Is the AIDS incubation time changing? A back-calculation approach
✍ Scribed by Sylvie Deuffic; Dominique Costagliola
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 294 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0277-6715
No coin nor oath required. For personal study only.
✦ Synopsis
Contradictory literature was recently published on possible changes in AIDS incubation time over the period [1978][1979][1980][1981][1982][1983][1984][1985][1986][1987][1988][1989][1990][1991][1992][1993][1994]. The purpose of this work was to test if a change in incubation time (shortening or lengthening) was observed in France, either globally or in specific transmission groups (homosexual-bisexual men, heterosexual subjects), using a back-calculation approach. An age dependent TSI model (time since infection), which took into account a temporary treatment effect and allowed us to test for a change in the incubation time, was applied to the French AIDS cases (Re´seau National de Sante´Publique). The EM algorithm was used to maximize the likelihood and the best model was selected on the basis of the likelihood ratio statistic. The analysis on all AIDS cases indicated a shortening of the AIDS incubation time estimated to begin in 1983 (95 per cent CI 1982(95 per cent CI -1984)). This shortening of incubation time was also apparent when analysis was restricted to homosexual-bisexual men and to heterosexual subjects. This shortening corresponded to a median incubation time of 9)6 years (95 per cent CI 8)1-10)5) for people infected at 30 years of age in 1983, versus 12)7 years for people infected at 30 years of age before the change.