ISSUES IN COMMUNICABLE DISEASES
| SEXUALLY TRANSMITTED DISEASES: AN EPIDEMIOLOGIC LOOK —Patricia J. Sulak, MD, Professor, Department
of Obstetrics and Gynecology, Texas A&M Health Science Center College of Medicine, and Medical Director,
Division of Research, Department of Obstetrics and Gynecology, Scott and White Clinic/Memorial Hospital,
Temple, TX
|
| Most common sexually transmitted disease (STD): answer depends on whether talking about incidence, prevalence,
reportable diseases, or age group; highest incidence—trichomoniasis; human papillomavirus (HPV) second
highest; highest prevalence—herpes simplex virus type 2 (HSV-2); HPV second highest prevalence; highest reportable
disease—chlamydia (nearly 1 million cases reported, estimated 2.8 to 3 million actual number); estimated incidence
by age group— HPV highest in adolescents and young adults (6 million cases); hepatitis C—estimated 2.7
million people in United States; primarily transmitted by intravenous (IV) drug abuse or from blood transfusions;
hepatitis B—1.2 million people; HIV—1.2 million cases
|
| Viral STDs: HSV—persistent infection; HIV—persistent infection; possible to reduce viral load to zero with therapy,
but viral load increases with discontinuance of therapy; hepatitis C—persistent infection in most infected
people; no vaccine available; most common reason for liver transplantation in United States; hepatitis B—most
people clear infection if acquired in adulthood; people at risk should be given hepatitis B vaccine series; HPV—
most infected people clear infection
|
 | Curable or suppressible: curable if caused by bacteria or protozoa; replication suppressed if viral (hepatitis C exception)
|
| Where do they live: lesions (syphilis, HSV, HPV); genital secretions (vaginal/cervical or semen); genital skin
(squamous epithelium)
|
| Modes of transmission: depends on where STD lives; most have potential to be transmitted to baby during pregnancy
or childbirth if mother infected; can adversely affect pregnancy itself; some sexual activities have greater
transmission rate, depending on STD; infection can occur with skin-to-skin contact or ejaculation outside vagina;
infection acquired through IV route can be transmitted sexually; transmission of HPV rare
|
| Mother-to-baby transmission: HIV—≈25% chance baby infected if mother infected; HSV—low risk if mother has
longstanding history of recurrent outbreaks; high risk if mother infected during third trimester; cesarean delivery
required; acyclovir recommended in last 4 to 6 wk of pregnancy to decrease chance of outbreak at time of delivery;
hepatitis B—prevented by vaccine and immunoglobulin given to newborn; hepatitis C —transmission rare;
no indication for cesarean delivery; mother can breast-feed; chlamydia—newborn eye infection; pneumonia;
gonorrhea—newborn eye infection; syphilis—severe ramifications for newborn; trichomoniasis—potential ramifications
unknown
|
| Types of sexual activity: vaginal and anal intercourse—all STDs can be transmitted through either route; more potential
for transmission of blood-borne STDs (especially HIV) with anal intercourse; oral sex—can transmit
most STDs, but usually not as efficient (exception HSV-1); oral infections acquired through oral sex usually asymptomatic
(eg, chlamydia); throat culture not necessary (therapy with azithromycin treats throat simultaneously);
increasing proportion of HSV-1 causing genital herpes infection in college students
|
| Asymptomatic carriers: most people infected with STDs do not know they are infected; chlamydia—75% of girls
asymptomatic, 50% of boys; 50% of girls asymptomatic for gonorrhea; 90% of people asymptomatic for HSV-2;
>90% of people asymptomatic for HPV (early-stage cervical cancer also asymptomatic); estimated 25% of people
infected with HIV unaware; large number of cases of pelvic inflammatory disease (PID) asymptomatic; gonorrhea
no longer treated with fluoroquinolone antibiotics (eg, ciprofloxacin [Cipro])
|
| Seroprevalence of HSV: HSV-1—≈20% in children <5 yr of age (result of social contact); rises in linear fashion
through 70 yr of age; HSV-2—virtually nonexistent in persons <12 yr of age (suspect child abuse if patient <12 yr
of age); peaks by 40 yr of age and remains stable thereafter (indicates almost all HSV-2 infections acquired between
15 and 40 yr of age); new sexual partner biggest risk factor for acquiring STD; change in seroprevalence of
HSV-2 in United States—data found 17% of population ≥14 yr of age positive for HSV-2 (decreased from 21% in
