Household Secondary Transmission of the Severe Acute Respiratory Syndrome Coronavirus 2 Alpha Variant From a Community Cluster in a Nursery in Japan.

BACKGROUND: Spread of variants of concerns (VOCs) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an increase in children with coronavirus disease 2019 (COVID-19). In February 2021, clusters of the Alpha variant of SARS-CoV-2 started to be reported in Niigata, Japan, including a large nursery cluster. We investigated the transmission routes and household secondary attack rates (SARs) in this cluster. METHODS: Epidemiologic data related to a nursery cluster in Niigata, Japan, particularly child-origin and adult-origin SARs, were analyzed. VOCs were confirmed by whole-genome sequencing of virus from patients. RESULTS: In total, 42 persons (22 children and 20 adults) in the cluster were infected with the Alpha variant. In the nursery, 13 of 81 children (16.0%) and 4 of 24 teachers (16.7%) were infected. SARS-CoV-2 later spread to 25 persons (10 children and 15 adults) outside the nursery. Child-origin and adult-origin household SARs were 27.7% (13/47) and 47.0% (8/17) ( P = 0.11), respectively, which were higher than rates attributable to non-VOCs in previous studies. CONCLUSIONS: As compared with non-VOCs, the Alpha variant of SARS-CoV-2 exhibited high transmissibility among children and adults and may pose a high risk for household secondary transmission from SARS-CoV-2-infected children. Increased transmissibility of current or future VOCs could lead to greater transmission from children to adults or other children.

[Fracture-related medical cost of aged people in Niigata Prefecture, Japan: analysis of data from health insurance claims].

OBJECTIVES: The purpose of this study is to determine the fracture-related medical cost of aged people to reduce such cost. METHODS: Using health insurance claims, we obtained data on the number of aged people (> or =60 years of age) with fractures among members of the National Health Insurance Organization in Niigata Prefecture and their fracture-related medical cost, every May from 2003 to 2005. We analyzed these data and stratified them by sex, age (5-year age range), and hospitalization history. RESULTS: The average number of fractures per 100,000 people and the fracture-related medical cost per capita for women were 1,316+/-11 and 1,344+/-66 yen, respectively. These values were found to be more than twofold, those for men (604+/-11 and 556+/-33 yen, respectively). The number of fractures per 100,000 people and the fracture-related medical cost per capita increased with age. The fracture-related medical cost per hospitalization admission, however, did not increase with age. The amount of two-year increase in the fracture-related medical cost of hospitalization per capita was the largest in the > or =85 age group, and increased with the number of fractures. The fracture-related medical cost of people > or =60 years of age in Niigata prefecture was estimated to increase with age for women, but not for men. CONCLUSIONS: It is suggested that lowering the prevalence of fractures among very old women would lead to a decrease in the total fracture-related medical costs. Additional studies are needed to confirm the findings using nation wide data.