Monitoring HPV type-specific prevalence over time through clinic-based surveillance: a perspective on vaccine effectiveness.

We investigated the feasibility of monitoring trends in prevalence of vaccine-preventable human papillomavirus (HPV) types in different clinic populations. We collected cervical specimens from women presenting to family planning, primary care, and sexually transmitted disease (STD) clinics for routine pap smears in five US cities during 2003-2005. We performed HPV genotyping and calculated annual type-specific prevalences; pre-vaccine era prevalence was highest for HPV 16 (6.0; 95% confidence interval [CI] 5.5-6.6%) and annual prevalences for vaccine-preventable types were stable, with few exceptions, after controlling for clinic type, age group, and city. With sufficient sample size and stable population characteristics, clinic-based surveillance systems can contribute to monitoring HPV vaccine impact in the cervical screening population.

Neurosyphilis during the AIDS epidemic, San Francisco, 1985-1992.

To investigate the epidemiology and clinical spectrum of neurosyphilis in a population with high rates of coexisting syphilis and human immunodeficiency virus (HIV) infection, a retrospective analysis of cases in all San Francisco hospitals from 1985 to 1992 was conducted. Neurosyphilis was defined by a newly reactive cerebrospinal fluid VDRL; 117 patients with neurosyphilis were identified. The median age was 39 years, 91% were male, 74 (63%) were white, and 75 (64%) were HIV-infected. Thirty-eight (33%) presented with an early symptomatic neurosyphilis syndrome. Six (5%) had late neurosyphilis. Thirty-eight (32%) patients were asymptomatic, and 35 (30%) had findings attributable to coexisting neurologic diseases. Patients demonstrated high serum nontreponemal (VDRL) titers (median, 1:128) at neurosyphilis presentation. In contrast to the findings from the preantibiotic era, neurosyphilis was identified in young patients most often with HIV coinfection, and early symptomatic syndromes were identified more frequently than late neurosyphilis syndromes.

Trends in HIV seroprevalence among persons attending sexually transmitted disease clinics in the United States, 1988-1992.

Trends in seroprevalence of the human immunodeficiency virus (HIV) were examined among patients attending sentinel clinics for sexually transmitted diseases (STDs) throughout the United States. Cross-sectional, unlinked (blinded) surveys of HIV seroprevalence were conducted annually within clinics in 40 metropolitan areas. From 1988 to 1992, 552,665 specimens were tested in 80 STD clinics. The overall HIV seroprevalence was 33% (range among metropolitan areas: 5-52%) among gay and bisexual men, 3% (range: 0.3-11%) among heterosexual men, 2% (range: 0.1-11%) among women, and 10% (range: 0.5-45%) among heterosexual injecting drug users (IDUs). Controlling for clinic, age, and race/ethnicity, HIV seroprevalence decreased among all gay and bisexual men, but especially among white gay and bisexual men from 32% in 1989 to 22% in 1992. Among heterosexual men and women, HIV seroprevalence decreased among whites and, to a lesser degree, Hispanics, but remained essentially stable among African-Americans over time. Among heterosexual IDUs, seroprevalence was also unchanged. These results reflect changes in the HIV epidemic, which is becoming increasingly characterized by infected heterosexuals and IDUs, especially within minority populations.

Routine hepatitis B vaccination in a clinic for sexually transmitted diseases.

Patients were assigned to one of two vaccine schedules to assess the feasibility of vaccinating a sexually transmitted disease clinic population against hepatitis B virus. Of 1386 patients entering an inner-city clinic between June and July 1990, 611 (44%) accepted a first dose of vaccine. Twenty-one percent of all susceptible patients received at least two doses of vaccine. Annualizing these findings shows that an ongoing program could prevent 636 hepatitis B virus infections per year. Although a significant proportion of sexually transmitted disease clinic patients can be successfully vaccinated, strategies for preventing hepatitis B virus infections in this high-risk population must consider patient behavior as well as vaccine efficacy.

Factors associated with condom use in a high-risk heterosexual population.

The use of condoms has been advocated as a means of preventing the transmission of the human immunodeficiency virus and other sexually transmitted agents. To better understand factors that may influence condom use, 300 heterosexuals were enrolled in a cross-sectional study of patients attending San Francisco's only public sexually transmitted disease clinic. Interviewer-administered questionnaires were conducted. Condom use at last sexual intercourse was examined by logistic regression analysis. Men who used drugs or alcohol at last intercourse and whose partners did not want to use condoms were less likely to have used them; women who were black or Hispanic, who reported difficulty getting their partners to use condoms, or who reported that condoms decrease sexual pleasure also were less likely to have used them. Efforts to increase condom use in this population should target minorities, assist women to negotiate their use, emphasize the dangers of using alcohol and other drugs with sex, and address the perception that condoms interfere with sexual pleasure.

