CLARIFYING CONFUSING ISSUES
| S EXUALLY TRANSMITTED DISEASES —Patricia J. Sulak, MD, Professor, Texas A&M University College of
Medicine; Director, Divison of Ambulatory Care; Director, Department of Obstetrics and Gynecology, Scott &
White Clinic and Hospital, Temple, Texas
|
| Epidemiology: according to recent data, most common sexually transmitted diseases (STDs) caused by Trichomonas,
human papillomavirus (HPV; 6.2 million), Chlamydia, and herpes simplex virus (HSV)-2 (1.6 million new cases/
yr)
|
 | Estimated prevalence: HSV-2 most common (45 million cases); disease incurable but nonfatal, so cases accumulate
from year to year, unlike HPV, which is curable; similar pattern starting with HIV, which is becoming
chronic condition
|
| Nationally notifiable (reportable) STDs: trichomoniasis most common across all age groups, but HPV most common
among adolescents and young adults; chlamydiosis most common reportable STD
|
| Hepatitis: hepatitis C—20% of cases sexually transmitted; however, only relatively small percentage of cases resolve;
most common indication for liver transplantation in United States; hepatitis B—most adult cases resolve;
1.25 million people now chronically infected, but number should diminish with wide vaccine availability
|
| Treatment: trichomoniasis—cure with antibiotics; chlamydiosis—current treatments so effective that Centers for
Disease Control and Prevention (CDC) no longer requires test of cure, but patient should be tested 3 to 4 mo later
for reinfection, and annually thereafter as long as patient persists in risky sexual behaviors; syphilis—treatment so
effective that 80% of counties in United States report no cases; CDC considered campaign to eradicate syphilis
|
| Transmission modes: reflected in infection sites; HIV mostly lives in blood, HSV in oral and genital nerves and ganglia,
HPV in squamous epithelium, especially if actively dividing, as in adolescent cervix; hepatitis B and C stay in
blood; syphilis dwells in chancres; Neisseria gonorrhoeae and Chlamydia prefer columnar epithelium and cause
cervicitis, unlike HPV, which causes vaginitis; in adolescents, columnar epithelium more abundant than squamous,
so infections tenacious in that age group; in general, immature and actively dividing cervix renders adolescents particularly
vulnerable to STDs; most STDs can be transmitted to fetus during pregnancy or delivery (trichomoniasis
relatively benign); most STDs also may affect pregnancy itself
|
| Contagiousness: type of sexual activity affects STD transmission; in general, anal most dangerous, followed by vaginal
and oral; HPV highly contagious; clinicians should not touch instruments or office items right after touching patient
infected with HPV (until hands washed); HSV and syphilis also easily transmitted via clinician who touches
patient’s sores; have assistant hand you items; if infected male ejaculates just outside vagina, organisms still may
infect partner; many adolescents get inaccurate information about contraception
|
| Transmission during pregnancy: blood-borne STDs—transmitted through intravenous drug use as well as sexual activity,
but pregnant woman’s chances of transmitting blood-borne STD (eg, HIV) to fetus only 25%; HPV—
transmission to fetus also rare; HSV—transmission risk low if woman has longstanding infection with recurrent
outbreaks (virus dwells in nerves, where it cannot reach fetus; odds of infecting infant at delivery, even during
outbreak, probably <1%); prophylactic acyclovir (400 mg bid) recommended only to reduce risk for cesarean delivery;
however, if woman experiences primary outbreak while pregnant, especially during third trimester, fetus
at risk; hepatitis B—success story; endemic in many third-world countries; practice of vaccination and providing
immunoglobulins to infected infants at birth dramatically reduced rate of new neonatal infections; hepatitis
C—maternal-fetal transmission rare; gonorrhea—may cause eye infection; chlamydiosis—may cause eye infection
or pneumonia; pneumonia easily treated and not life-threatening; syphilis—related to intrauterine growth
and mental retardation; all pregnant women tested
|
| Type of sexual activity: all STDs transmitted through anal or vaginal intercourse; anal intercourse more efficient at
transmitting blood-borne STDs; most STDs also transmitted through oral sex, but usually not as efficiently;
