Retrospective evaluation of the symptom-based work restriction strategy of healthcare providers in the first epidemic of COVID-19 at a tertiary care hospital in Tokyo, Japan

BACKGROUND

Effectiveness of restricting healthcare providers (HCPs) from working based on the coronavirus disease 2019 (COVID-19)-like symptoms should be evaluated.

METHODS

A total of 495 HCPs in a tertiary care hospital in Tokyo, Japan, participated in this study between June and July in 2020. Analysis of serum anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody to identify infected HCPs, questionnaire surveys, and medical record reviews were conducted to evaluate the appropriateness of symptom-based work restriction for 10 days.

RESULTS

Five participants (1.0%) were identified as infected. Forty-six participants (9.3%) experienced work restriction and all 5 infected participants (10.8%) restricted working, even though the real-time reverse transcription-polymerase chain reaction was positive only in 4 participants (80.0%). There were no unexpectedly infected participants among those who did not experience work restriction. However, only 46 of 110 HCPs with COVID-19-like symptoms (41.8%) restricted themselves from working.

DISCUSSION

Symptom-based work restriction strategy successfully prevented infected HCPs to work, but showed low specificity to identify truly infected HCPs, and their low adherence to the strategy was revealed.

CONCLUSIONS

HCPs with COVID-19-like symptoms should restrict working as the first step of infection prevention, but the strategy to identify truly infected HCPs is necessary.

False-positive detection of IgM anti-severe acute respiratory syndrome coronavirus 2 antibodies in patients with rheumatoid arthritis: Possible effects of IgM or IgG rheumatoid factors on immunochromatographic assay results

Objectives:

The severe acute respiratory syndrome coronavirus 2 causes coronavirus disease 2019. A serological test is conducted to determine prior infection by severe acute respiratory syndrome coronavirus 2. We investigated whether the results of anti-severe acute respiratory syndrome coronavirus 2 antibody tests are modified in patients with rheumatoid arthritis.

Methods:

Patients in Japan with rheumatoid arthritis were recruited at Sagamihara Hospital from July 2014 to October 2015 (n = 38; 2014 cohort) and at Tokyo Hospital from June to October 2020 (n = 93; 2020 cohort). Anti-severe acute respiratory syndrome coronavirus 2 antibodies were measured by electrochemiluminescence immunoassay or immunochromatographic assay.

Results:

Anti-severe acute respiratory syndrome coronavirus 2 antibodies were not detected in any of the samples from rheumatoid arthritis patients tested by electrochemiluminescence immunoassay. Anti-severe acute respiratory syndrome coronavirus 2 antibodies were detected by immunochromatographic assay in the 3 (7.9%) serum samples in the 2014 cohort and 15 (16.1%) serum samples in the 2020 cohort. The IgM rheumatoid factor levels were increased in rheumatoid arthritis patients with IgM anti-severe acute respiratory syndrome coronavirus 2 antibodies detected by immunochromatographic assay (mean ± standard deviation (IU/ml), 1223.0 ± 1308.7 versus 503.6 ± 1947.2; P = 0.0101). The levels of IgG rheumatoid factor were also upregulated in rheumatoid arthritis patients with IgM anti-severe acute respiratory syndrome coronavirus 2 antibodies detected by immunochromatographic assay (4.0 ± 0.7 versus 2.4 ± 0.9; P = 0.0013).

Conclusion:

The results of IgM anti-severe acute respiratory syndrome coronavirus 2 antibody testing by immunochromatographic assay are modified by IgM or IgG rheumatoid factors in rheumatoid arthritis patients.