XBB.1, BQ1.1 and atypical BA.4.6/XBB.1 recombinants predominate current SARS-CoV-2 Wavelets with flu-like symptoms in Cameroon: A snapshot from genomic surveillance.

As of December 2022, Cameroon had observed a slight resurgence of COVID-19, raising concerns on genomic surveillance of related-SARS-CoV-2 variants under circulation. Following a laboratory-based survey, positive SARS-CoV-2 samples detected from December-2022 through March-2023 were processed for targeted sequencing at the Chantal BIYA International Reference Centre (CIRCB) in Yaoundé-Cameroon. From all positive cases detected, 13 were successfully sequenced (mean age 34 years, 70% female); the majority of the cases were unvaccinated (70%, 9/13) and symptomatic (92%, 12/13); all with flu-like symptoms (100%, 12/12). Following RT-PCR, the median cycle threshold was 22.23 [18-24] for the N gene; and 24.09 [20-26] for the ORF gene, underscoring high viral loads. Phylogenetic analysis of nucleotide sequences identified four major sub-variants in circulation, of which BA.5 (3/13), the recombinants BQ.1.1 (4/13), XBB.1 (4/13) and novel atypical variant of BA.4.6/XBB.1 (2/13). This snapshot surveillance indicates the introduction/emergence and circulation of new Omicron sub-variants, all accompanied by minor/mild symptoms. However, these new sub-variants and recombinants call for continuous genomic surveillance to prevent further resurgence of Covid-19 epidemiological wave.

Evaluation of HIV-1 DNA levels among adolescents living with perinatally acquired HIV-1 in Yaounde, Cameroon: A contribution to paediatric HIV cure research in Sub-Saharan Africa.

Background: With the advent of antiretroviral therapy (ART), most children living with HIV in sub-Saharan Africa (SSA) are growing toward adolescence, with scarcity of evidence on the size of viral reservoirs to enhance paediatric cure research strategies. This study aims to compare HIV-1 proviral DNA levels according to virological response among adolescents living with perinatally acquired HIV-1 (ALPHIV) and identify associated-factors in the Cameroonian context. Methods: In this observational cohort study, HIV-1 RNA viremia and CD4+ T-cell count were assessed through RT-PCR and flow cytometry respectively at three time-points over 18 months of observation. At the third time-point, 80 randomly-selected participants were classified as with viremia (≥50 HIV-1 copies/mL; n = 40) or without viremia (<50 HIV-1 copies/mL; n = 40); immune-competent (≥500 CD4+ T cells/mm3) or immunocompromised (<500 CD4+ T cells/mm3). Among these participants, total HIV-1 DNA load was quantified through droplet digital PCR using Bio-Rad QX200. Results: Of the 80 randomly-selected adolescents, median [IQR] age was 15 (13-17) years, 56.2% were female, duration on ART was 9.3 [5.4-12.2] years. Among the 40 viremic ones (median viremia 7312 [283-71482]) HIV-1 copies/ml, 75.0% (30/40) were in virological failure (≥1000 HIV-1 copies/ml), while median of CD4 T cells were 494 [360-793] cell/mm3 with 48.8% (39/80) immunocompromised. No significant variation in HIV-1 RNA viremia and CD4 T cell count was observed between the three time-points, and 13.7% (11/80) adolescents remained aviremic and immune-competent throughout (stable adolescents). A positive and moderate correlation (r = 0.59; p < 0.001) was found between HIV-1 DNA levels and HIV- 1 RNA viremia. Regarding the CD4 T cell count, a negative and weak correlation (r = -0.28; p = 0.014) was found with HIV-1 DNA loads only among adolescents with viremia. Starting ART within the first year of life, ART for over 9 years and aviremia appear as predictors of low HIV-1 DNA loads. Conclusion: Among ALPHIV, high HIV-1 RNA indicates an elevated viral reservoir size, representing a drawback to cure research. Interestingly, early ART initiation and longer ARTduration lead to sustained viral control and limited HIV-1 reservoir size. As limited size of viral reservoir appears consistent with viral control and immune competence, adolescents with sustained viral control (about 14% of this target population) would be candidates for analytical ART interruptions toward establishing paediatric post-treatment controllers in SSA.

SARS-CoV-2 genomic surveillance and reliability of PCR single point mutation assay (SNPsig® SARS-CoV-2 EscapePLEX CE) for the rapid detection of variants of concern in Cameroon.

