A COVID-19 outbreak in a rheumatology department upon the early days of the pandemic

Objectives

To describe our experience with a coronavirus disease 2019 (COVID-19) outbreak within a large rheumatology department, early in the pandemic.

Methods

Symptomatic and asymptomatic healthcare workers (HCWs) had a naso-oropharyngeal swab for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and were followed clinically. Reverse transcription polymerase-chain reaction (RT-PCR) was repeated to document cure, and serological response was assessed. Patients with risk contacts within the department in the 14 days preceding the outbreak were screened for COVID-19 symptoms.

Results

14/34 HCWs (41%; 40±14 years, 71% female) tested positive for SARS-CoV-2, and 11/34 (32%) developed symptoms but were RT-PCR-negative. Half of RT-PCR-positive HCWs did not report fever, cough, or dyspnoea before testing, which were absent in 3/14 cases (21%). Mild disease prevailed (79%), but 3 HCWs had moderate disease requiring further assessment, which excluded severe complications. Nevertheless, symptom duration (28±18 days), viral shedding (31±10 days post-symptom onset, range 15-51) and work absence (29±28 days) were prolonged. 13/14 (93%) of RT-PCR-positive and none of the RT-PCR-negative HCWs had a positive humoral response, with higher IgG-index in individuals over 50 years (14.5±7.7 vs 5.0±4.4, p=0.012). Of 617 rheumatic patients, 8 (1.3%) developed COVID-19 symptoms (1/8 hospitalisation, 8/8 complete recovery), following a consultation/procedure with an asymptomatic (7/8) or mildly-symptomatic (1/8) HCW.

Conclusions

A COVID-19 outbreak can occur among HCWs and rheumatic patients, swiftly spreading over the presymptomatic stage. Mild disease without typical symptoms should be recognised, and may evolve with delayed viral shedding, prolonged recovery, and adequate immune response in most individuals.

Key messages

• High infection rates have been reported in healthcare workers (HCWs) dealing with COVID-19 patients. Less is known about potential transmission by pre/asymptomatic carriers, which may be important in the context of rheumatology practice, among both HCWs and patients.

• A COVID-19 outbreak in a rheumatology department affected 41% of HCWs, with fast spreading throughout the presymptomatic stage.

• Mild disease without typical symptoms was common, especially in early phases, evolving with delayed viral shedding (unto 51 days), prolonged recovery (average one month), and adequate immune response (93%) in most individuals.

• Transmission by mostly asymptomatic HCWs occurred to a minority of patients with rheumatic and musculoskeletal diseases (RMDs), who had a globally favourable outcome.

• Asymptomatic and mild disease forms among HCWs should be recognised. Assertive infection control measures and testing strategies are warranted to prevent subclinical contagion between HCWs and patients with RMDs.