Effectiveness of COVID-19 mRNA vaccine in preventing infection against Omicron strain: Findings from the Hiroshima Prefecture COVID-19 version J-SPEED for PCR center.

BACKGROUND AND PURPOSE: Despite the widespread adoption of various preventive measures since the spread of COVID-19, there remains a lack of consensus on universally acknowledged best practices. However, the significance of vaccination has risen to prominence as a paramount preventive strategy. Numerous investigations have demonstrated vaccine effectiveness against the omicron strain in severe disease and symptomatic disease, however, the scope of research pertaining to vaccine effectiveness in preventing infection is presently limited. Therefore, the current study aimed to evaluate COVID-19 mRNA (Pfizer-BioNTech BNT162b2 or Moderna mRNA-1273) vaccine effectiveness in preventing infection. METHODS: We conducted a test-negative case-control study using a dataset of 117,335 individuals. These data were collected through the COVID-19 J-SPEED form in the PCR center at Hiroshima Prefecture, Japan from 1 February to 17 March 2022. We estimated propensity score matching for vaccine status based on participants' demographic characteristics. Subsequently, odds ratio was calculated from logistic regression to determine the association between vaccination status and test positivity rate adjusting for symptoms, exposure to close contact, and previous infection history. Vaccine effectiveness was defined as (1 -aORs) ×100%. RESULTS: The PCR test positivity rates were 7.9%, 4.5%, and 2.8% for the non-vaccinated (non-vaccinated, vaccinated with a single dose, and vaccinated with two doses less than 14 days ago), vaccinated with two doses (vaccinated over 14 days ago), and three doses, respectively. In unadjusted and adjusted analyses, vaccine effectiveness of two doses against infection were 38.5% (95% confidence interval [CI]: 32.8%-43.8%) and 34.7% (95%CI: 28.4%-40.4%), respectively, compared to non-vaccinated group. Vaccine effectiveness of three doses were 33.8% (95%CI: 25.0%-41.5%) and 26.4% (95%CI: 16.4%-35.2%), respectively, compared to those vaccinated with two doses. CONCLUSIONS: These results illustrate the protective effect of mRNA vaccines against Omicron strain infections and emphasize the significance of completing the suggested vaccination schedule.

Epidemiological assessment of hepatitis E virus infection among 1565 pregnant women in Siem Reap, Cambodia using an in-house double antigen sandwich ELISA.

AIM: This study investigated hepatitis E virus (HEV) prevalence among pregnant women in Siem Reap, Cambodia, by developing a cost-effective, user-friendly in-house enzyme-linked immunosorbent assay (ELISA) for detecting total anti-HEV immunoglobulins (Ig). METHODS: The in-house ELISA was designed for large-scale screening in resource-limited settings. Its performance was benchmarked against two commercial tests: the Anti-HEV IgG EIA (Institute of Immunology, Co. Ltd) and the Anti-HEV IgG RecomLine LIA (Mikrogen). The in-house ELISA demonstrated a sensitivity of 76% and 71.4%, and a specificity of 94.1% and 98.6%, against the two commercial tests, respectively, with overall agreement rates of 92.4% and 94.3%. RESULTS: Among 1565 tested pregnant women, 11.6% were anti-HEV positive. Prevalence increased with age, particularly in women aged 35-40 years and over 40 years. No significant associations were found with education, number of children, family size, or history of blood transfusion and surgery, except for the occupation of the family head as a public officer. Of the total anti-HEV positive women, 22.7% had anti-HEV IgM, indicating recent or ongoing infection. CONCLUSION: The study concluded that the in-house ELISA is a viable option for HEV screening in regions with limited resources due to its high accuracy and cost-effectiveness. It is particularly suitable for large-scale studies and public health interventions in areas where HEV is endemic and poses a significant risk to pregnant women.

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.

Incidence and Prevalence of Epilepsy in Japan: A Retrospective Analysis of Insurance Claims Data of 9,864,278 Insured Persons.

