Objective: Carriers of hepatitis B virus (HBV) and hepatitis C virus (HCV) in Japan were estimated on a national basis. Methods: Sera from the first-time blood donors aged 16–64 years in eight jurisdictions of the Japanese Red Cross Blood Center during 1995–2000 were tested for hepatitis B surface antigen (HBsAg) and antibody to HCV (anti-HCV). Viremia with HCV was estimated to be present in 70% of donors with anti-HCV. Results: HBsAg was detected in 22,018 of 3,485,648 (0.63%) blood donors including 12,990 of 1,780,149 (0.73%) men and 9,028 of 1,705,499 (0.53%) women, and anti-HCV in 17,010 (0.49%) including 8,504 (0.48%) men and 8,506 (0.50%) women. Multiplying the carrier rate by the population registered in the Census 2000, the total HBV carriers aged 15–65 years were estimated at 967,753 (95% confidence interval 806,760–1,128,745), of whom 571,210 (479,267–663,152) were men and 396,543 (327,494–465,593) were women. Likewise, the total HCV carriers were estimated at 884,954 (95% confidence interval 725,082–1,044,826), of whom 464,363 (377,927–550,799) were men and 420,591 (347,156–494,027) were women. Conclusion: Estimated numbers of HBV and HCV carriers would help plan to prevent the development of hepatocellular carcinoma in Japan.

Objective: To determine the copy number of hepatitis C virus (HCV) RNA, determined by nucleic acid amplification test (NAT) for screening blood units in Japan, that can transmit infection to chimpanzees. Methods: Fresh-frozen plasma with markers of HCV infection, as well as inocula pedigreed from 1 of them, were evaluated for the infectious activity in chimpanzees. Results: One unit each (273–282 ml) of fresh-frozen plasma from 2 blood donors or a pool from 13 donors to make a unit, which contained high-titered antibody to HCV but without HCV RNA detectable by NAT, did not infect any of 3 chimpanzees. Two chimpanzees were infected, however, when they were inoculated with 1 ml of serum from a blood donor in the ‘window period’ of HCV infection and containing 7.0 × 10⁶ copies/ml of HCV RNA. The preacute phase serum from 1 of them harvested 7 weeks after the inoculation was titrated in 2 chimpanzees, and an inoculum containing approximately 2 × 10¹ copies of HCV RNA could transmit infection to both of them. Conclusion: Approximately 20 copies of HCV can transmit infection to recipients, which needs to be taken into consideration in planning the screening of blood units for HCV RNA by NAT. Although the sensitivity of present NAT could be improved further, there would be a limit of it in detecting a low-level HCV RNA in the window period of donors with the infectious capacity in recipients.

The Markov model was introduced to simulate natural histories of hepatitis C virus (HCV) infection in men and women. The data set was constructed on 942 HCV carriers who were examined at least once a year without receiving antiviral therapies. Based on 2,251 patient-year data, the probabilities of transition between any two of the four clinical states, i.e., asymptomatic carrier state, chronic hepatitis, liver cirrhosis and hepatocellular carcinoma in 1 year were calculated. Hepatocellular carcinoma was defined as the absorbing state from where no transitions occur. Probability matrices thus obtained on six each subsets of HCV infection (asymptomatic carrier state, chronic hepatitis and liver cirrhosis in men and women) in their forties, fifties, and sixties, were used to simulate long-term outcomes of HCV infection. Male asymptomatic carriers aged 40 years were expected to retain the asymptomatic carrier state in 2.6%, evolve into chronic hepatitis in 48.4%, liver cirrhosis in 14.6% and hepatocellular carcinoma in 34.4% after 30 years when they reached 70 years of age, in contrast to 1.9%, 45.3%, 32.8% and 20.0%, respectively, of female asymptomatic carriers. Likewise, male patients with chronic hepatitis aged 40 years were expected to remain with chronic hepatitis in 43.8%, evolve into liver cirrhosis in 15.0% and hepatocellular carcinoma in 41.1%, contrasting with 38.9%, 32.7% and 22.0%, respectively, of female patients during 30 years. The Markov model could simulate the outcomes of 153 HCV carriers identified among blood donors after 5 years. The Markov simulation would help in assessing the long-term outcome of HCV infection and making decisions in the management of HCV carriers toward prevention of hepatocellular carcinoma.

The J-DAVID Investigators IMPORTANCE Patients with chronic kidney disease have impaired vitamin D activation and elevated cardiovascular risk. Observational studies in patients treated with hemodialysis showed that the use of active vitamin D sterols was associated with lower risk of all-cause mortality, regardless of parathyroid hormone levels. OBJECTIVE To determine whether vitamin D receptor activators reduce cardiovascular events and mortality in patients without secondary hyperparathyroidism undergoing hemodialysis. DESIGN, SETTING, AND PARTICIPANTS Randomized, open-label, blinded end point multicenter study of 1289 patients in 207 dialysis centers in Japan. The study included 976 patients receiving maintenance hemodialysis with serum intact parathyroid hormone levels less than or equal to 180 pg/mL. The first and last participants were enrolled on

Patients on maintenance hemodialysis (HD) are at increased risk of infection with hepatitis C virus (HCV). A prospective follow-up study on HCV infection from November 1999 to February 2003 was conducted in nine hemodialysis (HD) units in Hiroshima. A total of 2,744 HD patients were surveyed regularly for HCV RNA in serum. The prevalence of HCV RNA decreased from 15.7% (262/1,664) on the first survey to 12.9% (242/1,882) in the last one (P<0.05). This decrease may be attributed to the inclusion of patients with a lower prevalence of HCV RNA compared to patients leaving dialysis centers (111/1,080 [10.3%] vs. 132/862 [15.3%], P<0.01). During the 40 months of this study, 16 de novo HCV infections were documented in the nine HD units corresponding to an incidence of 0.33% per year. These cases included eight new HCV infections, three re-infections, and five infections that presumably occured in the window period when tested during the first survey. Our study shows that the annual incidence of de novo HCV infection during HD was 0.33%, and emphasizes the need for frequent serum HCV RNA testing and for stringent disinfection procedures in order to prevent the transmission of HCV in these settings.