Clinical signs of hidden SARS-CoV-2 Omicron infections in young children

Objective Preoperative PCR testing is still routinely performed during the Omicron dominated phase of the COVID-19 pandemic in Germany. In young children, these are challenging to perform. The aim of this study was to investigate the rate of false negative cases and the clinical signs of these hidden SARS-CoV-2 infections.

Methods All children ≤6 years old admitted for adenoidectomy/tonsillotomy in the university hospital in Bochum between March-May 2022 with a negative preoperative PCR test were prospectively included. Intraoperatively, a rapid antigen test, separate naso- and oropharyngeal PCR swabs, adenoid/tonsillar tissue for PCR analysis, and a serological test were collected.

Results Out of 55 included children, 28 (51%) had a false negative preoperative PCR test. In the positive cases, 29% had a Ct value <30 and 32% had a known previous SARS-CoV-2 infection. The sensitivity of nasopharyngeal PCR tests was significantly higher than oropharyngeal swabs (P =.002). The antigen test was negative in all patients. In all children with a previous SARS-CoV-2 infection, the PCR test was positive (mean time after first diagnosis 82.4 days). Nasopharyngeal colonization of SARS-CoV-2 was not associated with the grade of adenoid hypertrophy, nor with age, nor with sex, nor with going to kindergarten. In children with a SARS-CoV-2 infection, rhinorrhea was significantly associated with a higher Ct value.

Conclusion Despite preoperative PCR screening, virus particles were still discovered in half of the children. Children with nasopharyngeal colonization of SARS-CoV-2 did not have a higher grade of adenoid hypertrophy. These findings question preoperative screening protocols that include testing asymptomatic children who have recovered from a recent infection.

Publication History

Article published online:
12 May 2023