RESUMO
Background: WHO recommends the use of COVID-19 antigen rapid diagnostic tests (Ag-RDT) with at least 80 % sensitivity and 97 % specificity. In the era of Omicron variants, we sought to ascertain the performance of the INDICAID™ Ag-RDT compared to real-time PCR (RT-PCR) as the gold standard. Methods: A laboratory-based study was conducted among consenting individuals tested for COVID-19 at the virology laboratory of the Chantal BIYA International Reference Centre, Yaoundé-Cameron. The samples were processed by INDICAID™ Ag-RDT and DaAn Gene real-time PCR according to the manufacturer's instructions, and PCR-results were interpreted as per cycle thresholds (CT). The sensitivity, specificity, positive and negative predictive values (PPV and NVP) of INDICAID™ Ag-RDT were evaluated according to PCR CT-values. Results: A total of 565 nasopharyngeal swabs were collected from participants (median age [IQR]: 40 [31-75]; M/F sex-ratio was 1.2 and 380 were vaccinated). Following PCR, overall COVID-19 positivity was 5.66 %. For CT < 37, INDICAID™ Ag-RDT sensitivity was 21.9 % (95%CI: [8.3-39.9]), specificity 100 % (95%CI: [99.3-100]); PPV 100 % (95%CI: [59.0-100]), NPV 95.5 % (95%CI: [93.4-97.1]) and kappa = 0.34 (95%CI: [0.19-0.35]). For CT < 25, sensitivity was 100 % (95%CI: [47.8-100.0]), specificity 99.6 % (95%CI: [98.7-99.9]); PPV 94.4 % (95%CI: [51.7-100]), NPV 100 % (95%CI: [99.3-100]) and kappa = 0.83 (95%CI: [0.6-1.0]). COVID-19 sequences generated were all Omicron BA.1 subvariants. Conclusion: For patients infected with high viral loads (CT < 25), INDICAID™ Ag-RDT has high intrinsic (sensitivity and specificity) and extrinsic (predictive values) performances for COVID-19 diagnosis. Due to its simplicity and short turnaround time, INDICAID™ Ag-RDT is, therefore a reliable tool to prevent the spread of COVID-19 at community level in the current era of Omicron subvariants.
RESUMO
Non-pharmaceutical interventions remain key in mitigating the spread of SARS-CoV-2. We sought to assess COVID-19 preventive, social-behavioural practices, and SARS-CoV-2 exposure through IgG rapid tests. This was a cross-sectional survey among 971 respondents residing in 180 households within the "Cite Verte" health district of Yaounde-Cameroon, from October-November 2020. Using a structured questionnaire, data on SARS-CoV-2 preventive and social behavioural practices were collected, while exposure to SARS-CoV-2 was determined by IgG profiling. p<0.05 was considered statistically significant. Overall, 971 participants were enrolled, among whom 56.5% were females. The age group 15-29 (33.5%) and those with a secondary level of education (44.7%) were most represented. Regarding preventive/social behavioural practices, the least respected measure was "stopped work", 49.1%, while the most respected was "Respect of hygiene rules", 93.8%. Women obeyed preventive measures more than men, with 87.6% vs 81.0% adhering to the lockdown, (p = 0.005) and 95.5% vs 91.7% to hygiene rules (p = 0.017). The age range 45-64 years was the least adherent to the lockdown rule, with 75.2% (38/153), p<0.0001. Only 24.7% (73/295) and 6.1% (59/295) of the symptomatic individuals reported having sought medical consultation and Covid-19 testing respectively. In addition, up to 69.8% (555/795) felt healthcare facilities were high-risk sites for getting infected, p = 0.002. Exposure to SARS-CoV-2 by IgG positivity was 31.1% (302/971), with men recording a higher proportion of viral exposure, 51.0% (154/302), p = 0.021. After adjusting for gender, age, education, and occupation; salaried worker (p = 0.029; OR: 0.29), and trading (p = 0.001; OR: 0.23) least complied with lockdown rule. In this community of Cameroonian residents highly exposed to COVID-19, many perceived healthcare facilities as high-risk zones for SARS-CoV-2 infection and consequently did not seek medical interventions. Thus, in the context of such a pandemic, advocacy on risk communication and community engagement for health-seeking attitudes should preferentially target men and those afraid of pandemics.
RESUMO
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.
