Alternative or Complementary Role of Serological Rapid Antibody Test in the Management of Possible COVID 19 Cases

Background Although the gold diagnostic method for COVID-19 is accepted as the detection of viral particles by reverse transcription polymerase chain reaction (RT-PCR), serology testing for SARS-CoV-2 is at increased demand. A primary aim for utilization of serological tests are to better quantify the number of COVID-19 cases including those RT-PCR samples were negative but showing clinical and radiological signs of COVID-19. In this study, we aimed to report the features of the patients that were diagnosed and treated as possible COVID-19 cases whose multiple nasopharyngeal swab samples were negative by RTPCR but serological IgM/IgG antibody against SARS-CoV-2 were detected by rapid antibody test. Method We retrospectively analyzed eighty suspected COVID-19 cases that have at least two negative consecutive COVID-19 PCR test and were subjected to serological rapid antibody test. Result The specific antibodies against SARS-CoV-2 were detected as positive in twenty-two patients. The mean age of patient group was 63.2 ± 13.1 years old with male /female ratio 11/11. Cough was the most common symptom with 90.9%. Most common presenting chest CT findings were bilateral ground glass opacities (77.2%) and alveolar consolidations (50.09%). The mean duration from symptom initiation to hospital admission, to hospitalization, to treatment initiation and to detection of antibody positivity were 8.6 ± 7.2, 11.2 ± 5.4, 7.9 ± 3.2 and 24 ± 17 days, respectively. Conclusion Our study demonstrated the feasibility of COVID-19 diagnosis based on rapid antibody test in the cases of patients whose RT-PCR samples were negative. We suggest that the detection of antibodies against SARS-CoV-2 with rapid antibody test should be included in the diagnostic algorithm in suspected COVID-19 patients. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement No funding has been received. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This is a retrospective study that was specifically approved by the health ministry of Turkey All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes The data used in this study is available upon request.