Symptom diaries as a digital tool to detect SARS-CoV-2 infections and differentiate between prevalent variants

The COVID-19 pandemic and the high numbers of infected individuals pose major challenges for public health departments. To overcome these challenges, the health department in Cologne has developed a software called DiKoMa. This software offers the possibility to track contact and index persons, but also provides a digital symptom diary. In this work, the question of whether these can also be used for diagnostic purposes will be investigated. Machine learning makes it possible to identify infections based on early symptom profiles and to distinguish between the predominant dominant variants. Focusing on the occurrence of the symptoms in the first week, a decision tree is trained for the differentiation between contact and index persons and the prevailing dominant variants (Wildtype, Alpha, Delta, and Omicron). The model is evaluated, using sex- and age-stratified cross-validation and validated by symptom profiles of the first 6 days. The variants achieve an AUC-ROC from 0.89 for Omicron and 0.6 for Alpha. No significant differences are observed for the results of the validation set (Alpha 0.63 and Omicron 0.87). The evaluation of symptom combinations using artificial intelligence can determine the individual risk for the presence of a COVID-19 infection, allows assignment to virus variants, and can contribute to the management of epidemics and pandemics on a national and international level. It can help to reduce the number of specific tests in times of low labor capacity and could help to early identify new virus variants.

Adherence to stay-at-home orders: awareness, implementation and difficulties of officially ordered quarantine measures in the context of the COVID-19 pandemic in Cologne - a retrospective cohort study.

OBJECTIVES: To estimate the awareness, implementation and difficulty of behavioural recommendations and their correlates in officially ordered domestic isolation and quarantine during the COVID-19 pandemic. DESIGN: Online retrospective cohort survey conducted from 12 December 2020 to 6 January 2021 as part of the Cologne-Corona Counselling and Support for Index and Contact Persons During the Quarantine Period study. SETTING: Administrative area of the city of Cologne, Germany. PARTICIPANTS: 3011 infected persons (IPs) and 5822 contacts over 16 years of age who were in officially ordered domestic isolation or quarantine between 28 February 2020 and 9 December 2020. Of these, 60.4% were women. OUTCOME MEASURES: Self-developed scores were calculated based on responses about awareness and implementation of 19 behavioural recommendations to determine community-based and household-based adherence. Linear regression analyses were conducted to determine factors influencing adherence. RESULTS: The average adherence to all recommendations, including staying in a single room, keeping distance and wearing a mask, was 13.8±2.4 out of 15 points for community-based recommendations (CBRs) and 17.2±6.8 out of 25 points for household-based recommendations (HBRs). IPs were significantly more adherent to CBRs (14.3±2.0 points vs 13.7±2.6 points, p<0.001) and HBRs (18.2±6.7 points vs 16.5±6.8 points, p<0.001) than were contact persons. Among other factors, both status as an IP and being informed about the measures positively influenced participants' adherence. The linear regression analysis explained 6.6% and 14.4% (corr. R²) of the adherence to CBRs and HBRs. CONCLUSIONS: Not all persons under official quarantine were aware of the relevant behavioural recommendations. This was especially true in cases where instructions were given for measures to be taken in one's own household. Due to the high transmission rates within households, HBRs should be communicated with particular emphasis.

Where is the greatest risk of COVID-19 infection? Findings from Germany's largest public health department, Cologne.

BACKGROUND: SARS-CoV-2 has been spreading worldwide since late 2019. Before vaccines became available, exclusively non-pharmaceutical measures were used to prevent transmission of infection. Despite the fact that vaccinations are now available, it is still important to identify relevant transmission routes in order to contain the COVID-19- or further pandemics. Therefore, this study aims to systematically analyse data from the largest public health department in Germany to determine the significance of the various known and unknown transmission situations in terms of the proportion of infections. METHODS: All infections in Cologne were systematically recorded by the local health department. In addition to clinical data, the transmission situations were recorded and categorised as pertaining to social contact, work contact, travellers, health care workers, users of educational institutions, visitors of community institutions, infection in the context of medical treatment, and unknown infection. FINDINGS: The analysis included 25,966 persons. A transmission situation could be identified in 82.7% of the cases (n = 21,477). Most persons (42.1%) were infected due to social contact, primarily within their own household. Another 22.3% were infected at their place of work; this was particularly common among staff members of medical facilities, nursing homes and educational institutions. In 17.3% of the cases, the transmission situation remained unknown; the cases with unknown transmission situation were slightly more often symptomatic (75.2%) than the cases with known transmission situation (69.4%). INTERPRETATION: Considering that during the study period the leading strains were the wild-type and alpha-variant transmission rather occurred during scenarios involving close contacts than in anonymous situations. Presumably, however, the findings can be transferred to the new variants. Therefore, in order to prevent transmission, besides vaccination regular antigen tests and/or appropriate protective measures remain relevant until this pandemic has subsided.

