HIV-1 residual risk and pre-treatment drug resistance among blood donors: A sentinel surveillance from Gabon.

BACKGROUND: Surveillance of HIV-1 pre-treatment drug resistance (PDR) is essential for ensuring the success of first-line antiretroviral therapy (ART). Beside population-based surveys, sentinel surveillance of PDR and circulating HIV-1 clades in specific populations such as blood donors could efficiently inform decision-making on ART program. We therefore sought to ascertain HIV-1 residual infection, the threshold of PDR and viral diversity among recently-diagnosed blood donors in Gabon. METHODS: A sentinel surveillance was conducted among 381 consenting blood donors at the National Blood Transfusion Center (NBTC) in Gabon from August 3,2020 to August, 31, 2021. In order to determine the residual risk of HIV transmission, viral load and HIV-1 Sanger-sequencing were performed at the Chantal BIYA International Reference Center (CIRCB)-Cameroon on HIV samples previously tested seronegative with ELISA in Gabon. Phylogeny was performed using MEGA X, PDR threshold>10% was considered high and data were analysed using p≤0.05 for statistical significance. RESULTS: Five HIV-negative blood donors had a detectable viral load indicating a high residual risk of HIV transmission. Among the samples successfully sequenced, four participants had major drug resistance mutations (DRMs), giving a threshold of PDR of 25% (4/16). By drug class, major DRMs targeting NNRTI (K103N, E138G), NRTIs (L210W) and PI/r (M46L). The most representative viral clades were CRF02_AG and subtype A1. The genetic diversity of HIV-1 had no significant effect on the residual risk in blood transfusion (CRF02_AG, P = 0.3 and Recombinants, P = 0.5). CONCLUSION: This sentinel surveillance indicates a high residual risk of HIV-1 transfusion in Gabon, thereby underscoring the need for optimal screening strategy for blood safety. Moreover, HIV-1 transmission goes with high-risk of PDR, suggesting suboptimal efficacy of ART. Nonetheless, the genetic diversity has limited (if any effect) on the residual risk of infection and PDR in blood donors.

Current knowledge of human Mpox viral infection among healthcare workers in Cameroon calls for capacity-strengthening for pandemic preparedness.

Introduction: An increased incidence of human Monkeypox (Mpox) cases was recently observed worldwide, including in Cameroon. To ensure efficient preparedness and interventions in the health system, we sought to assess the knowledge of Mpox's transmission, prevention, and response among healthcare workers (HCWs) in Cameroon. Methods: A cross-sectional online survey was conducted among HCWs in Cameroon using 21-item questions adapted from the United States Centers for Disease Control and Prevention (US-CDC) standard questionnaire on Mpox. The overall knowledge of Mpox was assessed by cumulative score and categorized as excellent (≥80%, 17/21) or good (≥70%, ≥15/21) knowledge. The regression analysis was used to identify the predictors of Mpox knowledge. Results: The survey enrolled 377 participants, but only responses from 342 participants were analyzed. Overall, 50.6% were female participants, and 59.6% aged 30 years or younger. The majority of the participants were medical doctors (50.3%); most worked in central-level hospitals (25.1%) and had 1-5 years of experience (70.7%). A total of up to 92.7% were aware of Mpox, with social media (58.7%) and radio/television (49.2%) as the main sources. The mean knowledge score was 14.0 ± 3.0 (4 to 20), with only 12.9% having excellent knowledge (≥80%) and 42.1% having good knowledge of Mpox. Younger age (26-30 years old) was associated with good knowledge, while workplace type was associated with excellent knowledge of Mpox (aOR [95% CI]: 4.01 [1.43-11.24]). Knowledge of treatment/management of Mpox was generally poor across the different professional categories. Conclusion: Knowledge of Mpox among HCWs is substandard across different professionals. Thus, for optimal preparedness and immediate interventions for Mpox and similar emerging pathogens, capacity-strengthening programs should be organized for HCWs while encouraging scientific literature and organizational social media websites.

HIV-1 genotypic profiling ensures effective response to third-line antiretroviral therapy in Cameroon.

