Abstract
The extent of SARS-CoV-2 circulation in many African countries remains unclear, underlining the need for antibody sero-surveys to assess the cumulative attack rate. Here, we present the ...results of a cross-sectional sero-survey of a random sample of residents of a health district in Yaounde, Cameroon, conducted from October 14 to November 26, 2020. Among the 971 participants, the test-adjusted seroprevalence of anti-SARS-CoV-2 IgG antibodies was 29·2% (95% CI 24·3–34·1). This is about 322 times greater than the 0.09% nationwide attack rate implied by COVID-19 case counts at the time. Men, obese individuals and those living in large households were significantly more likely to be seropositive, and the majority (64·2% 58·7–69·4) of seropositive individuals reported no symptoms. Despite the high seroprevalence, most of the population had not been infected with SARS-CoV-2, highlighting the importance of continued measures to control viral spread and quick vaccine deployment to protect the vulnerable.
The high endemicity of transfusion-transmissible infections (TTIs) in sub-Saharan Africa is a real public health problem. To reduce the risk of HIV transmission through blood donation, the NBTC of ...Gabon has launched in recent years a reorganization of its blood transfusion system. This study aims to characterize the molecular strains of HIV-1 circulating in donors and to estimate the risk of viral transmission.
A cross-sectional study was carried out during the period from August 2020 to August 2021 among 381 donors who had agreed to donate blood at the National Blood Transfusion Center (NBTC). Viral load was determined by Abbott Real-Time (Abbott m2000®, Abbott) and sequencing by the Sanger method (ABI 3500 Hitachi®). The phylogenetic tree was constructed by MEGA X software. Data were checked, entered, and analyzed using SPSS version 21.0 software, with p ≤ 0.05 considered statistically significant.
A total of 381 donors were enrolled in the study. Among the 359 seronegative donors, five (5) seronegative donors were detected positive for HIV-1 using Real-Time PCR. The residual risk was 648 per 1,000,000 donations. The prevalence of residual infection was 1.4% 0,01; 0,03. Sixteen (16) samples were sequenced. The strains obtained were CRF02_AG (50%), subtype A1 (18.8%), subtype G (12.5%), CRF45_cpx (12.5%) and subtype F2 (6.2%). Six sequences clustered with A1, G, CRF02_AG, and CRF45_cpx subtypes.
The residual risk of HIV-1 transmission by blood transfusion remains a concern in the Gabonese transfusional settings. A policy based on improving the current screening strategy would involve the implementation of the nucleic acid test (NAT) in order to optimize the safety of the donation by detecting the HIV-1 subtypes in circulation in the donors.
Prevention of mother-to-child transmission (PMTCT) has reduced HIV incidence among new-borns. However, PMTCT remains concerning in sub-Saharan Africa due to bottlenecks including viral load (VL) ...monitoring during pregnancy. We assessed VL coverage and materno-foetal outcomes of pregnancy among HIV-infected women within the Cameroonian context. A hospital-based study was conducted among HIV-infected mothers and their babies in three facilities of the Littoral region of Cameroon from January 2019 to May 2021. Maternal VL-coverage was monitored during pregnancy (VL>1000 copies/ml or unknown were classified as MTCT high-risk group); HIV early infant diagnosis (EID) was evaluated by PCR at six-weeks after birth, and EID results were analysed according to maternal VL; p<0.05 was considered statistically significant. Of 135 HIV-infected pregnant women enrolled (median IQR age 39 27-37 years), VL-coverage during antenatal care (ANC) was 50.4% (68/135), with a lower VL-coverage in 2019 (37.5% vs. 61.9%, p = 0.0069). Married women vs. single (61.8% vs. 42.5%, p = 0.0275) and those on treatment before vs. during pregnancy (56.7% vs. 5.8%, p = 0.0043) had a higher VL-coverage, respectively. Among those with known VL, 10.3% (7/68) had high (VL>1000 copies/mL), 22.1% (15/68) had low (50-1000 copies/mL), and 67.6% (46/68) had undetectable (<50 copies/mL) VL, suggesting an overall viral suppression (<1000copies/mL) of 89.7% (61/68). Vaginal delivery was 80.75% (109/135) regardless of VL, including 81.1% (59/74) women in the high-risk group. EID coverage was 88.1% (119/135) and the rate of HIV-1 MTCT was 1.68% (2/119). Both HIV-positive infants were from the high-risk group, had prolonged labour, had vaginal delivery and were breastfed. In these Cameroonian settings, VL-coverage remains suboptimal (below 90%) among ANC attendees, and women at high-risk of MTCT mainly have vaginal delivery. Viral suppression rate remains below the target (below 90%) for accelerating the elimination of MTCT. HIV-MTCT persists, and might be driven essentially by poor VL monitoring. Thus, achieving an optimal PMTCT performance requires a thorough compliance to virologic assessment during ANC.
