A SOCIAL NETWORK APPROACH TO ESTIMATING SEROPREVALENCE IN THE UNITED-STATES

Results from a representative survey of respondents in Florida are giv en, concerning their knowledge about members of their personal network , and specifically how many people respondents know in selected subpop ulations. We employ a method known as a ''network scale-up method''. B y using a collection of subpopulations of known size, and also asking about one subpopulation (those who are seropositive) of unknown size, we make various estimates of personal network size and the size of the seropositive subpopulation. Our best (maximum Likelihood, unbiased) e stimates are 108 members of the network defined by ''having been in co ntact with during the previous two years'', and (approximately unbiase d) 1.6 million for the seropositive subpopulation. Because of the prop ortional over-representation of AIDS (and presumably, therefore, serop ositive) in Florida, by a factor of about two, this latter estimate co uld be an overestimate. (C) 1998 Elsevier Science B.V.