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Background: We hypothesized that nationwide social distancing and other preventive measures for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were associated with reduced detection of other respiratory viruses in South Korea.Methods: We analyzed national surveillance data to compare incidence of respiratory viruses during 2016-2019 vs 2020. Results of multiplex reverse-transcription polymerase chain reaction assays for 8 respiratory viruses were included: adenovirus (ADV), parainfluenza virus (PIV), respiratory syncytial virus (RSV), influenza virus (IFV), human coronavirus (HCoV; non-SARS-CoV-2), human rhinovirus (HRV), human bocavirus (HBoV), and human metapneumovirus (HMPV).Results: During 2016-2019, rates of detection of respiratory viruses were relatively stable: ADV, 3.7%-9.2%; PIV, 1.4%-17.0%; RSV, 0.3%-15.3%; IFV, 0.4%-35.6%; HCoV, 1.5%-8.4%; HRV, 7.0%-25.1%; HBoV, 0.6%-6.3%; and HMPV, 0.7%-14.5%. Following implementation of social distancing in February 2020, rates of detection of enveloped viruses (HCoV, HMPV, IFV, PIV, and RSV) were significantly reduced by up to 100%. However, nonenveloped viruses (ADV, HRV, and HBoV) persisted throughout 2020, and HRV rates in hospitalized patients significantly increased.Conclusions: After implementation of social distancing for SARS-CoV-2 in South Korea, rates of detection of enveloped respiratory viruses decreased significantly, whereas nonenveloped viruses persisted, suggesting that enhanced infection prevention strategies are required to mitigate spread of these viruses. [ABSTRACT FROM AUTHOR]

• The incidence of Japanese encephalitis (JE) in South Korea increased dramatically since 2010. • The JE virus circulation increased in Artiodactyla species in 2008-2009. • JE virus activity in certain animals portends the disease in humans. The annual incidence of Japanese encephalitis (JE) has increased markedly in South Korea since 2010. We hypothesized that this increase was associated with higher frequencies of JE virus in animals. We analyzed 5201 serum samples collected from even-toed hoofed mammals (Artiodactyla species) across South Korea from 2008 to 2012 using a stratified two-stage probability approach. The highest annual incidence of human JE cases and deaths occurred in 2010. Cases increased from six (no deaths) in 2008-2009 to 26 cases (seven deaths) in 2010. The JE virus seroprevalence in deer and elk fawns increased from 2.4% in 2008 to 24.1% in 2009, and in wild boars, it increased from 19.3% to 55.0% in the same period, which preceded the surge of human cases. Furthermore, the seroprevalence in calves increased from 15.3% in 2008 to 35.8% in 2010, and that in lambs and goat kids, increased from 8.5% in 2009 to 26.2% in 2010, which coincided with the surge in humans. Our findings show that the increased incidence of human JE in South Korea was temporally associated with an increasing seroprevalence in the Artiodactyla species. Surveillance of sentinel animals may be useful to predict the emergence of JE in humans. [ABSTRACT FROM AUTHOR]

Coxiella burnetii is a Gram-negative bacterium that causes the zoonotic disease Q fever. Wild boars serve as reservoirs for C. burnetii. This study aimed to identify the risk factors associated with C. burnetii infection in wild boars. We analyzed the data from 975 wild boar samples collected from June to November 2021 in South Korea. We utilized the indirect ELISA to detect antibodies against C. burnetii. A sample optical density to positive-control optical density value exceeding 50% was classified as positive. We gathered data on the forestation, terrain, weather, agriculture, and animal density of the region where the samples were collected. Continuous variables were categorized into tertiles. We performed a univariate logistic regression analysis and included variables with a p-value < 0.2 in the final multivariable logistic regression model. In our multivariable logistic regression analysis to identify risk factors for C. burnetii infection in wild boars, we used a forward selection method to enter variables based on the order of their significance. We performed the final multivariable logistic regression analyses using either continuous variables or variables categorized into tertiles. The prevalence of C. burnetii was 14.6% (n=142). Locations with the highest maximum wind speeds (3.92–8.24 m/s) showed a 59% increase in infection odds compared to locations with the lowest speeds (1.45–3.25 m/s)(p=0.044). For each 1 m/s increase in maximum wind speed, infection odds increased by 24.1% (p=0.037). Regions with the highest percentage of paddy fields per area (8.3–45%) showed a 76% increase in infection odds compared to regions with the lowest percentage (0–1.5%)(p=0.011). For each 1% increase in the proportion of paddy fields per area, infection odds increased by 3.3% (p=0.003). High maximum wind speed and a high percentage of paddy field were identified as significant risk factors for C. burnetii infection in wild boars. [ABSTRACT FROM AUTHOR]