Topical microbicides. Current status and research considerations for adolescent girls

Qualitative Study on the Acceptability of and Adherence to a Vaginal Ring for HIV Prophylaxis Among Adolescent Girls

OBJECTIVE

This study aims to assess the product-related, relationship-related, and sex-related factors that act as facilitators and barriers to the acceptability of a vaginal ring (VR) for HIV prevention among adolescent girls.

DESIGN

Qualitative study.

METHODS

Ninety-six girls aged 15-17 years from 6 urban US sites were enrolled in MTN-023/IPM 030, a 24-week randomized controlled trial, for assessing the safety and acceptability of a dapivirine VR for HIV prevention. At week 24, 21 girls were randomly selected to participate in in-depth interviews. Interviews were transcribed verbatim and data analyzed using a thematic analysis approach. Facilitators and barriers to VR acceptability related to participants' relationships, sexual activity, and characteristics of the VR product were identified.

RESULTS

Factors related to relationships rarely seemed to act as barriers to VR acceptability; most participants disclosed VR use to sexual partners, and positive reactions from sexual partners, which were common, seemed to facilitate VR acceptability. Emotional and/or physical discomfort surrounding VR use during sex was mentioned occasionally as a barrier to VR acceptability. Product characteristics were most frequently mentioned as barriers to VR acceptability. Many participants reported concerns about the large size of the VR on first impression. Although most found the VR comfortable, some reported pain with VR insertion. Several participants were concerned about VR cleanliness, particularly during menstruation.

CONCLUSION

Product considerations, specifically size and use during menstruation, were the most commonly reported barriers to VR acceptability in this study. Adolescent girls may require additional counseling to assuage product concerns regarding a VR for HIV prevention.

Adolescent and Parent Willingness to Participate in Microbicide Safety Studies

STUDY OBJECTIVE

To understand adolescents' and parents' willingness to participate (WTP) in a hypothetical phase I prevention study of sexually transmitted infections, discordance within adolescent-parent dyads, and expectations of each other during decision-making.

DESIGN AND SETTING

Adolescent-parent dyads were recruited to participate in a longitudinal study about research participation attitudes.

PARTICIPANTS

Adolescents (14-17 years old) and their parents (n = 301 dyads) participated.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Individual interviews at baseline assessed WTP on a 6-level Likert scale. WTP was dichotomized (willing/unwilling) to assess discordance.

RESULTS

WTP was reported by 60% (182 of 301) of adolescents and 52% (156 of 300) of parents. In bivariate analyses, older adolescent age, sexual experience, and less involvement of parents in research processes were associated with higher level of WTP for adolescents; only sexual experience remained in the multivariable analysis. For parents, older adolescent age, perceived adolescent sexual experience, and conversations about sexual health were significant; only conversations remained. Dyadic discordance (44%, 132 of 300) was more likely in dyads in which the parent reported previous research experience, and less likely when parents reported higher family expressiveness. Adolescents (83%, 248 of 299) and parents (88%, 263 of 300) thought that the other would have similar views, influence their decision (adolescents 66%, 199 of 300; parents 75%, 224 of 300), and listen (adolescents 90%, 270 of 300; parents 96%, 287 of 300). There were no relationships between these perceptions and discordance.

CONCLUSION

Inclusion of adolescents in phase I clinical trials is necessary to ensure that new methods are safe, effective, and acceptable for them. Because these trials currently require parental consent, strategies that manage adolescent-parent discordance and support adolescent independence and parental guidance are critically needed.

Parents' and Adolescents' Attitudes about Parental Involvement in Clinical Research

STUDY OBJECTIVE

To understand parent and adolescent attitudes toward parental involvement during clinical trials and factors related to those attitudes.

DESIGN

As part of a study on willingness to participate in a hypothetical microbicide study, adolescents and their parents were interviewed separately.

SETTING

Adolescent medicine clinics in New York City.

PARTICIPANTS

There were 301 dyads of adolescents (ages 14-17 years; 62% female; 72% Hispanic) and their parents.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The interview included questions on demographic characteristics, sexual history, and family environment (subscales of the Family Environment Scale) that were associated with attitudes about parental involvement.

