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The SARS-CoV-2 pandemic ignited global efforts to rapidly develop testing, therapeutics, and vaccines. However, the rewards of these efforts were slow to reach many low- to middle-income countries (LMIC) across the African continent and globally. Therefore, two bead-based multiplexed serological assays were developed to determine SARS-CoV-2 exposure across four counties in Liberia. This study was conducted during the summer of 2021 on 189 samples collected throughout Grand Bassa, Bong, Margibi, and Montserrado counties. Our multiplexed immunoassay (MIA) detected elevated exposure to SARS-CoV-2 and multiple variant antigens. Additionally, we detected evidence of exposure to Dengue virus serotype 2, Chikungunya virus, and the seasonal coronavirus NL63. Our multiplexed inhibition test (MINT) was developed from the MIA to observe antibody-mediated inhibition of SARS-CoV-2 spike protein binding to its cognate cellular receptor ACE-2. We detected inhibitory antibodies in the tested Liberian samples, which were collectively consistent with a convalescent serological profile. These complementary assays serve to supplement existing serological testing needs and may enhance the technical capacity of scientifically underrepresented regions globally.
RESUMO
OBJECTIVES: Liberia is endemic to Lassa fever (LF) and has the largest reported per capita incidence of LF patients in the West African region. Cases of the disease increased unprecedentedly in 2019 and 2020, characterized by a geographical drift in epidemiology and seasonal variation of occurrence. This study aims to describe the epidemiological and clinical characteristics of LF in Liberia from 2019 to 2020. METHODS: A retrospective study was conducted on cases of LF confirmed at the National Public Health Reference Laboratory from January 2019 to December 2020. Medical records were reviewed, and epidemiological and clinical data were collected in an organized manner. Descriptive and inferential statistics were carried out using Epi Info (version 7.2.5.0). RESULTS: A total of 382 suspected LF cases were reported, of which 103 were laboratory-confirmed, yielding a case positivity rate of 27% (103/382). The median age of the LF cases was 20 (IQR: 9-30). Children younger than 18 years accounted for 40.8% (42/103) of the cases and healthcare workers' cases constituted 7.7% of the cases. Bong, Nimba, and Grand Bass accounted for 87.4% of the cases with cases in new counties like Lofa, Margibi, and Grand Kru. Hemorrhage (aOR:10.2; 95% CI: 3.11-33.81), patients who did not receive ribavirin (aOR: 4.4; 95% CI: 1.12-17.57, P = 0.034), and patients aged 40 years or older (aOR: 6.2; 95% CI: 1.19-32.53, P = 0.049) were associated with LF mortality. CONCLUSION: The LF cases in 2019 and 2020 had a high case fatality rate and spread to new counties that had not previously reported LF. The disease occurred during most of the rainy season instead of the usual dry season. There is an urgent need to lower morbidity and mortality, improve early presentation to the hospital, and early initiation of appropriate medical care.