Document Type : Original Article




Background: Longitudinal data on SARS-CoV-2 re-infection are scarce.
 Objectives: 1) Characterize COVID-19 reinfection cases clinically and epidemiologically; 2) Determine whether the risk of SARS-CoV-2 reinfection has altered over time in the context of the development of beta, delta, and omicron variants.
Methods: From March 1, 2020 to July 1, 2022, an observational, longitudinal, and prospective investigation of Covid-19 re-infections was done in a general medical practice in Toledo, Spain.
Results: There were 43 cases in total, including 45 reinfections (2 cases presented 2 reinfections). The average period between first infection and reinfection was 346 days (range: 95-813 days). The average age was 41 years (range: 17-70 years). 5% were over the age of 65. 56% were female. 14% belonged to an ethnic minority. 82% of reinfections occurred among individuals who had been vaccinated (19%, 28%, and 35% in those who had received one dose, two doses, and a booster, respectively). They were symptomatic in 96% of the cases. All cases of reinfection were minor, with nonspecific symptoms (discomfort, asthenia, myalgia, fever, arthralgia) predominating (39%). Chronic illnesses were present in 60% of reinfection cases, with the Genitourinary (19%), Endocrine (17%), and Respiratory (16%) systems predominately. Reinfections have been steadily growing since 2020, with 67% occurring in 2022.
Conclusion: We discovered evidence of a continual increase in the incidence of reinfections in Toledo, Spain, primarily beginning in January 2022, which is temporally congruent with the introduction of the omicron variety, indicating its improved ability to infect previously infected persons.


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