Development of Open Backend Structures for Health Care Professionals to Improve Participation in App Developments: Pilot Usability Study of a Medical App.

BACKGROUND: Efficient digitization in medicine still is in its infancy but undeniably has great potential for current and future challenges in health care. Thus far, the rollout of medical apps has not resulted in widespread use of smartphones in the German health care sector-the reasons for this have not been clarified so far. Nevertheless, the lack of user involvement in the development process and content creation might contribute to low acceptance of these products. OBJECTIVE: This study aims to outline an approach to involve medical expertise without any coding knowledge for developing medical app content and functions. METHODS: An end user-operable backend was built. Its usability was evaluated using a usability evaluation test protocol. The results of the usability tests were evaluated by the app development team, and the usability test was repeated for optimizing backend usability. In total, 40 criteria to measure the ease of app usage were defined a priori. The usability test comprised 20 tasks that had to be fulfilled. Usability tasks were analyzed for completion, dropout, and test duration. Due to the COVID-19 pandemic, digital videoconferencing platforms (Zoom and QuickTime Player) were used to complete usability questionnaires. Finally, several backend-based apps for several specialties (infectiology, plastic and reconstructive surgery, and orthopedics) were developed by health care professionals as prototypes. RESULTS: Initial usability testing was conducted with 5 participants (4 men and 1 woman; mean age 39.2, SD 5.97 years). All of them could complete the assigned backend tasks with only a few workflow interruptions and some minor errors. After usability optimization, the workflow completion time decreased from 5.03 minutes to 3.50 minutes, indicating a time saving. The basic backend structure was clear to all test users and the handling was intuitive to learn. Some minor errors in the backend occurred during the test rounds. The apps developed using the aforementioned approach are in clinical use as a proof of concept. CONCLUSIONS: Backends offering operability for medical professionals might have great potential for app development in the mobile health sector. Sophisticated and time-saving usability are pivotal for the acceptance of medical software, as illustrated by the backend-based apps presented herein, which are in clinical use as a proof of concept. Basic interventions are essential and sufficient for adequate usability optimization. Practicable, well-structured software usability evaluation is possible based on the usability evaluation test protocol.

Teaching Medical Microbiology With a Web-Based Course During the COVID-19 Pandemic: Retrospective Before-and-After Study.

BACKGROUND: The COVID-19 pandemic has imposed unprecedented hurdles on health care systems and medical faculties alike. Lecturers of practical courses at medical schools have been confronted with the challenge of transferring knowledge remotely. OBJECTIVE: We sought to evaluate the effects of a web-based medical microbiology course on learning outcomes and student perceptions. METHODS: During the summer term of 2020, medical students at Saarland University, Germany, participated in a web-based medical microbiology course. Teaching content comprised clinical scenarios, theoretical knowledge, and instructive videos on microbiological techniques. Test performance, failure rate, and student evaluations, which included open-response items, for the web-based course were compared to those of the on-site course from the summer term of 2019. RESULTS: Student performance was comparable between both the online-only group and the on-site comparator for both the written exam (n=100 and n=131, respectively; average grade: mean 7.6, SD 1.7 vs mean 7.3, SD 1.8; P=.20) and the oral exam (n=86 and n=139, respectively; average grade: mean 33.6, SD 4.9 vs mean 33.4, SD 4.8; P=.78). Failure rate did not significantly differ between the online-only group and the comparator group (2/84, 2.4% vs 4/120, 3.3%). While lecturer expertise was rated similarly as high by students in both groups (mean 1.47, SD 0.62 vs mean 1.27, SD 0.55; P=.08), students who took the web-based course provided lower scores for interdisciplinarity (mean 1.7, SD 0.73 vs mean 2.53, SD 1.19; P<.001), opportunities for interaction (mean 1.46, SD 0.67 vs mean 2.91, SD 1.03; P<.001), and the extent to which the educational objectives were defined (mean 1.61, SD 0.76 vs mean 3.41, SD 0.95; P<.001). Main critiques formulated within the open-response items concerned organizational deficits. CONCLUSIONS: Web-based courses in medical microbiology are a feasible teaching option, especially in the setting of a pandemic, leading to similar test performances in comparison to on-site courses. The lack of interaction and the sustainability of acquired manual skills warrant further research.

Expression of TRAIL, IP-10, and CRP in children with suspected COVID-19 and real-life impact of a computational signature on clinical decision-making: a prospective cohort study.

