Dynamic epidemiology of HIV/AIDS in Taiwan
Date Issued
2008
Date
2008
Author(s)
Liu, Chia-Hung
Abstract
Background It is a challenging task to estimate natural course of HIV and AIDS using empirical data because subjects infected with HIV are often asymptomatic and have remained occult for a long time (left-censored problem) without active surveillance system. It is imperative to apply a statistical model to estimate infection rate and the rate of conversion from HIV to AIDS making allowance for left-censored problem. In the view of infectious epidemiology, few studies in Taiwan considered using a dynamic concept to estimate and predict HIV infection and occurrence of AIDS with long-term follow-up. Furthermore, the administration of HAART further complicates the projection of HIV infection and AIDS cases.bjects The present study aimed to investigate descriptive epidemiology of HIV and AIDS cases, to estimate annual infection rate and conversion rate from HIV to AIDS, to investigate the effect of HARRT on total death and death due to AIDS.ethods Data used for the current study were derived from registered system of HIV and AIDS before the administration of HAART. A three-state Markov model was used to estimate the parameters pertaining to the natural history of HIV and AIDS. Logistic growth model was also used to estimate the growth rate of HIV. The effect of HARRT on reducing total death was investigated by the application of time-dependent proportional hazards Cox regression model. Both three-state-state Markov model and logistic growth model are further used to project HIV and AIDS after the HAART study.esults Annual infection rate for HIV infection was 0.0000006519 per person year. Annual conversion rate form HIV to AIDS for the overall group was 0.139 per year, namely 7.58 years of the average dwelling time staying in HIV state. By looking at different transmission modes, annual infection rate for homosexual and heterosexual modes was approximately two-fold compared with intravenous drug users and hemophiliacs. However, the opposite results were noted for annual conversion rates in terms of transmission modes. Using logistic growth model, we estimated 50% reduction of HIV and AIDS after the administration of HAART. By using survival data, we found 67% reduction in total death among HIV cohorts. The numbers of projection of HIV and AIDS in the absence of HAART intervention based on our three-state model were 9540 and 4164.onclusion Stochastic model and logistic growth model together with data before the administration of HAART were used to elucidate the natural history of HIV and AIDS in the absence of HAART intervention. We also found HAART can reduce 67% of total death and 50% of HIV or AIDS cases.
Subjects
Human immunodeficiency virus
Acquired immunodeficiency syndrome
Left censoring
Markov model
Survival analysis
HAART
SDGs
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-97-R95846010-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):f910309c2adb9be79d377ebff047f4c4