previous study); HSV-1 decreased also; infection rates higher among those—divorced, separated, or widowed; living
below poverty level; with history of cocaine use; who had sex for first time at ≤17 yr of age; who had large
number of sexual partners over lifetime (early onset of sexual activity number one risk factor for all STDs); study
showed decrease in HSV-2 concentrated in younger age groups; HSV-2 decreased from 5.8% to 1.6% in adolescents
and teenagers 14 to 19 yr of age (corresponds to 1 million fewer infections); fewer adolescents having vaginal
intercourse one reason pregnancy rate declining; subclinical HSV-2 infection—data show only 14% seropositive
persons reported genital herpes; often, patients have clinically mild infections; patient may think they have recurrent
yeast infection when in fact they have HSV; data show after education and counseling, 87% of previously asymptomatic
patients subsequently reported localized genital symptoms and 83% cultured positive for HSV-2
|
| Human immunodeficiency virus: significant problem worldwide; 11,000 new cases daily; 8000 deaths daily;
United States—44,000 new cases of AIDS in 2005; >400,000 persons living with AIDS; as of 2004, 500,000
deaths from AIDS; 1.2 million estimated to be living with HIV currently; transmission—men having sex with men
(MSM) account for 44% of transmission; 34% associated with heterosexual contact; blacks and Hispanics disproportionately
affected; leading cause of death in black women 25 to 34 yr of age in 2002; younger person is at diagnosis,
more likely infection acquired by heterosexual transmission; Centers for Disease Control and Prevention
(CDC) recommends testing everyone ≤65 yr of age; estimated 250,000 persons in United States unaware they are
infected; routine screening for HSV not indicated by CDC; ensure glycoprotein G-based technology used when
testing for HSV-2
|
| UPDATE ON ADOLESCENT VACCINATION —Katherine K. Hsu, MD, MPH, Assistant Professor of Pediatrics
and Attending Physician, Department of Pediatric Infectious Diseases, Boston University Medical Center, Boston,
MA
|
| Type of physician seen for adolescent medical care: younger adolescents (11-13 yr of age) likely seen by pediatricians
and family practitioners; obstetricians/gynecologists generally become health care providers as adolescent
ages; obstetricians/gynecologists play important role in vaccine delivery
|
| Meningococcal disease: rare in United States; ≈9 cases per 100,000 in babies aged ≤1 yr; mild peak in adolescence;
2 cases per 100,000 in college-freshman age group; wanes in early 20s; another peak in adults ≥65 yr of
age; Neisseria meningitidis causative agent; classified by sugar coat surrounding bacteria; in United States, ≈40%
of disease serogroup C, ≈30% serogroup B, and 20% serogroup Y; W-135 and A disease more common in sub-
Saharan Africa; no vaccine for serogroup B; mortality rate 10% to 15%; severe sequelae (eg, hearing loss, limb
loss, neurologic disability) in 10% to 20% of survivors; prophylaxis required for persons who come within 3 ft of
infected person
|
| Vaccine formulations: meningococcal conjugate vaccine (MCV)—MCV4 (Menactra); meningococcal polysaccharide
diphtheria toxoid conjugate vaccine; approved for use in patients ≥2 yr of age; conjugate and meningococcal
polysaccharide vaccines protect against meningococcal disease caused by serogroups A, C, Y, and W-135, but
differ in type of immunity; conjugate vaccine—elicits T-cell–dependent immunity; more durable; may decrease
amount of colonization in individual; recommendations—routine vaccination of all persons 11 to 18 yr of age
with 1 dose of MCV4 at earliest opportunity; also recommended for higher-risk individuals 19 to 55 yr of age, including
college freshmen living in dormitories, military recruits, microbiologists routinely exposed to isolates of
N meningitidis, travelers to or residents in countries in which N meningitidis hyperendemic or epidemic, immunocompromised
persons with terminal complement component deficiencies (eg, sickle cell disease) or functional
asplenia or persons infected with HIV; polysaccharide vaccine—MPSV4 (Menomune); used for higher-risk persons
≥56 yr of age; acceptable alternative for persons 11 to 55 yr of age if MCV4 not available; revaccination—
not recommended if individual vaccinated with MCV4 (durability of immunity unknown); may be indicated for
person who received MPSV4 2 to 5 yr earlier; MCV4 recommended for revaccination of persons 11 to 55 yr of
