Impact of COVID-19 on people living with HIV in Madagascar: a SARS-COV2 seroprevalence survey

Background: In Madagascar, no study has reported the impact of COVID-19 on people living with HIV (PLHIV). The present work aimed to analyze the seroprevalence of SARS-CoV-2 in Malagasy PLHIV before and during the three waves of COVID-19 pandemic. This is a retrospective study. Materials and Methods: We conducted a retrospective serological survey in PLHIV followed up for HIV viral load (VL) monitoring at the Centre d'Infectiologie Charles Mérieux Madagascar (CICM) between June 2019 and April 2022. The presence of IgM and/or IgG antibodies against SARS-CoV-2 nucleoprotein was detected using a rapid diagnostic test (COVID-PRESTO®). Results: A seroprevalence of 2.5% was found in the 877 patients tested before March 2020, compared to 25.4% (512/2,011) between March 2020 and April 2022. This seroprevalence was 21.7%, 22.3% and 60.1% after the first, second and third waves of COVID-19, respectively. We observed a marginally significant difference (p = 0.043) inSARS-CoV-2 seroprevalence between patients on highly active antiretroviral therapy (HAART) (27.5%) and those who were not (23.7%). No statistically significant difference was observed between PLHIV with undetectable HIV VL (27.4%) and the different detectable VL categories (p>0.05). Conclusions: Our data show the presence of antibodies to SARS-CoV-2 among PLHIV as early as December 2019 in Madagascar. At least 25.4% (512/2,011) of Malagasy PLHIV have been in contact with SARS-CoV-2 since March 2020. There is no significant relation between HIV-1 VL and SARS-CoV-2 seroprevalence. Additional studies with more robust assays in the general population are needed for a detailed knowledge of SARS-CoV-2 impact in Madagascar.

High Seroprevalence of IgG Antibodies to Multiple Arboviruses in People Living with HIV (PLWHIV) in Madagascar.

To estimate the prevalence of IgG antibodies against six arboviruses in people living with HIV-1 (PLWHIV) in Madagascar, we tested samples collected between January 2018 and June 2021. We used a Luminex-based serological assay to detect IgG antibodies against antigens from Dengue virus serotypes 1-4 (DENV1-4), Zika virus (ZIKV), West Nile virus (WNV), Usutu virus (USUV), Chikungunya virus (CHIKV), and O'nyong nyong virus (ONNV). Of the 1036 samples tested, IgG antibody prevalence was highest for ONNV (28.4%), CHIKV (26.7%), WNV-NS1 (27.1%), DENV1 (12.4%), USUV (9.9%), and DENV3 (8.9%). ZIKV (4.9%), DENV2 (4.6%), WNV-D3 (5.1%), and DENV4 (1.4%) were lower. These rates varied by province of origin, with the highest rates observed in Toamasina, on the eastern coast (50.5% and 56.8%, for CHIKV and ONNV, respectively). The seroprevalence increased with age for DENV1 and 3 (p = 0.006 and 0.038, respectively) and WNV DIII (p = 0.041). The prevalence of IgG antibodies against any given arborvirus varied over the year and significantly correlated with rainfalls in the different areas (r = 0.61, p = 0.036). Finally, we found a significant correlation between the seroprevalence of antibodies against CHIKV and ONNV and the HIV-1 RNA plasma viral load. Thus, PLWHIV in Madagascar are highly exposed to various arboviruses. Further studies are needed to explain some of our findings.