Cost-effectiveness of highly active antiretroviral therapy for HIV infection in Taiwan.

BACKGROUND/PURPOSE: Since the late 1980s, the Taiwanese government has provided all HIV-infected citizens with free access to antiretroviral therapy. Recently, there is controversy as to whether or not free access to expensive highly active antiretroviral therapy (HAART) should be continued for HIV-infected patients. This study aimed to evaluate the cost-effectiveness of HAART therapy. METHODS: HAART-associated improvement in survival was obtained by analyzing the follow-up data of all HIV-positive patients identified during April 1984 to March 1997 (pre-HAART era) and May 1997 to April 2003 (HAART era) in Taiwan. Data on quality of life in HIV-positive patients was obtained from a cross-sectional survey of 224 patients using standard gamble method and World Health Organization Quality of Life-BREF instrument. Information regarding the cost of HAART was obtained from the National Health Insurance (NHI). RESULTS: In 2000, the average annual NHI expenditure on HAART per HIV-positive patient receiving HAART was NT$210,018 (US$6177, at an exchange rate of 34.0 NT$/US$). In the AIDS group, the cost was NT$176,441 (US$5189) per life year gained and NT$241,700 (US$7109) per quality-adjusted life year gained. For non-AIDS patients, the corresponding costs were NT$226,156 (US$6652) and NT$332,582 (US$9782), respectively. These estimates have not yet included the additional cost savings from HAART-associated reduction in hospitalization and use of antimicrobial agents for opportunistic infections, and the additional life years gained from the reduction in HIV transmission under the universal availability of HAART. CONCLUSION: HAART for HIV infection is cost-effective, especially when the societal and epidemiologic factors are considered. We recommend that the policy of providing free HAART to all HIV-infected citizens be continued.

Prevention of hepatocellular carcinoma by universal vaccination against hepatitis B virus: the effect and problems.

PURPOSE: In spite of the success of hepatitis B immunization, still a significant proportion of childhood hepatocellular carcinoma (HCC) failed to be prevented by the hepatitis B immunization program. This study is aimed to investigate the problems in the HCC prevention in children. EXPERIMENTAL DESIGN: All HCC children ages 6 to 14 diagnosed between 1981 and 2000 in Taiwan were collected from two national childhood HCC registry systems. We analyzed the causes of HCC prevention failure and the risk ratio of HCC among hepatitis B carriers born before versus after the vaccination program. RESULTS: The incidence of HCC per 100,000 children declined from 0.54 to 0.20 in those born before versus after the vaccination program (risk ratio, 0.36). Vaccine failure (33.3-51.4%) and failure to receive hepatitis B immunoglobulin at birth (42.4-57.5%) were the main causes of HCC prevention failure. Mother-to-child transmission of hepatitis B virus infection is an important risk factor of HCC development. This is evidenced by the very high hepatitis B surface antigen seropositive rate in our HCC children (97%) and their mothers (96%). Hepatitis B carrier children born after the vaccination program had a higher risk of developing HCC than those born before the program (risk ratio, 2.3-4.5). CONCLUSIONS: Vaccine failure and failure to receive hepatitis B immunoglobulin are the main problems preventing eradication of HCC. Hepatitis B carrier children born after the immunization program have a higher risk of developing HCC than those born before.

Waning immunity to plasma-derived hepatitis B vaccine and the need for boosters 15 years after neonatal vaccination.

Neonatal immunization with hepatitis B (HB) vaccine is highly effective; however, more needs to be learned about the duration of protection and indications for boosters. We measured antibody to HB core antigen (anti-HBc), HB surface antigen (HBsAg), and pre- and postbooster titers of HBsAg antibody (anti-HBs) 15 years after primary neonatal immunization with plasma-derived HB vaccines in 2 cohorts of 15-year-old children. Group A consisted of 78 children who were born to HB e antigen-positive HBsAg carrier mothers and had developed protective levels of anti-HBs antibodies (> or =10 mIU/mL) following HB immunization. Group B consisted of 113 apparently healthy children whose anti-HBs titers after vaccination were unknown. Anti-HBs was undetectable (antibody titer <10 mIU/mL) in 29.9% in group A and 62.4% in group B (P < .001). Anti-HBc was detected in 33.3 % in group A and 4.4 % in group B (P < .001). After a single booster dose of HB vaccine, 2.7% in group A and 3.3% in group B remained anti-HBs-negative. A blunted serological response was noted in approximately 20% in both groups. One HBsAg carrier was detected in group A (1.3%) and 4 in group B (3.5%). Fifteen years after neonatal immunization with plasma-derived HB vaccine, a large proportion of children exhibited waning immunity. This poses the risk of breakthrough infection. A single booster augmented the serological response to the vaccine in most but not all subjects. In conclusion, our findings suggest that one or more booster immunizations are needed in seronegative subjects by at least 15 years following neonatal immunization with plasma-derived HB vaccine.

Decreased HIV transmission after a policy of providing free access to highly active antiretroviral therapy in Taiwan.

BACKGROUND: Taiwan established a nationwide surveillance system for human immunodeficiency virus (HIV) infection in 1989 and adopted a policy to provide all HIV-infected citizens with free access to highly active antiretroviral therapy (HAART) beginning in April 1997. This provided an opportunity to determine the effect of the widespread use of HAART on the evolution of the HIV epidemic. METHODS: We analyzed national HIV surveillance data. The HIV transmission rate was estimated by use of an exponential model of HIV epidemic evolution, with statistical projection over the interval between infection and detection to fit the surveillance data. RESULTS: By the end of 2002, the cumulative number of HIV-infected citizens in Taiwan had reached 4390 (0.019% of the total population). After free access to HAART was established, the estimated HIV transmission rate decreased by 53% (0.391 vs. 0.184 new cases/prevalent case-year [95% confidence interval, 31%-65%]). There was no statistically significant change in the incidence of syphilis, in the general population or among HIV-positive patients, during the same period. CONCLUSION: Providing free HAART to all HIV-infected citizens was associated with a 53% decrease in the HIV transmission rate and contributed to the control of the HIV epidemic in Taiwan.