RESULTS

Factor analysis of the parental involvement scale yielded 2 factors: LEARN, reflecting gaining knowledge about study test results and behaviors (4 items) and PROCEDURE, reflecting enrollment and permissions (4 items). Adolescents endorsed significantly fewer items on the LEARN scale and the PROCEDURE scale indicating that adolescents believed in less parental involvement. There was no significant concordance between adolescents and their own parents on the LEARN scale and the PROCEDURE scale. In final multivariate models predicting attitudes, adolescents who were female and had sexual contact beyond kissing, and non-Hispanic parents had lower LEARN scores. Adolescents who were older, had previous research experience, and reported less moral or religious emphasis in their family had lower PROCEDURE scores; there were no significant predictors for parents in the multivariate analyses.

CONCLUSION

Parents wanted greater involvement in the research process than adolescents. Recruitment and retention might be enhanced by managing these differing expectations.

Nano-microbicides: challenges in drug delivery, patient ethics and intellectual property in the war against HIV/AIDS

As we continue to be embroiled in the global battle against the human immunodeficiency virus (HIV), there has been an ongoing evolution in the understanding of the molecular mode of sexual transmission of HIV. This has gone hand-in-hand with a paradigm shift and research focus on the development of microbicides - compounds designed for vaginal (and possibly rectal) administration that are envisaged to put safe, affordable and accessible protection into the hands of women. However, an effective microbicide is not yet available; innovative approaches for the design of topical vaginal microbicides are urgently needed. The potential of the advancing field of nanomedicine has been earmarked in the increasing efforts to address the major health problems of the developing world. In this review, advances in the design of innovative microbicide nanocarriers and nano-enabled microbicides, henceforth referred to as 'nano-microbicides', are presented; elaborating on nanotechnology's role in the antiviral arena. The role of nanotechnology in the antiviral arena and the unique issues facing the generation of intellectual property relating to nano-microbicides in the ongoing global 'tug-of-war' of 'patients versus patents' are also explicated.

Pharmaceutical development of microbicide drug products

HIV infection rates in the developing world remain a serious problem. One potential approach to reduce infection rates is to use products known as microbicides, referred to herein as microbicide drug products (MDPs). These are drugs capable of, when administered topically to the vagina (or rectum), interfering with infection by one or more mechanisms. This review article covers the latest pharmaceutical developments in the area of microbicides dosage forms and delivery systems. These products are principally designed for use in the developing world and must therefore address cultural and societal issues generally unknown in the developed world. The first-generation microbicides evaluated clinically were principally polyanions. These drugs, administered intravaginally as gels, were found to be ineffective in preventing transmission of HIV from men to women. Second-generation drugs such as tenofovir, dapivirine, and UC781 are reverse transcriptase inhibitors developed as gels formulations and intravaginal rings (IVRs). Gels are considered coitally-related products while IVRs are coitally-independent systems designed to release the drug over a four-week period or possibly longer (up to 3 or 4 months). Other dosage forms under development include fast dissolving films, tablets/capsules, and possibly vaginal sponges. Dual protection systems are also under development. These systems include formulations capable of preventing HIV infection along with a second drug capable of preventing conception or other viral infections such as HSV.

Importance of drug resistance in gonococci: from mechanisms to monitoring

Neisseria gonorrhoeae isolates continue to develop an impressive arsenal of resistance mechanisms to antimicrobial agents, including resistance to some of the antibiotics presently recommended for the treatment of gonococcal infections.

