(1/196) Risk factors for abnormal anal cytology in young heterosexual women.

Although anal cancers are up to four times more common in women than men, little is known about the natural history of anal human papillomavirus (HPV) infections and HPV-related anal lesions in women. This study reports on the prevalence of and risks for anal cytological abnormalities over a 1-year period in a cohort of young women participating in a study of the natural history of cervical HPV infection. In addition to their regularly scheduled sexual behavior interviews and cervical testing, consenting women received anal HPV DNA and cytological testing. Anal cytology smears were obtained from 410 women whose mean age was 22.5 +/- 2.5 years at the onset of the study. Sixteen women (3.9%) were found to have abnormal anal cytology: 4 women had low-grade squamous intraepithelial lesions (SILs) or condyloma; and 12 women had atypical cells of undetermined significance. Factors found to be significantly associated with abnormal anal cytology were a history of anal sex [odds ratio (OR), 6.90; 95% confidence interval (CI), 1.7-47.2], a history of cervical SILs (OR, 4.13; 95% CI, 1.3-14.9), and a current anal HPV infection (OR, 12.28; 95% CI, 3.9-43.5). The strong association between anal intercourse and the development of HPV-induced SILs supports the role of sexual transmission of HPV in anal SILs. Young women who had engaged in anal intercourse or had a history of cervical SILs were found to be at highest risk.  (+info)

(2/196) Sexual transmission and prevention of the hepatitis viruses A-E and G.

OBJECTIVES: To assess current knowledge about the potential for sexual transmission of the hepatitis viruses A-E and G and how to prevent any such transmission. METHOD: A search of published literature identified through Medline 1966-June 1998 (Ovid v 3.0), the Cochrane Library and reference lists taken from each article obtained. Textword and MeSH searches for hepatitis A, B, C, D, E, G, delta, GB virus, GBV-C were linked to searches under the textword terms sex$, vaccine$, prevent$, and MeSH subheadings, epidemiology, transmission, prevention, and control. CONCLUSIONS: There is evidence for heterosexual transmission of hepatitis B, C, D, and G and homosexual transmission of hepatitis A-D and G. Condoms are an effective method for preventing transmission by penetrative vaginal or anal sex although spread of types A and B are linked also to oro-anal sex. Hepatitis types A and B can be prevented by pre- and post-exposure active or passive immunisation. There is still some uncertainty about appropriate target groups for pre-exposure vaccination, particularly against hepatitis A.  (+info)

(3/196) Sexual transmission of hepatitis C virus infection.

BACKGROUND: Hepatitis C virus (HCV) is the cause of almost all cases of parenterally transmitted non-A, non-B viral hepatitis (NANBH). HCV is an RNA virus, unrelated to the hepatitis viruses, A, B, D, or E; it was first identified in 1989. Although most infections become chronic, and it may lead to chronic liver disease, most patients with HCV infection are asymptomatic. The predominant modes of transmission are by blood, blood products, or other parenteral exposure, particularly injecting drug use. More contentious is the role of sexual transmission, although evidence for this was provided by studies of NANBH. OBJECTIVE: This review considers the evidence for sexual transmission, and the types of studies used to estimate the rate of transmission and the factors that may influence it. METHOD: A Medline search using the keywords hepatitis C, sex, transmission, and prevalence in MeSH and free text. References in papers were searched, and some unpublished data identified. References were further selected to illustrate different methodologies. FINDINGS: Evidence for sexual transmission is provided by several types of study including prevalence studies in groups at risk of other STDs, investigation of cases identified from surveillance reports, and cross sectional and longitudinal partner studies. Many studies are limited by their small size, the sensitivity and specificity of early assays, lack of controls, or the difficulty of excluding other routes of transmission. One prospective cohort study reported an incidence of 12 per 1000 person years in the sexual partners of HCV infected patients. 1-3% of partners of HCV infected patients are found to be infected in cross sectional studies. Co-infection with HIV, duration of the relationship, or chronic liver disease may be independent cofactors increasing the risk of transmission. A meta-analysis of selected studies may be informative, and further larger prospective studies are required. There is a small but definite risk of sexual transmission of hepatitis C.  (+info)

(4/196) Behavioural intervention trials for HIV/STD prevention in schools: are they feasible?

OBJECTIVE: To assess the feasibility of conducting a large randomised controlled trial (RCT) of peer led intervention in schools to reduce the risk of HIV/STD and promote sexual health. METHODS: Four secondary schools in Greater London were randomly assigned to receive peer led intervention (two experimental schools) or to act as control schools. In the experimental schools, trained volunteers aged 16-17 years (year 12) delivered the peer led intervention to 13-14 year old pupils (year 9). In the control schools, year 9 pupils received the usual teacher led sex education. Questionnaire data collected from year 9 pupils at baseline included views on the quality of sex education/intervention received, and knowledge and attitudes about HIV/AIDS and other sexual matters. Focus groups were also conducted with peer educators and year 9 pupils. Data on the process of delivering sex education/intervention and on attitudes to the RCT were collected for each of the schools. Analysis focused on the acceptability of a randomised trial to schools, parents, and pupils. RESULTS: Nearly 500 parents were informed about the research and invited to examine the study questionnaire; only nine raised questions and only one pupil was withdrawn from the study. Questionnaire completion rates were around 90% in all schools. At baseline, the majority of year 9 pupils wanted more information about a wide range of sexual matters. Focus group work indicated considerable enthusiasm for peer led education, among peer educators and year 9 pupils. Class discipline was the most frequently noted problem with the delivery of the peer led intervention. CONCLUSION: Evaluation of a peer led behavioural intervention through an RCT can be acceptable to schools, pupils, and parents and is feasible in practice. In general, pupils who received the peer led intervention responded more positively than those in control schools. A large RCT of the long term (5-7 year) effects of this novel intervention on sexual health outcomes is now under way.  (+info)

(5/196) Low prevalence of hepatitis B markers among Mexican female sex workers.

