The prevalence of and factors related to reinfection with COVID‐19 in Ahvaz, Iran: A comparative cross‐sectional study

BACKGROUND AND AIMS: Reinfection with the coronavirus disease 2019 (COVID‐19) virus may be as serious as the first infection, exposing people to risks such as admission to hospital or even death. This study aimed to evaluate the prevalence of and the factors related to reinfection in Ahvaz, Iran. METHODS: This was a comparative cross‐sectional study that was conducted on 200 reinfected individuals and 200 people who had once been infected with COVID‐19. Infection with COVID‐19 was confirmed using the polymerase chain reaction (PCR) test, and those with reinfection had to have a negative PCR test after recovery from the first infection and a positive PCR test for COVID‐19 > 90 days after the first infection. Data was collected using a questionnaire and a checklist. Data were analyzed using the Chi‐square test, independent t‐test, and logistic regression test. RESULTS: Around 7000 reinfections were observed in this study, and the prevalence of reinfection was 0.59% in Ahvaz City. A large proportion of the participants in the control group, 133 (66.5%) received two doses of COVID‐19 vaccines compared with 110 (55%) in the reinfected group (p = 0.003), and 43 (21.5%) of reinfected participants did not receive any vaccine. Older people were 0.982 times more likely to get reinfected with COVID‐19 (95% confidence interval [CI]: 0.966–0.997). Also, those receiving vaccination once or twice were 2.311 and 2.498 times less likely to get reinfected with COVID‐19, respectively (95% CI: 1.093–4.887 and 1.281–4.872, respectively). CONCLUSION: The findings of this study showed that the prevalence of reinfection among people in Ahvaz City was 0.59%. Older individuals, those without vaccination or with suboptimal vaccination, and people with comorbidities were at a higher risk for reinfection. Health policymakers should pay more attention to factors related to reinfection with COVID‐19.