INTRODUCTION: The burden of epilepsy is thought to be high but is difficult to measure. Very few studies in Japan have attempted to estimate prevalence and incidence rates of epilepsy in Japan. METHODS: This retrospective cohort study used commercially collected nationwide insurance claims data from a cohort of 10 million persons between 2012 and 2019 among those aged 0 to 74 years. Using the claims data, cases were identified, and incidence and prevalence rates were estimated. RESULTS: A total of 9,864,278 persons were included. The average age was 34.5 (standard deviation, 18.5) years. A total of 77,312 persons were diagnosed with epilepsy over the 8-year observation period, with a prevalence rate of 6.0 per 1,000 persons with almost no difference by gender. The highest rates were seen among those aged 70-74 years; prevalence rates tended to rise with calendar year (5.4/1,000 in 2012 and 6.0/1,000 in 2019). The incidence rate of epilepsy was 72.1 per 100,000 person-years with slightly higher rates seen among females. Incidence rates were highest at ages less than 12 months (199.8/100,000 person-years), followed by the eldest age group (70-74 years, 179.4/100,000 person-years). CONCLUSION: Understanding the magnitude of disease burden is the basis of determining health policies. In this study, the prevalence and incidence of epilepsy in Japan was shown based on the analysis results of a large-scale general population insurance claims data covering all over Japan.

The impact of COVID-19 on hepatitis B and C virus prevention, diagnosis, and treatment in Bangladesh compared with Japan and the global perspective.

AIM: This study aimed to assess the effect of COVID-19 on hepatitis-related services in Bangladesh and compared the situation with same study conducted in Japan and globally. METHODS: We conducted an online cross-sectional questionnaire survey among the clinicians of four societies associated with liver disease in Bangladesh from October to December 2022. The questionnaire included the same questions as a survey conducted in Japan and globally. RESULTS: A total of 83 clinicians from 8 divisions in Bangladesh participated; 66.3% were heads of departments/institutions. Except for HCV treatment initiation, more than 30% of clinicians reported a 76-99% decline in all services. Compared to Japan and the global survey, there was a significantly higher decline in all HBV and HCV services in Bangladesh. To resume services back to pre-COVID-19 levels, Patient anxiety and fear (Bangladesh Survey: 80.7% vs Japan Survey: 67.4% vs Global Survey: 37.9%, p < 0.0001), loss of space due to COVID-19 (Bangladesh Survey: 63.9% vs Japan Survey: 34.7% vs Global Survey: 19.4%, p < 0.0001) were the main challenges. As part of the mitigation strategy, usage of telemedicine (Bangladesh Survey: 83.1% vs. Japan Survey: 67.3% vs Global Survey: 78.6% p < 0.0001), COVID-19 benefits, such as increased laboratory testing platforms (Bangladesh Survey: 77.1% vs Japan Survey: 17.9% vs Global Survey: 41.8%, p < 0.0001) was reported significantly higher in Bangladesh than in Japan and global survey. CONCLUSION: All the services-related to HBV and HCV were highly affected during greatest impact month of COVID-19 in Bangladesh and the decline level was higher than Japan and global survey. Repeated countermeasures of COVID-19 and constrained healthcare-system were the probable reasons in Bangladesh. Positive impact resulting from COVID-19 countermeasures should be utilized in the national hepatitis program in Bangladesh.

Multi-phasic gene profiling using candidate gene approach predict the capacity of specific antibody production and maintenance following COVID-19 vaccination in Japanese population.

Background: Vaccination against severe acute respiratory syndrome coronavirus type 2 is highly effective in preventing infection and reducing the severity of coronavirus disease (COVID-19). However, acquired humoral immunity wanes within six months. Focusing on the different tempo of acquisition and attenuation of specific antibody titers in individuals, we investigated the impact of genetic polymorphisms on antibody production after COVID-19 vaccination. Methods: In total 236 healthcare workers from a Japanese municipal hospital, who received two doses of the vaccine were recruited. We employed a candidate gene approach to identify the target genetic polymorphisms affecting antibody production after vaccination. DNA samples from the study populations were genotyped for 33 polymorphisms in 15 distinct candidate genes encoding proteins involved in antigen-presenting cell activation, T cell activation, T-B interaction, and B cell survival. We measured total anti-SARS-Cov2 spike IgG antibody titers and analyzed the association with genetic polymorphisms at several time points after vaccination using an unbiased statistical method, and stepwise logistic regression following multivariate regression. Results: Significant associations were observed between seven SNPs in NLRP3, OAS1, IL12B, CTLA4, and IL4, and antibody titers at 3 weeks after the first vaccination as an initial response. Six SNPs in NLRP3, TNF, OAS1, IL12B, and CTLA4 were associated with high responders with serum antibody titer > 4000 BAU/ml as boosting effect at 3 weeks after the second vaccination. Analysis of long-term maintenance showed the significance of the three SNPs in IL12B, IL7R, and MIF for the maintenance of antibody titers and that in BAFF for attenuation of neutralizing antibodies. Finally, we proposed a predictive model composed of gene profiles to identify the individuals with rapid antibody attenuation by receiver operating characteristic (ROC) analysis (area under the curve (AUC)= 0.76, sensitivity = 82.5%, specificity=67.8%). Conclusions: The candidate gene approach successfully showed shifting responsible gene profiles and initial and boosting effect mainly related to the priming phase into antibody maintenance including B cell survival, which traces the phase of immune reactions. These gene profiles provide valuable information for further investigation of humoral immunity against COVID-19 and for building a strategy for personalized vaccine schedules.