Vaccination and Transmission Risk during the Outbreak of B.1.1.529 (Omicron).

Since its first description in November 2021, the SARS-CoV-2 variant of concern Omicron (B.1.1.529) has emerged as the dominant strain in the COVID-19 pandemic. To date, it remains unclear if boosted vaccination protects against transmission. Using data from the largest German Public Health Department, Cologne, we analyzed breakthrough infections in booster-vaccinated infected persons (IP; booster-vaccinated group (BVG); n = 202) and fully vaccinated, not boosted SARS-COV2-positive patients (>3 month after receiving the second dose; unboosted, fully vaccinated group (FVG); n = 202) to close contacts compared to an age- and sex-matched unvaccinated control group (UCG; n = 202). On average, IPs had 0.42 ± 0.52 infected contacts in relation to the total number of contacts in the BVG vs. 0.57 ± 0.44 in the FVG vs. 0.56 ± 0.43 in the UVG (p = 0.054). In the median test, pairwise comparison revealed a significant difference between the BVG and both other groups; no difference was found between the fully vaccinated and the unvaccinated control group. Now, these findings must be verified in larger samples, considering the role of Omicron subvariants and the vaccination status of the contact person. However, the importance of the booster vaccination in breaking possible chains of infection in the immune escape variant Omicron is obvious.

Impact of physical activity on COVID-19-related symptoms and perception of physical performance, fatigue and exhaustion during stay-at-home orders.

Objectives: The measures used to contain the COVID-19 pandemic led to a significant reduction in physical activity. Due to the health benefits of exercise, recommendations were made for lockdown restrictions. Within the CoCo-Fakt study (Cologne-Corona counselling and support for index and contacts during the quarantine period), we aimed to determine how these recommendations were implemented, especially by individuals who were officially quarantined due to an infected persons (IPs) or as close contacts (CPs), and how this affected their physical and psychological condition. Methods: From 12 December 2020 to 6 January 2021, all IPs and CPs registered by Cologne's public health department up to the survey period were surveyed online. Of 10 547 people in the CoCo-Fakt sample, 8102 were integrated into the current analysis. In addition to demographic data, information regarding COVID-19-specific and persistent symptoms or conditions and their association with the amount and type of exercise and screen time before and during the quarantine were collected. Results: Before quarantine, 66.9% of IPs and 69% of CPs were physically active; during quarantine, this decreased by 49.4% in IPs depending on the course of the disease and by 30.6% in CPs. Physically active IPs and CPs felt less exhausted and more fit during their quarantine periods than those who were inactive, with active IPs significantly less likely to report prolonged physical and psychological symptoms than their more sedentary counterparts. Conclusion: Given the acute and long-term positive effects of exercise on quarantined individuals, corresponding recommendations should be communicated to those affected, especially CPs. Recommendations for IPs depend on their health status.

Stay at Home Order—Psychological Stress in Children, Adolescents, and Parents during COVID-19 Quarantine—Data of the CoCo-Fakt Cohort Study, Cologne

Measures taken to contain the COVID-19 pandemic are particularly stressful for families. Limited data is available regarding the effects of a mandatory quarantine on the psychological stress of children, adolescents and their parents. Quarantined individuals participating in the online-based CoCo-Fakt study had at least one child <3, 3 to <6, 6 to <10, 10 to <14 and 14 to <16 years old (n = 2153). Parents were asked about how often their children felt nervous, anxious, or tense, down or depressed, lonely or physical reactions occur. A relative sum score characterizing psychosocial stress was determined and related to parents’ socio-demographic factors, psychosocial distress, coping strategies and resilience. Parents reported significantly higher psychological stress if at least one child was quarantined. Parents’ relative psychological stress sum score had the strongest influence on the psychological state of the children across all age groups (β = 0.315–0.457) besides male sex of the reporting parent, no partnership, low to medium socioeconomic status, lower resilience and coping scores, and parents quarantined as close contacts. The variance in the linear regression models was between 17.8% and 31.4%. These findings highlight that the entire family system must be considered during official mandatory quarantines.

Changes in Alcohol Consumption, Eating Behaviors, and Body Weight during Quarantine Measures: Analysis of the CoCo-Fakt Study.