In order to limit the emergence of human immunodeficiency virus (HIV) drug resistance in a context of limited antiretroviral options, we sought to evaluate the efficacy of third-line (3L) regimens considering HIV genotypic resistance profile at initiation of 3L in Cameroon. A cohort-study was conducted from January-September 2020 among patients initiating a 3L antiretroviral therapy regimen at the Yaoundé Central Hospital. HIV-1 protease-reverse transcriptase was sequenced at the Chantal Biya international reference center for research on HIV/AIDS prevention and management and results were interpreted using Stanford HIVdbv8.3. Good virological response (viral load < 390 copies/mL) was assessed after 12 months using OPP-ERA platform. Statistical analyses were performed using Epi Info v7.2.2.6, with P < .05 considered statistically significant. Of the 38 patients initiating 3L with an available genotyping (42% female; median age, 49 [39-57] years), median cluster of differentiation type 4 count and viral load were 173 [34-374] cells/µL and 169,322 [30,382-551,826] copies/mL, respectively. At enrollment, all patients harbored resistance to reverse transcriptase inhibitors and 66% (25/38) to protease-inhibitors, although 63% (24/38) were still susceptible to darunavir/ritonavir. Preferred 3L regimen was dolutegravir + darunavir/r + tenofovir + lamivudine (51%) and median duration on 3L was 21 [17-32] months. Interestingly, 82% (31/38) of the participants achieved good virological response on 3L, regardless of genotypic profile at recruitment, variations in 3L regimens (P = .9) and baseline cluster of differentiation type 4 count (P = .3). Despite the high burden of reverse transcriptase inhibitor - and protease inhibitor boosted by ritonavir drug resistance, genotyping-guided 3L regimens is accompanied by virological success in most patients. This high efficacy, most likely due to use of high genetic barrier antiretrovirals, requires continuous adherence support alongside close monitoring for long-term effectiveness in similar programmatic settings.

Viral suppression in the era of transition to dolutegravir-based therapy in Cameroon: Children at high risk of virological failure due to the lowly transition in pediatrics.

This study aimed to compare viral suppression (VS) between children, adolescents, and adults in the frame of transition to dolutegravir (DTG)-based antiretroviral therapy (ART) in the Cameroonian context. A comparative cross-sectional study was conducted from January 2021 through May 2022 amongst ART-experienced patients received at the Chantal BIYA International Reference Centre in Yaounde-Cameroon, for viral load (VL) monitoring. VS was defined as VL < 1000 copies/mL and viral undetectability as VL < 50 copies/mL. Chi-square and multivariate binary logistic regression models were used to identify factors associated with VS. Data were analyzed using SPSS v.20.0 (SPSS Inc., Chicago, Illinois), with P < .05 considered significant. A total of 9034 patients (72.2% females) were enrolled. In all, there were 8585 (95.0%) adults, 227 (2.5%) adolescents, and 222 (2.5%) children; 1627 (18.0%) were on non-nucleoside reverse transcriptase-based, 290 (3.2%) on PI-based, and 7117 (78.8%) on DTG-based ART. Of those on DTG-based ART, only 82 (1.2%) were children, 138 (1.9%) adolescents, and 6897 (96.9%) adults. Median (interquartile range) duration on ART was 24 (12-72) months (24 months on Tenofovir + Lamivudine + Dolutegravir [TLD], 36 months on other first lines, and 84 months on protease inhibitors boosted with ritonavir-based regimens). Overall, VS was 89.8% (95% confidence interval: 89.2-90.5) and viral undetectability was 75.7% (95% confidence interval: 74.8-76.7). Based on ART regimen, VS on Non-nucleoside reverse transcriptase-based, protease inhibitors boosted with ritonavir-based, and DTG-based therapy was respectively 86.4%, 59.7%, and 91.8%, P < .0001. Based on ART duration, VS was respectively 51.7% (≤24 months) versus 48.3% (≥25 months), P < .0001. By gender, VS was 90.9% (5929) in females versus 87.0% (2183) in males, P < .0001; by age-range, VS moved from 64.8% (144) in children, 74.4% (169) adolescents, to 90.8% (7799) adults, P < .0001. Following multivariate analysis, VS was associated with adulthood, female gender, TLD regimens, and combination antiretroviral therapy duration > 24 months (P < .05). In Cameroon, ART response indicates encouraging rates of VS (about 9/10) and viral undetectability (about 3/4), driven essentially by access to TLD based regimens. However, ART response was very poor in children, underscoring the need for scaling-up pediatric DTG-based regimens.

