++
Risk assessment in WSW should begin the way all STD-related risk
assessment begins in every patient: with a thorough sexual history.
Most importantly, providers should not make assumptions about sexual
practices based on the patient’s self-reported identity—in
this case, specifically, as a lesbian. Assuming that a self-identified
lesbian has not previously been or is not currently sexually active
with men is usually incorrect. In one study, 74% of self-identified
lesbians had male partners in the past, and of self-identified bisexual
women, 98% had prior or current male partners. Among lesbians
recruited for studies in Seattle, 80–86% reported
prior sex with men, 23–28% had had sex with a
man in the last year, and the median number of male and female lifetime partners
was the same. In a sample of women evaluated at a London STD clinic,
69% of those identifying as lesbian had prior male partners,
and at another London clinic specializing in the sexual health of
lesbians, 91% had prior male partners. Heterosexual intercourse
transmits the full range of STDs, some of which (notably, chronic
viral infections, including HPV, genital herpes, hepatitis B virus,
and HIV) may remain undetected for years.
++
Important components of the sexual history include number of
recent (prior 2 months and 1 year) and lifetime sexual partners,
both male and female. Other key components should include types
of sexual practices that could pose a risk of transmission of STDs.
Some sexual practices—including oral-genital sex; vaginal
or anal sex using hands, fingers, or penetrative sex toys; and oral-anal sex—are
practiced commonly between female sex partners. Practices involving
digital-vaginal or digital-anal contact, particularly with shared
penetrative sex toys, present a plausible means for transmission
of infected cervicovaginal secretions.
++
In several studies, women who report sex with both men and women
report more sex partners over their lifetimes than women who have
sex exclusively with either men or women. One population-based survey
in low-income neighborhoods found that women who had sex with men
only reported a mean of 16 lifetime partners, whereas women reporting
sex with men and women reported a mean of 307 lifetime partners.
Similarly, among patients attending an STD clinic in Seattle, women
with only female partners in the previous 2 months reported 3.4
partners in the past year; women with only male partners, 5.3 partners
in the past year; and women with male and female partners, 16.5
partners in the past year. Women who report sex with both men and
women are likely to be at higher risk for STDs than women who report
sex with women or men only.
++
WSW may have male partners who are at higher risk for HIV and
STDs than the partners of women who have sex with men only. In one
study of patients at an STD clinic, 10% of women who had
sex with only women in the previous 2 months had a prior male partner
who was gay or bisexual, compared with 6% of women reporting
sex with men only. Of women reporting sex with both men and women
in the prior 2 months, 29% had a prior gay or bisexual
male partner. Women who reported sex with both men and women in
the previous 2 months were also more likely than women who had sex
with only men or only women to have had more than four male sexual
partners in a year, more likely to exchange sex for money or drugs,
and more likely to have used intravenous drugs. In summary, lesbian
and bisexual women may have past or current sex partners at high
risk for HIV and other STDs.
Mosher WD, Chandra A, Jones J. Sexual behavior
and selected health measures: Men and women 15–44 years
of age, United States, 2002.
Adv Data 2005;(362):1–55.
[PubMed: 16250464]
(Among 12,571 respondents in this national sample,
11% of women reported having had a sexual experience with
another woman. The proportion of women who had a female sex partner
in the past year was 4.4%, representing approximately 2.71 million
women in the United States.)
Scheer S, Peterson I, Page-Shafer K, et al; Young Women’s
Survey Team. Sexual and drug use behavior among women who have sex
with both women and men: Results of a population-based survey.
Am J Public Health 2002;92:1110–1112.
[PubMed: 12084692]
(Population-based study in five northern California counties
describing sexual risk behaviors, STDs, and HIV infection in women
who have sex with women and men.)
+++
Risk Reduction Counseling
++
No studies have directly addressed the acceptability or efficacy
of STD risk reduction interventions among WSW. However, measures
that reduce the potential for transmission of cervicovaginal secretions
are likely to be effective in reducing STD transmission.
++
For women who practice digital-vaginal or digital-anal sex (hands
or fingers in partner’s vagina or anus), the risk is probably
low unless secretions are actually transferred on the hands from
the infected partner to the other. Interrupting this progression
by avoiding the behavior or by using and removing gloves after contact
is likely effective.