The objective of this study was to determine the rates of virological failure (VF) and HIV drug resistance (HIVDR) amongst adolescents on antiretroviral Therapy (ART). A retrospectively designed ...study was conducted in 10 healthcare centers for adolescents living with HIV (ALHIV) in the two main cities of Cameroon (Yaoundé and Douala), from November 2018 to May 2019. Sociodemographic, clinical, therapeutic and laboratory parameters were collected from medical records. All enrolled ALHIV had viral load (VL) measurements following the national guidelines. All patients with a VL ≥ 1000 copies/ml were called to perform genotyping tests. The chi-square test was used to determine the factors associated with VF. Out of the 1316 medical records of ALHIV, we included 1083 ALHIV having a VL result. Among them, 276 (25.5%) were experiencing VF, and VF was significantly higher in ALHIV with suboptimal adherence (p<0.001), older adolescents (p<0.05), those who lived outside the city where they were receiving ART (p<0.006), severely immunocompromised (p<0.01) and started ART at infancy (p<0.02). Among the 45/276 (16.3%) participants with an available genotyping resistance testing (GRT) result, the overall rate of HIVDR was 93.3% (42/45). The most common mutations were K103N (n = 21/42, 52.3%) resulting in high-level resistance to Efavirenz and Nevirapine, followed by M184V (n = 20/42, 47.6%) and thymidine analog mutations (n = 15/42, 35.7%) associated with high-level resistance to Lamivudine and Zidovudine respectively. The high rate of VF and HIVDR among ALHIV regularly followed in health facilities in Cameroon highlights the need to develop interventions adapted to an adolescent-centered approach to preserve future ART options.
Multiple factors, such as immune disruption, prophylactic co-trimoxazole, and antiretroviral therapy, may influence the structure and function of the gut microbiome of children infected with HIV from ...birth. In order to understand whether HIV infection altered gut microbiome and to relate changes in microbiome structure and function to immune status, virological response and pediatric ART regimens, we characterized the gut microbiome of 87 HIV-infected and 82 non-exposed HIV-negative children from Yaounde, a cosmopolitan city in Cameroon. We found that children living with HIV had significantly lower alpha diversity in their gut microbiome and altered beta diversity that may not be related to CD4+ T cell count or viral load. There was an increased level of Akkermansia and Faecalibacterium genera and decreased level of Escherichia and other Gamma proteobacteria in children infected with HIV, among other differences. We noted an effect of ethnicity/geography on observed gut microbiome composition and that children on ritonavir-boosted protease inhibitor (PI/r)-based ART had gut microbiome composition that diverged more from HIV-negative controls compared to those on non-nucleoside reverse-transcriptase inhibitors-based ART. Further studies investigating the role of this altered gut microbiome in increased disease susceptibility are warranted for individuals who acquired HIV via mother-to-child transmission.
Limited studies have reported the outcomes of lifelong antiretroviral therapy (ART) amongst adolescents living with HIV (ALWHIV) in resource-limited settings (RLS), thus classifying this population ...as underserved. We therefore aimed to ascertain the immunological and virological responses, and associated factors amongst Cameroonian ALWHIV.
A cross-sectional and observational study was conducted from January through May 2016 at the National Social Insurance Fund Health Centre in Yaoundé-Cameroon. Immunological and virological responses were evaluated using CD4 cell count and viral load respectively, with viral suppression (VS) defined as <50 copies/ml. Adherence was evaluated using self-reported missing doses during the past 14 days. Data were analyzed using R v.3.3.0, with p<0.05 considered statistically significant.
Of the 145 ALWHIV on ART enrolled in the study, 52% were female, median age interquartile (IQR) was 13 11-16 years, median IQR time-on-ART was 7 5-10 years, 48% were orphans, 92% were on first-line ART and 36% were adherent to ART. Following ART response, 79% (114/145) had CD4 ≥500/mm3, 71.0% (103/145) were on VS of whom 52.4% (76/145) had a sustained VS. Duration of ART was associated with immune restoration (Odd Ratio 3.73 1.26-12.21) but not with virological response. Risks of poor adherence were greater in orphans of both parents (p = 0.078).
