The use of environmental factors as adjuncts to traditional tuberculosis contact investigation

SETTING

A 25-year-old university student was diagnosed with cavitary pulmonary and laryngeal tuberculosis following symptoms of underlying cough of 6 months' duration.

OBJECTIVES

To estimate the hourly risk of infection (HRI) and examine the role of environmental factors, including room size and ventilation, in modulating this risk.

METHODS

Contact investigation.

RESULTS

Of 1100 contacts identified, 78.3% (n = 896) received a tuberculin skin test (TST), of whom 27.5% had a positive result. Among 634 Canadian-born contacts tested, 22.7% had a positive TST. The independent risk factors for a positive TST among Canadian-born university students were: > 35 h spent with the index case (adjusted OR 6.6, 95% CI 1.0-44.9) and smaller classroom size (aOR 5.0, 95% CI 1.4-10.0). In the first school term, the HRI among Canadian-born student contacts was 0.9%; in the second term, it was 1.6%.

CONCLUSION

There are inherent limitations in generalising findings from an outbreak investigation, due to the considerable variation in the infectiousness of cases. Nevertheless, in situations where the index case has a high degree of infectiousness, and there are numerous contacts with low expected prevalence of infection, the HRI can, together with ventilation measurements, be useful in guiding the extent of contact investigation needed.

DOTS implementation in a middle-income country: development and evaluation of a novel approach

BACKGROUND

DOTS is widely accepted as the most cost-effective strategy for tuberculosis (TB) control. However, there is little published information regarding methods for implementation in middle-income countries.

METHODS

Over 3 years, the Canadian Lung Association assisted the Ecuadorian TB programme to implement DOTS for over half the nation's total population. A multilevel strategy developed by a team of Ecuadorian health professionals provided initial, in-service, replica and reinforcement training at the local level, and training at national level for specialist physicians, specialist societies and medical schools. Evaluation was based on international guidelines for case finding, treatment and laboratory quality control, and costs of all implementation activities.

RESULTS

By January 2004, DOTS training had been provided to 1954 health professionals and 199 smear microscopy technicians, and DOTS was implemented in all 496 health facilities. Case detection activities at the local level increased substantially. Cure and treatment completion improved to 83% of new cases. Overall concordance of laboratory quality control readings was 98.7%. The total cost of DOTS implementation was US dollar 3 049 585.

CONCLUSIONS

To achieve international targets for TB control, DOTS implementation in a middle-income country required intensive training at the local level and at multiple other levels.

Testing for HIV among patients with tuberculosis in Montreal

OBJECTIVE

To determine the rate of HIV testing among patients with tuberculosis (TB) in Montreal, and to identify patient characteristics associated with physician screening patterns. Knowledge of local patterns of HIV testing among patients with TB could be used to facilitate the development of strategies to improve compliance with recommendations that all patients with TB be screened for HIV.

DESIGN

Retrospective chart review.

PATIENTS

All patients with TB reported to the Montreal Public Health Unit from 1992 to 1994 (ages 19 to 50) and from 1992 to 1995 (ages 18 and under) and for whom a chart could be reviewed.

OUTCOME MEASURES

Patients with TB screened versus not screened for HIV infection, analyzed to determine which variables independently predict the likelihood of screening for HIV infection.

RESULTS

Of the 376 patients with TB for whom data were available, 192 (51%) were screened for HIV. Of those, 33 (17%) had been tested before having received the diagnosis of TB. Multivariate analysis revealed that patients with TB who were male, aged 30 to 39, had a positive sputum smear, displayed at least 1 clinical symptom, received the TB diagnosis from a microbiologist or infectious disease specialist, or reported 1 or more HIV risk factors were more likely to be screened for HIV.

CONCLUSIONS

HIV screening of patients with TB is selective, depending on both patient and physician characteristics. Physicians' awareness of recommendations needs to be increased to improve the diagnosis and treatment of TB/HIV co-infection.

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.

Compliance of frail elderly with health services prescribed at discharge from an acute-care geriatric ward

OBJECTIVES

A model of compliance by frail elderly with prescribed healthcare services was developed and tested. The discrepancy between primary care, geriatric and community health center (CLSC) services prescribed at discharge after comprehensive geriatric evaluation and treatment was measured, as were those services actually used during a 6-week interval (compliance). In this model, compliance was directly related to elders' intention to adhere to prescribed services, but this relationship was modified by organizational factors, reinforcing factors, and changes in health status during the observation period. Intention to adhere resulted from individual and reinforcing factors existing before discharge.

METHODS

This model was tested on 211 patients discharged to community settings from an acute-care hospital geriatrics ward. Information was obtained through interviews with the patients or care givers and from hospital, outpatient, and local community health center charts.

RESULTS

On average, patients used 56.9% of services prescribed; 13% of patients did not use any of the services prescribed for them, whereas 22% used all the services prescribed. Intention to adhere was influenced by patients' perception of the benefits of prescribed services and by their perception of the ease of access to transportation. Intention itself was not found to be an important determinant of overall compliance. Among organizational factors, having the ward staff make a follow-up appointment with the patients' family doctor and with the geriatric clinic before discharge and communication with the local community health center increased overall compliance. Moreover, patients who perceived they had access to transportation and to an accompanying person were more likely to comply.

