothesis.

Predominance of hepatitis C virus genotype 4 infection and rapid transmission between 1935 and 1965 in the Central African Republic.

The molecular epidemiology of hepatitis C virus (HCV) in the Central African Republic (CAR) is poorly documented. Thus, we conducted phylogenetic analyses of NS5B gene sequences from 58 HCV-infected inhabitants of a remote area of south-west CAR, which indicated that 48 (82.8%) were infected with genotype 4 (HCV-4), five (8.6%) with genotype 2 and five (8.6%) with genotype 1. HCV-4 strains were highly heterogeneous, containing previously described subtypes 4k (48%), 4c (27%), 4r (4%), 4f (4%) and unclassified subtypes (17%). To estimate the epidemic history of these HCV-4 strains, an evolutionary analysis using the coalescent approach was used. The estimated date of the most recent common ancestor of the CAR HCV-4 strains was 1539 (95% confidence intervals, 1317-1697). They exhibited a rapid, exponential spread from 1935 to 1965, simultaneously with what was recently reported in neighbouring Cameroon and Gabon. The hypothesis of a massive iatrogenic transmission during interventions for the control of endemic tropical diseases is discussed.

Association between HSV-2 and HIV-1 viral load in semen, cervico-vaginal secretions and genital ulcers of Thai men and women.

We studied the association between herpes simplex virus type-2 (HSV-2) and HIV-1 viralload in plasma, semen, cervico-vaginal secretions and genital ulcers. Forty-seven (68%) men and 57 (80%) women were HSV-2 antibody positive, of whom 12 (26%, 95% confidence interval [CI] 20, 32) and five (8%, 95% CI 4, 12), respectively, had HSV-2 genital shedding detected by polymerase chain reaction. The mean HIV-1 seminal and cervico-vaginal viral loads did not differ significantly according to the presence of HSV-2 shedding. Eleven men and 15 women presented with genital ulcers; all ulcers were due to HSV-2. Ten men and nine women were followed up over six days: the mean (95% CI) HIV-1 log viral load copies/mL in the genital ulcers at baseline and final visits were 2.5 (2.3, 2.7) and 3.1 (2.0, 4.2) for men and 3.0 (2.6, 3.4) and 2.7 (2.3, 3.1) for women. These findings do not support the hypothesis that HSV-2 increases the HIV-1 viral load in genital secretions.

The complex vaginal flora of West African women with bacterial vaginosis.

BACKGROUND: The spectrum of bacteria associated with bacterial vaginosis (BV) has recently expanded through taxonomic changes and the use of molecular methods. These methods have yet to be used in large-scale epidemiological studies in Africa where BV is highly prevalent. METHODS: An analysis of samples obtained during a clinical trial of the management of vaginal discharge in four West African countries. Samples were available from 1555 participants; 843 (54%) had BV. Nucleic acids of 13 bacterial genera or species potentially associated with BV were detected through the polymerase chain reaction. RESULTS: The associations between various components of the vaginal flora were complex. Excluding Lactobacillus, the other 12 micro-organisms were all associated with each other at the p≤0.001 level. The prevalence of various bacterial genera or species varied according to age, sexual activity and HIV status. In multivariate analysis, the presence of Gardnerella vaginalis, Bifidobacterium, Megasphaera elsdenii, Dialister, Mycoplasma hominis, Leptotrichia, and Prevotella were independently associated with BV as was the absence of Lactobacillus and Peptoniphilus. However, Mobiluncus, Atopobium vaginae, Anaerococcus, and Eggerthella were not independently associated with BV. Unexpectedly, after treatment with a regimen that included either metronidazole or tinidazole, the proportion of patients with a complete resolution of symptoms by day 14 increased with the number of bacterial genera or species present at enrolment. CONCLUSIONS: Numerous bacterial genera or species were strongly associated with each other in a pattern that suggested a symbiotic relationship. BV cases with a simpler flora were less likely to respond to treatment. Overall, the vaginal flora of West African women with BV was reminiscent of that of their counterparts in industrialized countries.

Phylogeography and molecular epidemiology of hepatitis C virus genotype 2 in Africa.

