       Document 0439
 DOCN  M9490439
 TI    A methodological study of a nonlinear stochastic model of an AIDS
       epidemic with recruitment.
 DT    9411
 AU    Mode CJ; Gollwitzer HE; Salsburg MA; Sleeman CK; Department of
       Mathematics and Computer Science, Drexel; University, Philadelphia,
       Pennsylvania 19104.
 SO    IMA J Math Appl Med Biol. 1989;6(3):179-203. Unique Identifier :
       AIDSLINE MED/94334605
 AB    A nonlinear stochastic model of an AIDS epidemic with recruitment of
       infectives, susceptibles, and AIDS cases into a randomly mixing
       population of male homosexuals was formulated and studied from a
       methodological point of view through intensive computer experimentation.
       Probability generating functions were used to formulate a model for the
       monthly probability that a susceptible individual becomes infected with
       HIV, under the assumption that the probability of infection per sexual
       contact varies as a function of the duration of infection. A method for
       taking into account the use of condoms to prevent infection with HIV was
       also introduced. Nonlinear difference equations, resembling
       deterministic epidemic models, were embedded in the stochastic
       population process by iterating an initial conditional expectation.
       Examples of Monte Carlo experiments are presented, illustrating that
       solutions of these nonlinear difference equations are not always good
       measures of central tendency for variations in the sample functions of
       the process. Two important substantive conclusions drawn from the Monte
       Carlo experiments were that efforts should be made to collect
       quantitative information on the probability of infection per sexual
       contact as a function of duration of infection and the frequency of
       condom use within and among risk categories in a population.
 DE    Acquired Immunodeficiency Syndrome/*EPIDEMIOLOGY/PREVENTION &
       CONTROL/TRANSMISSION  *Epidemiologic Methods  Homosexuality  Human  HIV
       Infections/EPIDEMIOLOGY/TRANSMISSION  Male  Monte Carlo Method
       Probability  *Stochastic Processes  JOURNAL ARTICLE

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

