Geographic variation of HIV infection in childbearing women with syphilis in the United States

Objectives: Substantial biologic and epidemiologic data indicate the import ance of syphilis as a potential cofactor for sexual transmission of HIV inf ection, but few detailed data exist on the geographic covariation of these two important sexually transmitted infections. Design: HIV prevalence in ch ildbearing women and primary and secondary (P&S) syphilis data from 29 stat es were examined to explore the importance of the epidemiology of syphilis as a factor in facilitating HIV transmission. Method: The spatial relationship between P&S syphilis and HIV infection in the health districts of 29 states was analyzed and adjusted for demographic and socioeconomic factors such as racial composition, income, housing, edu cation levels, and access to medical services using the 1990 US census, and geographic location. Results: in 29 states and the District of Colombia, 448 health districts, r epresenting more than 75% of the US population, reported HIV prevalence rat es for mothers' district of residence. The HIV seroprevalence ranged from 0 to 1258/10 000 in these health districts. The incidence of PBS syphilis fr om 1984-1994 in these districts ranged from 0 to 87/100 000. The P&S syphil is incidence was positively associated with the prevalence of HIV infection among childbearing women (P < 0.0001). Conclusions: Syphilis that persists in communities in the United States app ears to represent a 'sentinel public health event' reflecting risk for sexu al HIV transmission. These findings, along with other biologic and epidemio logic information, reinforce the importance of syphilis as an indicator for targeting HIV prevention efforts generally, as well as syphilis control as a specific HIV-prevention strategy. (C) 2000 Lippincott Williams & Wilkins .