Pneumococcal immunization and public health: the Canadian experience.

Pneumococcal vaccine has been poorly used in Canada, despite strong recommendations for its use by the Canadian National Advisory Committee on Immunization. In a recent survey of health officials, however, seven of the 12 Canadian provinces and territories were found to either have a programme for all persons > 65 years of age or were planning to implement one within the next year. Factors that have contributed to this increased interest include: better data on disease incidence and preventable illness from population-based surveillance; data on emerging resistance of Streptococcus pneumoniae in Canada to penicillin and other antimicrobials; implementation of vaccine programmes for the elderly by public health officials in Ontario, Nova Scotia and British Columbia; completion of a cost-benefit study of pneumococcal vaccine for Canada; and increased attention to pneumococcal vaccination at national immunization meetings and in the medical literature.

Development of record linkage of hospital discharge data for the study of neonatal readmission.

Computerized record linkage has been used increasingly in epidemiologic studies. We developed a multistage, deterministic matching algorithm using various combinations of key variables. Then, from the records for March 1, 1993, to March 31, 1996, contained in the discharge abstract database of the Canadian Institute for Health Information (CIHI), we examined the relation between length of hospital stay at birth and neonatal readmission.

Monograph series on aging-related diseases: XII. Parkinson's disease--recent developments and new directions.

Parkinson's disease, a chronic progressive disorder of the central nervous system characterized by tremor, rigidity and bradykinesia, usually affects those over the age of 50. Recent developments in research on Parkinson's disease include investigation of the possible role of diet and a growing interest in genetics and inherited factors. The identification of biological markers and other environmental risk factors will play a significant role in future research of the disease as they will be important in the development of prevention strategies.

Changes in the registration of stillbirths < 500 g in Canada, 1985-95. Fetal-Infant Mortality Study Group of the Canadian Perinatal Surveillance System.

We assessed recent temporal trends in the registration of stillbirths in Canada, with particular regard to stillbirths < 500 g. Data from the Statistics Canada live birth and stillbirth databases for the period 1985-95 were used for the study. The primary analysis was restricted to data from 10 of the 12 provinces and territories of Canada.

Antibody response to the chlamydial heat-shock protein 60 in an experimental model of chronic pelvic inflammatory disease in monkeys (Macaca nemestrina).

A primate model of chlamydial pelvic inflammatory disease was used to characterize serum antibody responses to the 60 kDa chlamydial heat shock protein (CHSP60). Forty monkeys were infected in the fallopian tubes with Chlamydia trachomatis and then were treated. Twenty-three (58%) monkeys developed antibodies against CHSP60, of whom 6 (15%) had CHSP60 responses that persisted throughout the study and 17 (42.

Comparison of molecular methods for typing Vibrio parahaemolyticus.

An outbreak of Vibrio parahaemolyticus gastroenteritis on Canada's west coast in 1997 emphasized the need to develop molecular methods for differentiation and typing of these organisms. Isolates were analyzed by enterobacterial repetitive intergenic consensus sequence (ERIC) PCR, detection of restriction fragment length polymorphisms (RFLP) in rRNA genes (ribotyping), pulsed-field gel electrophoresis (PFGE), and RFLP analysis of the genetic locus encoding the polar flagellum (Fla locus RFLP analysis). ERIC PCR and ribotyping were the most informative typing methods, especially when used together, while Fla locus RFLP analysis was the least discriminatory.

Birth cohort effects underlying the increasing testicular cancer incidence in Canada.

Purpose: To examine the pattern of testicular cancer incidence by age, time period and birth cohort since 1969 in Canada.

Methods: In addition to analyses of the secular trends by age group and birth cohort separately, an age-period-cohort model and the submodels with standard Poisson assumptions were fitted to the data.

Results: The overall age-adjusted incidence of testicular cancer increased in Canada, from 2.

The 1996 and 1997 National survey of physician asthma management practices: background and study methodology.

Objectives: To collect national baseline information on asthma management practices by physicians, and to compare these practices with the recommendations of the Canadian Asthma Consensus Conference ('the guidelines').

Design: Cross-sectional survey of representative samples of physicians in Canada in late 1996 and early 1997.

Population Studied: Five specialty types of physicians who manage asthma patients: respirology, pediatrics, internal medicine, allergy and clinical immunology, and general practice and family medicine.

End-stage renal disease in Canada: prevalence projections to 2005.

Background: The incidence and prevalence of end-stage renal disease (ESRD) have increased greatly in Canada over the last 2 decades. Because of the high cost of therapy, predicting numbers of patients who will require dialysis and transplantation is necessary for nephrologists and health care planners.

Methods: The authors projected ESRD incidence rates and therapy-specific prevalence by province to the year 2005 using 1981-1996 data obtained from the Canadian Organ Replacement Register.

Look before you leap: stratify before you standardize.

This paper presents a mathematical model to show the conditions in which age standardization can be used to summarize age-specific rates for comparison purposes over calendar time. It shows that the conditions for valid comparison depend on the type of measure used for comparison, that is, difference, ratio, or percent change. If the measure for comparison is a difference of the standardized rates at two time points, then the age-specific rates need to maintain a constant rate difference over time for the comparison to be valid.

Health consequences of smoking among Canadian smokers: An update.

