An investigation on the suitability of hydrated building lime from travertine limestone outcrop of Bogongo, South West of Cameroon

peer reviewedIn the present study, physico-chemical investigations were carried out on hydrated lime produced from the limestone of the travertine outcrop of Bogongo in the South West Region of Cameroon. The aim was to evaluate the suitability of that hydrated lime as building lime. The raw material was characterized and then fired at 900 °C. The fired product was hydrated, dried and also characterized. Chemical and mineralogical analyses, density, BET specific surface measurements and thermal analyses were performed. Results were compared to those for an EN 459-1 CL 90-S industrial commercial hydrated lime. It has been shown that, hydrated lime production using the raw material from the Bogongo travertine could yield products with almost similar physico-chemical properties compared to imported CL 90 S hydrated lime, thus could have positive consequence in the commercial exploitation of the Bogongo travertine limestone outcrop.11. Sustainable cities and communitie

Early Warning Indicators for HIV Drug Resistance in Cameroon during the Year 2010

BACKGROUND: Rapid scale-up of antiretroviral therapy (ART) in resource-limited settings is accompanied with an increasing risk of HIV drug resistance (HIVDR), which in turn could compromise the performance of national ART rollout programme. In order to sustain the effectiveness of ART in a resource-limited country like Cameroon, HIVDR early warning indicators (EWI) may provide relevant corrective measures to support the control and therapeutic management of AIDS. METHODS: A retrospective study was conducted in 2010 among 40 ART sites (12 Approved Treatment Centers and 28 Management Units) distributed over the 10 regions of Cameroon. Five standardized EWIs were selected for the evaluation using data from January through December, among which: (1) Good ARV prescribing practices: target = 100%; (2) Patient lost to follow-up: target ≤ 20%; (3) Patient retention on first line ART: target ≥ 70%; (4) On-time drug pick-up: target ≥ 90%; (5) ARV drug supply continuity: target = 100%. Analysis was performed using a Data Quality Assessment tool, following WHO protocol. RESULTS: THE NUMBER OF SITES ATTAINING THE REQUIRED PERFORMANCE ARE: 90% (36/40) for EWI(1), 20% (8/40) for EWI(2); 20% (8/40) for EWI(3); 0% (0/37) for EWI(4); and 45% (17/38) for EWI 5. ARV prescribing practices were in conformity with the national guidelines in almost all the sites, whereas patient adherence to ART (EWI(2), EWI(3), and EWI(4)) was very low. A high rate of patients was lost-to-follow-up and others failing first line ART before 12 months of initiation. Discontinuity in drug supply observed in about half of the sites may negatively impact ARV prescription and patient adherence. These poor ART performances may also be due to low number of trained staff and community disengagement. CONCLUSIONS: The poor performance of the national ART programme, due to patient non-adherence and drug stock outs, requires corrective measures to limit risks of HIVDR emergence in Cameroon

Viral suppression in adults, adolescents and children receiving antiretroviral therapy in Cameroon: Adolescents at high risk of virological failure in the era of "test and treat"

Background: After the launching of the "Test & Treat" strategy and the wider accessibility to viral load (VL), evaluating virological success (VS) would help in meeting the UNAIDS targets by 2020 in Cameroon.Setting and methods: Cross-sectional study conducted in the Chantal BIYA International Reference Centre for research on HIV/AIDS prevention and management (CIRCB), Yaounde, Cameroon; data generated between October 2016 and August 2017 amongst adults, adolescents and children at 12, 24, 36 and >= 48 months on ART. VS was defined as < 1000 copies/mL of blood plasma and controlled viremia as VL < 50 copies/mL. Data were analysed by SPSS; p < 0.05 considered as significant.Results: 1946 patients (70% female) were enrolled (1800 adults, 105 adolescents, 41 children); 1841 were on NNRTI-based and 105 on PI-based therapy; with 346 patients at M12, 270 at M24, 205 at M36 and 1125 at >= M48. The median (IQR) duration on was 48 months (24-48). Overall, VS was 79.4% (95% CI 77.6-81.2) and 67.1% (95% CI 64.9-69.1) had controlled viral replication. On NNRTI-based, VS was 79.9% vs. 71.4% on PIs-based, p = 0.003. By ART duration, VS was 84.1% (M12), 85.9% (M24), 75.1% (M36) and 77.2% (>= M48), p = 0.001. By age, VS was 75.6% (children), 53.3% (adolescents) and 81.1% (adults), p < 0.001.Conclusions: In this sub-population of patients receiving ART in Cameroon, about 80% might be experiencing VS, with declining performance at adolescence, with NNRTI-based regimens, and as from 36 months on ART. Thus, improving VS may require an adapted adherence support mechanism, especially for adolescents with long-term treatment in resource-limited settings

Alarming rates of virological failure and HIV-1 drug resistance amongst adolescents living with perinatal HIV in both urban and rural settings: evidence from the EDCTP READY-study in Cameroon