++
For minimizing transfer of infected secretions associated with
insertive sex toys, several approaches are likely effective. These
include minimizing sharing of unclean sex toys (either not sharing
toys at all or cleaning them between use by one partner and the
other), use of condoms on sex toys, and avoiding use of sex toys
anally and vaginally in succession.
++
With regard to oral sex and STDs, WSW may be at increased risk
of genital herpes infection with herpes simplex virus type 1 (HSV-1)
due to a relatively higher frequency of orogenital sex. Serologic
screening for HSV-1 is not useful to screen for potential infectiousness,
because most adults are infected with HSV-1 orally, and serology
does not distinguish between oral and genital infection. However,
women should be counseled to avoid performing oral sex when lesions
consistent with an oral herpes outbreak (eg, a cold sore, recurrent
ulcer, or vesicle) are evident or if a recognizable prodrome (eg,
ear pain or local lymphadenopathy) is underway.
++
Other important components of complete risk reduction counseling
for all patients include a discussion of sex partner selection,
sexual network assessment, and the patient’s ability to
negotiate safer sex practices. More detailed information can be
found in Chapter 27.
+++
Screening of Asymptomatic Patients
++
Laboratory evaluation for STDs in WSW should closely mirror that
for heterosexual women. With regard to STD screening of asymptomatic
women without clinical findings, WSW should be screened for Chlamydia trachomatis as recommended
by current screening guidelines (annually up to age 25 years or
older, depending on risk). Although no data are available to estimate
the risk of chlamydia transmission between women, chlamydial infection
and pelvic inflammatory disease have been reported by WSW surveyed;
further, WSW may engage in sexual networks that involve men, as
previously noted, and may not be aware of their female partners’ exposure
to men. No cases of gonorrhea transmission between women have been
documented; given the relatively low prevalence of this STD in many clinical
settings, routine screening for gonorrhea in asymptomatic WSW without
relevant clinical symptoms is not indicated.
++
Other STDs in WSW deserve comment, but should not be sought in
asymptomatic women who report no contact with a male or female partner
with an STD. Each should be considered in the relevant clinical
setting (eg, complaint of abnormal vaginal discharge or of genital
ulcers).
+++
Patients with Abnormal Vaginal Discharge
++
Bacterial vaginosis is highly prevalent among WSW and has been the
most common diagnosis in WSW evaluated at STD clinics (frequently,
it is more common in WSW than in heterosexual women at those clinics).
Risks for bacterial vaginosis among WSW include a higher number
of lifetime female sex partners, having a female sex partner with
bacterial vaginosis, use of a shared vaginally inserted sex toy,
and receptive oral-anal sex. The exact cause of bacterial vaginosis
is unknown, but these data suggest that some factor that promotes
or causes this enigmatic condition may be transmissible between
women during sex. Whether female partners of women diagnosed with
bacterial vaginosis should be routinely tested and treated is not
known. One reasonable approach is to test a woman’s partner
for bacterial vaginosis if she is symptomatic, or if the infection
in the index case is recurrent, because treatment of the partner
might theoretically effect a higher cure rate in the index case.
However, the latter approach has not been studied.
++
Other etiologies of abnormal vaginal discharge include infection
with
Trichomonas vaginalis,
which has been self-reported in surveys by women with no history
of prior sex with men and has also been reported as metronidazole-resistant
trichomoniasis in both members of a monogamous lesbian couple. These
data, along with the plausibility of transmitting vaginal fluid
through the sexual practices of WSW, strongly support the conclusion
that this infection can be transmitted in this manner.
+++
Patients with Genital Lesions or Ulcers
+++
Human Papillomavirus Infection
++
HPV, a group of viruses that causes anogenital warts and cervical
cancer, may be transmissible between women by skin-to-skin contact,
digital-genital contact, and use of shared sex toys. Women who report
never having sexual contact with men have been found to have vulvar
warts, cervical neoplasia associated with HPV, and high-risk (associated
with oncogenic risk) HPV DNA by genetic testing (polymerase chain
reaction). In one study, HPV DNA was detected by genetic probe in
19% of women who had no prior sexual contact with men,
and 14% had cervical dysplasia. Anogenital warts and abnormal
Pap smears were also self-reported by women with no prior sexual
contact with men.