PURPOSE: We evaluated the host-response marker score "BV" and its components TRAIL, IP-10, and CRP in SARS-CoV-2 positive children, and estimated the potential impact on clinical decision-making. METHODS: We prospectively analyzed levels of TRAIL, IP-10, CRP, and the BV score, in children with suspected COVID-19. Classification of infectious etiology was performed by an expert panel. We used a 5-point-questionnaire to evaluate the intention to treat with antibiotics before and after receiving test results. RESULTS: We screened 111 children, of whom 6 (5.4%) were positive for SARS-CoV-2. A total of 53 children were included for the exploratory analysis. Median age was 3.1 years (interquartile range [IQR] 1.3-4.3), and 54.7% (n = 29) were girls. A viral and a bacterial biomarker pattern was found in 27/53 (50.9%) and 15/53 (28.3%), respectively. BV scores differed between COVID-19, children with other viral infections, and children with bacterial infections (medians 29.5 vs. 9 vs. 66; p = 0.0006). Similarly, median TRAIL levels were different (65.5 vs. 110 vs. 78; p = 0.037). We found no differences in IP-10 levels (555 vs. 504 vs. 285; p = 0.22). We found a concordance between physicians' "unlikely intention to treat" children with a viral test result in most cases (n = 19/24, 79.2%). When physicians expressed a "likely intention to treat" (n = 15), BV test revealed 5 bacterial, viral, and equivocal scores each. Antibiotics were withheld in three cases (20%). Overall, 27/42 (64%) of pediatricians appraised the BV test positively, and considered it helpful in clinical practice. CONCLUSION: Host-response based categorization of infectious diseases might help to overcome diagnostic uncertainty, support clinical decision-making and reduce unnecessary antibiotic treatment.

Comparative immunogenicity and reactogenicity of heterologous ChAdOx1-nCoV-19-priming and BNT162b2 or mRNA-1273-boosting with homologous COVID-19 vaccine regimens.

Comparative analyses of the immunogenicity and reactogenicity of homologous and heterologous SARS-CoV-2 vaccine-regimens will inform optimized vaccine strategies. Here we analyze the humoral and cellular immune response following heterologous and homologous vaccination strategies in a convenience cohort of 331 healthy individuals. All regimens induce immunity to the vaccine antigen. Immunity after vaccination with ChAdOx1-nCoV-19 followed by either BNT162b2 (n = 66) or mRNA-1273 (n = 101) is equivalent to or more pronounced than homologous mRNA-regimens (n = 43 BNT162b2, n = 59 mRNA-1273) or homologous ChAdOx1-nCoV-19 vaccination (n = 62). We note highest levels of spike-specific CD8 T-cells following both heterologous regimens. Among mRNA-containing combinations, spike-specific CD4 T-cell levels in regimens including mRNA-1273 are higher than respective combinations with BNT162b2. Polyfunctional T-cell levels are highest in regimens based on ChAdOx1-nCoV-19-priming. All five regimens are well tolerated with most pronounced reactogenicity upon ChAdOx1-nCoV-19-priming, and ChAdOx1-nCoV-19/mRNA-1273-boosting. In conclusion, we present comparative analyses of immunogenicity and reactogenicity for heterologous vector/mRNA-boosting and homologous mRNA-regimens.

TNF-related apoptosis-inducing ligand, interferon gamma-induced protein 10, and C-reactive protein in predicting the progression of SARS-CoV-2 infection: a prospective cohort study.

BACKGROUND: Early prognostication of COVID-19 severity will potentially improve patient care. Biomarkers, such as TNF-related apoptosis-inducing ligand (TRAIL), interferon gamma-induced protein 10 (IP-10), and C-reactive protein (CRP), might represent possible tools for point-of-care testing and severity prediction. METHODS: In this prospective cohort study, we analyzed serum levels of TRAIL, IP-10, and CRP in patients with COVID-19, compared them with control subjects, and investigated the association with disease severity. RESULTS: A total of 899 measurements were performed in 132 patients (mean age 64 years, 40.2% females). Among patients with COVID-19, TRAIL levels were lower (49.5 vs 87 pg/ml, P = 0.0142), whereas IP-10 and CRP showed higher levels (667.5 vs 127 pg/ml, P <0.001; 75.3 vs 1.6 mg/l, P <0.001) than healthy controls. TRAIL yielded an inverse correlation with length of hospital and intensive care unit (ICU) stay, Simplified Acute Physiology Score II, and National Early Warning Score, and IP-10 showed a positive correlation with disease severity. Multivariable regression revealed that obesity (adjusted odds ratio [aOR] 5.434, 95% confidence interval [CI] 1.005-29.38), CRP (aOR 1.014, 95% CI 1.002-1.027), and peak IP-10 (aOR 1.001, 95% CI 1.00-1.002) were independent predictors of in-ICU mortality. CONCLUSIONS: We demonstrated a correlation between COVID-19 severity and TRAIL, IP-10, and CRP. Multivariable regression showed a role for IP-10 in predicting unfavourable outcomes, such as in-ICU mortality. TRIAL REGISTRATION: Clinicaltrials.gov, NCT04655521.