Preclinical safety assessments of UC781 anti-human immunodeficiency virus topical microbicide formulations

The nonnucleoside reverse transcriptase inhibitor UC781 is under development as a potential microbicide to prevent sexual transmission of human immunodeficiency virus type 1 (HIV-1). Two gel formulations of UC781 (0.1% and 1.0%) were evaluated in a range of preclinical safety assessments, including systemic absorption analysis following topical application in the pig-tailed macaque models for vaginally and rectally applied topical microbicides. High-sensitivity high-performance liquid chromatography analysis of serum samples showed that no systemic absorption of UC781 was detected after repeated vaginal or rectal application of either product. However, high levels of UC781 were detectable in the cervicovaginal lavage samples up to 6 h after product exposure. Both formulations were safe to the vaginal microenvironment, even with repeated daily use, as evidenced by colposcopy, cytokine analysis, and lack of impact on vaginal microflora. By contrast, rectal application of the 1.0% UC781 formulation caused an increased expression of numerous cytokines not observed after rectal application of the 0.1% UC781 formulation. These results provide additional support for the continued development of UC781 formulations as anti-HIV microbicides.

Adolescents' descriptions of the physical characteristics of microbicide surrogates and experiences of use

PURPOSE

Our purpose was to describe adolescent girls' perceptions of microbicide surrogates and experiences of use, including impact on sexual pleasure.

METHODS

Sexually experienced girls, 14-21 years, were recruited for a study examining microbicide acceptability. The girls were given vaginal moisturizers (gel or suppository) to use as if they were microbicides. Girls (n = 175) discussed their perceptions and experiences of use of these products in response to semistructured interviews. Girls were asked at weekly phone interviews about the impact of product use on their and their partners' sexual pleasure. These answers were averaged, and girls were categorized into those for whom the product predominantely made sex feel worse, better less than half the time, or better half the time or more. The relationship of demographics and sexual history to the impact on pleasure was evaluated.

RESULTS

Overall, participants were positive about their experience with the products. More girls preferred the gel. Specific concerns about the suppository included the wait period, texture, and messiness of self-insertion. Many liked the lubricating quality of both of the surrogates. Girls discussed messiness, leakage, clumping, and the difficulties in communicating with partners. Over half reported an increase in pleasure most of the time for themselves and their partners. None of the demographic and sexual history predictors were significantly related to impact on pleasure.

CONCLUSIONS

Anticipatory guidance should help girls initiate and sustain use. Future research should examine the best way to accomplish counseling about microbicide use with adolescent girls.

Adolescent girls' communication with "mothers" about topical microbicides

STUDY OBJECTIVE

Topical microbicides, a female-initiated method to protect against sexually transmitted infections (STI) and pregnancy, will only be effective if found acceptable. Mothers may have an influence on acceptability and use among adolescent girls. The current study examined the communication between girls and mothers to understand the potential predictors and nature of conversations regarding surrogate microbicide products.

DESIGN

Sexually experienced girls, 14 to 21 years, were recruited for a 6-month study examining microbicide acceptability. During face-to-face interviews, qualitative data were collected regarding communication between girls and mothers. Two independent raters coded the responses, which were organized into themes. Themes were interpreted according to the conceptual understanding of mother-daughter communication.

RESULTS

Fifty percent of the 171 girls with codable responses had a conversation with their mother. Higher levels of indirect parental monitoring were related to being more likely to have a conversation. Concrete events related to the study (i.e. receiving phone call from the researcher, having an appointment, or seeing the product) or inquiries by mothers appeared to promote conversation. Barriers to conversation included the private nature of the information and relationship issues between the mother and daughter. Conversations often addressed issues related to girls' participation in the study, although some conversations included global issues related to sexuality.

CONCLUSIONS

Girls may talk to their mothers about new products for STI prevention, and such conversations may provide opportunities to promote use.

Adolescent issues associated with knowledge of and access to topical microbicides

PURPOSE

Topical microbicides could be a female-controlled method for prevention of sexually transmitted diseases (STDs). Microbicides could offer girls a potential preventive option, if they are able to access them. The purpose of this investigation was to evaluate girls', mothers', experienced healthcare providers', and medical students' views on adolescent girls' obtaining information about and acquiring microbicides and where adolescent girls would keep or carry a microbicide.

METHODS

Focus groups were conducted and videotaped with each group of individuals. The videotapes were transcribed, and the transcriptions were coded for relevant themes.

