Structured Abstract
Prevention of Gonorrhea
Prepared by Brenda L. Beagan, MSc, Department of Pediatrics, Dalhousie
University, Halifax, Nova Scotia, and Elaine E.L. Wang, MD, CM, FRCPC,
Department of Pediatrics, University of Toronto
These recommendations were finalized by the Task Force in March 1994
Contents
Objective
To make recommendations about screening and prevention of gonorrhea in
Canada.
Burden
of Suffering
In 1992, gonorrhea was the second most frequently reported notifiable disease
in Canada. However, the incidence of the disease, which peaked at
56,336 cases in 1981, has decreased steadily to 9,045 cases in 1992. In
the U.S., gonorrhea was the most frequently reported sexually transmitted
disease with 24% to 30% of cases occurring in adolescents. Rates
per 100,000 dropped from 573 to 327 cases in males and 356 to 230 cases
in females between 1981 and 1991. The incidence of gonorrhea in both
countries is particularly high among adolescent populations, with rates
as high as 3.5-7.3% among black adolescents in the U.S. However,
the proportion of gonorrhea organisms that are antibiotic-resistant has
been increasing. From 1985 to 1989 the incidence of gonorrhea caused
by penicillinase-producing Neisseria gonorrhoeae (PPNG) increased
from 0.5% to 5.5% and from less than 1% to 7% in Canada and the U.S., respectively.
Gonococcal infection may be symptomatic, asymptomatic and/or complicated
and may involve various anatomical sites. The majority of patients
have anogenital and/or pharyngeal infection. Local complications
may include epididymitis, lymphangitis, penile edema and urethral stricture
in men, and salpingitis or pelvic inflammatory disease in women, as well
as systemic complications in men or women, including disseminated gonococcal
infection, endocarditis and meningitis. Pelvic inflammatory disease
(PID), a serious complication of 10-20% of gonococcal infections, can result
in serious medical sequelae such as infertility, ectopic pregnancy, and
chronic pelvic pain.
Options
Primary screening options were bacterial cultures and Gram stains. Other
measures included serological tests to detect serum antigonococcal antibodies;
tests for specific endotoxins, enzymes or fatty acids; enzyme immunoassays;
and DNA hybridization techniques. Preventive manoeuvres were abstinence
and use of condoms or spermicides. Treatment included antibiotics (oral
amoxicillin, ceftriaxone, quinolone and cefixime) and educational interventions.
Outcomes
Sensitivity and specificity of screening measures, relative rate of infection
and cure rates associated with antibiotic treatment. Clinical follow-up
attendance rates, compliance with medication and willingness to contact
all partners were examined in relation to educational interventions.
Evidence
MEDLINE was searched for the years 1981 to January 1994 using the MeSH
heading "gonorrhea" with subheadings "complications", "diagnosis", "drug
therapy", "epidemiology", "prevention and control", "therapy", and "transmission".
Relevant published articles were reviewed, focusing on screening and treatment.
Articles about trials were given priority over editorials, case reports,
letters or commentaries. Bibliographies of these articles and recent review
articles were examined.
Recommendations were graded as:
|
A
|
Good evidence to support the recommendation that the condition
be specifically considered in a PHE. |
|
B
|
Fair evidence to support the recommendation that the condition
be specifically considered in a PHE. |
|
C
|
Poor evidence regarding inclusion or exclusion of the condition
in a PHE, but recommendations may be made on other grounds. |
|
D
|
Fair evidence to support the recommendation that the condition
be specifically excluded from consideration in a PHE. |
|
E
|
Good evidence to support the recommendation that the condition
be specifically excluded from consideration in a PHE. |
Quality of evidence was rated according to 5 levels:
|
I
|
Evidence from at least 1 properly randomized controlled
trial (RCT). |
|
II-1
|
Evidence from well-designed controlled trials without randomization. |
|
II-2
|
Evidence from well-designed cohort or case-control analytic
studies, preferably from more than 1 centre or research group. |
|
II-3
|
Evidence from comparisons between times or places with
or without the intervention. Dramatic results in uncontrolled experiments
could also be included here. |
|
III
|
Opinions of respected authorities, based on clinical experience,
descriptive studies or reports of expert committees. |
Values
The 13-member Task Force of experts in family medicine, geriatric medicine,
pediatrics, psychiatry and epidemiology used an evidence-based method for
evaluating the effectiveness of preventive health care interventions. Recommendations
were not based on cost-effectiveness of options. Patient preferences were
not discussed.
