Hepatitis A vaccination during an outbreak among gay men in Montréal, Canada, 1995-1997.

STUDY OBJECTIVE: To evaluate an intervention designed to curtail an outbreak of hepatitis A among gay men, especially the young and sexually active, by promoting their free vaccination. DESIGN: The study analysed routine passive surveillance data, carried out questionnaire and serological surveys of vaccinees, and surveys among the target population in non-clinical venues. SETTING AND INTERVENTION: 15 000 free doses of hepatitis A vaccine were made available through clinics with large gay clienteles, or at gay events, and advertised by various means, in Montréal, Canada, from August 1996 to November 1997. Simultaneous vaccination against hepatitis B (always free for gay men) was also encouraged. PARTICIPANTS: Information was obtained from persons with the disease during the epidemic period, a sample of men requesting vaccination, and five community samples of gay men. MAIN RESULTS: The outbreak involved 376 gay men and the vaccine was distributed to approximately 10 000. Vaccinees were older than cases, but had many sex partners and comprised more food handlers. Special vaccination clinics at gay events were well attended but did not reach more high risk men than regular medical venues. A self reported vaccine coverage of 49% was achieved, but 26% of vaccinees already had anti-HAV antibodies. Disease incidence declined rapidly during the campaign. CONCLUSIONS: The intervention nearly tripled self reported hepatitis A vaccine coverage but its late start precludes proving that it caused the subsequent drop in incidence. However, it also increased hepatitis B vaccination and it is believed it improved links between gay men, public health, clinicians and community groups.

[Lack of conviction about vaccination in certain Quebec vaccinators]. / Manque de conviction face à la vaccination chez certains vaccinateurs québécois.

A questionnaire was mailed to all vaccinators in Quebec in 1998. The objective of this survey was to document vaccinators' attitudes, knowledge, and practices related to vaccination. Vaccinators generally believe in the security, efficacy and usefulness of vaccines given to young children. However, 41% of nurses do not fully agree with these opinions. More than 94% of pediatricians completely disagree that "certain practices (homeopathy, good eating habits and a healthy lifestyle) can eliminate the need for vaccination", compared with 85% of general practitioners and only 60% of nurses. Less than 25% of doctors recall children who are late in getting their immunizations; approximately 45% of vaccinators are in complete agreement with simultaneous injections of two vaccines; many circumstances are incorrectly seen as contra indications for vaccination. Public health authorities should target systematic interventions towards vaccinators to improve this situation and to increase nurses' conviction regarding the benefits of vaccination.

Evaluation of the effectiveness of immunization delivery methods.

Scientific evidence documenting the effectiveness of immunization delivery methods was summarized using the generic approach developed by the Community Health Practice Guidelines Working Group. The delivery methods examined were those for the adult and childhood vaccines of influenza, pneumococcal infection, hepatitis B, measles-mumps-rubella and diphtheria-pertussis-tetanus-polio. Based on a critical appraisal of 54 eligible comparative studies, the effects of different interventions were obtained and pooled effects were calculated for delivery methods oriented to the client, the provider and the system. The results indicate those interventions found to be most effective for each vaccine. This review of the scientific evidence of the effectiveness of immunization delivery methods provides a base for policy development and assists in the planning of resource allocation.

Practice survey of immunization in Canada.

A survey was undertaken in September 1991 to document current immunization practice across Canada. Information was obtained during interviews with provincial epidemiologists and key persons involved in immunization programs and recorded on standard data collection forms. Variations in practice are described in five areas: public/private health administration; legislation; monitoring system/coverage rates/surveillance; vaccine management and costs. As changes are being considered to immunization programs, a critical examination of issues such as standardization (in coding, in assessment of waste, in assessment of coverage), surveillance systems and the use of serosurveys would be beneficial.

Immunization delivery methods: practice recommendations.

Immunization has unequivocally contributed to large-scale reductions in mortality and morbidity due to infectious diseases. In general, consensus on the scheduling of immunizations has been achieved at the national or international level by immunization advisory committees. However, immunization delivery methods are varied and numerous. Although specific methods have been proposed, compared and evaluated, the available evidence has not been comprehensively summarized for informed public health action. This paper integrates evidence based on scientific documentation, a Canada-wide practice survey and expert opinion to formulate practice recommendations for immunization delivery methods and to identify areas for further research.

Severe complications associated with varicella: Province of Quebec, April 1994 to March 1996.

