For more than two years after the emergence of COVID-19 (Coronavirus Disease-2019), significant regional differences in morbidity persist. These differences clearly show lower incidence rates in several regions of the African and Asian continents. The work reported here aimed to test the hypothesis of a pre-pandemic natural immunity acquired by some human populations in central and western Africa, which would, therefore, pose the hypothesis of an original antigenic sin with a virus antigenically close to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). To identify such pre-existing immunity, sera samples collected before the emergence of COVID-19 were tested to detect the presence of IgG reacting antibodies against SARS-CoV-2 proteins of major significance. Sera samples from French blood donors collected before the pandemic served as a control. The results showed a statistically significant difference of antibodies prevalence between the collected samples in Africa and the control samples collected in France. Given the novelty of our results, our next step consists in highlighting neutralizing antibodies to evaluate their potential for pre-pandemic protective acquired immunity against SARS-CoV-2. In conclusion, our results suggest that, in the investigated African sub-regions, the tested populations could have been potentially and partially pre-exposed, before the COVID-19 pandemic, to the antigens of a yet non-identified Coronaviruses.

Background: Sub-Saharan African countries are transitioning to dolutegravir-based regimens, even for patients with extensive previous drug exposure, including first-generation integrase strand-transfer inhibitors (INSTI) such as raltegravir. Such exposure might have implications on cross-resistance to dolutegravir-based antiretroviral therapies (ART).

Background HIV 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). Objective To describe the nutritional parameters of antiretroviral therapy (ART) recipients (without nutritional support) with respect to CD4 count and virological failure. Methods A 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 p<0.05 considered statistically significant. Results Median [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 (CD4<500 cell/μl) and 75.3% (110/146) had an undetectable viremia (<40 copies/mL). CD4 count inversely correlated with total protein concentration (r = -0.18, p = 0.005**). Viremia was inversely correlated with albumin (r = -0.21; p = 0.047*), nutritional risk index (r = -0.28; p = 0.013*), total cholesterol (r = -0.27; p = 0.007**), and positively correlated with total protein (r = 0.27; p<0.001**) concentrations. Conclusion In 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.

Background Thrombocytopenia is an abnormal decrease in blood platelets, which can affect the prognosis of people living with HIV (PLHIV). In order to limit the occurrence of this haematological disorder, we evaluated the frequency of thrombocytopenia according to antiretroviral drug combinations, viremia and the immune status of PLHIV. Methods A cross-sectional and analytical study was conducted from June-November 2016 among 310 PLHIV at the “Chantal BIYA” International Reference Centre for research on HIV/AIDS prevention and management (CIRCB), Yaoundé, Cameroon. Thrombocytopenia was assessed by blood count on Mindray BC 3000 plus, then categorized as mild (50,000-149,999 platelets/μL), moderate (20,000-49,999) and severe <20,000; HIV-1 viremia was measured by Abbott m2000RT and CD4 by BD Facs Calibur; treatment history was retrieved from medical records. Data were analysed using Graph Pad Prism.6, with p<0.05 considered statistically significant. Results Median age was 40 [IQR: 33-49] years with, and 60.9% of participants being female. Up to 79.0% (245) were receiving antiretroviral therapy (ART); 54.5% had CD4 counts <500 cells/mm3 and 25.4% had viremia >3log10 RNA/ml. Overall rate of thrombocytopenia was 19.0% (59/310), with 17.4% (54/310) mild, 1.6% (5/310) moderate and 0.0% severe. Following ART-exposure, rate of thrombocytopenia was 64.6% (42/65) versus 6.9% (17/245) in naïve versus treated patients respectively, p<0.0001. Following ART regimens, rate of thrombocytopenia was 64.7% (11/17) versus 35.3% (6/17) among AZT-containing versus AZT-sparing regimens, p=0.02. Following viral load ranges, rate of thrombocytopenia was 15.8% (20/130) in those with undetectable viral load, 11.0% (12/101) with viral loads 1.60-3.0 log10 RNA/ml and 34.1% (27/79) with viral loads >3 log10 RNA/ml (p=0.03; r=-0.12). As concerns CD4-count, rate of thrombocytopenia was 16.2% (42/259) in those with ≥200 CD4/mm3 versus 33.3% (17/51) with <200 CD4/mm3 (p=0.0003; r=0.21). After adjusting for age, sex, ART, viral load and CD4, only ART exposure was significantly associated with decreased risk of thrombopenia (p<0.0001). Conclusions Thrombocytopenia occurs generally at mild-level among PLHIV in Cameroon, especially among ART-naïve, AZT-treated, high viremia and severe immune-compromised patients. Interestingly, ART coverage appears as an independent factor in preventing the occurrence of thrombocytopenia, especially for AZT-sparing treatment combinations in countries with similar features like Cameroon.

Background: In the context of scaling the viral load in resource limited settings, following HIV infected patient's adults and children with CD4+ T-lymphocyte count still very important in settings where the decentralization of treatment still has some challenges. Effective HIV monitoring in these resource-constrained settings needs affordable and reliable CD4+ T lymphocytes enumeration methods. We investigated the validity of a BD FACSPresto POC which is a dedicated system for enumeration that uses immunofluorescent technologies. In this study, we have assessed the sensitivity, specificity and correlation between most representative flow cytometry instruments present in Cameroon with more than 5000 CD4 T cells tests per year including FACSCalibur, FACSCount, and PIMA POC from Becton-Dickinson and ALERE respectively. Methods: 268 patients aged from 1 to 72 years old were enrolled and included in the study after inform consent. The BD FACSPresto POC CD4+ T cell technology was placed at CIRCB and operated by technician staff. HIV infected patients were from Chantal BIYA international reference Center (CIRCB),