Background: Surveillance of SARS-CoV-2 variants of concern (VOCs) and lineages is crucial for decision-making. Our objective was to study the SARS-CoV-2 clade dynamics across epidemiological waves and evaluate the reliability of SNPsig® SARS-CoV-2 EscapePLEX CE in detecting VOCs in Cameroon. Material and methods: A laboratory-based study was conducted on SARS-CoV-2 positive nasopharyngeal specimens cycle threshold (Ct)≤30 at the Chantal BIYA International Reference Centre in Yaoundé-Cameroon, between April-2020 to August-2022. Samples were analyzed in parallel with Sanger sequencing and (SNPsig® SARS-CoV-2 EscapePLEX CE), and performance characteristics were evaluated by Cohen's coefficient and McNemar test. Results: Of the 130 sequences generated, SARS-CoV-2 clades during wave-1 (April-November 2020) showed 97 % (30/31) wild-type lineages and 3 % (1/31) Gamma-variant; wave-2 (December-2020 to May-2021), 25 % (4/16) Alpha-variant, 25 % (4/16) Beta-variant, 44 % (7/16) wild-type and 6 % (1/16) mu; wave-3 (June-October 2021), 94 % (27/29) Delta-variant, 3 % (1/29) Alpha-variant, 3 % (1/29) wild-type; wave-4 (November-2021 to August-2022), 98 % (53/54) Omicron-variant and 2 % (1/54) Delta-variant. Omicron sub-variants were BA.1 (47 %), BA.5 (34 %), BA.2 (13 %) and BA.4 (6 %). Globally, the two genotyping methods accurately identified the SARS-CoV-2 VOCs (P = 0.17, McNemar test; Ka = 0.67). Conclusion: Genomic surveillance reveals a rapid dynamic in SARS-CoV-2 strains between epidemiological waves in Cameroon. For wide-spread variant surveillance in resource-limited settings, SNPsig® SARS-CoV-2 EscapePLEX CEkit represents a suitable tool, pending upgrading for distinguishing Omicron sub-lineages.

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.

Determinants of Immunovirological Response among Children and Adolescents Living with HIV-1 in the Central Region of Cameroon.

About 90% of new HIV-1 infections in children occur in sub-Saharan Africa, where treatment monitoring remains suboptimal. We sought to ascertain factors associated with immunovirological responses among an ART-experienced paediatric population in Cameroon. A laboratory-based and analytical study was conducted from January 2017 throughout December 2020 wherein plasma viral load (PVL) analyses and CD4 cell counts were performed. Viral suppression (VS) was defined as PVL < 1000 copies/mL and immunological failure (IF) as CD4 < 500 cells/µL for participants ≤5 years and CD4 < 250 cells/µL for those >5 years; p < 0.05 was considered statistically significant. Overall, 272 participants were enrolled (median age: 13 [9-15.5] years; 54% males); median ART duration 7 [3-10] years. Globally, VS was achieved in 54.41%. VS was 56.96% in urban versus 40.48% in rural areas (p = 0.04). IF was 22.43%, with 15.79% among participants ≤5 years and 22.92% among those >5 years (p = 0.66). IF was 20.43% in urban versus 33.33% in rural areas (p = 0.10). Following ART, IF was 25.82% on first-line (non-nucleoside reverse transcriptase inhibitors; NNRTI-based) versus 10.17% on second-line (protease inhibitor-based) regimens (p = 0.01). Interestingly, IF was 7.43% among virally suppressed versus 40.32% among virally unsuppressed participants (p < 0.0001). A low VS indicates major challenges in achieving AIDS' elimination in this paediatric population, especially in rural settings and poor immune statuses. Scaling up NNRTI-sparing regimens alongside close monitoring would ensure optimal therapeutic outcomes.

Characterization of HIV-1 Reservoirs in Children and Adolescents: A Systematic Review and Meta-Analysis Toward Pediatric HIV Cure.

OBJECTIVE: To conduct a comprehensive, systematic review of the profile of HIV-1 reservoirs in children and adolescents with perinatally acquired HIV infection. STUDY DESIGN: Randomized and nonrandomized trials, cohort studies, and cross-sectional studies on HIV reservoirs in pediatric populations, published between 2002 and 2022, were included. Archived-drug resistance mutations (ADRMs) and the size of reservoirs were evaluated. Subgroup analyses were performed to characterize further the data, and the meta-analysis was done through random effect models. RESULTS: Overall, 49 studies from 17 countries worldwide were included, encompassing 2356 perinatally infected participants (48.83% females). There are limited data on the quantitative characterization of viral reservoirs in sub-Saharan Africa, with sensitive methodologies such as droplet digital polymerase chain reaction rarely employed. The overall prevalence of ADRMs was 37.80% (95% CI 13.89-65.17), with 48.79% (95% CI 0-100) in Africa, 42.08% (95% CI 6.68-82.71) in America, 23.88% (95% CI 14.34-34.90) in Asia, and 20.00% (95% CI 10.72-31.17) in Europe, without any difference between infants and adolescents (P = .656). Starting antiretroviral therapy (ART) before 2 months of age limited the levels of HIV-1 DNA (P = .054). Participants with long-suppressed viremia (>5 years) had lower levels of HIV-1 DNA (P = .027). Pre- and post-ART CD4 ≤29% and pre-ART viremia ≥5Log were all found associated with greater levels of HIV-1 DNA (P = .038, P = .047, and P = .041, respectively). CONCLUSIONS: The pooled prevalence of ADRMs is high in perinatally infected pediatric population, with larger proviral reservoir size driven by delayed ART initiation, a shorter period of viral suppression, and immunovirological failures. Thus, strategies for pediatric HIV functional cure should target children and adolescents with very early ART initiation, immunocompetence, and long-term viral suppression.