บทคัดย่อ
Demographic impact of the HIV/AIDS epidemic in Thailand : mathematical and statistical projectionsThis study assesses the impact of the HIV epidemic on the demographic development of the Thai population through a deterministic mathematical model in which epidemiological and demographic processes are integrated and predicted simultaneously. The model employs partial differential equations expressing the relations between biological, behavioural and demographic variables and allows evaluations of different sexual mixing patterns, transmission probabilities and incubation times. Sensitivity analysis was performed by generating antecedent HIV prevalence patterns among military recruits and pregnant women. At the national level, cumulative HIV infection exceeds one million by the year 2000. The number of deaths from AIDS totals more than 550,000 by 2000 and will reach one million by 2014. With the HIV epidemic, total population declines by 1 percent in 2000 and around 1.7 percent in 2014. The HIV epidemic starts to affect the population growth rate by 0.026 percent per year in 1991. The difference increases to approximately 0.12 percent per year during 1995-2000 but declines to 0.06 percent in 2005 and disappears by the year 2014. In the mid nineties, HIV mainly affects the 15-39 year age groups, but over time younger and older age groups get affected as a result of perinatal transmission and the 15-39 years old cohorts growing older. A decline in the labor force is also observed, with sharper decline in the male labor force, resulting in an increase in the dependency ration by 0.003 in 1994, 0.004 in 2004 and 0.006 in 2014. For the Northern region, the demographic impact of HIV/AIDS follows the same pattern as that of the country but with different severity. In terms of demographic characteristics, the decline in population growth rate, the increase in dependency ratio and the decline in proportion of population by age and sex approximately double those of the national figures.
