Publications by authors named "Masayuki Ohisa"

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.

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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.

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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.

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This study determined the prevalence of total hepatitis A antibody (anti-HAV) among 5-7 years old children and their mothers in the whole Cambodia, using a nationwide study, and examined the differences between the two cohorts. A total of 4535 dried blood spot-driven (DBS) samples (2021 mothers and their 2514 children of 5-7 years old) and the concomitant 922 whole blood samples (subset of the whole participants) were collected using a multistage random sampling strategy throughout Cambodia in 2017. Total anti-HAV was detected using the chemiluminescence enzyme immunoassay method.

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Background: In this study, we performed molecular characterization of SARS-CoV-2 strains in Hiroshima and its mutation pattern between the first and second waves of the outbreak.

Method: A total of 55 nasal swab samples from the first wave in Hiroshima and 13 from the second wave were examined quantitatively by RT-qPCR and qualitatively by nested PCR using specific primers. Four samples from each wave underwent next-generation sequencing and phylogenetic tree analysis including controls and all sequences retrieved in Japan from GISAID and GenBank.

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Monoclonal gammopathy (M-proteinemia) is a premalignant plasma cell disorder. The prevalence of M-proteinemia increases with age and is affected by genetic or environmental factors. Atomic bomb (A-bomb) survivors in Hiroshima are in an age range when they are susceptible to M-proteinemia.

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To investigate the long-term prognosis of liver disease in patients with hepatitis C virus (HCV) eradication after antiviral therapy versus those with persistent HCV infection. Four hundred and eighty patients (5259 person-years [PYs]) who received interferon-based therapy and achieved sustained virologic response and 848 patients (3853 PYs) with persistent HCV infection were included. In the analysis of 1-year liver disease state transition probability matrices using Markov chain models, progression to cirrhosis from the chronic hepatitis state was observed (0.

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This study aimed to investigate the prevalence trend of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections and their genotype distribution among hemodialysis patients, determining their long-term prognosis and the risk factors to the mortality. This cohort study used both the medical data and the blood samples of hemodialysis patients at nine dialysis centers in Hiroshima from 1999 to 2017. Hepatitis B surface antigen (HBsAg) and anti-HCV were screened and then amplification was done to positive sera by polymerase chain reaction for genotyping.

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Aim: The long-term prognosis of patients with chronic hepatitis C virus (HCV) infection who have received antiviral therapy and who demonstrate HCV eradication remains incompletely characterized. In this study, we investigated the long-term prognosis of liver disease in patients with eradication of HCV.

Methods: A total of 552 patients with chronic HCV infection (6815 person-years) who were treated with interferon-based therapy and who achieved sustained virologic response were included.

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Background: This study aimed to detect Hepatitis B virus (HBV) genome sequences and their variants as of nationwide scale using dried blood spot (DBS) samples and to provide up-to-date reference data for infection control and surveillance in Cambodia.

Method: Among 2518 children age 5-7 years and their 2023 mothers participated in 2017 Cambodia nationwide sero-survey on hepatitis B surface antigen (HBsAg) prevalence using multistage random sampling strategy, 95 mothers and 13 children positive to HBsAg were included in this study. HBV DNA was extracted from DBS, then performed polymerase chain reaction.

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Background: Hepatitis B virus (HBV) infection is highly endemic in most low income countries including Cambodia. This nationwide serosurvey was conducted to assess the impact of hepatitis B vaccination and to determine whether Cambodia met the WHO regional 2017 target of hepatitis B surface antigen (HBsAg) seroprevalence less than 1% in five-year-old children.

Methods: A cross-sectional multi-stage cluster survey was conducted among children born during 2010-2012 and their mothers in Cambodia.

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Background: Long-term prognosis of patients with chronic hepatitis C infection (HCV) remains incompletely characterized. We investigated the long-term prognosis of liver disease in patients with chronic HCV infection who have not received antiviral therapy.

Methods: A total of 2304 patients with chronic HCV who were not received interferon-based therapy were included.

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Aim: Even during nucleos(t)ide analogue therapy, development of hepatocellular carcinoma (HCC) has been observed in patients with chronic hepatitis B virus (HBV) infection. We simulated the long-term prognosis of liver disease in patients with chronic HBV who received nucleos(t)ide analogue therapy.

Patients And Methods: A total of 254 patients with chronic HBV receiving nucleos(t)ide analogue therapy were enrolled.

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Since the early 21 century, almost all developed countries have had a very low hepatitis A virus antibody (anti-HAV) sero-prevalence profile, as sanitation conditions and health care facilities have been optimized to a universal standard. There has not been a report on anti-HAV prevalence among a large scale population in Japan since 2003. Therefore, this study aimed to investigate the current HAV status among the general population in Hiroshima.

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Objective The fecal occult blood (FOB) test is commonly used for colorectal cancer screening; however, it is uncertain if further diagnostic interventions, such as a colonoscopy, should be performed based on its results. Method To better understand patient behavior following the FOB test, 6,414 patients (3,807 men and 2,607 women) who underwent colonoscopy between August 2015 and March 2016 at any of the 26 medical institutions throughout Hiroshima Prefecture were invited to participate in the study. All patients provided their written consent, after which they completed a questionnaire, and their colonoscopy results were obtained.