Variant-specific symptoms after COVID-19: a hospital-based study in Hiroshima.

BackgroundSymptoms after COVID-19 recovery by SARS-CoV-2 strains are unspecified.MethodsThis self-administered questionnaire-based study was conducted to investigate symptoms after COVID-19 recovery at one of the main hospitals for COVID-19 treatment in Hiroshima, Japan, from September 2020 to March 2022 for patients who visited follow-up consultations after COVID-19. Study subjects were divided into four groups (Wild-type, Alpha, Delta, and Omicron periods) according to COVID-19 onset date. Hierarchical cluster analysis was performed to determine symptom clusters and investigate risk factors for each symptom cluster using multivariate analysis.ResultsAmong 385 patients who enrolled in this study, 249 patients had any persistent symptoms at a median of 23.5 [IQR, 20-31] days after COVID-19 onset. Among patients with any persistent symptoms, symptom clusters including olfactory or taste disorders, respiratory symptoms, and cardiac symptoms were found. Respiratory symptoms were more frequent among patients infected in the Omicron period compared to the Wild-type period (AOR, 3.13; 95% CI, 1.31-7.48; p=0.0101). Compared to patients who recovered from mild COVID-19, patients who needed for oxygen or ventilation support suffered fewer post-COVID-19 respiratory symptoms (AOR, 0.46; 95% CI, 0.22-0.97; p=0.0415) but more post-COID-19 cardiac symptoms among them (AOR, 2.67; 95% CI, 1.26-5.65; p=0.0103). Olfactory or taste disorders were fewer among patients infected in the Omicron period compared to the Wild-type period (AOR, 0.14; 95% CI, 0.04-0.46; p=0.0011).ConclusionThis study revealed that symptoms after COVID-19 may vary depending on the infected strain.

Despite low viral titer in saliva samples, Sanger-based SARS-CoV-2 spike gene sequencing is highly applicable for the variant identification.

BACKGROUND: This study aimed to compare the performance of Sanger-based SARS-CoV-2 spike gene sequencing and Next Generation Sequencing (NGS)-based full-genome sequencing for variant identification in saliva samples with low viral titer. METHODS: Using 241 stocked saliva samples collected from confirmed COVID-19 patients between November 2020 and March 2022 in Hiroshima, SARS-CoV-2 spike gene sequencing (nt22735-nt23532) was performed by nested RT-PCR and Sanger platform using in-house primers. The same samples underwent full-genome sequencing by NGS using Illumina NextSeq2000. RESULTS: Among 241 samples, 147 were amplified by both the Sanger and the Illumina NextSeq2000 NGS, 86 by Sanger only, and 8 were not amplified at all. The overall amplification rates of Illumina NextSeq2000 NGS and Sanger were 61% and 96.7%, respectively. At low viral titer (< 103 copies/mL), Illumina NextSeq2000 NGS provided 19.2% amplification, while Sanger was 89.7% (p < 0.0001). Both platforms identified 38 wild type, 54 Alpha variants, 84 Delta variants, and 57 Omicron variants. CONCLUSIONS: Our study provided evidence to expand the capacity of Sanger-based SARS-CoV-2 spike gene sequencing for variants identification over full-genome by Illumina NextSeq2000 NGS for mass screening. Therefore, the feasible and simple Sanger-based SARS-CoV-2 spike gene sequencing is practical for the initial variants screening, which might reduce the gap between the rapid evolution of SARS-CoV-2 and its molecular surveillance.

Trend of blood donors entering the coronavirus pandemic era and challenges: Age-period-cohort analysis using 75.5 million all blood donations data during 2006-2020 in Japan.

