Prevalence of COVID-19 in Italian Children With Celiac Disease: A Cross-Sectional Study

Dear Editor:

We read with interest the recent article published in Clinical Gastroenterology and Hepatology by Zhen et al,¹ in which they reported that the risk of coronavirus disease 2019 (COVID-19) is not increased in adult patients with celiac disease (CD). To the best of our knowledge, there are no data about the risk for COVID-19 morbidity and mortality in children with CD. Italy was one of the first European countries where cases of community spread were detected; the Marche region, Central Italy, has been severely hit by this crisis, and hosts a large pediatric celiac center. Thus, our setting represented an opportunity to explore the prevalence and severity of COVID-19 in children with CD, and to compare it with the data of the general population.

Between February and June 2020 we performed a telephone-based survey using a 26-question questionnaire to explore the prevalence and clinical features of COVID-19 in patients with CD. All children with a diagnosis of CD, according to the ESPGHAN criteria,² followed at our center were recruited in the CD group. Questionnaires were administered to caregivers by telephone interview. Diagnosis of COVID-19 was considered in subjects with a positive test from a nasopharyngeal swab, using a real-time reverse-transcriptase polymerase chain reaction assay. Patients who presented symptoms possibly related to COVID-19 not tested for COVID-19 were considered as COVID-19-like group. Data about positivity of COVID-19 nasal swabs in the general population of the Marche region during the same period were obtained from national reports of the Italian National Institute of Health (Istituto Superiore di Sanità) and the Marche regional government.^{3 , 4} These data were used to calculate the prevalence of pediatric COVID-19 infection in the Marche region.

Overall, 419 patients with CD were contacted: of them, 387 patients responded and were enrolled (response rate, 92.4%). There were 143 (37%) males, the median age was 9.9 (range, 1–16 years), and the median age at diagnosis of CD was 7.5 (range, 6 months–16 years). Of the 387 patients with CD recruited, none received a laboratory-confirmed diagnosis of COVID-19. Prevalence of confirmed COVID-19 in our cohort was therefore 0/387 (95% confidence interval, 0.0000–0.0095). Fifteen (3.9%) patients reported fever without other associated symptoms, but tested negative for COVID-19 at the nasopharyngeal swab. Twenty-three (5.9%) patients were assigned to the COVID-19-like group (9 with fever and cough; 2 with fever, vomiting, and diarrhea; 10 with diarrhea and/or vomiting; 2 with cough); none of these patients had respiratory failure, developed pneumonia, needed oxygen administration, nor required hospital admission. As of June 22, 2020 the prevalence of confirmed COVID-19 in the age 0–16 years in the Marche region was 155/199289 (0.08%; 95% confidence interval, 0.0007–0.0009). Thus, the group of children with CD did not show a significant increase in the prevalence of COVID-19 as compared with the general population (P = .9). Also assuming that children in the COVID-19-like group had COVID-19, their disease was not severe or complicated. The calculated number of infections in the celiac group could be underestimated, because we could not count asymptomatic carriers of COVID-19; however, this was a limitation for the reference population as well. Therefore, our results are in line with the findings by Zhen et al,¹ showing that patients with CD, even in the pediatric age, are not at increased risk of COVID-19 disease.

The sudden appearance of COVID-19 has challenged health care system worldwide and led to rethink the management of patients with any sort of acute or chronic illness. Interestingly, CD follow-up is particularly suitable for a telemedicine approach.⁵ The knowledge that the risk of contracting COVID-19 is not increased may be reassuring for patients with CD and their treating physicians. For the time being, patients with CD should adhere to the preventive measures suggested for the general population. Nonetheless, longitudinal studies will contribute to a better understanding on whether the risk of contracting COVID-19 in CD changes over time.