The incidence of vasculitides in Israel from 2007 to 2021 and during the COVID-19 pandemic.

BACKGROUND

The incidence of various types of vasculitis conditions over time, specifically during coronavirus disease 2019 (COVID-19), is unknown.

OBJECTIVES

We aimed to assess recent trends in vasculitides and the effect of the COVID-19 pandemic on these trends.

DESIGN

We conducted a retrospective analysis of Israel's largest Health Maintenance Organization, which covers over 4.7 million patients and represents 55% of the country.

METHODS

We calculated the age- and sex-adjusted incidence of giant cell arteritis (GCA), Takayasu, ANCA-associated vasculitis (AAV), IgA vasculitis, cryoglobulinemia, and Behcet's disease (BD) during 2007-2021. We analyzed associations of COVID-19 with the incidence of each of the examined conditions.

RESULTS

During 2007-2021, the adjusted annual incidence decreased from 7.9 (95% confidence interval (CI) 3.5-17.9) to 1.5 (95% CI 0.7-3.6) per 100,000 for GCA, from 5.2 (95% CI 2.7-11.1) to 1.5 (95% CI 0.7-3.3) per million for IgA vasculitis, and from 6.3 (95% CI 3.0-13.5) to 1.0 (0.5-2.5) per 100,000 for BD. The relative risks for these conditions decreased: 0.92 (95% CI 0.91-0.93), 0.93 (95% CI 0.89-0.98), and 0.90 (95% CI 0.85-0.94), respectively. The incidences of Takayasu, AAV, and cryoglobulinemia remained unchanged. The COVID-19 pandemic was not associated with changes in the incidence of any examined vasculitides.

CONCLUSION

The incidences of GCA, IgA vasculitis, and BD decreased substantially in Israel during 15 years and were unaffected by the COVID-19 pandemic. Future studies should focus on possible environmental contributions to these findings.