Staphylococcus massiliensis isolated from human blood cultures, Germany, 2017-2020.

Clinical and laboratory data on newly described staphylococcal species is rare, which hampers decision-making when such pathogens are detected in clinical specimens. Here, we describe Staphylococcus massiliensis detected in three patients at a university hospital in southwest Germany. We report the discrepancy of microbiological findings between matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, 16S-rRNA polymerase chain reaction, and whole-genome sequencing for all three isolates. Our findings highlight the diagnostic pitfalls pertinent to novel and non-model organisms in daily microbiological practice, in whom the correct identification is dependent on database accuracy.

High heterogeneity on the accepted vaccines for COVID-19 certificates in European countries.

BACKGROUND: We aimed to elucidate which vaccines were accepted by European countries as valid proof of vaccination against COVID-19 for international travelers. METHOD: On 27-September-2021 a cross-sectional study was conducted on VisaGuide.World, that reports on valid vaccines for international travelers. Other databases, lay press and regulatory agencies were also checked. The main outcome measure was which of the vaccines included on the WHO emergency use listing (EUL) [ChAdOx1 (Vaxzevria, Covishield),BNT162b2,mRNA-1273,Ad26.CoV2.S,BBIBP-CorV,CoronaVac] and Sputnik V, were accepted in each country. The influence of the vaccines approved for COVID-19 vaccination programs on the vaccines recognized as proof of vaccination was assessed. RESULTS: There was a remarkable heterogeneity on the vaccines accepted as proof of vaccination among 46 countries. Russia accepted only one. Cyprus, Greece and Slovenia accepted all vaccines considered. Eleven countries accepted the seven WHO EUL vaccines: eight EU countries, plus Iceland, Norway and Switzerland. Seven EU countries accepted only the four EMA-authorized vaccines. Considering Covishield as equivalent to Vaxzevria, 69% of countries recognized only vaccinated travelers who received any of the vaccines approved for vaccination programs in the country of arrival as valid. CONCLUSION: Vaccines accepted as proof of vaccination should be harmonized. Accepting any of the WHO EUL vaccines would be a scientifically sound objective.

Autoantibodies against interleukin-1 receptor antagonist in multisystem inflammatory syndrome in children: a multicentre, retrospective, cohort study.