age; pregnancy—safety data lacking; submit patient information to Pregnancy Registry (1-800-822-2463) if vaccine
inadvertently administered; if MCV4 inadvertently given subcutaneously (SC)—manufacturer recommends
repeating dose; CDC does not recommend revaccination; Advisory Committee on Immunization Practices
(ACIP) does not recommend revaccination (based on small study showing serum bactericidal titers protective in
nearly all receiving SC vaccine)
|
| Pertussis: disease of infants and young children; peaks in adolescence and again in persons ≥65 yr of age because of
waning of immunity from tetanus (Td) vaccine; rationale for tetanus, diphtheria, and acellular pertussis vaccine
(Tdap); rationale for vaccination —protect Tdap recipient from pertussis; reduce reservoir of Bordetella pertussis in
community; decrease spread of B pertussis to persons at risk for severe pertussis (eg, infants); reduce cost of and disruption
from pertussis in institutional settings; clinical features reported by adolescents and adults—rib fracture (from
severe coughing spells); weight loss; vomiting; shortness of breath; urinary incontinence; Tdap vaccine—Boostrix licensed
for persons 10 to 18 yr of age; Adacel licensed for persons 11 to 64 yr of age; both licensed in 2005; different
age indications result of companies doing clinical trials in different age groups; recommendations—adolescents 11 to
18 yr of age should receive single dose of Tdap instead of Td if they completed recommended childhood diphtheria,
tetanus and pertussis (DTaP) vaccination series; adolescents 11 to 18 yr of age who already received Td encouraged to
receive single dose of Tdap to provided protection against pertussis if childhood DTaP vaccination series completed;
adults 19 to 64 yr of age should receive single dose of Tdap to replace single dose of Td; minimum interval between Td
and Tdap in adolescents—ACIP did not define absolute minimum; provider must decide based on whether benefit of
pertussis immunity outweighs risk for local adverse reaction; providers may consider shorter intervals during outbreaks
or increased community activity (interval as short as 2 yr supported by studies) or for individuals with comorbid
conditions, (eg, chronic obstructive pulmonary disease), caregivers of infants <12 mo of age, or health care
workers; pregnancy—not contraindication; transplacental maternal antibodies might protect infant in first months of
life, but could interfere with infant’s immune response to DTaP; when Tdap used instead of Td, administration in second
or third trimester preferred; off-label recommendations (both manufacturers have established registries); postpartum
use of Tdap to protect infants (cocoon strategy)—recommend Tdap to adults <65 yr of age in close contact with
infants <12 mo of age (includes health care workers); any woman who might become pregnant should also receive
Tdap; administration errors—if Tdap given to child as part of primary series, dosing probably not sufficient to develop
protection; do not count dose, give DTap; if DTap given to patient (≥7 yr of age), count dose as valid (risk for adverse
event may be increased); if Boostrix formulation inadvertently given to person 19 to 64 yr of age, do not repeat
dose
|
| HPV disease: genital warts related to HPV types 6 (HPV-6) and 11 (HPV-11), ≈90%; ≈70% of cervical cancer attributable
to HPV-6 and type 18 (HPV-18); epidemiologic association between HPV and other epithelial cancers
unclear; girls 11 to 12 yr of age targeted for vaccination because immunity from vaccine depends on vaccination
before initiation of sexual activity; higher antibody titers among girls 11 and 12 yr of age, compared to older
women (defined as >26 yr of age); data show no evidence of waning immunity; ongoing studies monitoring duration
of protection; rationale for vaccinating women 13 to 26 yr of age—women not yet sexually active can be expected
to have full benefit of vaccination; vaccination may provide partial protection for sexually active females
already infected with some HPV subtypes; recommendations—routine vaccination of girls 11 to 12 yr of age with 3
doses of quadrivalent HPV vaccine (eg, Gardasil); series can be started as young as 9 yr of age; catch-up vaccination
recommended for women 13 to 26 yr of age; special situations—positive HPV test; abnormal Papanicolaou
(Pap) test; genital warts (vaccine can still be given; may provide protection against other subtypes); immunosuppression;