CONCLUSIONS

The results suggest that when discharging patients to the community, steps taken for them by the discharging healthcare providers will improve compliance.

Prevalence of tuberculin skin test reactions among prison workers

OBJECTIVE

To determine the prevalence of positive tuberculin skin test (TST) reactions (10 mm or greater) among full-time employees of a provincial prison for women in Montreal.

METHODS

Participants underwent tuberculin skin testing and completed a self-administered questionnaire.

RESULTS

Among 129 employees identified, 118 (91%) underwent tuberculin testing. Among 102 born in Quebec who completed the questionnaire, 33 (32%) had positive TST reactions, including 12 (23%) of 52 subjects who had never been vaccinated. Positive TST reactions were significantly associated in multivariate analysis with BCG vaccination after infancy (OR = 4.5, 95% CI = 1.5-13.5), years of work at other provincial prisons (OR = 2.5 for each 5 years of work, 95% CI = 1.2-5.2), travel to tuberculosis endemic countries (OR = 7.7, 95% CI = 1.4-43), although not with work in the prison for women (OR = 1.3, 95% CI = 0.9-1.9)

CONCLUSION

The prevalence of positive TST reactions was greater among workers at a provincial prison for women than among a sample of students, suggesting increased occupational risk of tuberculosis infection.

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.

An approach to the development of practice guidelines for community health interventions

The Community Health Practice Guidelines (CHPG) project was initiated to develop a systematic approach to the critical evaluation of evidence on the effectiveness and efficiency of community health interventions and to the formulation of evidence-based practice recommendations. Three community health interventions--immunization delivery methods, partner notification for sexually transmitted diseases and the combination of restaurant inspection and education of food handlers--were used as prototypes to develop a standardized approach. The CHPG process consists of three components: a review of scientific evidence, a practice survey and formulation of practice guidelines. Imperatives for further development of the CHPG and define research priorities process include creating a coalition of public health organizations to sponsor the process and refining the consensus process so that the practice guidelines accurately reflect both the scientific basis of public health practice and the values of those affected.

Knowledge of nephrologists and patients about autosomal dominant polycystic kidney disease (ADPKD)

Because of the availability of presymptomatic testing for autosomal dominant polycystic kidney disease (ADPKD), we assessed the response of nephrologists, patients, and at-risk relatives to the introduction of a genetic counselling program for ADPKD. Fifty-six of seventy-six nephrologists responded. Ninety-eight percent reported 'generally' telling their patients that the disease was hereditary, but fewer reported screening relatives (81% for children and 70% for siblings and parents). Ninety percent were interested in referring patients to the service. Fourteen of the 24 patients in one renal clinic and 18 of their at-risk relatives were interviewed. Ten of the patients but only five of the relatives stated that the disease was hereditary. The precise mechanism of inheritance was poorly understood by most patients and relatives. Of 21 patients offered genetic counselling, nine made appointments to see the genetic counsellor. There remains a large gap between advancing technology and the delivery of information to at-risk populations.

Presymptomatic Diagnosis of Genetic Disorders: Is it worth the anxiety?

Through recent advances in DNA technology, presymptomatic diagnosis of several genetic disorders is now possible. This technology can determine whether an at-risk individual is at greatly increased risk of having inherited the gene for a particular disorder many years before symptoms are expected to occur. To provide effective care, the family physician must be aware of the potential benefits and risks of presymptomatic testing.

Measuring health status: an approach for family practice researchers

Research in family practice frequently involves the measurement of subjects' perceived health status. Those who are unfamiliar with this area may find the task difficult and frustrating. This paper offers an approach to the selection and assessment of measures of health status and specifically examines issues of feasibility, instrument content, appropriateness for subjects, instrument construction, reliability, validity, sensitivity to change, and measurement strategy.

Early detection and treatment of hyperlipidemia: physician practices in Canada

We surveyed primary care physicians in Canada to determine their current practices regarding the detection and treatment of hyperlipidemia in asymptomatic adults 20 years of age or more and to determine the role of selected patient characteristics (age, sex and the presence of coronary heart disease [CHD] risk factors) in their management decisions. The self-administered questionnaire was completed by 428 of 804 family physicians and general practitioners. The proportion of physicians who reported having tested at least 50% of their adult patients varied from 29% to 85% and was related to the number of CHD risk factors present and the patient's age. The proportion of respondents who reported starting dietary or drug therapy among patients with a cholesterol level of 6.2 mmol/L or less increased as the number of CHD risk factors increased and was not related to patient age or sex. According to the factors examined our results suggest that primary care physicians in Canada select patients for screening and treatment mainly on the basis of CHD risk factors present and that their approach is more conservative than that recommended by the Canadian and US consensus conferences.

Risk of fractures in an intermediate care facility for persons with mental retardation

The epidemiology of fractures among 553 residents of an intermediate care facility for persons with mental retardation was examined. In a 10-month period, 61 fractures occurred among 55 residents; application of fracture rates in the United States revealed an expected number of 15 fractures among the 553 residents, p less than .001. Although 52% of fractures involved small bones of the hands and feet, elderly residents were more likely to fracture major bones and to suffer their fractures from a fall than were younger residents. The relationship between potential risk factors and fracture risk were examined and implications for preventive and rehabilitative measures discussed.