OBJECTIVES: To estimate the prevalence and associated risk factors of hepatitis B virus (HBV) serological markers in female sex workers (FSW) in Mexico City. METHODS: The study population consisted of 1498 FSW who attended a detection centre for human immunodeficiency virus (HIV) in Mexico City, between January and October 1992. Study participants responded to a standardised questionnaire and provided a blood sample for serology of syphilis, HIV, and HBV. RESULTS: A total of 0.2% (95% CI 0.1-0.3) of the population were hepatitis B surface antigen (HBsAg) carriers. The general prevalence of antibodies to hepatitis B core antigen (anti-HBc) was 6.3% (95% CI 5.5-7.1). This marker of previous exposition to HBV, was independently associated by logistic regression multivariate analysis with age, working in the street, and history of blood transfusion (BT) before 1987 (OR 4.8, 95% CI 2.1-11.3). Syphilis prevalence was 7.6% (95% CI 6.2-8.9) and HIV prevalence was 0.1% (95% CI 0-0.3). CONCLUSIONS: The prevalence of HBV infection in this group of Mexican FSW is lower than previously reported in other countries. In addition, the frequency of HBsAg carriers is similar to that in the general Mexican population. The absence of two major risk factors for HBV transmission in this group of FSW--that is, injecting drug use and anal intercourse, could help to explain this finding. However, the positive association between anti-HBc and history of blood transfusion demonstrated here, highlights the need to reinforce strict control of blood supplies in Mexico.  (+info)

(6/196) Cluster of HIV-positive young women--New York, 1997-1998.

As of July 1997, six human immunodeficiency virus (HIV) infections in young women who reported sexual contact with the same HIV-infected man (putative index case-patient) were detected at health-service clinics in a rural county in upstate New York. During the next several months, other sexual contacts of the man were discovered by public health officials through routine voluntary partner notification interviews, interviews with exposed women, and after a public announcement resulted in counseling and testing of approximately 1400 persons in the county. This report presents epidemiologic and laboratory findings of the young women investigated as part of this cluster and suggests a common source of HIV infection for these women.  (+info)

(7/196) A theoretical model of the evolution of virulence in sexually transmitted HIV/AIDS.

INTRODUCTION: The evolution of virulence in host-parasite relationships has been the subject of several publications. In the case of HIV virulence, some authors suggest that the evolution of HIV virulence correlates with the rate of acquisition of new sexual partners. In contrast some other authors argue that the level of HIV virulence is independent of the sexual activity of the host population. METHODS: Provide a mathematical model for the study of the potential influence of human sexual behaviour on the evolution of virulence of HIV is provided. RESULTS: The results indicated that, when the probability of acquisition of infection is a function both of the sexual activity and of the virulence level of HIV strains, the evolution of HIV virulence correlates positively with the rate of acquisition of new sexual partners. CONCLUSION: It is concluded that in the case of a host population with a low (high) rate of exchange of sexual partners the evolution of HIV virulence is such that the less (more) virulent strain prevails.  (+info)

(8/196) In vitro inactivation of Chlamydia trachomatis and of a panel of DNA (HSV-2, CMV, adenovirus, BK virus) and RNA (RSV, enterovirus) viruses by the spermicide benzalkonium chloride.

Kinetics of inactivation by the detergent spermicide benzalkonium chloride (BZK) of Chlamydia trachomatis and of a panel of DNA viruses [herpes simplex virus hominis type 2 (HSV-2), cytomegalovirus (CMV), adenovirus (ADV) and BK virus (BKV)] and RNA [respiratory syncytial virus (RSV) and enterovirus (ENV)] were established in accordance with a standardized in vitro protocol. After a 5 min incubation, inactivation of >95% of HSV-2 and CMV was obtained at a concentration of 0.0025% (w/v) (25 Ig/L); concentrations as low as 0.0005%, 0.0050% and 0.0125%, induced a 3.0 log10 reduction in infectivity of HSV-2 and CMV, RSV and ADV, respectively. After a 60 min incubation, concentrations of 0.0125% and 0.050% provided a 3.0 log10 reduction in infectivity of ENV and BKV, respectively. These features indicate that sensitivity to BZK was very high (HSV-2 and CMV) or high (RSV) for enveloped viruses, intermediate (ADV) or low (ENV and BKV) for non-enveloped viruses. Furthermore, BZK had marked antichlamydial activity, showing >99% killing after only a 1 min incubation at a concentration of 0.00125%. BZK demonstrates potent in vitro activity against the majority of microorganisms causing sexually transmitted infectious diseases, including those acting as major genital cofactors of human immunodeficiency virus transmission. These attributes qualify BZK as a particularly attractive candidate for microbicide development.  (+info)