Allergic diseases as risk factors for Long-COVID symptoms: Systematic review of prospective cohort studies.

OBJECTIVE: The role of allergy as a risk factor for Long-COVID (LC) is unclear and has not been thoroughly examined yet. We aimed to systematically review and appraise the epidemiological evidence on allergic diseases as risk factors for LC. DESIGN: This is an initial systematic review. Two reviewers independently performed the study selection and data extraction using Covidence. Risk of bias (RoB) and certainty of evidence (GRADE) were assessed. Random effects meta-analyses were used to pool unadjusted ORs within homogeneous data subsets. DATA SOURCES: We retrieved articles published between January 1st, 2020 and January 19th, 2023 from MEDLINE via PubMed, Scopus, the WHO-COVID-19 database and the LOVE platform (Epistemonikos Foundation). In addition, citations and reference lists were searched. ELIGIBILITY CRITERIA: We included prospective cohort studies recruiting individuals of all ages with confirmed SARS-CoV-2 infection that were followed up for at least 12 months for LC symptoms where information on pre-existing allergic diseases was available. We excluded all study designs that were not prospective cohort studies and all publication types that were not original articles. RESULTS: We identified 13 studies (9967 participants, range 39-1950 per study), all assessed as high RoB, due to population selection and methods used to ascertain the exposures and the outcome. Four studies did not provide sufficient data to calculate Odds Ratios. The evidence supported a possible relationship between LC and allergy, but was very uncertain. For example, pre-existing asthma measured in hospital-based populations (6 studies, 4019 participants) may be associated with increased risk of LC (Odds Ratio 1.94, 95% CI 1.08, 3.50) and findings were similar for pre-existing rhinitis (3 studies, 1141 participants; Odds Ratio 1.96, 95% CI 1.61, 2.39), both very low certainty evidence. CONCLUSIONS: Pre-existing asthma or rhinitis may increase the risk of LC.

Pool Testing as a Strategy for Prevention of SARS-CoV-2 Outbreaks in Schools: Protocol for a Feasibility Study.

BACKGROUND: School closures are a widely implemented strategy for limiting infection spread in the current COVID-19 pandemic. The negative impact of school closures on children and young people is increasingly apparent, however. OBJECTIVE: We aim to evaluate the feasibility of an infection monitoring program in schools to enable targeted quarantining to replace school closures. The program is currently being implemented in two model schools in Magdeburg, Germany, within the framework of the Study of Coronavirus Outbreak Prevention in Magdeburg Schools (Studie zur Ausbruchsvermeidung von Corona an Magdeburger Schulen [STACAMA]). METHODS: Five pupils per class are pseudorandomly selected twice a week and asked to provide a gargle sample over a 16-week evaluation period. RNA is extracted from each sample individually in a laboratory and pooled according to school class for real-time reverse transcription polymerase chain reaction (rRT-PCR) analysis. Immediate individual sample testing will be carried out in the case of a positive pool test. Individual RNA extraction prior to pooling and application of rRT-PCR result in high test sensitivity. Testing will be performed in strict adherence to data protection standards. All participating pupils will receive a 16-digit study code, which they will be able to use to access their test. RESULTS: When the study commenced on December 2, 2020, 520 (52%) pupils and their families or guardians had consented to study participation. The study was suspended after four test rounds due to renewed school closures resulting from rising regional infection incidence. Testing resumed when schools reopened on March 8, 2021, at which time consent to participation was provided for 54% of pupils. We will quantitatively and qualitatively evaluate the logistics and acceptability of the program. CONCLUSIONS: The findings from this study should inform the design of infection surveillance programs in schools based on gargle samples and a PCR-based pool testing procedure, enabling the identification of aspects that may require adaptation before large-scale implementation. Our focus on each step of the logistics and on the experiences of families should enable a robust assessment of the feasibility of such an approach. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/28673.

Feasibility of a surveillance programme based on gargle samples and pool testing to prevent SARS-CoV-2 outbreaks in schools.

School closures have a negative impact on physical and mental well-being, and education, of children and adolescents. A surveillance programme to detect asymptomatic SARS-CoV-2 infection could allow schools to remain open, while protecting the vulnerable. We assessed the feasibility of a programme employing gargle samples and pool testing of individually extracted RNA using rRT-qPCR in a primary and a secondary school in Germany, based on programme logistics and acceptance. Twice a week, five participants per class were selected to provide samples, using an algorithm weighted by a risk-based priority score to increase likelihood of case detection. The positive response rate was 54.8% (550 of 1003 pupils). Logistics evaluation revealed the rate-limiting steps: completing the regular pre-test questionnaire and handing in the samples. Acceptance questionnaire responses indicated strong support for research into developing a surveillance programme and a positive evaluation of gargle tests. Participation was voluntary. As not all pupils participated, individual reminders could lead to participant identification. School-wide implementation of the programme for infection monitoring purposes would enable reminders to be given to all school pupils to address these steps, without compromising participant anonymity. Such a programme would provide a feasible means to monitor asymptomatic respiratory tract infection in schools.