High Seroprevalence of SARS-CoV-2 (COVID-19)-Specific Antibodies among Healthcare Workers: A Cross-Sectional Study in Guilan, Iran.

Background: This study was conducted to evaluate the anti-SARS-CoV-2 IgM and IgG antibodies among healthcare workers in Guilan. Methods: This cross-sectional study was conducted on 503 healthcare workers. Between April and May 2020, blood samples were collected from the healthcare workers of Razi Hospital in Rasht, Guilan, Iran. Enzyme-linked immunosorbent assay (ELISA) was used for the detection and quantitation of anti-SARS-CoV-2 IgM/IgG antibodies by using kits made by Pishtaz Teb Company, Tehran, Iran. Results: From a total of 503 participants, the result of the anti-SARS-CoV-2 IgM antibody test was positive in 28 subjects (5.6%) and the anti-SARS-CoV-2 IgG antibody test was positive in171 subjects (34%). Participants in the age group of 35-54 years were significantly more likely to have a positive anti-SARS-CoV-2 antibody test than the age group of 20-34 years (odds ratio = 1.53, 95% CI: 1.04-2.25, P=0.029). Also, physicians were significantly more likely to have a positive antibody test than office workers (odds ratio = 1.92, 95% CI: 1.04-3.54, P=0.037). The wide range of symptoms was significantly associated with the positive anti-SARS-CoV-2 antibody test. The most significant association was observed between fever and a positive anti-SARS-CoV-2 antibody test (odds ratio = 3.03, 95% CI: 2.06-4.44, P < 0.001). Conclusion: The results of the current study indicated that the seroprevalence of COVID-19 was high among healthcare workers of Guilan Province. It seems that this finding was due to the earlier exposure to COVID-19 and the lack of awareness and preparedness to deal with the pandemic in Iran, compared to other countries.

Persistence of SARS-CoV-2 RNA in the nasopharyngeal, blood, urine, and stool samples of patients with COVID-19: a hospital-based longitudinal study.

BACKGROUND: The persistence of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) RNA in the body fluids of patients with the novel coronavirus disease 2019 (COVID-19) may increase the potential risk of viral transmission. There is still uncertainty on whether the recommended quarantine duration is sufficient to reduce the risk of transmission. This study aimed to investigate the persistence of SARS-CoV-2 RNA in the nasopharyngeal, blood, urine, and stool samples of patients with COVID-19. METHODS: In this hospital-based longitudinal study, 100 confirmed cases of COVID-19 were recruited between March 2020 and August 2020 in Guilan Province, north of Iran. Nasopharyngeal, blood, urine, and stool samples were obtained from each participant at the time of hospital admission, upon discharge, 1 week after discharge, and every 2 weeks until all samples were negative for SARS-CoV-2 RNA by reverse transcription-polymerase chain reaction (RT-PCR) assay. A survival analysis was also performed to identify the duration of viral persistence. RESULTS: The median duration of viral RNA persistence in the nasopharyngeal samples was 8 days from the first positive RT-PCR result upon admission (95% CI 6.91-9.09); the maximum duration of viral shedding was 25 days from admission. Positive blood, urine, and stool RT-PCR results were detected in 24%, 7%, and 6% of the patients, respectively. The median duration of viral persistence in the blood, urine, and stool samples was 7 days (95% CI 6.07-7.93), 6 days (95% CI 4.16-8.41), and 13 days (95% CI 6.96-19.4), respectively. Also, the maximum duration of viral persistence in the blood, urine, and stool samples was 17, 11, and 42 days from admission, respectively. CONCLUSION: According to the present results, immediately after the hospitalized patients were discharged, no evidence of viral genetic materials was found. Therefore, appropriate treatments were selected for the patients at this hospital. However, we recommend further investigations on a larger sample size in multi-center and prospective randomized controlled trials (RCTs) to evaluate the effects of different drugs on the shedding of the virus through body secretions.