BACKGROUND: In Japan, "Blood Donation Promotion 2025," a blood donation target, was established based on a predicted blood donation rate of 5.7% in 2025, which was calculated by the Blood Donation Promotion Study Group (BD research group) of the Ministry of Health, Labor and Welfare using nationwide blood donation data through 2018. However, COVID-19 since 2020 may affect the blood donation rate in Japan. METHOD: Data from 75.5 million blood donations from 2006 to 2020 was used. The age-period-cohort model (APC model) was applied to estimate age, period, and birth cohort factors on blood donation rate and to predict the age-specific blood donation rates from 2021 to 2035. RESULTS: The APC model was highly reproducible for blood donation rates (modified R2 = 0.99). The blood donation rate in 2020 was 6.0% (5.04 million), an increase compared to 2019. Comparing this study with the BD research group, the predicted blood donation rates in 2025 for those 16-19 years old and in 20s are lower (4.8% vs. 5.2% and 5.3% vs. 5.5%) but those among 50s and 60s are higher (7.9% vs. 7.5% and 4.2% vs. 3.9%, respectively). DISCUSSION: The number of blood donations in 2020 increased despite COVID-19 and it proved that the blood donation promotion was effective. The different age-specific blood donation rates between our study and the report of BD research group infers the effect of COVID-19 on blood donation were differed by age and suggested the need for different approaches to blood donation promotion by generation.

Residual risk of mother-to-child transmission of HBV despite timely Hepatitis B vaccination: a major challenge to eliminate hepatitis B infection in Cambodia.

BACKGROUND: In countries with intermediate or high hepatitis B virus (HBV) endemicity, mother-to-child transmission (MTCT) represents the main route of chronic HBV infection. There is a paucity of information on HBV MTCT in Cambodia. This study aimed to investigate the prevalence of HBV infection among pregnant women and its MTCT rate in Siem Reap, Cambodia. METHODS: This longitudinal study included two parts, study-1 to screen HBsAg among pregnant women and study-2 to follow up babies of all HBsAg-positive and one-fourth of HBsAg-negative mothers at their delivery and six-month post-partum. Serum or dried blood spot (DBS) samples were collected to examine HBV sero-markers by chemiluminescent enzyme immunoassay (CLEIA), and molecular analyses were performed on HBsAg-positive samples. Structured questionnaires and medical records were used to examine the risk factors for HBV infection. MTCT rate was calculated by HBsAg positivity of 6-month-old babies born to HBsAg-positive mothers and ascertained by the homology of HBV genomes in mother-child pair at 6-month-old. RESULTS: A total of 1,565 pregnant women were screened, and HBsAg prevalence was 4.28% (67/1565). HBeAg positivity was 41.8% and was significantly associated with high viral load (p < 0.0001). Excluding subjects who dropped out due to restrictions during COVID-19, one out of 35 babies born to HBsAg-positive mothers tested positive for HBsAg at 6 months of age, despite receiving timely HepB birth dose and HBIG, followed by 3 doses of HepB vaccine. Hence the MTCT rate was 2.86%. The mother of the infected baby was positive for HBeAg and had a high HBV viral load (1.2 × 109 copies/mL). HBV genome analysis showed 100% homology between the mother and the child. CONCLUSIONS: Our findings illustrate the intermediate endemicity of HBV infection among pregnant women in Siem Reap, Cambodia. Despite full HepB vaccination, a residual risk of HBV MTCT was observed. This finding supports the recently updated guidelines for the prevention of HBV MTCT in 2021, which integrated screening and antiviral prophylaxis for pregnant women at risk of HBV MTCT. Furthermore, we strongly recommend the urgent implementation of these guidelines nationwide to effectively combat HBV in Cambodia.

Intermediate hepatitis B virus infection prevalence among 1622 pregnant women in rural Burkina Faso and implications for mother-to-child transmission.

In highly endemic countries for hepatitis B virus (HBV) infection, childhood infection, including mother-to-child transmission (MTCT), represents the primary transmission route. High maternal DNA level (viral load ≥ 200,000 IU/mL) is a significant factor for MTCT. We investigated the prevalence of HBsAg, HBeAg, and high HBV DNA among pregnant women in three hospitals in Burkina Faso and assessed the performance of HBeAg to predict high viral load. Consenting pregnant women were interviewed on their sociodemographic characteristics and tested for HBsAg by a rapid diagnostic test, and dried blood spot (DBS) samples were collected for laboratory analyses. Of the 1622 participants, HBsAg prevalence was 6.5% (95% CI, 5.4-7.8%). Among 102 HBsAg-positive pregnant women in DBS samples, HBeAg was positive in 22.6% (95% CI, 14.9-31.9%), and viral load was quantified in 94 cases, with 19.1% having HBV DNA ≥ 200,000 IU/mL. HBV genotypes were identified in 63 samples and predominant genotypes were E (58.7%) and A (36.5%). The sensitivity of HBeAg by using DBS samples to identify high viral load in the 94 cases was 55.6%, and the specificity was 86.8%. These findings highlight the need to implement routine HBV screening and effective MTCT risk assessment for all pregnant women in Burkina Faso to enable early interventions that can effectively reduce MTCT.

