How can we define early COVID-19 reinfection?

In a recent study published in Emerging infectious diseases Journals and researchers investigated reinfection with coronavirus disease 2019 (COVID-19).

Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) reinfection is defined as a positive polymerase chain reaction (PCR) test or rapid. antigen The test was detected 60 days after the previous detection of positive PCR or rapid antigen test. However, new reports indicate that reinfection of the SARS-CoV-2 Omicron BA.1 mutant can occur within 60 days of diagnosis with the Delta mutant. In addition, the study revealed that young, unvaccinated individuals were reported to be re-infected with Omicron BA.2 60 days after diagnosis of Omicron BA.1. Therefore, reinfection affects subsequent retest policies and must be redefined.

About research

In this study, researchers evaluated the impact of COVID-19 reinfection on case definition and retesting policy.

The team reported a case involving a 10-year-old immunocompetent child who had no significant medical history and was not vaccinated against COVID-19. Patients tested positive for PCR for the SARS-CoV-2 delta mutant on December 3, 2021. The patient’s mother and siblings also tested positive for COVID-19, but both were vaccinated. All 3 patients showed mild COVID-19 Symptoms..

Due to a sports-related injury, the child was hospitalized for surgery on January 1, 2022. Preoperative COVID-19 screening revealed that patients were positive for SARS-CoV-2 infection with the Omicron BA.1 variant. The team noted that the BA.1 reinfection was diagnosed only 39 days after the previous Delta diagnosis. The patient had weak symptoms throughout the process of reinfection. Screening for infections in the patient’s siblings revealed that the mother was negative for COVID-19, whereas the viral load was low.

To investigate this clinical case from a broader epidemiological perspective, the team teamed up with early Omicron BA.1 reinfection after a history of delta infection and Omicron BA.2 reinfection after BA.1 infection in a community environment. We evaluated the incidence of. The team compared the vaccination status and age of 96 patients who reported early reinfection with the vaccination rates reported for the corresponding age groups within the same geographic area.

result

Between December 1, 2021 and February 7, 2022, the team found that nearly 59,515 patients tested positive for COVID-19, resulting in SARS-CoV-2 delta variant infection becoming Omicron BA.1 infection. I noticed that it was replaced. Of these patients, 0.15% detected the SARS-CoV-2 spike (S) gene in the first sample using a PCR test suggesting the presence of delta variants in the sample. However, S gene targeting disorder (SGTF) was detected in the second COVID-19-positive sample collected during the period. This indicates Omicron BA.1 reinfection immediately after Delta infection.

Similarly, the period from January 1st to March 10th, 2022 is characterized by the replacement of the Omicron BA.1 variant with the BA.2 variant. During this period, nearly 58,166 patients tested positive for COVID-19. Of these, 0.01% of the first sample collected showed SGTF and the S gene was found in the second positive sample. This indicated a BA.2 reinfection after the diagnosis of a BA.1 infection.

The team observed that patients who reported early reinfection were more likely to be vaccinated, partially unvaccinated, or vaccinated but not boosted, compared to the general population age group. Did. In addition, the median time between detections of two positive samples infected with different variants was 47 days.

Data collected by the team show that Omicron BA.1 reinfection diagnosed within 60 days of previous delta variant infection and Omicron BA.2 reinfection detected after BA.1 infection are unvaccinated young. Clarified that it can occur in individuals. Individuals in the elderly patient group who were not vaccinated or who received basic vaccination but did not receive booster immunization were re-vaccinated compared to patients who received the first booster dose. It was susceptible to infection. The team also observed that reinfection generally showed symptoms of mild illness and did not require hospitalization.

Conclusion

Overall, this study showed that complete viral replacement continues to affect as much as the duration. Effectiveness of Vaccination and immune response. Therefore, retesting of patients with a history of SARS-CoV-2 infection during a state of persistent mutational circulation is limited. However, if antigenic drift results in dominant mutant switching, minimum test intervals should not be considered for timely detection of COVID-19 reinfection.