Objectives: Adolescents living with perinatal HIV infection (ALPHI) experience persistently high mortality rates, particularly in resource-limited settings. It is therefore clinically important for us to understand the therapeutic response, acquired HIV drug resistance (HIVDR) and associated factors among ALPHI, according to geographical location. Methods: A study was conducted among consenting ALPHI in two urban and two rural health facilities in the Centre Region of Cameroon. World Health Organization (WHO) clinical staging, self-reported adherence, HIVDR early warning indicators (EWIs), immunological status (CD4 count) and plasma viral load (VL) were assessed. For those experiencing virological failure (VF, VL ≥ 1000 copies/mL), HIVDR testing was performed and interpreted using the Stanford HIV Drug Resistance Database v.8.9-1. Results: Of the 270 participants, most were on nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens (61.7% urban vs. 82.2% rural), and about one-third were poorly adherent (30.1% vs. 35.1%). Clinical failure rates (WHO-stage III/IV) in both settings were < 15%. In urban settings, the immunological failure (IF) rate (CD4  < 250 cells/μL) was 15.8%, statistically associated with late adolescence, female gender and poor adherence. The VF rate was 34.2%, statistically associated with poor adherence and NNRTI-based antiretroviral therapy. In the rural context, the IF rate was 26.9% and the VF rate was 52.7%, both statistically associated with advanced clinical stages. HIVDR rate was over 90% in both settings. EWIs were delayed drug pick-up, drug stock-outs and suboptimal viral suppression. Conclusions: Poor adherence, late adolescent age, female gender and advanced clinical staging worsen IF. The VF rate is high and consistent with the presence of HIVDR in both settings, driven by poor adherence, NNRTI-based regimen and advanced clinical staging

Assessing the potential impact of disruptions due to COVID-19 on HIV among key and lower-risk populations in the largest cities of Cameroon and Benin

Background: The COVID-19 pandemic indirectly impacts HIV epidemiology in Central/West Africa. We estimated the potential impact of COVID-19-related disruptions to HIV prevention/treatment services and sexual partnerships on HIV incidence and HIV-related deaths among key populations including female sex workers (FSW), their clients, men who have sex with men (MSM), and overall. Setting: Yaoundé (Cameroon) and Cotonou (Benin). Methods: We used mathematical models of HIV calibrated to city- and risk-population-specific demographic/behavioural/epidemic data. We estimated the relative change in 1-year HIV incidence and HIV-related deaths for various disruption scenarios of HIV prevention/treatment services and decreased casual/commercial partnerships, compared to a scenario without COVID-19. Results: A 50% reduction in condom use in all partnerships over 6 months would increase 1-year HIV incidence by 39%, 42%, 31% and 23% among MSM, FSW, clients, and overall in Yaoundé respectively, and 69%, 49% and 23% among FSW, clients and overall respectively in Cotonou. Combining a 6-month interruption of ART initiation and 50% reduction in HIV prevention/treatment use would increase HIV incidence by 50% and HIV-related deaths by 20%. This increase in HIV infections would be halved by a simultaneous 50% reduction in casual and commercial partnerships. Conclusions: Reductions in condom use following COVID-19 would increase infections among key populations disproportionately, particularly FSW in Cotonou, who need uninterrupted condom provision. Disruptions in HIV prevention/treatment services have the biggest impacts on HIV infections and deaths overall, only partially mitigated by equal reductions in casual/commercial sexual partnerships. Maintaining ART provision must be prioritised to minimise short-term excess HIV-related deaths

The severity of rheumatoid arthritis at the first rheumatology consultation and factors associated with initial structural damage in sub Saharan patients

Background: The severity of Rheumatoid Arthritis (RA) at diagnosis has not been fully described in sub-Saharan Africa in recent years, nor have been the factors associated with it.Objective: The aim of this study was to determine the frequency of severe RA at the first rheumatology consultation and assess the factors associated with this early severity.Design: This was a retrospective study.Methods: The study was carried out in the rheumatology service of the Yaoundé Central Hospital, Cameroon. Files (one patient = one file) of patients diagnosed with RA during January 2004-May 2018 were included. RA severity was defined by the presence of at least one of these markers: Disease Activity Score-28 with Erythrocyte Sedimentation Rate (DAS28-ESR) > 5.1, initial structural damage on hand X-rays which was defined by a Larsen score ≥ 2 per joint and the presence of Rheumatoid Factor (RF) and/or Anticitrullinated Protein Antibodies (ACPA). Files with no information to assess disease severity at the time of diagnosis were excluded. Data were analyzed with Epi-info version 7.0. Statistical significance was set at p-values less than 0.05.Results: Forty-nine patients were included. Their mean age was 48 ± 14 years. Eighty percent of them were females. Sixty-seven percent had established RA, 33% had early-stage RA and two patients had ever smoked. None of them had received biological diseasemodifying antirheumatic drugs. RA was severe in 82% of patients, with DAS28- ESR > 5.1 in 71%, positivity of at least one autoantibody found in 63% to 82%, and initial structural damage found in 55% of them. Initial structural damage was only associated with the presence of ≥ 10 swollen joint counts.Conclusions: RA was severe from the onset in most patients and structural damage was associated with the presence of ≥ 10 swollen joint counts. Key words: Rheumatoid arthritis, Severity, Initial presentation, Structural damage, Sub-Saharan Africa

