Comparative Performance of Serological (IgM/IgG) and Molecular Testing (RT-PCR) of COVID-19 in Three Private Universities in Cameroon during the Pandemic

• Published in: Viruses 2023-01, Vol.15 (2), p.407
• Main Authors: Kamga Wouambo, Rodrigue, Djuikoué, Cecile Ingrid, Esemu, Livo Forgu, Kagoue Simeni, Luc Aime, Tchitchoua, Murielle Chantale, Djouela Djoulako, Paule Dana, Fokam, Joseph, Singwe-Ngandeu, Madeleine, Mpoudi Ngolé, Eitel, Apalata, Teke
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Antibodies; Cameroon; Cameroon - epidemiology; Child; Coronaviruses; COVID-19; COVID-19 - diagnosis; COVID-19 - epidemiology; COVID-19 diagnostic tests; COVID-19 Testing; Disease transmission; Epidemiology; Female; Genomes; Humans; Immunoglobulin G; Immunoglobulin M; Infections; Informed consent; Laboratories; Male; Molecular Diagnostic Techniques; Onsite; Pandemics; prevalence; Private schools; private universities; Proteins; Reverse Transcriptase Polymerase Chain Reaction; Sample size; SARS-CoV-2 - genetics; serological markers (IgM/IgG); Severe acute respiratory syndrome coronavirus 2; Statistical analysis; Universities; Young Adult
• ISSN: 1999-4915; 1999-4915
• DOI: 10.3390/v15020407

COVID-19 remains a rapidly evolving and deadly pandemic worldwide. This necessitates the continuous assessment of existing diagnostic tools for a robust, up-to-date, and cost-effective pandemic response strategy. We sought to determine the infection rate (PCR-positivity) and degree of spread (IgM/IgG) of SARS-CoV-2 in three university settings in Cameroon Method: Study volunteers were recruited from November 2020 to July 2021 among COVID-19 non-vaccinated students in three Universities from two regions of Cameroon (West and Centre). Molecular testing was performed by RT-qPCR on nasopharyngeal swabs, and IgM/IgG antibodies in plasma were detected using the Abbott Panbio IgM/IgG rapid diagnostic test (RDT) at the Virology Laboratory of CREMER/IMPM/MINRESI. The molecular and serological profiles were compared, and < 0.05 was considered statistically significant. Amongst the 291 participants enrolled (mean age 22.59 ± 10.43 years), 19.59% (57/291) were symptomatic and 80.41% (234/291) were asymptomatic. The overall COVID-19 PCR-positivity rate was 21.31% (62/291), distributed as follows: 25.25% from UdM-Bangangte, 27.27% from ISSBA-Yaounde, and 5% from IUEs/INSAM-Yaounde. Women were more affected than men (28.76% [44/153] vs. 13.04% [18/138], < 0.0007), and had higher seropositivity rates to IgM+/IgG+ (15.69% [24/153] vs. 7.25% [10/138], < 0.01). Participants from Bangangté, the nomadic, and the "non-contact cases" primarily presented an active infection compared to those from Yaoundé ( = 0.05, = 0.05, and = 0.01, respectively). Overall IgG seropositivity (IgM-/IgG+ and IgM+/IgG+) was 24.4% (71/291). A proportion of 26.92% (7/26) presenting COVID-19 IgM+/IgG- had negative PCR vs. 73.08% (19/26) with positive PCR, < 0.0001. Furthermore, 17.65% (6/34) with COVID-19 IgM+/IgG+ had a negative PCR as compared to 82.35% with a positive PCR (28/34), < 0.0001. Lastly, 7.22% (14/194) with IgM-/IgG- had a positive PCR. This study calls for a rapid preparedness and response strategy in higher institutes in the case of any future pathogen with pandemic or epidemic potential. The observed disparity between IgG/IgM and the viral profile supports prioritizing assays targeting the virus (nucleic acid or antigen) for diagnosis and antibody screening for sero-surveys.