CTF Structured Abstract: Congenital Rubella Syndrome

Canadian Task Force on Preventive Health Care

Structured Abstract

Please note: In 2003, the CTF updated its Grades of Recommendations to include an "I Recommendation" for situations where insufficient evidence exists to allow a recommendation to be made. (Formerly, these situations were captured under a "C Recommendation".) This change is not retroactive, and all "C Recommendations" made prior to 2003 have not been reevaluated in light of the new "I" recommendation grade. For a discussion of these recommendation grades, please link to the 2003 article in the Canadian Medical Association Journal here.

Screening and Vaccinating Adolescents and Adults to Prevent Congenital Rubella Syndrome

Adapted by Marie-Dominique Beaulieu, MD, MSc, FCFP, Department of Family Medicine, University of Montreal, from a report prepared for the US Preventive Services Task Force by Carolyn DiGuiseppi, MD, MPH

These recommendations were finalized by the Task Force in January 1994

Objective
Burden of Suffering
Options
Outcomes

Evidence
Values
Benefits, Harms, and Costs
Recommendations

Validation
Sponsors
Selected References

Objective

To make recommendations for universal vaccination and screening for vaccination in Canadian men and women to prevent the congenital rubella syndrome.

Burden of Suffering

Rubella is generally a mild illness but when contracted by pregnant women, especially in the first 16 weeks of pregnancy, it frequently causes serious complications including miscarriage, abortion, stillbirth, and congenital rubella syndrome (CRS). The most common manifestations of CRS are hearing loss, developmental delay, growth retardation, and cardiac and ocular defects. The lifetime cost of treating a patient with CRS was estimated in 1985 to exceed 220,000 U.S. dollars.

Options

Congenital rubella syndrome can be prevented by 2 vaccination strategies. One is to screen for the immunization status of all women of child-bearing age and vaccinate those at risk. The second strategy is to immunize all adolescents and young women. Screening can be done with serological tests for antibodies or obtaining proof of vaccination history. Tests are hemagglutination inhibition antibody immunoassay (HI) and enzyme immunoassay latex agglutination. Vaccination history can be verbal or taken from vaccination cards, school records or medical charts.

Outcomes

Sensitivity and specificity of tests, rates of vaccination, adverse effects of vaccination, adverse effects for the fetus and for infants whose mothers had rubella during early pregnancy (miscarriage, abortion, and stillbirth), congenital rubella syndrome (hearing loss, developmental delays, growth retardation, and cardiac and occular deficits), rubella susceptibility and infection and immune status.

Evidence

These recommendations were adapted from a report prepared for the 1989 U.S. Preventive Services Task Force. MEDLINE was searched for 1989 - 1993 using the keywords rubella vaccine, adverse effects, and rubella. English language studies were selected.

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 from October 1993 to January 1994. Consensus was reached on final recommendations.

Benefits, Harms, and Costs

HI is labour-intensive and has a high rate of false positive and negative results. Enzyme and latex agglutation tests have sensitivities of 92% to 100% and specificities of 71% to 100%, and are easier to perform and more accurate than HI.

No population studies evaluated effectiveness of screening and rubella vaccination in reducing congenital rubella syndrome.

Vaccination is long lasting and efficacious. 6% to 12% of the young adult population is seronegative. A cohort study showed that after 6 to 7 years, 98.7% of girls who had been naturally immune were still immune compared with 95.1% of girls who had been susceptible and been vaccinated, and 42.8% who were susceptible and chose not to be vaccinated.

Vaccination of adolescents and children aged 14-18 months in Sweden & Finland reduced seronegativity and rubella infection in girls compared with untreated boys and men.

Rubella vaccine is contraindicated during pregnancy because of the theoretical possibility of teratogenicity.

There is no direct evidence that either screening or routine vaccination of males in military bases or colleges reduces CRS.

Adverse effects of live attenuated vaccine are mild and commonly include joint symptoms in adults.

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.

Screening for Immunization Status Followed by Vaccination

Fair evidence exists to include screening for immunization status followed by vaccination in the PHE for women of child-bearing age at risk for rubella [B, II].
Fair evidence exists to include screening for serological proof of immunization in the PHE of pregnant women along with counselling of women who are seronegative [B, III].

Universal Vaccination

Fair evidence exists to include universal vaccination of adolescent and young women of child-bearing age independent of knowledge of immunization status [B, II].
Evidence is lacking to include or exclude universal immunization of young men in settings where large numbers of people are gathered [C, II].

The decision of which strategy to use should be tailored to the individual clinician's practice population, depending on the availability of vaccination records, the rate of immunity, the cost of serologic testing and of follow-up vaccination for susceptible people.

Validation

This report was externally peer reviewed. The Canadian Immunization Guide recommended universal vaccination for adolescent girls and women of child-bearing age unless they have laboratory evidence of detectable antibodies or documented evidence of vaccination. They also recommended routine screening during pregnancy. The 1989 United States Preventive Services Task Force recommended testing for rubella antibodies at the first clinical encounter for all pregnant and nonpregnant women of child-bearing age who do not have evidence of immunization. Susceptible nonpregnant women are then vaccinated and pregnant women are vaccinated after delivery.

Selected References

Source Document

Beaulieu M.D. Screening and vaccinating adolescents and adults to prevent congenital rubella syndrome. In: Canadian Task Force on the Periodic Health Examination. Canadian Guide to Clinical Preventive Health Care. Ottawa: Health Canada, 1994; 126-33.

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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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.

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.