Risk factors for multidrug-resistant tuberculosis in the Central African Republic: A case-control study.

BACKGROUND: The emergence and spread of multidrug-resistant tuberculosis (MDR-TB) presents a challenge to the "End TB by 2035" strategy. This study aimed to identify the risk factors associated with MDR-TB in patients admitted to the pneumo-physiology clinic of the National University Hospital of Bangui in Central African Republic. METHODS: This was a "retrospective" chart review study. Cases were represented by patients more than 18 years of age treated for MDR-TB and controls were patients with "at least rifampicin-susceptible" TB treated "with first-line anti-TB regimen" and who at the end of treatment were declared cured. The status of "cured" was exclusively applicable to non-MDR TB. Risk factors associated with MDR-TB were identified by multivariate analysis. RESULTS: We included 70 cases and 140 controls. The median age was 35 years, IQR (22;46 years). The main factors associated with the occurrence of MDR-TB in multivariate analysis were male gender (0 R = 3.02 [1.89-3.99], p = 0.001), residence in a peri-urban/urban area (0 R = 3.06 [2.21-4.01], p = 0.002), history of previous TB treatment (0 R= 3.99 [2.77-4.25], p < 0.001) and the presence of multidrug-resistant TB in the family (0 R=1.86 [1.27-2.45], p = 0.021). CONCLUSION: The emergence of MDR-TB can be reduced by implementing appropriate strategies, such as preventive therapy in contacts of MDR-TB patients and detecting and appropriately treating MDR-TB patients to prevent further spread of infection.

Persistent high-risk behavior and escalating HIV, syphilis and hepatitis B incidences among men who have sex with men living in Bangui, Central African Republic.

INTRODUCTION: HIV in sub-Saharan Africa remains a great concern in men who have sex with men (MSM). Intervention on MSM is a key strategy to control the burden of HIV among this population. Herein we assessed the effect of 2 years of HIV testing and counseling on risk-tacking and HIV and STI incidences among MSM living in Bangui in the Central African Republic. METHODS: The incidences of HIV, syphilis and hepatitis B and the sexual behavior characteristics were assessed at inclusion and after 2 years of follow up in the prospective MSM cohort. RESULTS: 99 MSM were included and followed up during 2 years. The mean age of study MSM was 24 years (range, 14-39); among those, the majority was single (84.8%) and unemployed (33.3%) or students (23.9%). The majority (up to 80%) were living in only 4 (out of 10) neighboring district of Bangui. Insertive anal intercourse showed significant decrease from 54% at inclusion to 46% after 2 years of follow up (P < 0.001). In contrast, we observed slight increase in receptive anal intercourse (60% versus 66%) and oral sex (70% versus 74%), but the difference did not reach statistical significance. Finally, the prevalences of HIV, syphilis and hepatitis B increased significantly from 29% to 41%, 12% to 21% and 14% to 23%, respectively. CONCLUSION: These observations indicate that medical care and counseling on MSM does not provide significant changes in risk-taking, whereas the incidences of HIV, syphilis and hepatitis B remained high. Innovative interventions should be conceived for the MSM population living in Bangui.

Virological response and resistance profiles after 24 months of first-line antiretroviral treatment in adults living in Bangui, Central African Republic.

The rate of virological failure was assessed in 386 adult patients attending the Centre National Hospitalier Universitaire of Bangui, the capital city of the Central African Republic (CAR), receiving their first-line antiretroviral (ARV) drug regimen for 24 months, according to the World Health Organization (WHO) recommendations. In addition, genotypic resistance testing was carried out in 45 of 145 randomly selected patients whose plasma HIV-1 RNA load was detectable. Overall, 28.5% of ARV-treated patients were in virological failure (e.g., HIV-1 RNA >3.7 log(10) copies/ml). Twenty-four percent of patients in virological failure showed wild-type viruses, likely indicating poor adherence. Even after excluding the M184V mutation, all 76% of patients in virological failure displayed viruses harboring at least one major drug resistance mutation to nucleoside reverse transcriptase inhibitors (NRTI), non-NRTI, or protease inhibitors. Whereas the second-line regimen proposed by the 2010 WHO recommendations, including zidovudine, tenofovir, lopinavir, and atazanavir, could be effective in more than 90% of patients in virological failure with resistant viruses, the remaining patients showed genotypic profiles highly predictive of resistance to the usual WHO second-line regimen, including complex genotypic profiles diagnosed only by genotypic resistance tests in some patients. In conclusion, our observations highlight the high frequency of therapeutic failure in ARV-treated adults in this study, as well as the urgent and absolute need for improving viral load assessment in the CAR to prevent and/or, from now on, to monitor therapeutic failure.

Infection of macrophages and dendritic cells with primary R5-tropic human immunodeficiency virus type 1 inhibited by natural polyreactive anti-CCR5 antibodies purified from cervicovaginal secretions.