RESULTS

Participants anticipated that adolescents would learn about microbicides from a variety of sources and that specific educational efforts for each of these sources (mothers, healthcare providers, and school-based sexuality education) would be needed. Healthcare providers stressed the importance of enhancing access by having both prescription and over-the-counter (OTC) options. For nonprescription products, the participants felt that the microbicide should be in stores and venues to which adolescents typically go by themselves. A microbicide that was girl-friendly and adolescent-friendly consistently was highlighted by the participants. Participants thought this would increase discretion and decrease embarrassment. The location of keeping and carrying the microbicide was anticipated to be dependent on parents' knowledge of their adolescent's sexuality and the likelihood that parents search their adolescent's belongings.

CONCLUSIONS

Consideration of the adolescent-specific issues in the design of microbicides and marketing strategies may be crucial for adolescent adoption of this female-controlled method.

Prevention of HIV-1 infection by platinum triazines

To identify and explore the activity of compounds which may act as anti-HIV virucidal agents, we have investigated platinum compounds, especially those containing N-donor aromatic ligands. After screening over 70 related agents, including N-donor aromatic ligands and metal precursors, we have identified a novel class of platinum(II) complexes with 2-pyridyl-1,2,4-triazine derivatives and Pt(II) formulations with these derivatives (ptt compounds) as having the highest anti-HIV activity. The maximum activity was observed when the agents were added immediately post-infection. The ptt agents did not block cell fusion activity of HIV-1 Env proteins in cells bearing CD4X4 or CD4R5 receptors, indicating a lack of interaction with the Env protein. The ptt compounds exhibit low toxicity for human epithelial cells, and are thus promising candidates for use as microbicides or antiviral agents against HIV.

Blocking of cell-free and cell-associated HIV-1 transmission through human cervix organ culture with UC781

OBJECTIVE

To determine the efficacy of UC781 in preventing HIV-1 transmission through cervical tissue.

DESIGN

Use of human cervical tissue organ culture, in which the cervix is in the upper chamber of a transwell and transmission of infective virus is quantified in the lower chamber.

METHODS

Five-millimeter pieces of cervical tissues are exposed to UC781. After thorough removal of the drug, the tissues are exposed to high doses of cell-free or cell-associated HIV-1. Transmission of HIV-1 through the cervix is measured by determining infection of target cells in the lower chamber.

RESULTS

Exposure of cervix to 0.5 microM UC781 for 30 min, followed by extensive washing away of the residual drug, resulted in 95% reduction of subsequent viral transmission. Exposure of the cervix to 1 microM UC781 for 20 min, or 10 microM UC781 for 2 min, resulted in neutralization of T- and M-tropic HIV-1 isolates of various clades, and prevention of cell-associated HIV-1 transmission. Moreover, a 20 min incubation with 10 microM UC781 abolished HIV-1 transmission through the cervix for 48 h after drug pretreatment. Importantly, UC781 was not toxic, even when the cervical tissues were exposed to 20 microM UC781 for 24 h. UC781 was effective against transmission of both cell-free and cell-associated HIV-1 also when formulated into a non-spermicidal (Replen) or spermicidal (BufferGel) gel.

CONCLUSIONS

Exposure of the cervix to UC781 results in blocking of subsequent HIV-1 transmission with no toxicity. Therefore, UC781 is an excellent candidate microbiocide.

Recombinant Streptococcus gordonii for mucosal delivery of a scFv microbicidal antibody

The gram-positive bacterium Streptococcus gordonii was engineered to express the microbicidal molecule H6, which is an antiidiotypic single chain antibody mimicking a yeast killer toxin. S. gordonii is a human commensal which we developed as a model system for mucosal delivery of heterologous proteins. The in vivo candidacidal activity of both H6-secreting and H6-surface-displaying streptococcal strains were assayed in a well-established rat model of vaginal candidiasis. At day 21 full clearance of Candida albicans infection was observed in 75% of animals treated with the H6-secreting strain, and in 37.5% of animals treated with the strain expressing H6 on the surface, while all animals treated with the control strain were still infected. The observed candidacidal effect was comparable with that observed with the antimycotic drug fluconazole. These data confirm the potential of H6 as a candidacidal agent and show how promising is the approach of using recombinant bacteria for mucosal delivery of biologically active molecules.