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Background: Health care workers (HCWs) are at high risk of contracting blood-borne infections including hepatitis B virus (HBV) infection. In Japan, all HCWs are required to receive HB vaccination before beginning work. This study aimed to investigate the dynamics of the HB surface antibody (anti-HBs) titer after a three-dose HB vaccination in HCWs and to determine effective scheduling of HB vaccination for non-responders.

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This population-based study examined the natural course of hepatitis B e antigen (HBeAg)-positive or HBeAg-negative persistent hepatitis B virus (HBV) infection, adjusted by age and liver disease states using a Markov model. Using 12 417 person-years data (n = 862), annual transition probabilities were estimated, and age-adjusted cumulative incidence and natural history of persistent HBV infection were simulated in both sexes of groups 1 (HBeAg-negative status with HBV DNA level <4.0 log IU/mL at entry) and 2 (persistent HBeAg-positive status throughout the study).

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Article Synopsis
  • Hepatitis B virus (HBV) infection is a significant public health issue in Burkina Faso, contributing to liver cancer and cirrhosis, prompting the adoption of a national strategic plan for hepatitis elimination in 2017.
  • This study conducted a systematic review and meta-analysis of 22 papers published from 1996 to 2017, involving nearly 100,000 participants, to estimate the prevalence of HBV in the country.
  • The overall HBV prevalence was found to be 11.21%, with higher rates in specific populations and rural areas, and a trend of decreasing prevalence following the introduction of universal vaccination.
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Background: The relationship between the hepatitis B e antigen (HBeAg) seroconversion and the long-term natural history of liver disease has not been sufficiently investigated.

Methods: A total of 408 [4352 person-year (PY) units] patients with chronic hepatitis B virus (HBV) without antiviral therapy were enrolled. The study patients were divided into three groups, as follows: Group A (2666 PY units), seroconverted of HBeAg at age < 40; Group B (413 PY units), seroconverted of HBeAg at age ≥ 40; Group C (1273 PY units), persistently HBeAg positive.

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Aim: We estimated the cost-effectiveness of direct-acting antiviral treatment (DAA) compared to triple therapy (simeprevir, pegylated interferon-α [Peg-IFN], and ribavirin [RBV]) (scenario 1), Peg-IFN + RBV (scenario 2), and non-antiviral therapy (scenario 3).

Methods: Cost-effectiveness was evaluated as incremental cost-effectiveness ratios (ICERs) using direct costs and indirect costs, which included loss of wages during the patient's lifetime due to early death caused by viral hepatitis infection. Quality of life (QOL) scores were determined by EQ-5D-3L questionnaire survey on 200 HCV patients in Hiroshima.

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Background And Aim: Although mortality rates of colorectal cancer (CRC) have been increasing in Japan, its screening rates remain stagnant at 19.2% among Japanese population aged > 40 years in 2014. To evaluate the importance of CRC screening by fecal occult blood test (FOBT), this study estimated the incidence of FOBT-positivity and CRC by sex-age stratification and clarified the risk factors for CRC.

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Aim: Countermeasures against hepatitis B and C virus (HBV, HCV) infection at work sites in Japan have not yet been implemented. This study aimed to determine the status of viral hepatitis infection among employees in Japan.

Methods: We undertook a workplace-based cross-sectional study from 2011 to 2016 in Hiroshima, Japan.

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Aim: We aimed to estimate hepatitis B surface antigen (HBsAg) positivity among birth year-stratified pregnant women in Hiroshima, Japan, and compare prevalence rates between women born before and after implementation of a national immunoprophylactic vaccination program for babies born to hepatitis B virus (HBV) carrier mothers in Japan.

Methods: Pregnant women who gave birth at all delivery hospitals/clinics in Hiroshima prefecture between 1 April 2010 and 31 March 2011 were eligible. Lists collected from each institution included survey items such as age (pregnant woman's birth year) and HBsAg and hepatitis C virus (HCV) antibody (anti-HCV) test results, which were posted anonymously and non-consolidated from medical records.

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Aim: This study aimed to survey the prevalence and incidence of hepatitis B (HBV) and hepatitis C virus (HCV) infection among elementary school students in Siem Reap province, Cambodia and to evaluate the effects of a national infant HBV vaccination program introduced in 2001.

Methods: Students in 3rd grade during the 2011, 2012, and 2013 academic years were enrolled in this study; at the time of the second examination, in the 2014-2015 academic year, the students were in 5th or 6th grade. The incidence and prevalence rates of HBV and HCV infection were estimated and full HBV sequences were analyzed.

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Background: Simulation studies were performed to predict the future supply and demand for blood donations, and future shortfalls.

Study Design And Methods: Using data from all donations in 2006 to 2009, the Markov model was applied to estimate future blood donations until 2050. Based on data concerning the actual use of blood products, the number of blood products needed was estimated based on future population projections.

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