Background papers providing critical appraisal of the evidence and tentative
recommendations prepared by the chapter author were pre-circulated to the
members. Evidence for this topic was presented and deliberated upon in
1- to 2-day meetings, 2 to 3 times per year from November 1991 to March
1994. Consensus was reached on final recommendations.
Benefits,
Harms, and Costs
In Canada, 2 factors were found to be predictive in asymptomatic patients:
history of contact with a person with a sexually transmitted disease and
age < 30 years. A Boston cohort study of 1441 obstetrical/gynecological
patients estimated that the risk for infection for women with 1 risk factor
(i.e., partner with gonorrhea or urethral discharge, endocervical bleeding
induced by swab, 16 yrs at first intercourse, low abdominal or pelvic pain)
was 2.5% compared with 0.2% for those with no risk factors.
The accuracy of male urethral specimens is higher than that for female
cervical specimens. Stained smears have a specificity of 95% to 100% (all
anatomic sites); sensitivity is low for asymptomatic males (50% to 70%),
female anogenital infections (45% to 70%) and all pharyngeal and rectal
infections. Bacterial cultures have better sensitivity for these 3 groups.
Single endocervical cultures have a sensitivity of 80% to 95%. Alternatives
to Gram stain and culture have not been studied in an asymptomatic population.
Epidemiological and case-control studies have found that consistent
condom use reduces frequency of gonorrhea. There is some epidemiological
evidence that spermicidal preparations help prevent infection.
Treatment with antibiotics is 95% effective. Oral amoxicillin is an
effective and inexpensive antibiotic if a non-resistant strain is involved.
Uncontrolled trials examining antibiotic-resistant strains, found average
cure rates of 99.2% for ceftriaxone and 99.5% for 4 different quinolones.
Quinolones and cefixime can be administered orally.
3 RCTs evaluated the impact of educational interventions (e.g., educational
pamphlets, counselling, intensive counselling, 10-minute videotape) at
initial STD visit and found no increase in compliance with medications,
willingness to inform sexual contacts, but did find an increase in follow-up
attendance.
Recommendations
Recommendation grade [A, B, C, D, E] and level of evidence
[I, II-1, II-2, II-3, III] are indicated after each recommendation. Citations
in support of individual recommendations are identified in the guideline
text.
-
There is fair evidence to include, in the PHE of asymptomatic people, counselling
and educational materials to prevent the spread of gonorrhea [B,
I, II-2].
-
There is fair evidence not to screen the general population using Gram
stain and culture of cervical or urethral smears [D,
I, II-2].
-
There is good evidence to screen persons at high risk (<30 years with
at least 2 sexual partners in the previous year or 16 years at first intercourse,
prostitutes, sexual contacts of persons known to have STD) using Gram stain
and culture of cervical or urethral smears [A,
I, II-2].
Validation
This report was externally peer-reviewed. The 1989 U.S. Preventive Services
Task Force recommended routine cultures for persons at high risk. The U.S.
Centers for Disease Control recommend diagnosis by culture, and treatment
for uncomplicated urogenital or rectal infection with one intramuscular
dose of ceftriaxone 250 mg, plus doxycycline 100 mg oral twice daily. The
Canadian Laboratory Centre for Disease Control recommends treatment with
ceftriaxone plus tetracycline or doxycycline, and screening of high risk
groups as well as women who are pregnant, seeking an abortion or IUD insertion.
Sponsors
The Canadian Task Force on Preventive Health Care
developed this guideline with funding from Health Canada.
Selected
References
Source Document
Link to Full Text of this
review
Link to Summary Table of Recommendations of this review
Link to Selected References list of this review
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