HSV-1 STD most commonly transmitted through this route (many people carry virus asymptomatically, transmit
it unknowingly); 20% of children <5 yr of age have antibodies to HSV-1; Chlamydia or HPV may occur in
adults’ mouths or throats from oral sex with infected partner, but both usually asymptomatic; relationship to oral
cancer probably coincidental
|
| HSV transmission: according to University of Wisconsin study, newly diagnosed genital herpes from HSV-1 increased
among college students from 31% in 1993 to 78% in 2001; due to oral sex; always determine HSV type
whenever genital infection diagnosed, so patients know how they contracted it (may affect relationship); however,
type 1 much less likely than type 2 to recur on genitals
|
| Asymptomatic carrier states: Chlamydia—75% of female patients and 50% of male patients asymptomatic (screen
high-risk individuals); HSV—>90% of those infected unaware; HIV—50% unaware of infection or do not disclose
it
|
| Silent pelvic inflammatory disease (PID): usually caused by Chlamydia; organism invades fallopian tubes, damages
cilia and prevents them from moving eggs from tubes to uterus; PID causes most ectopic pregnancies; patients
usually unaware of infection until they try (unsuccessfully) to conceive
|
| HSV seroprevalence: according to National Health and Nutrition Examination Survey (NHANES-III), seroprevalence
of HSV-2 rose 30% between 1976 and 1994; in all, 22% of US population >12 yr of age test positive for
HSV-2 (45 million people); HSV-2 antibodies develop only through sexual transmission (other routes possible
for HSV-1 antibodies); starting sexual activity at young age and high number of lifetime partners risk factors for
HSV-2 antibodies
|
| Other findings from NHANES-III: only 9% of people seropositive for HSV-2 knew they were infected (therefore,
>90% of patients unaware of infection); symptoms usually mild enough to ignore; often associated with recurring,
if minor, vulvar infections (should raise red flag in doctor’s mind; take culture during attack); patients may
think they have yeast infections; according to one study, 83% of people who did not know they were infected
transmitted HSV to their partners; severe symptoms suggest infection from recent partner, while mild symptoms
mean patient most likely infected for years
|
| Changing nature of HIV: patients >25 yr of age most likely male, but proportion of women higher among younger
patients; many teenaged girls engage in anal sex to prevent pregnancy and to remain “a virgin”; infection with
Chlamydia or HSV facilitates HIV infection (pre-existing STD increases risk for HIV infection 3- to 4-fold)
|
| IMPROVING THE EFFECTIVENESS OF CERVICAL CANCER SCREENING —Edward Wiesmeier, MD, Clinical
Professor, Department of Obstetrics and Gynecology, David Geffen School of Medicine at the University of California,
Los Angeles, and Director, Arthur Ashe Student Health and Wellness Center, UCLA
|
| Colposcopy: current gold standard for gynecologic examination, but lacks sensitivity and specificity
|
| Advances in cervical screening: Papanicolaou (Pap) test—essentially unchanged since first used in 1940s; 50% of
new cases of cervical cancer diagnosed in women who have not been screened in ≥5 yr; some women screened
unnecessarily
|
| Women most likely to be underscreened: immigrants (may have taboos about being examined); cervical cancer
second most common cause of death among women worldwide (>250,000 deaths/yr); better tests being sought
|
| Pap test: ≈50 million performed annually in United States; if normal, can be repeated within 1 to 3 yr; management
straightforward if low-grade squamous intraepithelial lesions (LSIL) or high-grade squamous intraepithelial
lesions (HSIL) found; management of atypical squamous cells of undetermined significance (ASCUS) less
clear; technologic advances include automated Pap screening systems; liquid-based methods of capturing cells
(ThinPrep; SUREPATH); Hybrid Capture DNA assay for HPV (indications are ASCUS triage and age >30 yr)
|
| Limitations of Pap test: false-negative results in ≤33% of cases with conventional test; 5% to 10% falsely positive;
another 5% to 10% inconclusive due to sampling or interpretive errors; liquid-based samples—more complete,
