Positivity of typhidot test in COVID cases: An observational cohort study from the second wave of the pandemic

Abstract

Introduction: Typhidot has been known to cross-react with a variety of viral illnesses. There has been some communication throwing light on the possible false-positive results in COVID cases, but overall there is a dearth of studies directly investigating the association. This is a small-sized observational cohort study to detect and analyze the association between these two conditions. Materials and Methods: During a period of 1 month, starting from April 1, 2021, to April 30, 2021, all patients admitted with a Reverse Transcriptase- Polymerase Chain Reaction (RT-PCR)- positive report for SARS-CoV-2 to a nursing home in Ghaziabad were prescribed typhidot immunoglobulin M (IgM) test. Other parameters such as the radiological computed tomography score, hemoglobin levels, total leukocyte counts, serum glutamic-oxaloacetic transaminase, serum glutamic pyruvic transaminase enzyme levels, and the cycle threshold values of the RT-PCR test were recorded. The data thus collected were entered into a structured electronic data collection system and analyzed. Results: Thirty-seven percent of patients who were admitted with a diagnosis of RT-PCR-positive mild-to-moderate COVID pneumonia were also positive for typhoid IgM antibody. The distribution of this positive typhidot test was equal among both genders and was not found to be significantly associated with any of the other test variables. Conclusion: Our study reveals the anamnestic response of typhoid IgM antibodies against SARS-CoV-2. A positive typhidot test should not mislead or delay the diagnosis of any other viral respiratory illness.