Long COVID in a highly vaccinated but largely unexposed Australian population following the 2022 SARS‐CoV‐2 Omicron wave: a cross‐sectional survey

Abstract

ObjectiveTo estimate the prevalence of long COVID among Western Australian adults, a highly vaccinated population whose first major exposure to the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) was during the 2022 Omicron wave, and to assess its impact on health service use and return to work or study.Study designFollow‐up survey (completed online or by telephone).Setting, participantsAdult Western Australians surveyed 90 days after positive SARS‐CoV‐2 test results (polymerase chain reaction or rapid antigen testing) during 16 July – 3 August 2022 who had consented to follow‐up contact for research purposes.Main outcome measuresProportion of respondents with long COVID (ie, reporting new or ongoing symptoms or health problems, 90 days after positive SARS‐CoV‐2 test result); proportion with long COVID who sought health care for long COVID‐related symptoms two to three months after infection; proportion who reported not fully returning to previous work or study because of long COVID‐related symptoms.ResultsOf the 70 876 adults with reported SARS‐CoV‐2 infections, 24 024 consented to contact (33.9%); after exclusions, 22 744 people were invited to complete the survey, of whom 11 697 (51.4%) provided complete responses. Our case definition for long COVID was satisfied by 2130 respondents (18.2%). The risk of long COVID was greater for women (v men: adjusted risk ratio [aRR], 1.5; 95% confidence interval [CI], 1.4–1.6) and for people aged 50–69 years (v 18–29 years: aRR, 1.6; 95% CI, 1.4–1.9) or with pre‐existing health conditions (aRR, 1.5; 95% CI, 1.4–1.7), as well as for people who had received two or fewer COVID–19 vaccine doses (v four or more: aRR, 1.4; 95% CI, 1.2–1.8) or three doses (aRR, 1.3; 95% CI, 1.1–1.5). The symptoms most frequently reported by people with long COVID were fatigue (1504, 70.6%) and concentration difficulties (1267, 59.5%). In the month preceding the survey, 814 people had consulted general practitioners (38.2%) and 34 reported being hospitalised (1.6%) with long COVID. Of 1779 respondents with long COVID who had worked or studied before the infection, 318 reported reducing or discontinuing this activity (17.8%).ConclusionNinety days after infection with the Omicron SARS‐CoV‐2 variant, 18.2% of survey respondents reported symptoms consistent with long COVID, of whom 38.7% (7.1% of all survey respondents) sought health care for related health concerns two to three months after the acute infection.