The role of discrimination in the relation between COVID-19 sequelae, psychological distress, and work impairment in COVID-19 survivors.

Perceived discrimination and work impairment are commonly observed in COVID-19 survivors, but their relationship has not been well understood. We aimed to evaluate the role of discrimination in the development of psychological distress and work impairment in COVID-19 survivors. From April 2020 to November 2021, 309 patients were recruited at two designated COVID-19 hospitals in Japan. Participants completed a standardized questionnaire including COVID-19 sequelae, psychological distress, impairments in work performance and perceived discrimination. The majority of participants (62.5%) experienced one or more COVID-19 sequelae. Psychological distress was observed in 36.9% and work impairment in 37.9%. In multivariate logistic regression analyses, COVID-19 sequelae and discrimination were associated with both psychological distress and work impairment. Mediation analysis demonstrated that the direct effect of sequelae on work impairment was non-significant after accounting for psychological distress, suggesting that the effect of sequelae on work impairment was mainly mediated through psychological distress. These findings were replicated in a subgroup analysis limited to patients with mild COVID-19. We conclude that discrimination plays an important role in the development of psychological distress and work impairment, and that both discrimination and psychological distress should be targets of intervention in COVID-19 survivors.

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 fatty liver and advanced fibrosis by ultrasonography and FibroScan in a general population random sample.

AIM: Fatty liver is the most common liver disease. This study examined fatty liver and advanced fibrosis prevalence in a random sample of the Japanese general population. METHODS: A total of 6000 people randomly selected from two cities in Hiroshima Prefecture were invited to participate in this cross-sectional study originally carried out for hepatitis virus screening. Ultrasonography and FibroScan (controlled attenuation parameter [CAP] and liver stiffness measurement [LSM]) were provided as additional tests. RESULTS: Of 6000 invited individuals, 1043 participated in hepatitis virus screening, of which 488 randomly selected individuals (median age, 56 years; interquartile range, 45-68 years; male participants, 49.8%) underwent ultrasonography, CAP, and LSM. Ultrasonography showed fatty liver in 24.6% and mild fatty liver in 32.8%. Controlled attenuation parameter showed severe steatosis in 27.5%, moderate steatosis in 12.5%, and mild steatosis in 11.1%. Overall, 62.1% were diagnosed with fatty liver based on ultrasonography or CAP. Nonalcoholic fatty liver disease (NAFLD) prevalence was 50.6%. Liver stiffness measurement found cirrhosis in 1.0% and severe fibrosis in 1.8%. Multivariate analysis of risk factors associated with ≥F2 or higher liver fibrosis showed that age ≥60 years and above (adjusted odds ratio [AOR], 3.2; 95% confidence interval [CI], 1.5-6.9; p = 0.0031), hepatitis C virus antibody positivity (AOR, 8.4; 95% CI, 1.0-68.4; p = 0.0467), and fatty liver (AOR, 2.3; 95% CI, 1.1-6.2; p = 0.0317) are independent risk factors. CONCLUSIONS: In the general population, 62.1% had fatty liver, and NAFLD prevalence was twice as high as previously reported. Screening that is noninvasive, low-cost, and does not require special techniques or equipment is needed to detect advanced liver fibrosis.

Effect of COVID-19 on hepatitis B and C virus countermeasures: Hepatologist responses from nationwide survey in Japan.