The expected number of deaths in four hypothetical Canadian cohorts (male current smokers, male never-smokers, female current smokers and female never-smokers) was examined by constructing abridged life tables. The expected number of premature deaths (before age 70) among lifelong smokers was found to be about twice that expected among lifelong never-smokers for both males (2.3) and females (1.

Measles in adults in Canada and the United States: implications for measles elimination and eradication.

Background: Despite the implementation of mass school catch-up campaigns for measles in Canada, an outbreak of measles occurred in early 1997 mostly affecting the adult population. The higher incidence in Canada in adults led us to compare immunization policies and the evolution of measles among adults in Canada and the US.

Methods: Based on information gathered from both national immunization programmes and surveillance systems.

A Canadian multicentre case-control study of sporadic Escherichia coli 0157:H7 infection.

Objective: To evaluate further risk factors for Escherichia coli 0157:H7 infection including consumer preferences related to the consumption of ground beef and the role of person-to-person transmission of this infection.

Patients And Methods: A case-control study of sporadic E coli 0157:H7 infection was undertaken in five Canadian cites from June to December 1991. One hundred cases of E coli 0157:H7 infection were age- and sex-matched to 200 neighbourhood controls.

Perspectives on epidemiologic surveillance in the 21st century.

This paper describes the importance of epidemiologic surveillance as a systematic, ongoing and population-based system for early warning and program development in the 21st century. Such a system routinely collects data on three classes of indicators (health outcomes, risk factors and intervention strategies) to set up both an early warning system (to identify associations and make predictions on health outcomes) and a program development system (to assess the need for intervention strategies, to plan and implement such strategies and to assess their effectiveness). A comprehensive surveillance system must be systematic (evidence-based selection of indicators, not hypothesis-driven), ongoing (continuous data collection, including repeated surveys) and population-based (whole population, or representative samples of the population).

Saccharopolyspora rectivirgula from Quebec dairy barns: application of simplified criteria for the identification of an agent responsible for farmer's lung disease.

Saccharopolyspora rectivirgula (Micropolyspora faeni) is one of the major agents responsible for farmer's lung disease, a form of hypersensitivity pneumonitis. It is frequently isolated from the air of contaminated barns. The identification of this actinomycete is difficult because most of its phenotypic characteristics are variable and classical tests are not easy to perform on actinomycetes.

Identification and characterisation of a cytotoxic porin-lipopolysaccharide complex from Campylobacter jejuni.

A clinical isolate of Campylobacter jejuni, previously found to produce a toxin active in cell culture assays, was used for identification and characterisation of a cytotoxic porin-lipopolysaccharide (LPS) complex. This cytotoxic complex was isolated by high-performance liquid chromatography of crude concentrated culture supernate and DEAE-anion exchange chromatography. The complex had a toxic activity of 20.

Uses of ecologic studies in the assessment of intended treatment effects.

Because of the potential for confounding by indication (disease severity) in individual-level observational studies of intended treatment effects, a treatment designed to prevent an adverse event may appear to cause it. We use a hypothetical example to show that despite substantial variation in the frequency of treatment among patients residing in different geographic areas, a constant area-specific mortality rate can be observed, indicating the absence of confounding by indication at the ecologic level. The advantage of ecologic over individual-level observational studies in the assessment of intended treatment effects holds even if variations in disease severity, socioeconomic status, and other unmeasured factors are taken into account, as long as treatment utilization is influenced by practice style in the local medical community independently of disease severity.

Risk factors and course of illness among children with invasive penicillin-resistant Streptococcus pneumoniae. The Streptococcus pneumoniae Working Group.

Objectives: To assess differences in risk factors, clinical presentation, and course of illness between children infected with penicillin-sensitive and drug-resistant Streptococcus pneumoniae (DRSP).

Design: A retrospective cohort study conducted in Uruguay and Argentina using information from a hospital-based surveillance system. Hospitalized children 5 years of age and younger who had S pneumoniae isolated from a normally sterile site between June 1993 and October 1996 were eligible.

Measles vaccines: a review of adverse events.

A great deal of controversy has recently been generated over the publication of several articles implicating measles vaccine in the induction of Crohn's disease and autism. The publication of this work has already had a negative impact on measles vaccine acceptance in the UK. These allegations are particularly troubling because they arise in the context of increased use of measles vaccine as global control of measles nears and the international community considers strategies for a drive towards eradication.

Molecular Techniques for HIV and STDs : Implications for Research and Disease Control in the New Millennium.

Molecular techniques have gradually shifted the paradigm in the laboratory diagnosis of sexually transmitted infections from biological to molecular amplification. It is now possible to combine the sensitivity and specificity of culture with all the convenience of nonculture tests, such as ambient specimen transport, automation, and fast turnaround time. Pathogens that cannot be cultivated in vitro, such as the human papillomavirus (HPV), can now be detected and typed to determine if they have oncogenic potential.

Role of clinicians and public health professionals for measles surveillance in Canada.

The current strategy to eliminate measles in Canada requires stringent surveillance efforts including the laboratory confirmation of measles cases. Clinicians and public health professionals are involved with the events and actions surrounding the initial contact with suspected measles cases, identification of suspected measles cases, collection of the appropriate clinical information, collection of samples for laboratory confirmation and notification of the appropriate public health authority. Clinical information is necessary for the interpretation of laboratory results and is used, together with the laboratory results, to confirm measles cases.