A multicentre study comparing post-mortem SARS-CoV-2 antibody testing in Cape Town mortuaries.

Area of Science:

• Virology
• Immunology
• Public Health

Background:

• Coronavirus disease 2019 (COVID-19) remains a global health concern with unclear infection numbers.
• Limited research exists on the efficacy of post-mortem antibody testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
• Accurate antibody detection in deceased individuals is crucial for understanding infection prevalence and mortality.

Purpose of the Study:

• To evaluate the SureScreen COVID-19 immunoglobulin (Ig) G and IgM Rapid Test Cassette in deceased individuals.
• To compare the SureScreen test performance against gold-standard antibody tests in South Africa.
• To identify the most appropriate antibody testing method for post-mortem serum samples.

Main Methods:

• Fifty deceased individuals with suspected lifetime COVID-19 infection were recruited from two mortuaries.
• Blood samples were collected during autopsy and tested using SureScreen, Roche Diagnostics Elecsys, and Abbott Architect assays.
• Antemortem polymerase chain reaction (PCR) test results were used for confirmation in 39 participants.

Main Results:

• Among PCR-confirmed cases, Roche's Elecsys showed the highest sensitivity (97.1%), followed by SureScreen IgG (82.1%).
• The SureScreen IgG results were significantly associated with PCR confirmation (p < 0.05).
• Roche's Elecsys yielded the most positive results in post-mortem serum samples, followed by SureScreen, then Abbott Architect.

Conclusions:

• The SureScreen test shows potential as a screening tool for COVID-19 antibodies in mortuary settings.
• Roche's Elecsys assay is recommended for diagnostic confirmation of SARS-CoV-2 infection in post-mortem samples.
• This study contributes to establishing reliable methods for post-mortem serological testing.