Background: Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious complication of infection with SARS-CoV-2. A possible involvement of pathogenetically relevant autoantibodies has been discussed. Recently, neutralising autoantibodies against inflammatory receptor antagonists progranulin and interleukin-1 receptor antagonist (IL-1Ra) were found in adult patients with critical COVID-19. The aim of this study was to investigate the role of such autoantibodies in MIS-C. Methods: In this multicentre, retrospective, cohort study, plasma and serum samples were collected from patients (0-18 years) with MIS-C (as per WHO criteria) treated at five clinical centres in Germany and Spain. As controls, we included plasma or serum samples from children with Kawasaki disease, children with inactive systemic juvenile idiopathic arthritis, and children with suspected growth retardation (non-inflammatory control) across four clinical centres in Germany and Spain (all aged ≤18 years). Serum samples from the CoKiBa trial were used as two further control groups, from healthy children (negative for SARS-CoV-2 antibodies) and children with previous mild or asymptomatic COVID-19 (aged ≤17 years). MIS-C and control samples were analysed for autoantibodies against IL-1Ra and progranulin, and for IL-1Ra concentrations, by ELISA. Biochemical analysis of plasma IL-1Ra was performed with native Western blots and isoelectric focusing. Functional activity of the autoantibodies was examined by an in vitro IL-1ß-signalling reporter assay. Findings: Serum and plasma samples were collected between March 6, 2011, and June 2, 2021. Autoantibodies against IL-1Ra could be detected in 13 (62%) of 21 patients with MIS-C (11 girls and ten boys), but not in children with Kawasaki disease (n=24; nine girls and 15 boys), asymptomatic or mild COVID-19 (n=146; 72 girls and 74 boys), inactive systemic juvenile idiopathic arthritis (n=10; five girls and five boys), suspected growth retardation (n=33; 13 girls and 20 boys), or in healthy controls (n=462; 230 girls and 232 boys). Anti-IL-1Ra antibodies in patients with MIS-C belonged exclusively to the IgG1 subclass, except in one patient who had additional IL-1Ra-specific IgM antibodies. Autoantibodies against progranulin were only detected in one (5%) patient with MIS-C. In patients with MIS-C who were positive for anti-IL-1Ra antibodies, free plasma IL-1Ra concentrations were reduced, and immune-complexes of IL-1Ra were detected. Notably, an additional, hyperphosphorylated, transiently occurring atypical isoform of IL-1Ra was observed in all patients with MIS-C who were positive for anti-IL-1Ra antibodies. Anti-IL-1Ra antibodies impaired IL-1Ra function in reporter cell assays, resulting in amplified IL-1ß signalling. Interpretation: Anti-IL-1Ra autoantibodies were observed in a high proportion of patients with MIS-C and were specific to these patients. Generation of these autoantibodies might be triggered by an atypical, hyperphosphorylated isoform of IL-1Ra. These autoantibodies impair IL-1Ra bioactivity and might thus contribute to increased IL-1ß-signalling in MIS-C. Funding: NanoBioMed fund of the University of Saarland, José Carreras Center for Immuno and Gene Therapy, Dr Rolf M Schwiete Stiftung, Staatskanzlei Saarland, German Heart Foundation, Charity of the Blue Sisters, Bavarian Ministry of Health, the Center for Interdisciplinary Clinical Research at University Hospital Münster, EU Horizon 2020.

Availability of oral antivirals against SARS-CoV-2 infection and the requirement for an ethical prescribing approach.

The first two oral antivirals, molnupiravir and nirmatrelvir-ritonavir, are now becoming available in many countries. These medicines will be indicated to treat mild-to-moderate COVID-19 in non-hospitalised patients who are at high risk of progressing to severe COVID-19. These antivirals should be prescribed within 5 days of symptom onset, and after SARS-CoV-2 infection has been confirmed. However, the availability of these antivirals will be scarce for some time due to manufacturing constraints. Each country should establish a policy on the conditions under which these antivirals can be prescribed. Such a policy should be based on the fulfilment of five ethical elements: transparency, relevance, appeals, enforcement, and fairness. Following the principles of distributive justice, molnupiravir and nirmatrelvir-ritonavir should be prescribed according to a hierarchy of predicted efficacy, ideally on the basis of an evidence-based scoring system. The placebo-controlled randomised trials that supported the temporary authorisation of these two antivirals were conducted in unvaccinated patients with COVID-19, so an evidence-based prescription practice would only use these drugs for unvaccinated patients until further data become available. However, in the countries that authorised these antivirals in 2021 (the UK and the USA), both vaccinated and unvaccinated patients meeting particular requirements have access to these antivirals. Due to the complexity of prioritisation, national health authorities should start issuing their draft policies as soon as possible and these policies should be regularly updated. The effectiveness of these antivirals against the omicron variant of SARS-CoV-2 must be urgently assessed. Once implemented, molnupiravir and nirmatrelvir-ritonavir must show their effectiveness and safety in the real world, and health systems must be adequately adapted for the correct use of these antivirals.

Investigation of MALDI-TOF Mass Spectrometry for Assessing the Molecular Diversity of Campylobacter jejuni and Comparison with MLST and cgMLST: A Luxembourg One-Health Study.

