Prevalence of integrase strand transfer inhibitor resistance mutations in antiretroviral-naive HIV-1-infected individuals in Cameroon.

OBJECTIVES: In Cameroon, the integrase (IN) strand transfer inhibitor (INSTI) dolutegravir was recently introduced for the treatment of HIV-1 infection. Since pretreatment HIV-1 drug resistance can jeopardize the success of ART, and considering the high heterogeneity of circulating HIV-1 subtypes in Cameroon, we investigated the prevalence of pretreatment HIV-1 resistance to INSTIs. METHODS: Fingerprick dried blood spot samples were collected from 339 newly diagnosed HIV-1-infected individuals between 2015 and 2016 in four hospitals in Cameroon. Universal primers were designed to amplify the HIV-1 IN region from amino acid 1 to 276. Amplicons were sequenced with Illumina next-generation sequencing and analysed with the Polymorphism Analysis Sequencing (PASeq) platform, using the Stanford HIV Drug Resistance Database to interpret HIV-1 drug resistance mutations (DRMs). RESULTS: The amplification/sequencing success rate was 75.2% with 255/339 sequences obtained. Applying a cut-off of 1%, major DRMs to INSTIs were detected in 13 (5.1%) individuals, but only 1 individual harboured an INSTI DRM (E92G) at a nucleotide frequency ≥15%. However, 140/255 (54.9%) individuals harboured polymorphic accessory INSTI DRMs, mainly at high frequencies. In line with that observation, HIV-1 subtype diversity among individuals was high. CONCLUSIONS: Pretreatment HIV-1 resistance to INSTIs was low in the study sites, which supports the use of INSTIs in Cameroon. Nevertheless, further studies are necessary to assess the impact of polymorphic accessory INSTI DRMs on INSTI-based ART regimens.

Low prevalence of transmitted HIV-1 drug resistance detected by a dried blood spot (DBS)-based next-generation sequencing (NGS) method in newly diagnosed individuals in Cameroon in the years 2015-16.

Objectives: To determine the most recent prevalence, transmission patterns and risk factors of transmitted drug-resistance mutations (TDRMs) in Cameroon, we initiated a multicentre study monitoring HIV-1 drug resistance in newly HIV-1-diagnosed individuals using a novel next-generation sequencing (NGS) assay applicable to fingerprick dried blood spot (DBS) samples. Methods: Fingerprick DBS samples and questionnaires were collected from 360 newly HIV-1-diagnosed individuals in four hospitals in urban areas in Cameroon in the years 2015-16. We developed an HIV-1 protease and reverse transcriptase drug resistance genotyping assay applicable to DBS samples and HIV-1 genomes of groups M, N and O. The WHO 2009 list of mutations for surveillance of transmitted drug-resistant HIV strains was used to analyse TDRMs. Results: Applying our 'DBS-NGS-genotypic resistance test', baseline HIV-1 drug resistance data were successfully obtained from 82.8% (298/360) of newly diagnosed individuals. At nucleotide frequencies >15%, TDRMs to NRTIs were observed in 3.0% (9/298), to NNRTIs in 4.0% (12/298) and to PIs in 1.3% (3/240). The NNRTI mutation K103N was most commonly detected (2.7%). Expanding the analysis to low-abundance TDRMs, i.e. 3%-15%, 12 additional individuals (4.0%) harbouring TDRMs were identified. Having unprotected sex with a known HIV-1-positive person was significantly associated with the transmission of DRMs (adjusted OR 9.6; 95% CI 1.79-51.3). Conclusions: The prevalence of transmitted HIV-1 drug resistance is currently low in the study sites in Cameroon. Evidence of some risky sexual behaviours depicts a public health problem with possible implications for the prevention of new HIV-1 infections.

Tuberculosis incidence in Cameroonian prisons: a 1-year prospective study.

BACKGROUND: Rates of tuberculosis (TB) transmission in prisons are reported to be high worldwide. However, a recent systematic review identified only 19 published studies reporting TB incidence in prisons, most of them from the last century and only one from sub-Saharan Africa. OBJECTIVES: To assess the persisting risk of smear-positive pulmonary tuberculosis (PTB) among prison populations benefiting from a comprehensive TB/HIV control programme in Cameroon, compared with that in the community. METHODS: This descriptive and prospective study evaluated PTB incidence rates over a 1-year period. The study population was inmates of 10 major prisons, sampled by convenience, comprising about 45% of the country's prison population. As PTB incident cases, all prisoners with incident PTB after a prison stay of > or = 90 days were considered. The prison TB incidence rate was compared with that of the corresponding male population in the community. RESULTS: The mean annual PTB incidence in Cameroonian prisons in this study was 1 700 cases in 100 000 person-years at risk, the incidence rate ratio being 9.4 (95% confidence interval 8.1-10.9). CONCLUSION: Findings suggest that internationally recommended prison TB control measures alone may not help protect prisoners from within-prison spread of TB. Imprisonment policies and conditions therefore require fundamental changes.

Controlling tuberculosis in prisons against confinement conditions: a lost case? Experience from Cameroon.

BACKGROUND: Tuberculosis (TB) is recognised as a major public health problem in the prisons of sub-Saharan Africa. In Cameroon, the main prisons have created diagnostic and treatment units linked to the National Tuberculosis Programme (NTP). OBJECTIVE: To assess the effectiveness of routine TB control activities in a prison population by determining the prevalence of undetected pulmonary tuberculosis (PTB). METHODS: In 2009, a PTB case-finding survey was undertaken at the Central Prison of Yaounde (CPY), Cameroon. All prisoners with cough of ≥1 week's duration were screened by sputum smear microscopy. Smears were sent to the national reference laboratory for culture and drug susceptibility testing (DST). Voluntary testing for human immunodeficiency virus (HIV) was offered to all inmates. RESULTS: Among 3219 inmates screened, 40 (1.2%) identified with PTB had been missed by the prison TB control programme. Missed PTB was positively associated with severe crowding, low body mass index and previous TB treatment. Of the 40 inmates, four (10%) were TB-HIV co-infected. The DST of three inmates revealed resistance to anti-tuberculosis drugs. CONCLUSION: Despite a well-performing TB control programme in the CPY, the number of undetected PTB cases remains unacceptably high. It is doubtful whether TB transmission can be controlled under conditions of confinement, such as the CPY.