Understanding the origin and nature of hepatitis C virus (HCV) genetic diversity is critical for improving treatment and vaccine design, and such diversity is the sole source of information about the virus' epidemic history prior to its identification 20 years ago. In this paper, we study the molecular epidemiology of HCV genotype 2 in its region of endemic origin, west and central Africa. Our analysis includes 56 new and highly diverse HCV isolates sampled from infected individuals in Guinea-Bissau. By combining phylogenetic, geographical and epidemiological information, we find a previously unappreciated geographical structure in the diversity of HCV genotype 2, pointing to a history of eastwards spatial spread from the west African coast to Cameroon that took place over several centuries. Molecular clock analysis dates the common ancestor of HCV in Guinea-Bissau to 1470 (1414-1582). The phylogenetic position of isolates from Madagascar and Martinique suggests a role for the historical slave trade in the global dissemination of HCV and of the epidemic subtypes 2a and 2c. Coalescent-based estimates of epidemic growth indicate a rapid 20th-century spread of HCV genotype 2 in Cameroon that is absent in Guinea-Bissau. We discuss this contrast in the context of possible parenteral HCV exposure during public-health campaigns undertaken during the colonial era.

A tale of two countries: HIV among core groups in Togo.

OBJECTIVE: To describe the epidemiology of HIV among core groups in Togo. METHODS: We enumerated sex workers (SWs) and conducted cross-sectional surveys of SWs and their clients in 2003 in Lomé and in 2005 in the whole country. RESULTS: Sex work was concentrated in Lomé, which comprised 15% of the population, but 52% of the 5397 SWs enumerated in Togo in 2005 and 68% of the estimated 101,376 men who had bought sex in the year before the 2005 survey. HIV prevalence among SWs was highest in Lomé (45.4% in 2005) and progressively decreased from south to north. A similar geographical pattern was seen for clients (8.3% were HIV infected in Lomé in 2005) and had already been reported for pregnant women. In Lomé, the population attributable fraction of prevalent cases of HIV acquired during transactional sex was estimated at 32%; in the rest of the country, this was only 2%. CONCLUSIONS: This is the first study quantifying sex work at a national level in Africa. Variations in HIV prevalence within Togo, with a north-south gradient among SWs, their clients, and pregnant women, may to a large extent reflect the concentration of the sex trade within Lomé. Prostitution played only a modest a role in HIV dynamics outside Lomé.

Hepatitis C virus infection in Guinea-Bissau: a sexually transmitted genotype 2 with parenteral amplification?

BACKGROUND: Sub-Saharan Africa is the continent with the highest prevalence of Hepatitis C virus (HCV) infection. Genotype 2 HCV is thought to have originated from West Africa several hundred years ago. Mechanisms of transmission remain poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: To delineate mechanisms for HCV transmission in West Africa, we conducted a cross-sectional survey of individuals aged >or=50 years in Bissau, Guinea-Bissau. Dried blood spots were obtained for HCV serology and PCR amplification. Prevalence of HCV was 4.4% (47/1066) among women and 5.0% (27/544) among men. In multivariate analysis, the independent risk factors for HCV infection were age (baseline: 50-59 y; 60-69 y, adjusted odds ratio [AOR]: 1.67, 95% CI: 0.91-3.06; >or=70 y, AOR: 3.47, 95% CI: 1.89-6.39), belonging to the Papel, Mancanha, Balanta or Mandjako ethnic groups (AOR: 2.45, 95% CI:1.32-4.53), originating from the Biombo, Cacheu or Oio regions north of Bissau (AOR: 4.16, 95% CI: 1.18-14.73) and having bought or sold sexual services (AOR: 3.60, 95% CI: 1.88-6.89). Of 57 isolates that could be genotyped, 56 were genotype 2. CONCLUSIONS: Our results suggest that transmission of HCV genotype 2 in West Africa occurs through sexual intercourse. In specific locations and subpopulations, medical interventions may have amplified transmission parenterally.

Improving second-generation surveillance: the biological measure of unprotected intercourse using prostate-specific antigen in vaginal secretions of West African women.