Tailoring clinical management practices to meet the special needs of adolescents: sexually transmitted infections

Sexually transmitted infections are a major health risk to all sexually active adolescents and improving clinical management for this age group is of major importance. Currently, adolescents are managed in the same way as adults. This paper summarizes recommendations by the World Health Organization that services be more responsive to adolescent concerns about confidentiality, risk assessment be more attuned to their sexual behavioral patterns, and services be tailored to give more time for counseling, assessment of stage of maturity and continuity of reproductive health care.

Thermoreversible gel as a candidate barrier to prevent the transmission of HIV-1 and herpes simplex virus type 2

BACKGROUND

Sexually transmitted diseases (STDs) caused by HIV, herpes simplex virus (HSV), and other pathogens are spreading dramatically. The need to develop active products and vehicles to reduce this epidemic is urgent.

GOAL

The efficacy of a thermoreversible gel formulation as a possible barrier to prevent the transmission of pathogens causing STDs was evaluated.

STUDY DESIGN

This evaluation investigated the ability of the gel formulation to prevent infection of susceptible cells by HIV-1 and HSV-2 in vitro, the diffusion of radiolabeled herpes virus and micelles of polymer through an insertion membrane, and the electron microscopic appearance of herpes virus and gel alone or mixed together.

RESULTS

The gel formulation prevents infection of susceptible cells by HIV-1 and HSV-2. It acts as an effective artificial physical barrier against the herpes virus within the first 4 hours of incubation. Herpes virus is coated by the gel or entrapped within micelles of the gel, which could hinder its attachment to target cells and inhibit its infectivity.

CONCLUSION

This thermoreversible gel formulation represents an attractive matrix for the incorporation of microbicides to prevent the spread of STDs.

Interventions against sexually transmitted infections (STI) to prevent HIV infection

STIs have taken on a more important role with the advent of the HIV/AIDS epidemic, and there is good evidence that their control can reduce HIV transmission. The challenge is not just to develop new interventions, but to identify barriers to the effective implementation of existing tools, and to devise ways to overcome these barriers. This 'scaling-up' of effective strategies will require an international and a multisectoral approach. It will require the formation of new partnerships between the private and public sectors and between governments and the communities they represent.

Candidate microbicides block HIV-1 infection of human immature Langerhans cells within epithelial tissue explants

Initial biologic events that underlie sexual transmission of HIV-1 are poorly understood. To model these events, we exposed human immature Langerhans cells (LCs) within epithelial tissue explants to two primary and two laboratory-adapted HIV-1 isolates. We detected HIV-1(Ba-L) infection in single LCs that spontaneously emigrated from explants by flow cytometry (median of infected LCs = 0.52%, range = 0.08-4.77%). HIV-1-infected LCs downregulated surface CD4 and CD83, whereas MHC class II, CD80, and CD86 were unchanged. For all HIV-1 strains tested, emigrated LCs were critical in establishing high levels of infection (0.1-1 microg HIV-1 p24 per milliliter) in cocultured autologous or allogeneic T cells. HIV-1(Ba-L) (an R5 HIV-1 strain) more efficiently infected LC-T cell cocultures when compared with HIV-1(IIIB) (an X4 HIV-1 strain). Interestingly, pretreatment of explants with either aminooxypentane-RANTES (regulated upon activation, normal T cell expressed and secreted) or cellulose acetate phthalate (potential microbicides) blocked HIV-1 infection of LCs and subsequent T cell infection in a dose-dependent manner. In summary, we document HIV-1 infection in single LCs after exposure to virus within epithelial tissue, demonstrate that relatively low numbers of these cells are capable of inducing high levels of infection in cocultured T cells, and provide a useful explant model for testing of agents designed to block sexual transmission of HIV-1.