Heterosexual contact is the primary mode of human immunodeficiency virus (HIV) type 1 (HIV-1) transmission worldwide. The chemokine receptor CCR5 is the major coreceptor that is associated with the mucosal transmission of R5-tropic HIV-1 during sexual intercourse. The CCR5 molecule is thus a target for antibody-based therapeutic strategies aimed at blocking HIV-1 entry into cells. We have previously demonstrated that polyreactive natural antibodies (NAbs) from therapeutic preparations of immunoglobulin G and from human breast milk contain NAbs directed against CCR5. Such antibodies inhibit the infection of human macrophages and T lymphocytes by R5-tropic isolates of HIV in vitro. In the present study, we demonstrate that human immunoglobulins from the cervicovaginal secretions of HIV-seronegative or HIV-seropositive women contain NAbs directed against the HIV-1 coreceptor CCR5. Natural affinity-purified anti-CCR5 antibodies bound to CCR5 expressed on macrophages and dendritic cells and further inhibited the infection of macrophages and dendritic cells with primary and laboratory-adapted R5-tropic HIV but not with X4-tropic HIV. Natural anti-CCR5 antibodies moderately inhibited R5-tropic HIV transfer from monocyte-derived dendritic cells to autologous T cells. Our results suggest that mucosal anti-CCR5 antibodies from healthy immunocompetent donors may hamper the penetration of HIV and may be suitable for use in the development of novel passive immunotherapy regimens in specific clinical settings of HIV infection.

Early archives of genetically-restricted proviral DNA in the female genital tract after heterosexual transmission of HIV-1.

OBJECTIVES AND METHOD: In order to characterize human immunodeficiency virus type 1 (HIV-1) variants that are transmitted in women via heterosexual intercourse, the env V1-V3 sequences of HIV-1 provirus (DNA) and free virus (RNA) in paired samples of blood and cervicovaginal secretions of untreated chronically and primary infected African women were compared. RESULTS: Env RNA sequences retrieved from plasma and genital compartments formed a single cluster in primary infection. In contrast, env RNA sequences from these two compartments were distinct in chronically infected women. Analysis of proviral DNA of primary infected women showed that most HIV-1 sequences derived from the genital epithelia form independent clusters from HIV-1 sequences of DNA from peripheral blood mononuclear cells and RNA recovered from plasma and genital secretions. Similarly, the analysis of proviral DNA in the genital compartment of chronically infected women showed the persistence of genetically-restricted cluster of HIV-1. CONCLUSIONS: These observations indicate that a viral subpopulation is archived as proviral DNA in the female genital tract early in primary infection, and suggest that HIV-1 variants from the male donor are selected in the female mucosal site during male to female transmission of HIV-1.

Real-time PCR quantification of genital shedding of herpes simplex virus (HSV) and human immunodeficiency virus (HIV) in women coinfected with HSV and HIV.

The accuracy and usefulness of laboratory-developed real-time PCR procedures using a Light Cycler instrument (Roche Diagnostics) for detecting and quantifying human immunodeficiency virus type 1 (HIV-1) RNA and DNA as well as herpes simplex virus type 1 (HSV-1)/HSV-2 DNA in cervicovaginal secretions from women coinfected with HIV and HSV were evaluated. For HIV-1, the use of the NEC152 and NEC131 primer set and the NEC-LTR probe in the long terminal repeat gene allowed us to detect accurately the majority of HIV-1 subtypes of group M circulating in sub-Saharan Africa, including subtypes A, B, C, D, and G as well as circulating recombinant forms 02 and 11. The detection threshold of real-time PCR for HIV in cervicovaginal lavage samples was 5 copies per assay for both RNA and DNA; the intra- and interassay coefficients of variation of C(T) values were 1.30% and 0.69% (HIV-1 RNA) and 1.84% and 0.67% (HIV-1 DNA), respectively. Real-time PCR for HSV using primers and probe targeting the HSV DNA polymerase gene allowed both detection and quantification of HSV DNA and also differentiation between HSV-1 and HSV-2 genotypes. The detection threshold of real-time PCR for HSV was 5 copies per assay; the intra- and interassay coefficients of variation of C(T) values were 0.96% and 1.49%, respectively. Both manual and automated silica-based procedures were appropriate for combined extraction of HIV and HSV genomes from female genital secretions. Taken together, these findings indicate that real-time PCR may be used as a unique nucleic acid amplification procedure to detect and quantify HIV and HSV genomes in cervicovaginal secretions and thus to assess at reduced costs the genital shedding of both viruses in women included in intervention studies.

Independent levels of cell-free and cell-associated human immunodeficiency virus-1 in genital-tract secretions of clinically asymptomatic, treatment-naive African women.

Using ultrasensitive polymerase chain reaction-based techniques, we assessed levels of cell-free and cell-associated human immunodeficiency virus (HIV)-1 in paired blood and genital samples of 30 clinically asymptomatic, treatment-naive women. Levels of HIV-1 RNA in cervicovaginal-lavage samples were positively correlated with those in plasma samples (r=.50; P=.008), whereas levels of HIV-1 DNA in genital samples were loosely correlated with those in blood samples (r=.31; P=.041). In plasma of peripheral blood, levels of HIV-1 DNA were positively correlated with those of HIV-1 RNA (r=.64; P<.001), whereas no correlation between HIV-1 DNA and HIV-1 RNA was evident in genital secretions. Our results indicate that levels of HIV-1 RNA and HIV-1 DNA are unrelated in the genital tracts of treatment-naive women and suggest that the level of genital HIV-1 RNA is influenced by systemic viral replication-in contrast to genital HIV-1 provirus, which may be influenced as well by local cofactors triggering the migration of HIV-infected cells originating from the cervicovaginal submucosa. These features may be relevant for an understanding of HIV-1 transmission in heterosexual individuals.