Document 2247
 DOCN  M94A2247
 TI    Changes in the age-at-onset of HIV infection among IVDU's in Italy.
 DT    9412
 AU    Mariotto A; Verdecchia A; Istituto Superiore di Sanita, Roma, Italy.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):348 (abstract no. PC0626). Unique
       Identifier : AIDSLINE ICA10/94370328
 AB    OBJECTIVE: To shown how the age distribution of new HIV infections in
       Italy changed with time. The result may early indicates that the course
       of the epidemic among IVDU's is changing, possibly as the consequence of
       preventive strategies and suggesting future ones. METHOD: An age, period
       and cohort model is used to reconstruct the HIV epidemic among IVDU's in
       Italy. It is an extension of the backcalculation method which includes
       age-at-onset, the age specific incubation time distribution, therapy
       effect, susceptible population and age-period interaction (cohort
       effect). RESULTS: The estimated age-at-onset of the HIV infection among
       IVDU's in Italy changed its peak during the course of the epidemic from
       24 years in 1984, to 30 in 1986, 33 in 1988, and 35 years after 1990,
       indicating an excess of risk of individuals born around 1955-1956
       (generation effect). The dispersion of the age distribution
       progressively reduced. The overall form of the epidemic curve was
       estimated to decline in recent years after reaching its maximum in 1987
       with 16,500 (13,700 males and 2,800 females) new HIV infections among
       IVDU's (rate of 7.7 per 1,000) and is decreasing in all age groups: for
       those aged < or = 25, 26-35 and > 35 years the peak was estimated to
       occur, respectively, before 1987, between 1987-1989 and after 1989.
       Among younger generations, who began the use of drugs at a later date,
       the estimated risk of infection began to decrease earlier than for older
       generations, already too involved with drugs, suggesting a change in
       their risk behaviour. This can be interpreted as an important prevention
       result. The results are also supported by evidence that the age
       distribution of IVDU's with AIDS has also changed. CONCLUSIONS AND
       DISCUSSION: Age-at-onset of HIV infection is of considerable public
       health importance and the reconstruction of the HIV epidemic by age,
       period and cohort gives a much deeper insight into the pattern of the
       course of the epidemic. The value of health education, directed in
       particular to teenagers at school, is greatly supported by our findings.
 DE    Adult  Age Factors  Disease Outbreaks/*STATISTICS & NUMER DATA  Female
       Human  HIV Infections/EPIDEMIOLOGY/PREVENTION & CONTROL/*TRANSMISSION
       HIV Seroprevalence/*TRENDS  Italy/EPIDEMIOLOGY  Male  Population
       Surveillance  Risk Factors  Substance Abuse,
       Intravenous/COMPLICATIONS/*EPIDEMIOLOGY  MEETING ABSTRACT

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).