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. 2023 Jun;95(6):e28862.
doi: 10.1002/jmv.28862.

Prevalence and risk factors of long COVID 6-12 months after infection with the Omicron variant among nonhospitalized patients in Hong Kong

Jingyuan Luo  1   2 , Jialing Zhang  1   2 , Hiu To Tang  1 , Hoi Ki Wong  1 , Aiping Lyu  1   3 , Chun Hoi Cheung  1   3 , Zhaoxiang Bian  1   2   3
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Prevalence and risk factors of long COVID 6-12 months after infection with the Omicron variant among nonhospitalized patients in Hong Kong

Jingyuan Luo et al. J Med Virol. 2023 Jun.

Abstract

Long COVID has been reported among patients with COVID-19, but little is known about the prevalence and risk factors associated with long COVID 6-12 months after infection with the Omicron variant. This is a large-scale retrospective study. A total of 6242 out of 12 950 nonhospitalized subjects of all ages with SARS-CoV-2 infection (confirmed by polymerase chain reaction/rapid antigen test) during the Omicron dominant outbreak (December 31, 2021-May 6, 2022) in Hong Kong were included. Prevalence of long COVID, frequencies of symptoms, and risk factors were analyzed. Three thousand four hundred and thirty (55.0%) subjects reported at least one long COVID symptom. The most reported symptom was fatigue (1241, 36.2%). Female gender, middle age, obesity, comorbidities, vaccination after infection, having more symptoms, and presenting fatigue/chest tightness/headache/diarrhea in the acute stage of illness were identified as associated risk factors for long COVID. Patients who had received three or more doses of vaccine were not associated with a lower risk of long COVID (adjusted odds ratio 1.105, 95% confidence interval 0.985-1.239, p = 0.088). Among patients with at least three doses of vaccine, there was no significant difference in the risk of long COVID between the CoronaVac vaccine and BNT162b2 vaccine (p > 0.05). Omicron infection can lead to long COVID in a significant proportion of nonhospitalized patients 6-12 months after infection. Further investigation is needed to uncover the mechanisms underlying the development of long COVID and determine the impact of various risk factors such as vaccines.

Keywords: Omicron; long COVID; risk factors; symptom.

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REFERENCES

    1. WHO. 2023. WHO coronavirus (COVID-19) dashboard. Accessed February 28, 2023. https://covid19.who.int/
    1. Sudre CH, Murray B, Varsavsky T, et al. Attributes and predictors of long COVID. Nat Med. 2021;27(4):626-631.
    1. O'Mahoney LL, Routen A, Gillies C, et al. The prevalence and long-term health effects of long covid among hospitalized and non-hospitalized populations: a systematic review and meta-analysis. EClinicalMedicine. 2023;55:101762.
    1. WHO. 2021. A clinical case definition of post COVID-19 condition by a Delphi consensus. Accessed February 13, 2023. https://www.who.int/publications/i/item/WHO-2019-nCoV-Post_COVID-19_cond...
    1. Subramanian A, Nirantharakumar K, Hughes S, et al. Symptoms and risk factors for long COVID in non-hospitalized adults. Nat Med. 2022;28(8):1706-1714.

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