++
Importantly, the finding that HPV is present in women whose sexual
contact with men is either remote or nonexistent has important implications
regarding Pap screening for these women. Such women may consider
themselves at low risk for cervical cancer, and their health care
providers may assume the same. Thus, routine screening for cervical
dysplasia may be neglected in these women. WSW should receive Pap
screening for cervical dysplasia according to the same guidelines
as other sexually active women.
++
Case reports of sexual HIV transmission between women have been
published, with a recent report substantiated by a finding of identical
genotype of the HIV isolates from both women and a plausible clinical
history. Oral-genital contact, mucosa-to-mucosa genital contact,
sharing of blood or menstrual fluid, and contact with genital herpes
lesions could facilitate transmission. Because the Centers for Disease
Control and Prevention now recommends universal HIV screening in
all primary care settings, WSW should be tested for HIV at least
once, and retested depending on sexual risk behavior. Decisions
to rescreen for HIV should be based on risk factors such as unprotected
sex with men, particularly gay or bisexual men, number of recent
female sex partners, and intravenous drug use.
+++
Genital Herpes Infection
++
Genital herpes, usually caused by herpes simplex virus type 2 (HSV-2)
but occasionally by HSV-1, can be transmitted by contact of mucous
membrane to mucous membrane or vulnerable skin. Therefore, transmission
between women is theoretically possible. Genital herpes has been reported
in women who had no prior sexual contact with men. In a study of
nearly 400 WSW in Seattle in 1998–2001, 2.6% of
women who reported no male partners had antibodies to HSV-2. Likelihood
of having HSV-2 antibodies increased with increasing lifetime number
of male sex partners. The authors concluded that HSV-2 can be transmitted
between women, although less efficiently than between men and women.
Thus, routine screening for HSV-2 infection using type-specific
serology is not recommended for WSW unless individual risk assessment
indicates it should be performed (eg, history of unexplained genital
lesions; recent multiple sex partners, especially men). In the Seattle
study, the likelihood of WSW having antibodies to HSV-1, which typically
causes oral herpes, increased with increasing number of lifetime
female partners, suggesting a role for orogenital sex in facilitating
transmission in this population. However, serologic screening is
not indicated for this virus, because infection is widely prevalent,
the test does not distinguish between oral and genital infection,
and HSV-1 genital infection is associated with fewer recurrences
and less subclinical shedding.
++
Although Treponema pallidum, the causative agent of syphilis,
is relatively uncommon compared with the viral STDs discussed in
the preceding paragraphs, sexual transmission between female partners
has recently been reported. Because some WSW who choose to have
sex with men may be more likely to choose bisexual men for partners,
health care providers should bear in mind that recently the incidences
of early syphilis and of fluoroquinolone-resistant
Neisseria gonorrhoeae
have markedly increased among men who have sex with men. Providers
should thus screen and treat WSW appropriately based on STD risk
assessment.
Kwakwa HA, Ghobrial MW. Female-to-female transmission
of human immunodeficiency virus.
Clin Infect
Dis 2003;36: e40–41.
[PubMed: 12539088]
(Although
sexual transmission of HIV between women is probably relatively
uncommon, this case report suggests that it can occur.)
Marrazzo JM, Stine K, Koutsky LA. Genital human papillomavirus
infection in women who have sex with women: A review.
Am J Obstet Gynecol 2000;183:770–774.
[PubMed: 10992207]
(Summarizes the available data regarding infection
with HPV among WSW.)
Marrazzo J, Koutsky LA, Eschenbach DA, et al. Characterization
of vaginal flora and bacterial vaginosis in women who have sex with
women.
J Infect Dis 2002;185:1307–1313.
[PubMed: 12001048]
(In this study of 329 self-referred WSW in Seattle, prevalence
of bacterial vaginosis was 27%, and infection was more
common among women who reported higher numbers of female partners,
sharing of insertive sex toys, and receptive oral-anal sex. The
likelihood of a woman having bacterial vaginosis was also greatly
increased if her female partner had bacterial vaginosis, supporting
the hypothesis that this infection may be sexually transmitted between
women.)