Epidemiological, virological and clinical features of SARS-CoV-2 among individuals during the first wave in Cameroon: Baseline analysis for the EDCTP PERFECT-Study RIA2020EF-3000.

In Cameroon, COVID-19 infection spread rapidly and nationwide, with up to 721 deaths reported. To the best of our knowledge, no study reported the on-theground data using a large patients' dataset to give a comprehensive knowledge on COVID-19 pandemic in Cameroon. The objective of this study was to shade lights on the epidemiological, virological and clinical features of COVID-19 in the Cameroonian context. An observational study was conducted among symptomatic and asymptomatic individuals tested for SARS-CoV-2 by PCR on nasopharyngeal samples from April 22nd, 2020 to January 5th, 2021. Out of 14119 individuals (59.8% male), overall SARS-CoV-2 positivity was 12.7% (from 7.9% in <10 years to 17.3% in >60 years, p<0.001). The positivity rate of symptomatic individuals was 36.1% versus 9.8% among asymptomatic ones, p<0.001. Age group ≤10 [aOR (95%CI): 0.515 (0.338-0.784), p=0.002] and being symptomatic [aOR (95% CI): 5.108 (4.521-5.771), p<0.001] were predictors of SARS-CoV-2 positivity. Regarding PCR Cycle Threshold (CT), 53.8% of positive individuals had a CT <30. According to age, compared to older individuals, those aged 21-40 years showed a higher proportion with high viraemia (CT<20; 21.3% versus 12.5% respectively, p=0.003). Similarly, symptomatic individuals showed a higher proportion with high viraemia (22.4%), when compared to asymptomatic (13.9%); p<0.001. During this first wave of the pandemic, overall SARS-CoV-2 positivity remained high (>10%) and was associated with the presence of symptoms and older age. Most of the infection is among young and asymptomatic individuals, suggesting the "track-and-test" strategy should target these potential transmitters.

High concordance in SARSCoV-2 detection between automated (Abbott m2000) and manual (DaAn gene) RT-PCR systems: The EDCTP PERFECT-Study in Cameroon.

Molecular diagnosis of COVID-19 is critical to the control of the pandemic, which is a major threat to global health. Several molecular tests have been validated by WHO, but would require operational evaluation in the field to ensure their interoperability in diagnosis. In order to ensure field interoperability in molecular assays for detection of SARS-CoV-2 RNA, we evaluated the diagnostic concordance of SARS-CoV-2 between an automated (Abbott) and a manual (DaAn gene) realtime PCR (rRT-PCR), two commonly used assays in Africa. A comparative study was conducted on 287 nasopharyngeal specimens at the Chantal BIYA International Reference Centre (CIRCB) in Yaounde- Cameroon. Samples were tested in parallel with Abbott and DaAn gene rRT-PCR, and performance characteristics were evaluated by Cohen's coefficient and Spearman's correlation. A total of 273 participants [median age (IQR) 36 (26-46) years] and 14 EQA specimens were included in the study. Positivity was on 30.0% (86/287) Abbott and 37.6% (108/287) DaAn gene. Overall agreement was 82.6% (237/287), with k=0.82 (95%CI: 0.777-0.863), indicating an excellent diagnostic agreement. The positive and negative agreement was 66.67% (72/108) and 92.18 % (165/179) respectively. Regarding Viral Load (VL), positive agreement was 100% for samples with high VLs (CT<20). Among positive SARS-CoV- 2 cases, the mean difference in Cycle Threshold (CT) for the manual and Cycle Number (CN) for the automated was 6.75±0.3. The excellent agreement (>80%) between the Abbott and DaAn gene rRTPCR platforms supports interoperability between the two assays. Discordance occurs at low-VL, thus underscoring these tools as efficient weapons in limiting SARS-CoV-2 community transmission.