Kow -Tong Chen, M.D., Ph.D ., Hsiao-Ling Chang, Ph.D ., Chu-Tzu Chen, M.P.H .,

1. The Changing Face of the HIV Epidemic in Taiwan:A New Challenge for Public Health Policy Strategies Kow-Tong Chen, M.D., Ph.D., Hsiao-Ling Chang, Ph.D., Chu-Tzu Chen, M.P.H., and Ying-An Chen, M.P.H. Volume 23, Number 3, 2009 AIDS PATIENT CARE and STDs

2. Introduction • In 1984, soon after the first case of AIDS was reported, the Taiwan CDC as well as local health departments began to collect case reports of AIDS • In this paper, we used national HIV/AIDS case surveillance data in Taiwan for the years 1990–2005 to describe epidemiologic trends

3. Methods • Taiwan has a population of approximately 22.7 million • The national Department of Health has passed legislation and written rules to mandate data collection on AIDS cases since 1990 • Local health departments use active and passive surveillance methods to collect information on AIDS cases • Collected information were entered in local databases and electronically forwarded to the Taiwan CDC

4. Methods • The Taiwan AIDS surveillance definition and its modification are modeled after the CDC, USA • HIV – receive diagnosis of HIV • AIDS - has AIDS when first received HIV diagnosis, or progress to having AIDS after reported with HIV infection • people with AIDS • Diagnosis year: the year of AIDS diagnosis • number of people living with AIDS: total number of AIDS – deceased people with AIDS

5. Methods • HIV diagnosis • Late - HIV diagnosis was within 3 months of AIDS diagnosis • Early – HIV diagnosis more than 3 months prior to AIDS diagnosis • clinically relevant periods • Pre-HAART era – 1990-1996 • HAART era – 1997-2005 • excluded children younger than 13 years due to differences in transmission and disease progression patterns

6. Methods • IPR(t) – incidence-to-prevalence ratio • R(t) – mean number of new infections originating per already-infected individual • D – mean duration of infectiousness • R(t) = IPR(t) *D • R(t) > 1 → IPR(t) > TE • TE– epidemic threshold = 1/D • IPR(t) for year ‘‘y’’ – • new (incident) diagnoses in year (y + d) / (prevalent) diagnosed and subsequently diagnosed infections at the end of the year (y - 1).

7. Result

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11. Result • Relative to the group with HIV diagnosis, the protective survival effect associated with being in the HAART era was stronger for both groups • Hazard ratio • Early HIV - 0.45 (95% CI 0.36–0.54) • Late HIV - 0.39 (95% CI 0.31–0.49) • Relative to the group before and after HAART, no significant differences in the protective survival effect associated with being in the early or late HIV diagnosis groups

12. Discussion • Important changes • absolute number of HIV diagnoses has increased at a greater rate in the last 2 years • The vast majority of HIV infections occurred among IDUs • proportion of annual diagnoses that occurred in IDUs rose rapidly from 9% in 1990 to 72% in 2005 • IPR(t) has exceeded epidemic threshold in recent years • growing epidemic of AIDS among IDUs in Taiwan

13. Discussion • Risk groups except for IDUs • IPR on the decline, likely due to proportion of population falls • increasing number of incident and prevalent infections, means increasing acquisition risk • IDUs group • IPR increased sharply and exceeded TE recently

14. Discussion • Mandatory HIV screening has been initiated since 1984, when first HIV/AIDS diagnosed • Data reflect the increasing rates of HIV transmission • The spread of HIV among IDUs continues to rapidly increase • Needle exchange programs are potentially a key for containing the HIV epidemic among drug users • Current trends in mortality indicate the success of using HAART in persons living with HIV

15. DiscussionLimitations • The study used national surveillance data so the completeness of reporting is important. An estimate of the completeness of AIDS case reported in Taiwan is needed in the future • AIDS case follow-ups with providers to identify exposure category may be incomplete • Calculation of the IPR is misleading as we did not have data on incidence of HIV infection, only incidence of reporting of HIV status

16. Conclusion • The potential for an AIDS epidemic among IDUs in Taiwan will necessitate changes in AIDS prevention programs, which are currentlypredominantly oriented toward the homosexual • Promoting the use of sterile needles by addicts unable to stop injection may be the most effective means of halting the spread of the AIDS epidemic