Therapy of mucosal candidiasis by expression of an anti-idiotype in human commensal bacteria

Two recombinant strains of Streptococcus gordonii, secreting or displaying a microbicidal single-chain antibody (H6), and stably colonizing rat vagina, were used to treat an experimental vaginitis caused by Candida albicans. A post-challenge intravaginal delivery of the H6-secreting strain was as efficacious as fluconazole in rapidly abating the fungal burden. Three weeks after challenge, 75% and 37.5% of the rats treated with the H6-secreting or displaying bacteria, respectively, were cured of the infection, which persisted in 100% of the animals treated with a S. gordonii strain expressing an irrelevant single-chain antibody. Thus, a human commensal bacterium can be suitably engineered to locally release a therapeutic antibody fragment.

Dendrimers, a new class of candidate topical microbicides with activity against herpes simplex virus infection

Dendrimers are large highly branched macromolecules synthesized from a polyfunctional core. They have shown a variety of biological properties, including, in some instances, antiviral activity. In this study, five dendrimers were evaluated for in vitro activity against herpes simplex virus (HSV) types 1 and 2 by cytopathic effect (CPE) inhibition and plaque reduction (PR) assay in human foreskin fibroblast cells. All of the compounds were active against both virus types in the CPE inhibition assay, in which drug was added to the cells prior to the addition of virus. Antiviral activity was reduced or lost in the PR assays, in which the cells were incubated with the virus before the drug was added. The prophylactic efficacy suggested that the dendrimers might have potential as topical microbicides, products intended to be applied to the vaginal or rectal mucosa to protect against sexually transmitted infections. Three dendrimers were evaluated for this application against genital HSV infection in mice. Two of the compounds, BRI-2999 and BRI-6741, significantly reduced infection rates when 15 microl of a 100-mg/ml solution was administered immediately prior to intravaginal challenge, and the most effective compound, BRI-2999, provided significant protection even when applied 30 min before challenge. This is the first report of microbicidal activity by dendrimers in vivo.

Clinical management and prevention of sexually transmitted diseases: a review focusing on women

This review highlights some of the difficulties inherent in controlling sexually transmitted diseases (STDs) in developing countries--especially amongst women. Considerable efforts have been made to improve the syndromic approach to STD management but the poor performance of the algorithm for managing vaginal discharge limits the effectiveness of this strategy. The facilitating role of the human immunodeficiency virus (HIV) has been the main impetus to STD control rather than reduction of morbidity in women, especially pregnant women and their children. There are no easy solutions--but action on several fronts, with more attention to core groups, men and adolescents is indicated.

Sexually transmitted infections in teenagers

Prevention of sexually transmitted infection in teenagers is a high priority. The introduction of non-invasive methods for diagnostic testing of Chlamydia trachomatis and Neisseria gonorrhoeae has enabled screening for these sexually transmitted micro-organisms in a range of community-based settings among populations at high risk, such as teenagers, who do not readily access existing sexual health services.

In vitro and in vivo evaluations of sodium lauryl sulfate and dextran sulfate as microbicides against herpes simplex and human immunodeficiency viruses

The efficacy of sodium lauryl sulfate (SLS), a sulfated anionic chaotropic surfactant, and dextran sulfate (DS), a polysulfated carbohydrate, against herpes simplex virus (HSV) and human immunodeficiency virus (HIV) infections was evaluated in cultured cells and in different murine models of HSV infection. Results showed that both SLS and DS were potent inhibitors of the infectivities of various HSV-1 and HSV-2 strains. Pretreatment of HIV-1 (strain NL4-3) with SLS also reduced its infectivity to 1G5 cells. DS prevented the binding of HSV to cell surface receptors and therefore its entry into cells. Pretreatment of HSV-1 (strain F) with 50 microM SLS resulted in a complete loss of virus infectivity to Vero cells. However, viruses were able to enter into cells and to produce in the nuclei capsid shells devoid of a DNA core. The amount of the glycoprotein D gene produced in these cells remained unchanged compared to controls, suggesting that SLS could interfere with the maturation of the virus. At a higher SLS concentration (100 microM), HSV was highly damaged by SLS pretreatment and only a few viral particles could enter into cells to produce abnormal capsids. Although DS was a more potent inhibitor of HSV infectivity in vitro, it was unable to provide any protection in murine models of HSV infection. However, SLS conferred a complete protection of animals infected cutaneously with pretreated viruses. In addition, skin pretreatment of mice with a polymer formulation containing SLS completely prevented the development of cutaneous lesions. More interestingly, intravaginal pretreatment of mice with SLS in a buffered solution also completely protected against lethal HSV-2 infection. Taken together, our results suggest that SLS could thus represent a candidate of choice as a microbicide to prevent the sexual transmission of HIV, HSV, and possibly other pathogens that cause sexually transmitted diseases.