AIM: Achieving hepatitis B virus (HBV) and hepatitis C virus (HCV) elimination requires continuous and sustained high volumes of diagnosis and treatment, which have been affected by the ongoing COVID-19 pandemic. This study assessed the effects of COVID-19 on hepatitis-related services in Japan and compared Japan's situation with a global survey. METHODS: We conducted an online cross-sectional questionnaire survey of hepatologists from the Japan Society of Hepatology from August to October 2021 by using the same questionnaire from which a survey was conducted globally to address the effects of COVID-19 on hepatitis-related services. Hepatologists responded based on own impressions of their affiliated institutions. RESULTS: In total, 196 hepatologists participated from 35 prefectures including 49.5% in managerial positions. Approximately 40% survey participants reported a 1%-25% decline in HBV and HCV screening and confirmatory testing. In addition, 53.6% and 45.4% reported no decline in HBV and HCV treatment initiation, respectively. Comparing any level of decrease with the global survey, there was less of a decline observed in Japan for screening (HBV: 51% vs. 56.3%, HCV: 51% vs. 70.9%) and treatment initiation (HBV: 32.7% vs. 52.4%, HCV: 41.8% vs. 66%). However, patient anxiety/fear (67.4%) and loss of staff due to COVID-19 (49.0%) were reported as challenges for resuming services to pre-COVID-19 levels. CONCLUSION: Although in Japan all-inclusive decline in HBV- and HCV-related services were lower than in other countries, a greater decline was observed in HBV and HCV screening and diagnosis than in treatment initiation. Prolonged anxiety/fear among patients, and loss of staff and facilities from the COVID-19 response activities must be addressed to achieve elimination of hepatitis by 2030.

A longitudinal study of anti-SARS-CoV-2 antibody seroprevalence in a random sample of the general population in Hiroshima in 2020.

BACKGROUND: This longitudinal study aimed to determine chronological changes in the seroprevalence of prior SARS-CoV-2 infection, including asymptomatic infections in Hiroshima Prefecture, Japan. METHODS: A stratified random sample of 7,500 residents from five cities of Hiroshima Prefecture was selected to participate in a three-round survey from late 2020 to early 2021, before the introduction of the COVID-19 vaccine. The seroprevalence of anti-SARS-CoV-2 antibodies was calculated if at least two of four commercially available immunoassays were positive. Then, the ratio between seroprevalence and the prevalence of confirmed COVID-19 cases in Hiroshima was calculated and compared to the results from other prefectures where the Ministry of Health, Labour and Welfare conducted a survey by using the same reagents at almost the same period. RESULTS: The numbers of participants in the first, second, and third rounds of the survey were 3025, 2396, and 2351, respectively and their anti-SARS-CoV-2 antibodies seroprevalences were 0.03% (95% confidence interval: 0.00-0.10%), 0.08% (0.00-0.20%), and 0.30% (0.08-0.52%), respectively. The ratio between the seroprevalence and the prevalence of confirmed COVID-19 cases in Hiroshima was 1.2, which was smaller than that in similar studies in other prefectures. CONCLUSIONS: The seroprevalence of anti-SARS-CoV-2 antibodies in Hiroshima increased tenfold in a half year. The difference between seroprevalence and the prevalence of confirmed COVID-19 cases in Hiroshima was smaller than that in other prefectures, suggesting that asymptomatic patients were more actively detected in Hiroshima.

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.

Burden of chronic hepatitis B and C infections in 2015 and future trends in Japan: A simulation study.

Background: Determining the number of chronic hepatitis B (HBV) and C virus (HCV) infections is essential to assess the progress towards the World Health Organization 2030 viral hepatitis elimination goals. Using data from the Japanese National Database (NDB), we calculated the number of chronic HBV and HCV infections in 2015 and predicted the trend until 2035. Methods: NDB and first-time blood donors data were used to calculate the number of chronic HBV and HCV infections in 2015. A Markov simulation was applied to predict chronic infections until 2035 using transition probabilities calculated from NDB data. Findings: The total number of chronic HBV and HCV infections in 2015 in Japan was 1,905,187-2,490,873 (HCV:877,841-1,302,179, HBV:1,027,346-1,188,694), of which 923,661-1,509,347 were undiagnosed or diagnosed but not linked to care ("not engaged in care"), and 981,526 were engaged in care. Chronic HBV and HCV infections are expected to be 923,313-1,304,598 in 2030, and 739,118-1,045,884 in 2035. Compared to 2015, by 2035, the number of persons with HCV not engaged in care will decline by 59·8 - 76·1% and 86·5% for patients in care. For HBV, a 47·3 - 49·3% decrease is expected for persons not engaged in care and a decline of 26·0% for patients engaged in care. Interpretation: Although the burden of HBV and HCV is expected to decrease by 2035, challenges in controlling hepatitis remain. Improved and innovative screening strategies with linkage to care for HCV cases, and a functional cure for HBV are needed. Funding: Japan Ministry of Health, Labour and Welfare.