with more representative sample of cells and minimal obscuring; offer better predictive value and opportunity for
reflex testing (further testing based on results of initial smear); fewer samples read as ASCUS, more as HSIL or
LSIL
|
| HPV: associated with >95% of cervical cancers, 50% of vaginal cancers, and >50% of vulvar cancers; also associated
with 50% of penile cancers, 70% of anal cancers, and 20% of oropharyngeal cancers
|
| Likelihood of infection: prevalence peaks at ≈19 yr of age, but cancer almost never occurs in this age group; reasonable
to test for HPV infection and cervical cancer in women >30 yr of age; most common sexually transmitted
viral disease; most infections transient
|
| Clearance: in one study of college-age women, most infections resolved within 18 mo of contraction
|
| Essential facts: persistent infection with high-risk strains essential for cancer development; >130 strains currently
known, but most rare, occur mostly in immunocompromised patients, and probably represent subtle variants of
more common strains; strains 16 and 18 present in 75% of women with high-grade disease
|
| Potential uses of HPV-DNA test: to confirm ASCUS Pap test or to resolve discordant cytology, colposcopy, or histology
findings; if woman >30 yr of age has negative Pap and HPV tests, risk for cervical cancer in next few years close
to zero; in study of >10,000 women with negative Pap tests at baseline, positive test for HPV DNA after 1 yr associated
with risk for cervical cancer 692 times greater than in HPV-negative women; among women who tested positive
again 1 yr later, likelihood of cervical cancer 813 times greater
|
| Vaccine study: enrolling women with low-grade disease who have HPV-16; sponsored by National Institutes of
Health (NIH); doctors interested in enrolling patients can call speaker at 310-825-7692 and ask assistant for information
|
| Approach to women >30 yr of age with normal Pap tests who test positive for HPV: perform colposcopy; repeat it and
HPV test at 6 to 12 mo; woman with persistent positive HPV DNA should be colposcoped, regardless of cytology;
patients with atypical squamous cells and in whom HSIL (ASC-H) cannot be ruled out deserve endocervical curettage
and return visit in 4 to 6 mo; of women with ASCUS, percentage who have high-grade disease low, but because
they number 3 million, highest absolute number of patients with high-grade disease come from those with
ASCUS; represent 39% of patients with high-grade neoplasia
|
| ASCUS management options: interobserver variability high; in study of 1473 women diagnosed with ASCUS by
pathologist at clinical center, 840 (57%) read differently by pathology quality control group (most downgraded
to normal); sometimes, same pathologist reads same sample differently on different days
|
| ASCUS/LSIL Triage Study (ALTS): enrolled 3488 women with ASCUS and 1572 with LSIL, randomized to immediate
colposcopy, HPV triage, or repeat cytology; clinical follow-up every 6 mo for 2 yr; LSIL arm discontinued
due to limited utility of positive test result; all ASCUS patients had exit colposcopy; results—HPV testing detected
96% of cervical intraepithelial neoplasias (CIN 2/3), with 56% colposcopy referral; repeat Pap test detected
85% of CIN 2/3, with 59% colposcopy referral; compared to colposcopy for all women, HPV triage reduced unnecessary
biopsies by 50%; if HPV negative, significant pathology unlikely, but if patient has history of abnormal
findings, HPV test unnecessary (go directly to colposcopy); some patients who are HPV-positive will not have
disease (may be dormant)
|
| Guidelines: most liberal guidelines state women with normal liquid-based Pap tests can be tested every 2 yr; United
States Public Health Service states that women <23 yr of age with normal conventional test 3 yr running can wait >1
yr for next examination; wait 2 to 3 yr if woman >30 yr of age and has negative Pap test and HPV DNA; discontinue
altogether if woman has had hysterectomy; according to one survey, most patients prefer annual examinations nevertheless
|
Educational Objectives
| The goal of this program is to educate the listener about the most common sexually transmitted diseases and to improve
screening for cervical cancer. After hearing and assimilating this program, the clinician will be better able to:
|
| 1. Name the most common sexually transmitted diseases.
