Pre-existing immunity to SARS-CoV-2 before the COVID-19 pandemic era in Cameroon: A comparative analysis according to HIV-status

BackgroundThe lower burden of COVID-19 in tropical settings may be due to preexisting cross-immunity, which might vary according to geographical locations and potential exposure to other pathogens. We sought to assess the overall prevalence of SARS-CoV-2 antibodies and determine SARS-CoV-2 seropositivity according to HIV-status before the COVID-19 pandemic era. MethodsA cross-sectional and comparative study was conducted at the Chantal BIYA International Reference Centre (CIRCB) on 288 stored plasma samples (163 HIV-positive versus 125 HIV-negative); all collected in 2017-2018, before the COVID-19 pandemic era. Abbott Panbio (TM) COVID-19 IgG/IgM assay was used for detecting SARS-CoV-2 immunoglobulin G (IgG) and M (IgM). Among people living with HIV (PLHIV), HIV-1 viral load and TCD4 cell count (LTCD4) were measured using Abbott Real Time PCR and BD FACSCalibur respectively. Statistical analyses were performed, with pResultsThe median [IQR] age was 25 [15-38] years. Overall seropositivity to SARS-CoV-2 antibodies was 13.5% (39/288) of which 7.3% (21) was IgG, 7.3% (21) IgM and 1.0% (3) IgG/IgM. According to HIV-status in the study population, SARS-CoV-2 seropositivity was 11.0% (18/163) among HIV-positive versus 16.8% (21/125) among HIV-negative respectively, p=0.21. Specifically, IgG was 6.1% (10/163) versus 8.8% (11/125), p=0.26; IgM was 5.5% (9/163) versus 9.6%, (12/125), p=0.13 and IgG/IgM was 0.6% (1/163) versus 1.6% (2/125) respectively. Among PLHIV, SARS-CoV-2 seropositivity according to CD4 count was 9.2% (>= 500 cells/mu L) versus 1.8% (200-499 cells/mu L), (OR=3.5; p=0.04) and 0.6% (<200 cells/mu L), (OR=17.7; p<0.01). According to viral load, SARS-CoV-2 seropositivity was 6.7% (>= 40 copies/mL) versus 4.9% (<40 copies/mL), (OR= 3.8; p<0.01). ConclusionBefore COVID-19 in Cameroon, cross-reactive antibodies to SARS-CoV-2 were in circulation, indicating COVID-19 preexisting immunity. This preexisting immunity may contribute in attenuating disease severity in tropical settings like Cameroon. Of relevance, COVID-19 preexisting immunity is lower with HIV-infection, specifically with viral replication and poor CD4-cell count. As poor CD4-count leads to lower cross-reactive antibodies (regardless of viral load), people living with HIV appear more vulnerable to COVID-19 and should be prioritized for vaccination

Correlation between the immuno-virological response and the nutritional profile of treatment-experienced HIV-infected patients in the East region of Cameroon.

BackgroundHIV management remains concerning and even more challenging in the frame of comorbidities like malnutrition that favors disease progression and mortality in resource-limited settings (RLS).ObjectiveTo describe the nutritional parameters of antiretroviral therapy (ART) recipients (without nutritional support) with respect to CD4 count and virological failure.MethodsA cross-sectional study was conducted from October to December 2018 among 146 consenting participants enrolled in two health facilities of the East-Region of Cameroon. Socio-demographic data, basic clinical information and treatment history were collected; blood samples were collected by venipuncture for laboratory analysis (HIV-1 viral load, CD4 Tcells measurement and biochemical analysis) performed at the "Chantal Biya" International Reference Center", Yaounde, Cameroon. The nutritional profile was assessed by using anthropometric and biochemical parameters. Data were analyzed using Excel 2016, Graph pad prism version 6; Spearman correlation and Kruskal-Wallis test were used; with pResultsMedian [IQR] age was 42 [33-51] years, 76.0% (111/146) were female and median [IQR] duration on ART was 54 [28-86] months. Of these participants, 11.6% (17/146) were underweight based on the body mass index and 4.7% (7/146) were at the stage of advanced weight loss. According to immunovirological responses, 44.5% (65/146) were immunocompromised (CD4ConclusionIn this RLS, with patients having about five years of ART-experience, malnutrition appears to be driven mainly by a poor BMI, indicating that about one of ten patients falls within this severe condition. However, the largely normal nutritional profiles should be interpreted with caution, considering local realities and food support programs in place. The present outcomes highlight the need for monitoring nutritional status of people receiving ART in RLS, toward the design of optimal food interventions

The mother-to-child transmission of HIV-1 and profile of viral reservoirs in pediatric population: A systematic review with meta-analysis of the Cameroonian studies.

BackgroundThe mother-to-child transmission of HIV-1 (MTCT) remains on the major route of HIV-transmission among pediatric populations in Africa. Though a prevention of MTCT (PMTCT) high-priority country, data on the MTCT burdens in Cameroon remains fragmented.ObjectiveWe sought to assess the pooled MTCT rate, its risk-factors, and to characterize viral reservoirs of infected-children in Cameroon.MethodsAll relevant observational cohort and cross-sectional studies conducted in Cameroon were searched from PubMed, African Journals Online, Google scholar, ScienceDirect and academic medical education databases. Heterogeneity and publication bias were respectively assessed by the I2 statistic and the Egger/funnel plot test. Meta-analysis was performed using the random effects model. MTCT rate >5% was considered as "high". This review was registered in the Prospero database, CRD42021224497.ResultsWe included a total of 29 studies and analyzed 46 684 children born from HIV-positive mothers. The overall rate of MTCT was 7.00% (95% CI = 6.07-8.51). According to regions, the highest burden was in Adamaoua-region (17.51% [95% CI:14.21-21.07]) with only one study found. PMTCT option-B+ resulted in about 25% reduction of MTCT (8.97% [95% CI: 8.71-9.24] without option-B+ versus 2.88% [95% CI: 5.03-9.34] with option-B+). Regarding risk-factors, MTCT was significantly associated with the absence of PMTCT-interventions both in children (OR:5.40 [95% CI: 2.58-11.27]) and mothers (OR: 3.59 [95% CI: 2.15-5.99]). Regarding viral reservoirs, a pro-viral DNA mean of 3.34±1.05 log10/mL was observed among 5/57 children and archived HIV drug resistance mutations were identified in pro-viral DNA marker among 21/79 infected-children.ConclusionIn spite of the dropdown in MTCT following option-B+ implementation, MTCT remains high in Cameroon, with substantial disparities across regions. Thus, in this era of option-B+, achieving MTCT elimination requires interventions in northern-Cameroon. The variation in pro-viral load in infected-children underlines the relevance of characterizing viral reservoirs for possible infection control in tropical settings

Forest plot of MTCT in the ten regions of Cameroon.

The number of participants obtained in this forest plot depend on the studies that reported the region of sampling.</p

Flow chart of the study selection process.

Flow chart of the study selection process.</p

Pooled vertical transmission rate of HIV in Cameroon.

The figure was conceived and adapted by the authors of this review; the base layer of the map was downloaded from http://viewer.nationalmap.gov/viewer/.</p

General characteristics of the included studies for prevalence of MTCT and quality of assessment.

General characteristics of the included studies for prevalence of MTCT and quality of assessment.</p

Association between MTCT of HIV and prevention of mother-to-child transmission intervention.

Association between MTCT of HIV and prevention of mother-to-child transmission intervention.</p

Forest plot of the prevalence of MTCT.

Forest plot of the prevalence of MTCT.</p

Association between MTCT of HIV and feeding mode/childbirth delivery mode.

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