Objectives Seroprevalence studies to assess the spread of SARS-CoV-2 infection in the general population and subgroups are key for evaluating mitigation and vaccination policies and for understanding the spread of the disease both on the national level and for comparison with the international community. Methods Corona Immunitas is a research program of coordinated, population-based, seroprevalence studies implemented by Swiss School of Public Health (SSPH+). Over 28,340 participants, randomly selected and age-stratified, with some regional specificities will be included. Additional studies in vulnerable and highly exposed subpopulations are also planned. The studies will assess population immunological status during the pandemic. Results Phase one (first wave of pandemic) estimates from Geneva showed a steady increase in seroprevalence up to 10.8% (95% CI 8.2–13.9, n = 775) by May 9, 2020. Since June, Zurich, Lausanne, Basel City/Land, Ticino, and Fribourg recruited a total of 5973 participants for phase two thus far. Conclusions Corona Immunitas will generate reliable, comparable, and high-quality serological and epidemiological data with extensive coverage of Switzerland and of several subpopulations, informing health policies and decision making in both economic and societal sectors. ISRCTN Registry: https://www.isrctn.com/ISRCTN18181860.

Background Research on SARS-CoV-2 transmission within households and other close settings using serological testing is scarce. Methods We invited COVID-19 cases diagnosed between February 27 and April 1, 2020, in canton of Vaud, Switzerland, to participate, along with household members and other close contacts. Anti-SARS-CoV-2 IgG antibodies were measured using a Luminex immunoassay. We estimated factors associated with serological status using generalized estimating equations. Results Overall, 219 cases, 302 household members, and 69 other close contacts participated between May 4 and June 27, 2020. More than half of household members (57.2%, 95%CI 49.7-64.3) had developed a serologic response to SARS-CoV-2, while 19.0% (95%CI 10.0-33.2) of other close contacts were seropositive. After adjusting for individual and household characteristics, infection risk was higher in household members aged 65 or more than in younger adults (aOR 3.63, 95%CI 1.05-12.60), and in those not strictly adhering to simple hygiene rules like hand washing (aOR 1.80, 95%CI 1.02-3.17). The risk was lower when more than 5 people outside home were met during semi-confinement, compared to none (aOR 0.35, 95%CI 0.16-0.74). Individual risk of household members to be seropositive was lower in large households (22% less per each additional person). Conclusions During semi-confinement, household members of a COVID-19 case were at very high risk of getting infected, 3 times more than close contacts outside home. This highlights the need to provide clear messages on protective measures applicable at home. For elderly couples, who were especially at risk, providing external support for daily basic activities is essential.

Abstract210Po is a radioactive component of conventional cigarette tobacco smoke and is a recognized carcinogen. Despite the expanding market of heated tobacco products, no data are available on the activity of 210Po in the smoke of IQOS Heets cigarette. We determined the 210Po activity in the mainstream smoke of thirteen cigarette brands available on the Swiss market using a smoking machine and compared the results to the 210Po activity measured in the mainstream smoke of the IQOS system. In addition, we measured the 210Po and 210Pb loss on heating after uniform heating from 50 to 600 °C for several cigarette brands and the Heets cigarettes. 13.6 ± 4.1% of 210Po activity was found in the mainstream smoke in conventional cigarette smoking (7% for 210Pb). This dropped to 1.8 ± 0.3% in the mainstream smoke of IQOS Heets. Conversely, when the tobacco was heated uniformly at 330 °C, a loss of 210Po of more than 80% was observed for all type of cigarettes. Apparently, IQOS significantly reduced the 210Po and 210Pb activities in the mainstream smoke. However, our results show that only 15% of the Heets tobacco reaches 330 °C with IQOS. While IQOS reduces the 210Po and 210Pb activities in the mainstream smoke compared to conventional cigarettes, it only heats a marginal fraction of the tobacco present in the Heets cigarette. Because smoking is an addiction (mostly due to nicotine), IQOS could possibly deliver an unsatisfactory dose of nicotine to a Heets cigarette smoker, as most of the tobacco is left unaltered.

