# The hidden burden: prevalence and risk factors of long COVID among university students in Chiang Mai, Thailand

## TL;DR

This study found that about 22% of university students in Chiang Mai, Thailand, experienced long COVID symptoms, with severe initial infection and poor sleep being key risk factors.

## Contribution

The study provides new insights into long COVID prevalence and risk factors specifically among Thai university students.

## Key findings

- 21.9% of students reported long COVID symptoms, with respiratory and neurological issues being most common.
- Severe initial infection and poor sleep quality were significant predictors of long COVID.
- Each additional mRNA vaccine dose reduced the risk of severe outcomes by 14%.

## Abstract

As the COVID-19 pandemic transitions to an endemic phase, long COVID symptoms following SARS-CoV-2 infection have emerged as a new global health challenge. However, its impact on university students remains underexplored. This study aimed to assess the prevalence of long COVID symptoms and identify its predictive factors.

A cross-sectional study was conducted from February to August 2023 among Thai university students in Chiang Mai. An online questionnaire collected data on demographics, COVID-19 history, vaccination, and health status. Multivariable binary logistic regression was used to identify factors associated with long COVID.

A total of 997 students participated (60.5% female, mean age 20.6 years). Of these, 60.9% had received at least three COVID-19 vaccine doses, and 21.4% had received more than three mRNA vaccine doses. The prevalence of long COVID symptoms was 21.9% (n = 218). Common symptoms included respiratory issues (54.6%), neurological complaints (50.4%), psychological symptoms (42.7%), and poor sleep quality (34.9%). Significant predictors of long COVID included severe initial infection (aOR = 15.3; 95% CI: 5.3–44.3; p < 0.001), longer illness duration (aOR = 1.05; 95% CI: 1.0-1.1; p = 0.031), and poor sleep quality (aOR = 2.1; 95% CI: 1.4–3.1). Each additional dose of mRNA vaccine reduced the likelihood of severe outcomes by 14% (aOR = 0.86; 95% CI: 0.8-1.0; p = 0.044).

A minority of Thai university students reported long COVID symptoms. Vaccination, especially with multiple mRNA doses, was linked to reduced risk. Early detection and targeted support during recovery may help mitigate long-term health consequences in this group.

The online version contains supplementary material available at 10.1186/s12889-025-25457-3.