In this urban setting of Cameroon, ALWHIV receiving ART show favorable immunological and virological response in a medium run. For long-term ART success, implementing a close monitoring of adherence and risks of viral rebound would be highly relevant, especially for orphans of both parents.
Background The SARS-CoV-2 pandemic is a global threat affecting 210 countries, with 2,177,469 confirmed cases and 6.67% case fatality rate as of April 16, 2020. In Africa, 17,243 cases have been ...confirmed, but many remain undiagnosed due to limited laboratory-capacity, suboptimal performance of used molecular-assays (~30% false negative, Yu et al. and Zhao et al., 2020) and limited WHO-recommended rapid-tests. Objectives We aim to implement measures to minimize risks for COVID-19 in Cameroon, putting together multidisciplinary highly-experienced virologists, immunologists, bioinformaticians and clinicians, to achieve the following objectives: (a) to integrate/improve available-infrastructure, methodologies, and expertise on COVID-19. For this purpose, we will create a platform enabling researchers/clinicians to better integrate and translate evidence into the COVID-19 clinical-practice; (b) to enhance capacities in Cameroon for screening/detecting individuals with high-risks of COVID-19, by setting-up effective core-facilities on-site; (c) to validate point-of-care SARS-CoV-2 molecular assays allowing same-day result delivery, thus permitting timely diagnosis, treatment, and retention in care of COVID-19 patients; (d) to implement SARS-CoV-2 diagnosis with innovative/highly sensitive ddPCR-based assays and viral genetic characterization; (e) to validate serological assays to identify COVID-19-exposed persons and follow-up of convalescents. Methods This is a prospective, observational study conducted among COVID-19 suspects/contacts during 24 months in Cameroon. Following consecutive sampling of 1,536 individuals, oro/nasopharyngeal swabs and sera will be collected. Well characterised biorepositories will be established locally; molecular testing will be performed on conventional real-time qPCR, point-of-care GeneXpert, antigen-tests and digital droplet PCR (ddPCR); SARS-CoV2 amplicons will be sequenced; serological testing will be performed using ELISA, and antibody-based kits. Sensitivity, specificity, positive- and negative-predictive values will be evaluated. Expected outcomes These efforts will contribute in creating the technical and clinical environment to facilitate earlier detection of Sars-CoV-2 in Africa in general and in Cameroon in particular. Specifically, the goals will be: (a) to implement technology transfer for capacity-building on conventional and point-of-care molecular assays, achieving a desirable performance for clinical diagnosis of SARS-CoV2; (b) to integrate/improve the available infrastructure, methodologies, and expertise on Sars-CoV2 detection; (c) to improve the turn-around-time for diagnosing COVID-19 infection with obvious advantage for patients/clinical management thanks to low-cost assays, thus permitting timely treatment and retention in care; (d) to assess the epidemiology of COVID-19 and circulating-variants in Cameroon as compared to strains found in other countries.
The Viral hepatitis elimination by 2030 is uncertain in resource-limited settings (RLS), due to high burdens and poor diagnostic coverage. This sounds more challenging for hepatitis C virus (HCV) ...given that antibody (HCVAb) sero-positivity still lacks wide access to HCV RNA molecular testing. This warrants context-specific strategies for appropriate management of liver impairment in RLS. We herein determine the association between anti-HCV positivity and liver impairment in an African RLS.
A facility-based observational study was conducted from July-August 2021 among individuals attending the "St Monique" Health Center at Ottou, a rural community of Yaounde,Cameroon. Following a consecutive sampling, consenting individuals were tested for anti-HCV antibodies, hepatitis B surface antigen (HBsAg) and HIV antibodies (HIVAb) as per the national guidelines. After excluding positive cases for HBsAg and/or HIVAb, liver function tests (ALT/AST) were performed on eligible participants (HBsAg and HIVAb negative) and outcomes were compared according to HCVAb status; with p < 0.05 considered statistically significant.
Out of 306 eligible participants (negative for HBsAg and HIVAb) enrolled, the mean age was 34.35 ± 3.67 years. 252(82.35%) were female and 129 (42.17%) were single. The overall HCVAb sero-positivity was 15.68%(48/306), with 17.86% (45/252) among women vs. 5.55%(3/54) among men OR (95%CI) = 3.69(2.11-9.29),p = 0.04. HCVAb Carriage was greater among participants aged > 50 years compared to younger ones 38.46%(15/39) versus 12.36% (33/267) respectively, OR(95%CI) = 4.43(2.11-9.29), p < 0.000 and in multipartnership 26.67%(12/45)vs.13.79%(36/261) monopartnership, OR (95%CI) = 2.27(1.07-4.80),p = 0.03. The liver impairment rate (abnormal ALT+AST levels) was 30.39%(93/306), with 40.19%(123/306) of abnormal ALT alone. Moreover, the burden of Liver impairment was significantly with aged> 50 versus younger ones 69.23% (27/39) versus 24.72%(66/267) respectively, p < 0.000). Interestingly, the burden of liver impairment (abnormal AST + ALAT) was significantly higher in HCVAb positive (62.5%, 30/48) versus HCVAb negative (24.42%, 63/258) participants, OR: 3.90 1.96; 7.79, p = 0.0001.