BACKGROUND: Second-generation surveillance for HIV includes measures of high-risk behaviors among the general adult population and sex workers (SW). Questionnaires are prone to social desirability biases because individuals minimize the frequency of behaviors not expected from them. OBJECTIVE: Determine whether the prostate-specific antigen (PSA) could be used as a biological marker of unprotected intercourse. METHODS: We measured the presence of PSA in vaginal secretions of women who were (n = 508) or were not (n = 658) SW presenting with vaginal discharge in health facilities of Ghana, Togo, Guinea, and Mali. The cutoff for a positive assay was determined as > or =0.4 microg/L based on a subsample of 95 non-SW claiming abstinence for 3 months. RESULTS: A positive PSA assay was correlated with infections with Neisseria gonorrhoeae, Chlamydia trachomatis, and Mycoplasma genitalium. Among non-SW, a positive PSA was more common among those with HIV, but less frequent in those better educated. Among SW and non-SW, women from Ghana were less likely to have a positive PSA and had a lower prevalence of sexually transmitted infections than those from elsewhere. CONCLUSIONS: PSA can be used as a biological marker of unprotected intercourse, allowing interventions to target efforts on those at highest risk.

The syndromic management of vaginal discharge using single-dose treatments: a randomized controlled trial in West Africa.

OBJECTIVE: To evaluate whether single-dose treatments are as effective as standard therapy in the syndromic management of vaginal discharge. METHODS: A randomized controlled effectiveness trial compared single-dose tinidazole plus fluconazole (TF) with treatment for 7 days with metronidazole plus 3 days of treatment with vaginal clotrimazole (MC) among 1570 women presenting with vaginal discharge at primary health care institutions in Ghana, Guinea, Mali and Togo. Participants were randomly allocated to one of the two treatments by research nurses or physicians using precoded envelopes. Effectiveness was assessed by symptomatic response on day 14. CLINICAL IDENTIFIER ClinicalTrials.gov NCT00313131. FINDINGS: The two treatment regimens had similar effectiveness: complete resolution was seen in 66% (TF) and 64% (MC) and partial resolution in 33% (TF) and 34% (MC) of participants (P = 0.26). Effectiveness was similar among subgroups with vulvovaginal candidiasis, Trichomonas vaginalis vaginitis or bacterial vaginosis. The two treatment regimens had a similar effectiveness among human immunodeficiency virus (HIV)-infected (TF: n = 76, 71% complete resolution, 28% partial; MC: n = 83, 72% complete resolution, 25% partial, P = 0.76) and HIV-uninfected women (TF: n = 517, 68% complete, 32% partial; MC: n = 466, 65% complete, 33% partial, P = 0.20). Cervical infections with Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium were uncommon among women not involved in sex work, were associated with bacterial vaginosis or T. vaginalis vaginitis, and did not alter response to treatment with agents active against vaginal infections. Four-fifths of women not relieved by a single dose of TF had a favourable response when MC was administered as second-line treatment. CONCLUSION: Single-dose TF is as effective as multiple-dose MC in the syndromic management of vaginal discharge, even among women with HIV-infection. Given its low price and easier adherence, TF should be considered as a first-line treatment for vaginal discharge syndrome.

Comparison of the Directigen flu A+B test, the QuickVue influenza test, and clinical case definition to viral culture and reverse transcription-PCR for rapid diagnosis of influenza virus infection.

The diagnostic performances of the clinical case definition of influenza virus infection based on the combination of fever and cough and of two rapid influenza diagnostic tests, the Directigen Flu A+B test (Directigen; BD Diagnostic Systems, Sparks, Md.) and the QuickVue influenza test (QuickVue; Quidel, San Diego, Calif.), were compared to those of viral culture and an in-house reverse transcription (RT)-PCR during the 2000-2001 flu season. Two hundred consecutive nasopharyngeal aspirates were analyzed from 192 patients, including 122 adults and 70 children. Viral culture identified influenza virus A in 16 samples and influenza virus B in 55 samples, whereas RT-PCR identified influenza virus A in 21 samples and influenza virus B in 64 samples. When RT-PCR was used as the reference standard, the likelihood ratios for a positive test were 40.0 for Directigen, 8.6 for QuickVue, and 1.4 for the combination of fever and cough, whereas the likelihood ratios for a negative test were 0.22, 0.16, and 0.48, respectively. Our study suggests that (i). the poor specificity (35 to 58%) and the poor positive predictive value (41 to 60%) of the clinical case definition of influenza preclude its use for prediction of influenza virus infections during epidemics, especially when infection control decision making in the hospital setting is considered; (ii). Directigen has a higher diagnostic yield than QuickVue but is associated with a larger number of invalid results; (iii). the sensitivities of the rapid diagnostic tests are significantly lower with samples from adults than with samples from children, with the rates of false-negative results reaching up to 29%; and (iv). RT-PCR detects more cases of influenza than viral culture, and this greater accuracy makes it a more useful reference standard.