OBJECTIVE: To determine the frequency and severity of serious complications associated with varicella in Quebec; the frequency and severity of cases of congenital varicella; and hospital costs associated with hospitalizations for varicella. STUDY DESIGN: All hospitalizations related to varicella were identified through the use of a hospital data bank and pertinent data were collected from hospital records. SETTING: Province of Quebec with a population of 6,895,960 people. STUDY POPULATION: All cases with a principal or secondary diagnosis of varicella hospitalized in Quebec between April 1, 1994 and March 31, 1996. OUTCOME MEASURES: Types of complications and reason for hospitalization, risk of complications and calculation of associated costs were studied. RESULTS: Nine hundred nine eligible hospitalizations were identified between April 1, 1994 and March 31, 1996. In all, 583 (64.1%) hospitalizations were for the treatment of complications, 127 (14.0%) for administration of intravenous acyclovir and 199 (21.9%) for supportive care. Healthy people accounted for 644 (70.8%) hospitalizations and immunosuppressed individuals for 136 (15.0%). Among children, one-half of the principal complications were skin infections, while 13.5% and 8.4% of principal complications were pneumonia and neurological complications, respectively. Among adults, the most common complication was pneumonia, with a rate of 43.5%, followed by thrombocytopenia and skin infections, with rates of 22.2% and 14.8%, respectively. The complication rate was 29.2 cases/10,000 cases of varicella. CONCLUSIONS: Although perceived as a benign childhood disease by the general population, varicella may be accompanied by severe complications. Morbidity associated with varicella is one of the elements that must be considered when evaluating the usefulness of varicella vaccine.

Opinions of Quebec parents and vaccinators on the usefulness of chickenpox vaccine.

BACKGROUND: A chickenpox vaccine was recently licensed in Canada. Because this vaccine has caused some controversy within the health care profession, studies among Quebec parents and vaccine providers were carried out, surveying their opinions concerning chickenpox vaccination. METHODS: Three studies among parents of preadolescents, parents of two-year-old children completely or incompletely vaccinated and vaccinators were completed. The studies asked for opinions concerning the usefulness of vaccinating children against chickenpox. RESULTS: The majority of parents of preadolescents (56%), and parents of two-year-old children completely (64%) and incompletely vaccinated (60%) favoured chickenpox vaccination. Among vaccinators, 53% of paediatricians, 37% of general practitioners and 33% of nurses considered universal vaccination of young children to be useful. A greater proportion of health care professionals were in favour of a policy of vaccinating groups at risk, such as susceptible adolescents (86%, 75% and 58%, respectively). There was a positive association between the perceived severity of chickenpox and the potential usefulness of the vaccine. CONCLUSION: Quebec parents are more favourably disposed to chickenpox vaccine than vaccine providers. In contrast, strategies targeting susceptible groups would be generally well received by health care professionals. A considerable amount of work will be needed to convince vaccinators of the benefits of a universal childhood vaccination against chickenpox.

How to Befriend Your Health Department: Public health for family physicians.

Family physicians play an important role in reporting infectious diseases to their local health departments. However, many physicians shy away from following this procedure for a variety of reasons, such as they don't have the right forms or they're concerned about violating patient confidentiality. Whatever the reason might be, physicians and public health departments can work together to prevent epidemics and promote better health in the community.

Evaluation of rubella screening in pregnant women.

BACKGROUND: The rationale for rubella vaccination in the general population and for screening for rubella in pregnant women is the prevention of congenital rubella syndrome. The objective of this study was to evaluate the effectiveness of the prenatal rubella screening program in Quebec. METHODS: A historical cross-sectional study was designed. Sixteen hospitals with obstetric services were randomly selected, 8 from among the 35 "large" hospitals in the province (500 or more live births/year) and 8 from among the 50 "small" hospitals (fewer than 500 live births/year). A total of 2551 women were randomly selected from all mothers of infants born between Apr. 1, 1993, and Mar. 31, 1994, by means of stratified 2-stage sampling. The proportions of women screened and vaccinated were ascertained from information obtained from the hospital chart, the physician's office and the patient. RESULTS: The overall (adjusted) screening rate was 94.0%. The rates were significantly different between large and small hospitals (94.4% v. 89.6%). Five large hospitals and one small hospital had rates above 95.0%. The likelihood of not having been screened was statistically significantly higher for women who had been pregnant previously than for women pregnant for the first time (4.8% v. 1.4%; p < 0.001). Of the 200 women who were seronegative at the time of screening (8.4%), 79 had been vaccinated postpartum, had a positive serological result on subsequent testing or did not require vaccination, and 59 had not been vaccinated postpartum; for 62, subsequent vaccination status was unknown. INTERPRETATION: Continued improvement in screening practices is needed, especially in small hospitals. Because vaccination rates are unacceptably low, it is crucial that steps be taken to address this issue.