Objective: To estimate total numbers of undiagnosed carriers of hepatitis C virus (HCV) and hepatitis B virus (HBV) in Japan. Methods: Area- and age-specific prevalence of HCV as well as HBV was determined in the first-time blood donors [20–39 years (n = 2,429,364)] and examinees of periodical health check-ups [40–74 years (6,204,968 for HCV and 6,228,967 for HBV)] in Japan. Prevalence in adolescents [5–19 years (79,256 for HCV and 68,792 for HBV)] was determined in a single prefecture, and that of HCV in the elderly (≧75 years) was estimated by the exponential model. HBV infection was determined by the detection of hepatitis B surface antigen, and HCV infection by either the algorithm or assuming persistent infection in 70% of the individuals with antibody to HCV. Results: Of the total population of 127,285,653 in 2005, 807,903 (95% CI 679,886–974,292) were estimated to be infected with HCV at a carrier rate of 0.63%, and 903,145 (837,189–969,572) with HBV at that of 0.71%. Conclusion: Accurate estimation of undiagnosed HCV and HBV carriers in the general population would help to predict the future burden of liver disease, and take appropriate measures for improving healthcare.

Our results showed that operation and blood transfusion were potential risk factors for HBV and HCV infection, respectively, and supposed that horizontal HBV transmission may be frequent in adults in Cambodia. Hence, for reducing HBV and HCV infections, it is necessary to improve the safety of blood and medical treatment.

In Binh Thuan, prevalences of HBV and HCV infections are high, HBV genotype B and HCV genotype 6a are predominant, and horizontal HBV transmission may still occur. Therefore, raising the coverage of a universal HBV vaccination program may be an effective liver cancer control in Vietnam.

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. Results Among 248 students (107 male and 141 female) born between 1999 and 2005, five students were HBV surface antigen (HBs‐Ag) positive (2.02%), and all of them were infected with genotype C. Among them, subgenotype C1 was found in four students and, unexpectedly, complete genetic sequence identity of subgenotype C1 was found in two students from different families. The anti‐HBV core (HBc) and anti‐HBs prevalence rates were 10.89% and 16.13%, respectively. Twenty‐five students were positive for anti‐HBs and negative for both HBsAg and anti‐HBc (10.08%; estimated serological vaccination rate); this rate increased significantly with the birth year (P = 0.0229). Prevalence of anti‐HCV was 2.82%, and HCV RNA was not detected. The estimated incidence of HBV and HCV infection were both 0/1000 person‐years (PY) (95% confidence interval, 0–20.61/1000 PY and 0–14.50/1000 PY, respectively). Conclusion Hepatitis B virus full‐genome sequencing and serological analysis revealed the possibility of horizontal transmission of HBV among Cambodian schoolchildren. However, the anti‐HBc positivity rate decreased along with increasing age and estimated serological vaccination rates.

The aim of this study was to compare ultrasonographic assessment of fecal loading in adults with that of computed tomography. Ultrasonography (US) was performed on 43 adult patients immediately after abdominal computed tomography images had identified fecal loading in their colons. In 18 of 43 patients (haustrations-visualized cases), fecal loading was detected as crescent-shaped acoustic shadows associated with haustrations behind the strong echoes off the colon wall. In the remaining 25 patients (haustrations-not-visualized cases), fecal loading was detected as attenuating echoes with multiple high echoic spots behind weak high echoes off the colon wall in 17 patients and similar to those seen in the haustrations-visualized cases but without haustrations in 8 patients. US can be used for qualitative assessment of fecal loading in the colon. This new technique is simple and noninvasive and can be used concomitantly with physical examination to assess severity of constipation.