Locus of control for general health and STD acquisition among adolescent girls

PURPOSE

To examine adolescent girls' perception of control over general health and sexually transmitted disease (STD) acquisition.

METHODS

Adolescents participating in a longitudinal study were asked questions regarding their perception of their locus of control. These questions, adopted from a previous measure, focused on six loci: internal control, control by parents, partners, peers, and health care providers, and chance.

RESULTS

There were 128 girls (mean age, 17 years; range, 14.5 to 18.8); 82% were black and 18% white. Statistically significant associations were found between control of general health and STD acquisition for each locus of control subscale, with the exception of partner control. However, the girls reported significantly less control over STD acquisition than over general health for health care providers, parents, and by chance, and significantly more partner and internal control over STD acquisition than general health. The correlations between parental control over general health and over STD acquisition were inversely correlated with age. Partner control was positively related to current condom use, but internal control was not.

CONCLUSIONS

The degree of the locus of control was specific for STD acquisition. Girls who believe they should be able to control STD acquisition may not be using condoms. The view of partners as having control over STD acquisition may represent joint communication or coercion. However, in general these findings support the development of female-controlled methods for STD prevention, such as topical microbicides.

Plant products as topical microbicide candidates: assessment of in vitro and in vivo activity against herpes simplex virus type 2

There is considerable interest in developing topical microbicides; products to be used intravaginally by women for protection against sexually transmitted diseases. Many compounds derived from plants have been shown to have antimicrobial properties. We examined 19 such compounds in vitro by plaque reduction assay to determine their activity against a common sexually transmitted pathogen, herpes simplex virus type 2. Compounds with an ED50 < or = 7.0 mg/ml were tested for efficacy in vivo. Four compounds, carrageenan lambda type IV, cineole, curcumin, and eugenol, provided significant protection (P < 0.05) in a mouse model of intravaginal HSV-2 challenge. Eugenol, which provided the greatest protection in mice was also evaluated using the guinea pig model of genital HSV-2 infection where it also demonstrated significant protection. Based on these results, several plant-derived compounds appear to warrant further evaluation as potential microbicides.

Effect of undecylenic acid as a topical microbicide against genital herpes infection in mice and guinea pigs

There is increasing interest in the use of topical microbicides to help prevent the spread of sexually transmitted diseases (STD). Undecylenic acid (UA), a monosaturated fatty acid, is the active ingredient in a number of over-the-counter (OTC) antifungal spray powders, that also exhibits in vitro antibacterial and antiviral activity, including herpes simplex virus (HSV) activity. We, therefore, evaluated UA as a topical microbicide against genital HSV infection using the murine and guinea pig models of genital herpes. Mice were administered a 20% solution of UA in polyethylene glycol (PEG) vehicle, vehicle alone or phosphate buffered saline (PBS) intravaginally immediately prior to vaginal challenge with HSV-2. Pre-treatment with UA decreased the number of mice that became infected (P < 0.001 vs. PBS or vehicle control), developed symptoms (P <0.001) or died (P <0.001). However, when treatment was extended to either 5 min prior to or after viral inoculation, protection was lost. Similar findings were found using the guinea pig model, where UA treatment completely prevented HSV-2 vaginal infection when given immediately prior to HSV-2 inoculation (P<0.001 vs. PBS or vehicle control). Thus, UA, an approved OTC medication, provided significant protection against HSV disease and infection only when applied immediately before viral inoculation, indicating that better formulations were needed to extend the duration of protection.