Population-based monitoring of emerging HIV-1 drug resistance on antiretroviral therapy and associated factors in a sentinel site in Cameroon : low levels of resistance but poor programmatic performance

Background: Scale-up of antiretroviral therapy (ART) in resource-limited settings has drastically reduced HIV-related morbidity and mortality. However, challenges in long-term ART, adherence and HIV drug resistance (HIVDR) itself, require monitoring to limit HIVDR emergence among ART-experienced populations, in order to ensure regimen efficacy. Methods: A longitudinal study was conducted from 2009-2011 in a cohort of 141 HIV-infected adult patients (aged >21) at the national social insurance centre hospital in Yaounde, Cameroon. As per-WHO HIVDR protocol, HIV-1 protease-reverse transcriptase genotyping was performed at baseline and at endpoint (12 months) on first-line ART using ViroSeq (TM) Genotyping kit. Results: At baseline, a prevalence of 3.6% (5/139) HIVDR was observed &#91;protease inhibitors M46I (1/5), G73A (1/5), L90LM (1/5); nucleoside reverse transcriptase inhibitors: M184V (1/5), T215F (1/5); non-nucleoside reverse transcriptase inhibitors: K103N (1/5), Y181Y/C (2/5), M230ML (1/5)&#93;. At endpoint, 54.0% (76) patients were followed-up, 9.2% (13) died, and 3.5% (5) transferred, 38.5% (47) lost to follow-up (LTFU). 69.7% (53/76) of those followed-up had viremia <40 copies/ml and 90.8% (69/76) <1000 copies/ml. 4/7 patients with viremia >= 1000 copies/ml harbored HIVDR (prevalence: 5.3%; 4/76), with M184V/I (4/4) and K103K/N (3/4) being the most prevalent mutations. LTFU was favored by costs for consultation/laboratory tests, drug shortages, workload (physician/patient ratio: 1/180) and community disengagement. Conclusions: Low levels of HIVDR at baseline and at endpoint suggest a probable effectiveness of ART regimens used in Cameroon. However the possible high rate of HIVDR among LTFUs limited the strengths of our findings. Evaluating HIVDR among LTFU, improving adherence, task shifting, subsidizing/harmonizing costs for routine follow-up, are urgent measures to ensure an improved success of the country ART performance

Monitoring HIV Drug Resistance Early Warning Indicators in Cameroon: A Study Following the Revised World Health Organization Recommendations

<div><p>Background</p><p>The majority (>95%) of new HIV infection occurs in resource-limited settings, and Cameroon is still experiencing a generalized epidemic with ~122,638 patients receiving antiretroviral therapy (ART). A detrimental outcome in scaling-up ART is the emergence HIV drug resistance (HIVDR), suggesting the need for pragmatic approaches in sustaining a successful ART performance.</p><p>Methods</p><p>A survey was conducted in 15 ART sites of the Centre and Littoral regions of Cameroon in 2013 (10 urban versus 05 rural settings; 8 at tertiary/secondary versus 7 at primary healthcare levels), evaluating HIVDR-early warning indicators (EWIs) as-per the 2012 revised World Health Organization’s guidelines: EWI₁ (<i>on-time pill pick-up</i>), EWI₂ (<i>retention in care</i>), EWI₃ (<i>no pharmacy stock-outs</i>), EWI₄ (<i>dispensing practices</i>), EWI₅ (<i>virological suppression</i>). Poor performance was interpreted as potential HIVDR.</p><p>Results</p><p>Only 33.3% (4/12) of sites reached the desirable performance for <i>“on-time pill pick-up”</i> (57.1% urban versus 0% rural; p<0.0001) besides 25% (3/12) with fair performance. 69.2% (9/13) reached the desirable performance for <i>“retention in care”</i> (77.8% urban versus 50% rural; p=0.01) beside 7.7% (1/13) with fair performance. Only 14.4% (2/13) reached the desirable performance of <i>“no pharmacy stock-outs”</i> (11.1% urban versus 25% rural; p=0.02). All 15 sites reached the desirable performance of 0% <i>“dispensing mono- or dual-therapy”</i>. Data were unavailable to evaluate <i>“virological suppression”</i> due to limited access to viral load testing (min-max: <1%-15%). Potential HIVDR was higher in rural (57.9%) compared to urban (27.8%) settings, p=0.02; and at primary (57.9%) compared to secondary/tertiary (33.3%) healthcare levels, p=0.09.</p><p>Conclusions</p><p>Delayed pill pick-up and pharmacy stock-outs are major factors favoring HIVDR emergence, with higher risks in rural settings and at primary healthcare. Retention in care appears acceptable in general while ART dispensing practices are standard. There is need to support patient-adherence to pharmacy appointments while reinforcing the national drug supply system.</p></div