In this rural health facility, HCVAb is highly endemic and the burden of liver impairment is concerning. Interestingly, HCVAb carriage is associated with abnormal liver levels of enzyme (ALT/AST), especially among the elderly populations. Hence, in the absence of nuclei acid testing, ALT/AST are relevant sentinel markers to screen HCVAb carriers who require monitoring/care for HCV-associated hepatocellular carcinoma in RLS.
Background COVID-19 has been the most important public health concern worldwide since 2020. Several vaccines are now available to help in controlling COVID-19 associated morbidity and mortality. This ...study will aim to provide the global and regional prevalence of SARS-CoV-2 infection as well as an estimate of disease severity among COVID-19 vaccinated individuals. Materials and methods In order to determine the global burden of SARS-CoV-2 infection among vaccinated individuals, we will systematically extract and review papers from PubMed/MEDLINE, Excerpta Medica database (EMBASE), Cochrane Central Register of Controlled Trials (CENTRAL), Science direct and Cumulative Index to Nursing and Allied Health Literature (CINAHL). All the studies describing the prevalence and/or disease severity (hospitalization and case fatality rate) data of COVID-19 among individuals who received a partial or complete dose of WHO-approved COVID-19 vaccines will be eligible. A random effect model will be used to calculate the pooled prevalence and to estimate the disease severity. Subgroup analysis will be performed to explore the association between the number of vaccine doses received and the COVID-19 burdens. Discussion This systematic review and meta-analysis will provide the global estimate data on pooled prevalence, hospitalization and case fatality rates of COVID-19 among vaccinated individuals. Moreover, the factors associated with reinfection and disease severity will be equally investigated in the meta-analysis. The results of this study will contribute in the understanding and estimation of the global burden of COVID-19 among vaccinated individuals. Findings will provide meaningful information for the success of the current global rollout of COVID-19 vaccination strategies and pave the way for future interventions. Systematic review registration CRD42021273074.
Health personnel (HP) are on the frontlines during response to public health emergencies like COVID-19. This risk of exposure suggests the need for safety in responding to any pandemic. Therefore, to ...ascertain the rate of SARS-CoV-2 infection and immunity, and their determinants amongst HP become relevant.
A cross sectional health facility-based study was carried-out amongst HP in the Centre Region of Cameroon from 1st February to 30th June 2021. Characteristics and access to preventive tools were collected using face-to-face administered questionnaire. Nasopharyngeal swabs and whole blood were collected for PCR, IgG and IgM testing respectively. STATA version 17 software was used for data analysis. Determinants of COVID-19 infection were explored by estimating crude and adjusted Odd Ratio.
Out of 510 HP reached, 458 were enrolled with mean age of 35 (±10) years. Thirty-four (7.4%) were PCR-positive to SARS-CoV-2 with 73.5% being clinicians versus 9 (26.4%) non-clinicians (p = 0.05). Sero-positivity to SARS-CoV-2 IgG/IgM was 40.2% (184/458), with 84.2% being clinicians versus 29 (15.8%) non-clinicians (p = 0.733). Amongst the 34 HP with PCR-positivity, 16 (47%) had no antibodies, while, 15 (44%) were IgG only. An estimate of HP (43.7%) had at least an evidence of PCR, IgG or IgM contact to COVID-19. Determinants of PCR-positivity was being clinical staff (AOR = 0.29, P = 0.039); and that of IgG/IgM were being non clinical staff (AOR = 0.41, p = 0.018) and regular use of face masks (AOR = 0.44, p = 0.001). HP trained on IPC (24%) were mainly from peripheral level (74.7%, p = 0.002).
Active infections were within the range of pandemic control (<10%). However, around two-fifths of participants have had contact with the virus, indicating that HP remains a population at risk of COVID-19 and other similarly-transmitted epidemic prone diseases, and also an important source of transmission. There is need of vaccine to achieve protectiveness, and optimal response also requires capacity building to improve the health system when challenged by a future pandemic.
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