The role of serological testing in the SARS-CoV-2 outbreak

Antibody tests for the novel coronavirus, SARS-CoV2, have been developed both as rapid diagnostic assays and for high-throughput formal serology platforms. Although these tests may be a useful adjunct to a diagnostic strategy, they have a number of limitations. Because of the antibody and viral dynamics of the coronavirus, their sensitivity can be variable, especially at early time points after symptom onset. Additional data are required on the performance of the tests in the South African population, especially with regard to development and persistence of antibody responses and whether antibodies are protective against reinfection. These tests may, however, be useful in guiding the public health response, providing data for research (including seroprevalence surveys and vaccine initiatives) and development of therapeutic strategies

Hepatitis E virus in patients with acute hepatitis in Cape Town, South Africa, 2011

Background. Early hepatitis E virus (HEV) seroprevalence studies in South Africa (SA) showed seroprevalence rates of 2 - 10%, and suggested waterborne transmission. More recent studies in Cape Town, SA, reported HEV seroprevalence rates of 28% and 26% in outpatients without liver disease and blood donors, respectively. An association was found with eating pork or bacon/ham. Only 3 human cases of hepatitis E in SA have been reported in the literature. Objectives. To find evidence of HEV infection in hospitalised patients with acute hepatitis and no other identified cause. Methods. Leftover serum samples were retrieved for patients negative for hepatitis viruses A, B and C, where no other cause of hepatitis was identified. Samples were tested for HEV by polymerase chain reaction (PCR) and IgM and IgG enzyme-linked immunosorbent assay (ELISA). Results. Anti-HEV IgG was detected in 39/132 specimens (29.5%; 95% confidence interval (CI) 22.4 - 37.8), and anti-HEV IgM in 2/125 specimens (1.6%; 95% CI 0.4 - 5.7). No specimen tested positive by PCR. Conclusions. IgG seroprevalence found in this study was similar to that previously reported in Cape Town. IgM positivity in 2 patients was not confirmed by PCR. Locally, hepatitis E may not be a common cause of clinically apparent hepatitis that requires hospitalisation