|
| 2. Explain the circumstances under which a pregnant woman may transmit the herpes simplex virus to her fetus.
|
| 3. State why so many people do not know they have a sexually transmitted disease.
|
| 4. Identify the women most likely not to be screened for cervical cancer.
|
| 5. Describe the advantages of a liquid-based Papanicolaou (Pap) test.
|
Discussed on this Program
Acyclovir (acycloguanosine) [Zovirax]
Metronidazole [Flagyl, Flagyl 375, Flagyl ER, Flagyl IV, Flagyl IV RTU, Metric 21, MetroCream, MetroGel,
MetroGel-Vaginal, MetroLotion, Noritate, Protostat]
Miconazole nitrate [several preparations and trade names]
Penicillin G [Bicillin C-R, Bicillin C-R 900/300, Bicillin L-A, Permapen, Pfizerpen, Wycillin]
Editor’s Note
Sexually Transmitted Diseases: FACTS You Need to Know available on CD at www.worththewait.org
Suggested Reading
Adderley-Kelly B, Stephens EM: Chlamydia: A major health threat to adolescents and young adults. ABNF J 16: 52,
2005; Cronje HS: Screening for cervical cancer in the developing world. Best Pract Res Clin Obstet Gynecol 19:517,
2005; De Lang, A et al: Significance of HPV tests on women with cervical smears showing ASCUS. Acta Obstet Gynecol
Scand 84: 1001, 2005; Denny LA, Wright TC Jr.: Human papillomavirus testing and screening. Best Pract Res
Clin Obstet Gynecol 19:501, 2005; Khan A et al: The prevalence of chlamydia, gonorrhea, and trichomonas in sexual
partnerships: implications for partner notification and treatment. Sex Transm Dis 32: 260, 2005; Little SE, Caughey
AB: Acyclovir prophylaxis for pregnant women with a known history of herpes simplex virus: a cost-effectiveness
analysis. Am J Obstet Gynecol 193:1274, 2005; Ness RB et al: Effectiveness of treatment strategies of some women
with pelvic inflammatory disease: a randomized trial. Obstet Gynecol 106: 573, 2005; Scheurer ME et al: Human
papillomavirus infection: biology, epidemiology, and prevention. Int J Gynecol Cancer 15:727, 2005; Schiffman M
et al: A study of the impact of adding HPV types to cervical cancer screening and triage tests. J Natl Cancer Inst 97:
147, 2005; Sivapalan S et al: Triage criteria in genitourinary medicine. Int J STD AIDS 16: 630, 2005; Sobel JD:
What’s new in bacterial vaginosis and trichomoniasis? Infect Dis Clin North Am 19: 387, 2005; Stoler MH, Schiffman
M: Atypical squamous cells of undetermined significance-Low-grade squamous intraepithelial lesion Triage
Study (ALTS) group. Interobserver reproducibility of cervical cytologic and histologic interpretations: realistic estimates
from the ASCUS-LSIL Triage Study. JAMA 285: 1500, 2001; Zuna RE et al: Determinants of human papillomavirus-negative,
low-grade squamous intraepithelial lesions in the atypical squamous cells of undetermined
significance/low-grade squamous intraepithelial lesions triage study (ALTS). Cancer June 30, 2005 (e-published
ahead of print).
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. The following
has been disclosed: Dr. Wiesmeier has received grant funding from Merck and has been a speaker for Merck, Digene,
Lab Corp, and Quest Diagnostics.
Dr. Sulak spoke at The Adult Patient: Male and Female Issues, held June 20-24, 2005, on South Padre Island, Texas,
and sponsored by Scott & White Medical Center, Temple, Texas. Dr. Wiesmeier spoke at the Office Gynecology/
Women’s Health Symposium, held August 18-21, 2005, in Anaheim, California, and sponsored by University of California,
Los Angeles. The Audio-Digest Foundation thanks the speakers and the sponsors for their cooperation in the
production of this program.
|