BackgroundUnderstanding community-based SARS-CoV-2 transmission is crucial to inform public health decisions. Research on SARS-CoV-2 transmission within households and other close settings using serological testing is scarce.MethodsWe invited COVID-19 cases diagnosed between February 27 and April 1, 2020 in canton of Vaud, Switzerland, to participate, along with household members and other close contacts. Anti-SARS-CoV-2 IgG antibodies were measured using a Luminex immunoassay. We estimated factors associated with serological status using generalized estimating equations.FindingsOverall, 219 COVID-19 index cases, 302 household members, and 69 other close contacts participated between May 4 and June 27, 2020. More than half of household members (57·2%, 95%CI 49·7-64·3) had developed a serologic response to SARS-CoV-2, while 19·0% (95%CI 10·0-33·2) of other close contacts were seropositive. After adjusting for individual and household characteristics, infection risk was higher in household members aged 65 or more than in younger adults (aOR 3·63, 95%CI 1·05-12·60), and in those not strictly adhering to simple hygiene rules like hand washing (aOR 1·80, 95%CI 1·02-3·17). The risk was lower when more than 5 people outside home were met during the semi-confinement, compared to none (aOR 0·35, 95%CI 0·16-0·74). The individual risk of household members to be seropositive was lower in large households (22% less per each additional person).InterpretationWe find that, during semi-confinement, household members of a COVID-19 case were at very high risk of getting infected, 3 times more than close contacts outside home. This highlights the need to provide clear messages on specific protective measures applicable at home. For elderly couples, who were especially at risk, providing them external support for daily basic activities is essential.FundingCenter for Primary Care and Public Health (Unisanté), Canton of Vaud, Leenaards Foundation, Fondation pour l’Université de Lausanne. SerocoViD is part of Corona Immunitas coordinated by SSPH+.

Objectives: We quantified adherence to COVID-19 preventive measures and explored associated factors, after the first and during the second Swiss epidemic waves.Methods: With an observational cohort study in a representative sample of individuals aged 15 years and more, we analysed the association between self-reported adherence to COVID-19 preventive measures (respect of simple hygiene rules; respect of social distancing rules; wearing a mask) and socio-demographic factors, the existence of a chronic disease, and the existence of a previous confirmed COVID-19 episode.Results: Highest adherence was to simple hygiene rules, followed by social distancing rules and mask wearing, with a slight decrease for simple hygiene rules and a strong increase for mask wearing between visits. Men were significantly less likely to respect simple hygiene rules and wear a mask in public. Participants aged 65 years and more (versus 25–64 years) and those with at least one chronic disease (versus none) were two times more likely to respect social distancing rules and wear a mask.Conclusion: Adherence to social distancing rules and mask wearing was rather poor, especially compared to other countries.

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Nouvelles recommandations européennes et américaines pour les dyslipidémies : similitudes et différencesLes recommandations d'experts pour la prise en charge des dyslipidémies varient d'un pays à l'autre, avec des différences importantes entre les sociétés médicales d'Europe et des États-Unis. Récemment, de nouvelles recommandations américaines et européennes ont été établies. Elles diffèrent principalement dans la stratification du risque cardiovasculaire en prévention secondaire, ainsi que dans les cibles de LDL-cholestérol (LDL-c) à atteindre. Le point commun reste que l'indication au traitement hypolipémiant se base en premier sur le risque cardiovasculaire global, puis sur le taux de LDL-c. Nous présentons une comparaison et une interprétation de ces recommandations. New European and American guidelines on the management of blood cholesterol : similarities and differencesExperts' guidelines for the management of dyslipidemias differ from country to country, with important differences between medical societies of Europe and the United States. Recently, new American and European guidelines have been established. These guidelines mainly differ for cardiovascular risk stratification in secondary prevention, and for LDL-cholesterol (LDL-c) goals to achieve. Similitudes between guidelines include the global strategy to initiate lipid-lowering drugs, which is based first on the global cardiovascular risk, then on the LDL-c level. We are here presenting a comparison and an interpretation of these guidelines.

Risk of SARS-CoV-2 transmission within households is very high. Enforcing protective measures at home during COVID-19 episodes, as well as supporting self-isolation within the house by shortening the time between symptom onset and test result, could help mitigating such risk.