There is a need for active molecular surveillance of human and veterinary Campylobacter infections. However, sequencing of all isolates is associated with high costs and a considerable workload. Thus, there is a need for a straightforward complementary tool to prioritize isolates to sequence. In this study, we proposed to investigate the ability of MALDI-TOF MS to pre-screen C. jejuni genetic diversity in comparison to MLST and cgMLST. A panel of 126 isolates, with 10 clonal complexes (CC), 21 sequence types (ST) and 42 different complex types (CT) determined by the SeqSphere+ cgMLST, were analysed by a MALDI Biotyper, resulting into one average spectra per isolate. Concordance and discriminating ability were evaluated based on protein profiles and different cut-offs. A random forest algorithm was trained to predict STs. With a 94% similarity cut-off, an AWC of 1.000, 0.933 and 0.851 was obtained for MLSTCC, MLSTST and cgMLST profile, respectively. The random forest classifier showed a sensitivity and specificity up to 97.5% to predict four different STs. Protein profiles allowed to predict C. jejuni CCs, STs and CTs at 100%, 93% and 85%, respectively. Machine learning and MALDI-TOF MS could be a fast and inexpensive complementary tool to give an early signal of recurrent C. jejuni on a routine basis.

[The impact of immunosuppression and chronic kidney disease on immunogenicity of COVID-19 vaccines]. / Der Einfluss von Immunsuppression und chronischen Nierenerkrankungen auf das Ansprechen auf COVID-19-Impfungen.

HOW EFFECTIVE ARE THE APPROVED VACCINES IN KIDNEY DISEASES AND THOSE RECEIVING IMMUNOSUPPRESSION?: Several observational studies indicated that immunosuppression is associated with a weakened or absent humoral response. Patients with chronic kidney diseases or undergoing maintenance dialysis without immunosuppression have a reduced humoral response to COVID-19 vaccines. I HAD COVID-19. SHOULD I GET VACCINATED?: It is recommended to receive a booster after SARS-CoV-2 infection with a mRNA vaccine. IS A COVID-19 VACCINATION DESPITE ONGOING IMMUNOSUPPRESSION POSSIBLE?: Patients receiving immunosuppression have a reduced humoral response, and this is especially observed when anti-CD20 therapy is used. IS THERE A POSSIBILITY THAT THE VACCINE PROVOKES REJECTION OF MY TRANSPLANTED KIDNEY OR RELAPSE OF MY GLOMERULAR DISEASE?: Several reports were published in the last months highlighting new-onset diseases, recurrences and relapses of different glomerular diseases, which occurred after the receipt of the first or second vaccine dose. As a clear association of vaccines and induction of autoimmunity still needs to be established, most of these diseases are treatable, and COVID-19 in patients under immunosuppression is often fatal, there is a clear net benefit of vaccination. DO I HAVE A PERMANENT PROTECTION AFTER VACCINATION?: The antibody titers and likely the cellular immune response is significantly reduced in patients with kidney diseases, and titers are reducing at a fast pace under ongoing immunosuppression. A booster dose should be considered, especially taking into consideration the evolvement of virus variants and their impact on vaccine efficacy. AFTER THE FIRST SERIES OF VACCINATION, NO OR ONLY A MARGINAL AMOUNT OF ANTIBODIES WERE DETECTABLE. ARE THERE STRATEGIES TO IMPROVE VACCINE RESPONSE?: Many countries recommend the application of a third dose for vulnerable patient cohorts, especially because of a weakened response and their risk to develop a severe disease course of COVID-19. Prospective clinical trials are ongoing to test the ideal strategy to improve vaccine response in these cohorts.

Immunogenicity and reactogenicity of heterologous ChAdOx1 nCoV-19/mRNA vaccination.

Heterologous priming with the ChAdOx1 nCoV-19 vector vaccine followed by boosting with a messenger RNA vaccine (BNT162b2 or mRNA-1273) is currently recommended in Germany, although data on immunogenicity and reactogenicity are not available. In this observational study we show that, in healthy adult individuals (n = 96), the heterologous vaccine regimen induced spike-specific IgG, neutralizing antibodies and spike-specific CD4 T cells, the levels of which which were significantly higher than after homologous vector vaccine boost (n = 55) and higher or comparable in magnitude to homologous mRNA vaccine regimens (n = 62). Moreover, spike-specific CD8 T cell levels after heterologous vaccination were significantly higher than after both homologous regimens. Spike-specific T cells were predominantly polyfunctional with largely overlapping cytokine-producing phenotypes in all three regimens. Recipients of both the homologous vector regimen and the heterologous vector/mRNA combination reported greater reactogenicity following the priming vector vaccination, whereas heterologous boosting was well tolerated and comparable to homologous mRNA boosting. Taken together, heterologous vector/mRNA boosting induces strong humoral and cellular immune responses with acceptable reactogenicity profiles.