INTRODUCTION: Public health measures enacted to reduce COVID-19 transmission have affected individuals' lifestyles, mental health, and psychological well-being. To date, little is known how stay-at-home orders have influenced the eating behaviors, weight development, and alcohol consumption of quarantined persons. The CoCo-Fakt cohort study analyzed these parameters and their association with psychological distress and coping strategies. METHODS: An online survey was conducted of all persons who tested positive for SARS-CoV-2 (infected persons [IP]) between December 12, 2020, and January 6, 2021, as well as their close contacts (contact persons [CP]) registered by the public health department of Cologne. 8,075 of 33,699 individuals were included in the analysis. In addition to demographic data, psychological distress, and coping strategies, information on changes in body weight, eating, and drinking behaviors was collected. RESULTS: IP lost 1.2 ± 4.4 kg during the quarantine period, and CP gained 1.6 ± 4.1 kg. The reasons given by IP for weight change were mainly loss of taste and feeling sick, whereas CP were more likely than IP to eat out of boredom. Higher psychological burden and lower coping strategies were associated with both weight gain and loss. Of the 30.8% of participants who changed their alcohol consumption during the quarantine period, CP in particular drank more alcohol (IP 15.2%; CP 47.7%). Significantly less alcohol was consumed by individuals with higher coping scores. CONCLUSION: In this short but psychologically stressful period of stay-at-home orders, changes in eating and drinking behavior as well as weight development are evident, mainly in high-risk contacts. To avoid possible long-term sequelae, health authorities should take these findings into account during the quarantine period; in particular, general practitioners should consider these findings during follow-up.

COVID-19 Breakthrough Infections and Transmission Risk: Real-World Data Analyses from Germany's Largest Public Health Department (Cologne).

BACKGROUND AND METHODS: Vaccination is currently considered the most successful strategy for combating the SARS-CoV-2 virus. According to short-term clinical trials, protection against infection is estimated to reach up to 95% after complete vaccination (≥14 days after receipt of all recommended COVID-19 vaccine doses). Nevertheless, infections despite vaccination, so-called breakthrough infections, are documented. Even though they are more likely to have a milder or even asymptomatic course, the assessment of further transmission is highly relevant for successful containment. Therefore, we calculated the real-world transmission risk from fully vaccinated patients (vaccination group, VG) to their close contacts (CP) compared with the risk from unvaccinated reference persons matched according to age, sex, and virus type (control group = CG) utilizing data from Cologne's health department. RESULTS: A total of 357 breakthrough infections occurred among Cologne residents between 27 December 2020 (the date of the first vaccination in Cologne) and 6 August 2021. Of the 979 CPs in VG, 99 (10.1%) became infected. In CG, 303 of 802 CPs (37.8%) became infected. Factors promoting transmission included non-vaccinated status (ß = 0.237; p < 0.001), male sex (ß = 0.079; p = 0.049), the presence of symptoms (ß = -0.125; p = 0.005), and lower cycle threshold value (ß = -0.125; p = 0.032). This model explained 14.0% of the variance (corr. R2). CONCLUSION: The number of transmissions from unvaccinated controls was three times higher than from fully vaccinated patients. These real-world data underscore the importance of vaccination in enabling the relaxation of stringent and restrictive general pandemic control measures.

How to manage quarantine-adherence, psychosocial consequences, coping strategies and lifestyle of patients with COVID-19 and their confirmed contacts: study protocol of the CoCo-Fakt surveillance study, Cologne, Germany.

INTRODUCTION: The current coronavirus (SARS-CoV-2) pandemic has placed unprecedented restrictions on people's lives and routines. To counteract the exponential spread of this virus, a lockdown was implemented in Germany in March 2020. Infected persons and their contacts were also quarantined. Compliance with quarantine measures is essential for containing the spread of the virus and avoiding incalculable consequences in terms of morbidity and mortality. On the other hand, prolonged homestays, particularly quarantining, may lead to fear, panic, anxiety and depression. Hence, determining the psychological response in people during quarantine and their coping strategies is relevant for the counselling and support of affected persons by healthcare workers. METHODS AND ANALYSIS: The CoCo-Fakt-Survey (Cologne-Corona-Beratung und Unterstützung Für Index- und KontAKt-Personen während der Quarantäne-ZeiT; Cologne-Corona counselling and support for index and contacts during the quarantine period-author's translation) will examine a cohort of persons in Cologne quarantined since the beginning of the SARS-CoV-2 outbreak during March 2020. The questionnaire will include demographic data, transmission route, health status, knowledge of and adherence to quarantine measurements, psychological impact on individuals and their family members including children, mental health status, and lifestyle (physical activity/sedentary behaviour, relaxation techniques, nutrition, smoking). All Cologne residents who needed to be quarantined due to a coronavirus infection and the individuals with whom they had contact will be surveyed. ETHICS AND DISSEMINATION: No risks have been identified and no complications are expected. Ethics approval was obtained from the Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen Human Ethics Research Committee (351/20), and the research will be conducted in accordance with the approved protocol. The results will be disseminated through peer-reviewed journals and social medicine conferences.