lactating women; pregnancy (category B; lack of data; not recommended); vaccine schedule—series does
not need to be repeated if schedule interrupted; minimal interval between second and third dose, 3 mo; cervical cancer
screening—recommendations have not changed for women receiving vaccine; comparing quadrivalent to bivalent
vaccines—slightly different adjuvants (substance added to vaccine to generate better immune response); no
data showing which vaccine generates better immunity; comparable efficacy and safety; comparable immunologic
end points; Cervarix targets older women (>26 yr of age); competition may lower cost
|
| Adverse events associated with vaccine administration: injection-site pain (majority of patients); erythema
(≈25% of patients); fever in 5% of patients receiving MCV4 and Tdap; ibuprofen (eg, Motrin) or acetaminophen
(eg, Tylenol) recommended to reduce risk for adverse event; reports of Guillain-Barré syndrome (GBS) after MCV4
vaccination—≈20 cases reported as of June 2007; no statistical difference between persons receiving vaccine and
person acquiring GBS from Campylobacter jejuni; personal or family history listed as precaution, but not contraindication;
fainting after HPV vaccination—head trauma reported after syncope, seizure, subarachnoid hemorrhage,
and parietofrontal subdural hematoma (also reported with MCV4 vaccination); reports of unintentional injury related
to vasovagal syncope; recommend patient be observed after injection (63% of fainting episodes occur within
5 min, 89% within 15 min); vaccine storage —all 3 vaccines require refrigeration; check refrigerator temperature
twice daily; federal law requires patient receive written information about vaccine
|
Suggested Reading
Centers for Disease Control and Prevention et al: Sexually transmitted disease treatment guidelines, 2006.
MMWR Recomm Rep 55(RR-11), 2006; Cortese MM et al: A “new age” in pertussis prevention new opportunities
through adult vaccination. Am J Prev Med 32:177, 2007; Middleman AB: New adolescent vaccination recommendations
and how to make them “stick”. Curr Opin Pediatr 19:411, 2007; Markowitz LE et al: Quadrivalent
Human Papillomavirus Vaccine: Recommendations of the Advisory Committee on Immunization Practices (ACIP).
MMWR Recomm Rep 56(RR-2):1, 2007; Sulak PJ: Sexually transmitted diseases. Semin Reprod Med 21:399, 2003;
Van Vranken M: Prevention and treatment of sexually transmitted diseases: an update. Am Fam Physician 76:1833,
2007; Xu F et al: Trends in herpes simplex virus type 1 and 2 seroprevalence in the United States. JAMA 296:964,
2006.
Educational Objectives
| The goal of this program is to improve vaccination strategies for adolescents and improve prevention and management
of sexually transmitted diseases (STDs) through a better understanding of their epidemology. After hearing and assimilating
this program, the clinician will be better able to:
|
| 1. Identify the most common STDs by incidence, prevalence, most reportable, and age group
|
| 2. Counsel patients about the modes of transmission of STDs.
|
| 3. Discuss the asymptomatic carrier state associated with STDs.
|
| 4. List the 3 vaccines that make up the adolescent vaccine platform.
|
| 5. Implement an appropriate vaccination program for an adolescent patient.
|
Faculty Disclosure
In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the
planning committee to disclose relevant financial relationships within the past 12 months that might create any personal
conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes
quality in health care and not a proprietary business or commercial interest. For this program, the following has been
disclosed: Dr. Sulak has received research grants from Berlex, Organon, and Warner Chilcott and is on the Speakers’
Bureaus of Berlex, Barr, Wyeth, and Warner Chilcott. Dr. Sulak has been a consultant to Warner Chilcott, Wyeth,
Barr, and Berlex. Dr. Hsu and the planning committee reported nothing to disclose.
Acknowledgments
Dr. Sulak was recorded at The Female Patient: Current Issues in the Care of Women, sponsored by Texas A&M Health
Science Center College of Medicine and Scott and White Clinic/Memorial Hospital, held on June 18-22, 2007, in
South Padre Island, TX. Dr. Hsu was recorded at the 10th Annual Practical Women’s Health Issues, sponsored by Boston
University School of Medicine, held on October 27, 2007 in Dedham, MA. The Audio-Digest Foundation thanks
the speakers and the sponsors for their cooperation in the production of this program.
|
