Natural course of post-COVID symptoms in adults and children.

More than 200 million COVID-19 survivors have lasting symptoms after recovering, but the duration and related risk factors remain uncertain. This study focused on all 6551 patients diagnosed with COVID-19 at a medical institution in Hiroshima from March 2020 to July 2022. In November 2022, a questionnaire survey was conducted regarding post-COVID symptoms and their duration. The prevalence and duration of post-COVID symptoms were illustrated using the Kaplan-Meier method. Risk factors for symptoms lasting over 3 months and interfering with daily life were assessed via multivariate logistic regression. A total of 2421 survivors responded: 1391 adults, 1030 children, median age 34 years (IQR 9-55), 51·2% male, 36·7% hospitalized, median time from infection to the survey was 295 days (IQR 201-538). Upon their initial recovery, the prevalence of post-COVID symptoms was 78·4% in adults and 34·6% in children. Three months later, the rates were 47·6% and 10·8%. After over one year, they were 31·0% and 6·8%. Regarding symptoms interfere with daily life, 304 people (12.6%) experienced symptoms lasting for over three months, with independent risk factors including age, being female, diabetes mellitus, infection during the Delta period, and current smoking. There was no significant association between vaccination history and post-COVID symptoms.

Seroepidemiological study of factors affecting anti-spike IgG antibody titers after a two-dose mRNA COVID-19 vaccination in 3744 healthy Japanese volunteers.

Several factors related to anti-spike(S) IgG antibody titers after mRNA COVID-19 vaccination have been elucidated, but the magnitude of the effects of each factor has not been fully understood. This cross-sectional study assessed anti-S and anti-nucleocapsid (N) antibody titers on 3744 healthy volunteers (median age, 36 years; IQR, 24-49 years; females, 59.0%) who received two doses of mRNA-1273 or BNT162b2 vaccine and completed a survey questionnaire. Multiple regression was conducted to identify factors associated with antibody titers. All but one participant tested positive for anti-S antibodies (99.97%). The following factors were independently and significantly associated with high antibody titer: < 3 months from vaccination (ratio of means 4.41); mRNA-1273 vaccine (1.90, vs BNT162b2); anti-N antibody positivity (1.62); age (10's: 1.50, 20's: 1.37, 30's: 1.26, 40's: 1.16, 50's: 1.15, vs ≧60's); female (1.07); immunosuppressive therapy (0.54); current smoking (0.85); and current drinking (0.96). The largest impact on anti-S IgG antibody titers was found in elapsed time after vaccination, followed by vaccine brand, immunosuppressants, previous SARS-CoV-2 infection (anti-N antibody positive), and age. Although the influence of adverse reactions after the vaccine, gender, smoking, and drinking was relatively small, they were independently related factors.

Prevalence of Helicobacter pylori infection in the general population evaluated by a resident-register-based epidemiological study.

BACKGROUND: The current status of Helicobacter pylori infection in Japan has not been investigated. We evaluated the status of H. pylori infection in a Japanese general population using large-scale resident-register-based sampling. METHODS: All 6069 adults in a rural town and 6000 adults in two urban cities (3000 each), selected by register-based random sampling, were enrolled in our health check-up program. Antibody titers against Helicobacter pylori (cut-off value was 3 U/mL by Eiken E-plate) were evaluated, and subjects with a positive result were encouraged to undergo further examinations. RESULTS: A total of 1586 subjects participated in serum sampling. The overall prevalence of H. pylori infection was 40.0% (634/1586), and it increased with age both in rural and urban areas. Although the overall positive rate was higher in the rural area (49.4%) than in the urban areas (35.6 and 32.3%), there was no difference in H. pylori status of younger subjects between the two areas. Among 634 patients with a positive titer, 374 (59.0%) underwent further examinations including endoscopic examination, and 180/634 (28.4%) patients received eradication therapy. Gastric neoplasms (three adenocarcinomas and one adenoma) were found in our screening program. CONCLUSION: We clarified population-based random sampling data of H. pylori infection in a Japanese general population. In younger subjects, a decrease in the prevalence of H. pylori infection was confirmed both in rural and urban areas. This provides basic information for establishing a strategy to reduce gastric cancer deaths.