A survey of the sexual behaviour of gonorrhoea patients in Newark was undertaken to evaluate parameters within a model of gonorrhoea transmission. Modelling work aimed to explain observed epidemiological patterns and to explore the potential impact of interventions. Reported behaviours, along with values derived from the literature, were used within a standard deterministic model of gonorrhoea transmission, where the population was stratified according to sex and rates of sex-partner change. The behaviours reported, particularly among women, are insufficient by themselves to explain the continued existence of gonorrhoea within the population. The majority of symptomatic patients seek treatment within a few days, and report that they do not have unprotected sex while symptomatic. The proportion of patients with low numbers of sex partners suggests that sexual mixing between people categorized according to sexual behaviour is near random. To explain the persistence of gonorrhoea, there must be some patients who, when infected, do not seek care in public clinics. In addition, gonorrhoea incidence in the model is sensitive to change, such that very small reductions in risk behaviour could lead to its elimination. This does not accord with the observed failure of many interventions to eliminate infection, suggesting that the modelled infection is too sensitive to change. The model, which has been influential in gonorrhoea epidemiology, is not consistent with the observed epidemiology of gonorrhoea in populations. Alternative models need to explore the observed stability of gonorrhoea before robust modelling conclusions can be drawn on how best to control infection. However, the current results do highlight the potential importance of asymptomatic infections and infections in those who are diseased and do not attend public health services. Screening and contact-tracing to identify asymptomatic infections in both men and women will be more effective in reaching those who maintain the infection within the community rather than simply treating symptomatic cases.

To determine the etiology of genital ulcers and to assess the prevalence of human immunodeficiency virus (HIV) infection in ulcer patients in 10 US cities, ulcer and serum specimens were collected from approximately 50 ulcer patients at a sexually transmitted disease clinic in each city. Ulcer specimens were tested using a multiplex polymerase chain reaction assay to detect Haemophilus ducreyi, Treponema pallidum, and herpes simplex virus (HSV); sera were tested for antibody to HIV. H. ducreyi was detected in ulcer specimens from patients in Memphis (20% of specimens) and Chicago (12%). T. pallidum was detected in ulcer specimens from every city except Los Angeles (median, 9% of specimens; range, 0%-46%). HSV was detected in >/=50% of specimens from all cities except Memphis (42%). HIV seroprevalence in ulcer patients was 6% (range by city, 0%-18%). These data suggest that chancroid is prevalent in some US cities and that persons with genital ulcers should be a focus of HIV prevention activities.

STD positivity among persons entering corrections facilities is high. Most chlamydial and gonococcal infections are asymptomatic and would not be detected without routine screening. Monitoring the prevalence of STDs in this population is useful for planning STD prevention activities in corrections facilities and elsewhere in the community.