Slovakia conducted multiple rounds of population-wide rapid antigen testing for SARS-CoV-2 in late 2020, combined with a period of additional contact restrictions. Observed prevalence decreased by 58% (95% CI: 57-58%) within one week in the 45 counties that were subject to two rounds of mass testing, an estimate that remained robust when adjusting for multiple potential confounders. Adjusting for epidemic growth of 4.4% (1.1-6.9%) per day preceding the mass testing campaign, the estimated decrease in prevalence compared to a scenario of unmitigated growth was 70% (67-73%). Modelling indicated that this decrease could not be explained solely by infection control measures, but required the additional impact of isolation and quarantine of household members of those testing positive.

Non-pharmaceutical interventions have been extensively used worldwide to limit the transmission of SARS-CoV-2, but they also place an enormous social and economic burden on populations. We report the results of recent mass testing for SARS-CoV-2 in Slovakia where rapid antigen tests were used to screen the whole population and to isolate infectious cases together with their household members. Prevalence of detected infections decreased by 58% (95% CI: 57-58%) within one week in the 45 counties that were subject to two rounds of mass testing. Adjusting for geographical clustering and differences in attendance rates and the epidemiological situation at the time of the first round, this changed to 61% (95% CI: 50-70%). Adjusting for an estimated growth rate in infections of 4.4% (1.1-6.9%) per day in the week preceding the mass testing campaign and the corresponding expected growth in infection prevalence, the estimated decrease in prevalence compared to a scenario of unmitigated growth was 70% (67-73%). Using a microsimulation model we find that this decrease can not be explained solely by infection control measures that were introduced in the weeks preceding the intervention, but requires the additional impact of isolation as well as quarantine of household members of those testing positive during the mass testing campaign.

The consumption of alcohol in a population is usually monitored through individual questionnaires, forensics, and toxicological data. However, consumption estimates have some biases, mainly due to the accumulation of alcohol stocks. This study’s objective was to assess alcohol consumption in Slovakia during the COVID-19 pandemic-related lockdown using wastewater-based epidemiology (WBE). Samples of municipal wastewater were collected from three Slovak cities during the lockdown and during a successive period with lifted restrictions in 2020. The study included about 14% of the Slovak population. The urinary alcohol biomarker, ethyl sulfate (EtS), was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). EtS concentrations were used to estimate the per capita alcohol consumption in each city. The average alcohol consumption in the selected cities in 2020 ranged between 2.1 and 327 L/day/1000 inhabitants and increased during days with weaker restrictions. WBE can provide timely information on alcohol consumption at the community level, complementing epidemiology-based monitoring techniques (e.g., population surveys and sales statistics).

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