PIP: Better information is needed to understand sexual behavior and other variables that may influence condom use in order to develop successful education campaigns promoting their use. To this end, this study examined the AIDS Risk Reduction Model among an equal number of men and women (300) attending the public sexually transmitted disease (STD) clinic in San Francisco in 1989. The population is indicative of the population diagnosed with syphilis and gonorrhea. Clinical data from medical charts were linked with questionnaire data. Variables that were identified as affecting condom use at last intercourse were perceived susceptibility to HIV infection, knowledge of HIV transmission, and perception of the seriousness of HIV infection. Also included were condom use factors such as ill fit of condoms or decreased sexual spontaneity, and sexual communication. Attitudes and beliefs were scaled items which had to have alpha coefficients greater than .60 in order to be included. Evaluation of significant factors was accomplished with the Mantel-Haenzel chi-square and student's t-test. Gender specific multivariate logistic regression was used to control for confounding factors such as age, stability of the relationship, and total number of sex partners in a year. Condom breakage was reported. The population was 57% (78) male and black or Hispanic and 51% (84) female and black or Hispanic. 46% (138) had incomes of $5000. 47% were newly diagnosed with an STD on the interview day. 64% had prior STDs. 2 reported having HIV infection and 2 reported having a sex partner with HIV infection. 51% stated that their steady partner had at least one STD during the prior sexual encounters. Sexual behavior was reported for partner's sexual involvement with others in the past 2 months, condom use among steady and casual partners, knowledge of HIV transmission, past condom usage, and use of condoms at last intercourse. In the multivariate analysis, black or Hispanic men who used drugs or alcohol at last sexual encounter and black or Hispanic men whose partners did not want to use condoms were less likely to use condoms at last intercourse. Less condom use for women was associated with blacks or Hispanics, the belief that condoms reduce sexual pleasure, the difficulty in exercising control over their use, and involvement with a steady partner.

Hepatitis C virus infection among patients attending a clinic for sexually transmitted diseases.

OBJECTIVE: To evaluate the association between hepatitis C virus (HCV) infection and sexual behavior in a sexually active population. DESIGN: Cross-sectional study. SETTING: Inner-city clinic for sexually transmitted diseases. SUBJECTS: The study included 1292 patients attending the clinic for care during a 1-month period and having syphilis serologic tests performed. OUTCOME MEASURES: Antibody to HCV (anti-HCV) positivity as defined by a repeatedly-reactive enzyme immunoassay and a positive neutralization enzyme immunoassay (Abbott Laboratories, Chicago, Ill). RESULTS: Of 1292 patients screened for anti-HCV, 99 (7.7%) were positive. Logistic regression analysis found that patients who reported intravenous drug use, were positive for antibody to hepatitis B core antigen, reported a history of a blood transfusion, were black, or reported crack cocaine use were more likely to be anti-HCV-positive. Forty-five percent of patients who were anti-HCV-positive reported intravenous drug use. Sex with an intravenous drug user and a history of gonorrhea and syphilis were associated with anti-HCV positivity in a univariate analysis, but after controlling for confounding variables, no such associations remained. While having multiple sexual partners in the previous 3 months, being homosexual or bisexual, and engaging in receptive anal intercourse were associated with being positive for antibody to hepatitis B core antigen, those behaviors were not associated with anti-HCV positivity. CONCLUSIONS: While these results cannot exclude a role for the sexual transmission of HCV, they do suggest that, in this sexually active population, the sexual transmission of HCV occurs infrequently and that HCV is largely associated with intravenous drug use.

Chlamydia trachomatis infection in women: a need for universal screening in high prevalence populations?

Chlamydia trachomatis is the most prevalent sexually transmitted bacterial pathogen. Nevertheless, selective, rather than universal, screening for chlamydia has been recommended, largely because testing is expensive and requires considerable technical expertise. A total of 1,348 women in four family planning clinics in San Francisco, California, were screened from March 1987 to January 1988 to identify criteria for selective screening. Of these, 9.2% had a positive chlamydia test using direct fluorescence. Logistic regression analysis identified five factors associated with infection: age less than 25 years, cervical friability, single marital status, a new sexual partner within the past 3 months, and lack of barrier contraceptive use. No single risk factor or combination of risk factors had both a high sensitivity and a high positive predictive value for infection. While screening all women who were unmarried would detect 93% of those with chlamydia, the positive predictive value of 10.7% was not much higher than the overall prevalence. Conversely, screening all women with cervical friability, which had a positive predictive value of 23.2%, would only detect 11% of those with chlamydia. On the basis of the authors' findings, selective screening should not be used in high prevalence populations in which all women are at risk and should be screened for chlamydia.