False Positivity of Anti-SARS-CoV-2 Antibodies in Patients with Acute Tropical Diseases in Thailand
1
Issued Date
2022-07-01
Resource Type
eISSN
24146366
Scopus ID
2-s2.0-85135464206
Journal Title
Tropical Medicine and Infectious Disease
Volume
7
Issue
7
Rights Holder(s)
SCOPUS
Bibliographic Citation
Tropical Medicine and Infectious Disease Vol.7 No.7 (2022)
Suggested Citation
Luvira V., Leaungwutiwong P., Thippornchai N., Thawornkuno C., Chatchen S., Chancharoenthana W., Tandhavanant S., Muangnoicharoen S., Piyaphanee W., Chantratita N. False Positivity of Anti-SARS-CoV-2 Antibodies in Patients with Acute Tropical Diseases in Thailand. Tropical Medicine and Infectious Disease Vol.7 No.7 (2022). doi:10.3390/tropicalmed7070132 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/85736
Title
False Positivity of Anti-SARS-CoV-2 Antibodies in Patients with Acute Tropical Diseases in Thailand
Author's Affiliation
Other Contributor(s)
Abstract
Serology remains a useful indirect method of diagnosing tropical diseases, especially in dengue infection. However, the current literature regarding cross-reactivity between SARS-CoV-2 and dengue serology is limited and revealed conflicting results. As a means to uncover relevant serological insight involving antibody classes against SARS-CoV-2 and cross-reactivity, anti-SARS-CoV-2 IgA, IgM, and IgG ELISA, based on spike and nucleocapsid proteins, were selected for a fever-presenting tropical disease patient investigation. The study was conducted at the Faculty of Tropical Medicine during March to December 2021. The study data source comprised (i) 170 non-COVID-19 sera from 140 adults and children presenting with acute undifferentiated febrile illness and 30 healthy volunteers, and (ii) 31 COVID-19 sera from 17 RT-PCR-confirmed COVID-19 patients. Among 170 non-COVID-19 samples, 27 were false positives (15.9%), of which IgA, IgM, and IgG cross-reactive antibody classes were detected in 18 (10.6%), 9 (5.3%), and 3 (1.8%) cases, respectively. Interestingly, one case exhibited both IgA and IgM false positivity, while two cases exhibited both IgA and IgG false positivity. The false positivity rate in anti-SARS-CoV-2 IgA and IgM was reported in adults with dengue infection (11.3% and 5%) and adults with other tropical diseases (16.7% and 13.3%). The urea dissociation method applied to mitigate false positivity resulted in significantly decreased ELISA-based false and true positives. In conclusion, the analysis of antibody against SARS-CoV-2 in sera of patients with different tropical diseases showed that high IgA and IgM false positivity thus potentially limits serological assay utility in fever-presenting patients in tropical areas.