Seroprevalence of SARS-CoV-2 antibodies and associated risk factors during the second wave of infection in a university community in Cameroon.

Background: The COVID-19 pandemic has caused a public health emergency in all sectors of society, including universities and other academic institutions in Cameroon. However, little is known concerning the real prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among student communities during the second wave of infection in Cameroon. This study aimed to estimate SARS-CoV-2 antibodies seroprevalence among participants in a university community in Cameroon. Methodology: A cross-sectional study was conducted from March to April 2021 in 547 students aged ≥18 years during a mass diagnostic campaign at the School of Health Sciences of the Catholic University of Central Africa (ESS/UCAC). The anti-SARS-CoV-2 antibody screening was done using the Panbio™ COVID-19 IgG/IgM Rapid Diagnostic Test. Results: The overall seroprevalence of SARS-CoV-2 antibodies was 27%, of which 89.9% (n = 133) was IgG, 6.7% (n = 10) IgM and 3.4% (n = 5) IgG/IgM positive. The undergraduate students represented 79% (432/547) of the total population and were highly positive with anti-SARS-CoV-2 antibodies 30% (130/432) as compared with postgraduate students 20% (23/115). The total antibody seropositivity was higher in males (34.4%) than females (24.9%). Several factors were associated with an increased risk of SARS-CoV-2 seroprevalence including the male gender (OR: 1.61 [95% confidence interval, CI 1.0-2.4]), specialization to medical laboratory (OR: 2.8 [95% CI 1.1-7.1]) and nursing sciences (OR: 2.6 [95% CI 1.1-6.2]). Conclusion: Our findings point to extensive and underreported circulation of SARS-CoV-2 in a university community during the second wave of infection in Cameroon, which likely resulted in artificially low case counts.

Plasma IL-33 levels and immune activation in HIV-TB coinfection: a cross-sectional study in Yaoundé, Cameroon.

Introduction: HIV-1 and Mtb are characterized by immune activation and unbalances production of cytokines, but the expression of IL33 in HIV/TB coinfection remain understudied. This study aimed to evaluate the level of IL-33 in plasma of HIV and M. tuberculosis (HIV/TB) coinfected patients compared to patients with respective mono infections in Yaoundé. Methods: a cross-sectional study was conducted among patients attending the pneumology service and HIV treatment center of the Yaoundé Jamot Hospital. Plasma samples of 157 HIV/TB coinfected patients (n =26, 50% males and 50% females, mean age 39), HIV-1 monoinfected patients (n = 41, 41% males and 59% females, mean age 35), TB monoinfected patients (n = 48, 56% males and 44% females, mean age 37) and healthy controls (n = 42, 29% males and 71% females, mean age 32) were examined by enzyme-linked immunoassay (ELISA) to detect the levels of IL-33 cytokine. Results: plasma level of IL-33 were higher in HIV/TB coinfected (33.1±30.9 pg/ml) and TB monoinfected individuals (15.1±2.9 pg/ml) compared to healthy controls (14.0±3.4 pg/ml) and could not be detected in most of the HIV-1 monoinfected individuals (12.6±8.7 pg/ml). Interestingly, the increased plasma level of IL-33 in HIV/TB coinfected patients showed a statistically significant difference between healthy controls (33.1±30.9 pg/ml vs 14.0±3.4 pg/ml, P<0.0001) and HIV-1 monoinfected patients (33.1±30.9 pg/ml vs 12.6±8.7 pg/ml, P=0.0002). We further found that IL-33 was higher in patients with high viral load group (40.6±59.7 pg/ml vs 12.6±1.8 pg/ml), P= 0.47) whereas patients under highly active antiretroviral therapy (HAART) showed decreased level of IL-33 concentration as the number of years under ART increased. Our data showed a positive association between plasma IL-33 and viral load in the context of HIV/TB coinfection in our study population with a positive Pearson coefficient of r=0.21. Conclusion: this study indicates that plasma level of IL-33 differs among HIV/TB coinfected patients and respective monoinfections patients. The increased level of plasma IL-33 reveals that IL-33 measurement in HIV-1 monoinfected patients may represent an early predictor of development of tuberculosis.