Acute Respiratory Distress Syndrome due to Mycoplasma pneumoniae Misinterpreted as SARS-CoV-2 Infection.

BACKGROUND: In 2020, a novel coronavirus caused a global pandemic with a clinical picture termed COVID-19, accounting for numerous cases of ARDS. However, there are still other infectious causes of ARDS that should be considered, especially as the majority of these pathogens are specifically treatable. Case Presentation. We present the case of a 36-year-old gentleman who was admitted to the hospital with flu-like symptoms, after completing a half-marathon one week before admission. As infection with SARS-CoV-2 was suspected based on radiologic imaging, the hypoxemic patient was immediately transferred to the ICU, where he developed ARDS. Empiric antimicrobial chemotherapy was initiated, the patient deteriorated further, therapy was changed, and the patient was transferred to a tertiary care ARDS center. As cold agglutinins were present, the hypothesis of an infection with SARS-CoV-2 was then questioned. Bronchoscopic sampling revealed Mycoplasma (M.) pneumoniae. When antimicrobial chemotherapy was adjusted, the patient recovered quickly. CONCLUSION: Usually, M. pneumoniae causes mild disease. When antimicrobial chemotherapy was adjusted, the patient recovered quickly. The case underlines the importance to adhere to established treatment guidelines, scrutinize treatment modalities, and not to forget other potential causes of severe pneumonia or ARDS.

[SARS-CoV-2 vaccines - what the nephrologist should know]. / SARS-CoV-2-Impfungen ­ Was muss der Nephrologe wissen?

Only fifteen months after the beginning of the COVID-19 pandemic, several vaccines are already available for clinical use. While the spike protein of SARS-CoV-2 constitutes the main target of all predominant SARS-CoV-2 vaccines, they work by different mechanisms (mRNA-based vaccines vs. vector-based vaccines vs. protein-based vaccines).Though there are slight differences regarding the level of protection against mild COVID-19, all five vaccines that have been through phase 3 trials were nearly 100 % effective in preventing severe or fatal cases of COVID-19. The side effects were of short duration.Patients with chronic kidney disease (or other significant comorbidities) were largely excluded from Phase 3 trials, which makes definite recommendations concerning their vaccination difficult. The vaccine's effectiveness may be reduced in that population due to a uremic immune defect and/or immunosuppressive medication. However, these patients have an increased risk for severe or fatal COVID-19, so that they may particularly benefit from the vaccine.

Simple Questionnaires to Improve Pooling Strategies for SARS-CoV-2 Laboratory Testing.

Background: Liberal PCR testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is key to contain the coronavirus disease 2019 (COVID-19) pandemic. Combined multi-sample testing in pools instead of single tests might enhance laboratory capacity and reduce costs, especially in low- and middle-income countries. Objective: The purpose of our study was to assess the value of a simple questionnaire to guide and further improve pooling strategies for SARS-CoV-2 laboratory testing. Methods: Pharyngeal swabs for SARS-CoV-2 testing were obtained from healthcare and police staff, hospital inpatients, and nursing home residents in the southwestern part of Germany. We designed a simple questionnaire, which included questions pertaining to a suggestive clinical symptomatology, recent travel history, and contact with confirmed cases to stratify an individual's pre-test probability of having contracted COVID-19. The questionnaire was adapted repeatedly in face of the unfolding pandemic in response to the evolving epidemiology and observed clinical symptomatology. Based on the response patterns, samples were either tested individually or in multi-sample pools. We compared the pool positivity rate and the number of total PCR tests required to obtain individual results between this questionnaire-based pooling strategy and randomly assembled pools. Findings: Between March 11 and July 5, 2020, we processed 25,978 samples using random pooling (n = 6,012; 23.1%) or questionnaire-based pooling (n = 19,966; 76.9%). The overall prevalence of SARS-CoV-2 was 0.9% (n = 238). Pool positivity (14.6% vs. 1.2%) and individual SARS-CoV-2 prevalence (3.4% vs. 0.1%) were higher in the random pooling group than in the questionnaire group. The average number of PCR tests needed to obtain the individual result for one participant was 0.27 tests in the random pooling group, as compared to 0.09 in the questionnaire-based pooling group, leading to a laboratory capacity increase of 73% and 91%, respectively, as compared to single PCR testing. Conclusions: Strategies that combine pool testing with a questionnaire-based risk stratification can increase laboratory testing capacities for COVID-19 and might be important tools, particularly in resource-constrained settings.