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Biomedical subjects

S Grzybowski

Publications and source records attributed to S Grzybowski.

At least 37 records · Page 2Linked to original sources
PubMed1992

Deaths in tuberculosis patients in British Columbia, 1980-1984.

Records of all 1884 newly notified tuberculosis cases, over the 5-year period 1980-1984 in British Columbia, Canada, were reviewed and 201 deaths were identified, including 48 diagnosed only after death, and 153 who died while on treatment; 56 of unrelated causes, 67 in whom tuberculosis was a contributing cause, and 30 in whom it was the principal cause. Significant predictors of death while on treatment (specific to tuberculosis) were the extent of disease, history of previous disease and sputum smear-positive for acid-fast organisms. Significant predictors of failure of diagnosis, in patients who died, were the presence of disseminated disease and the absence of a history of previous disease. The presenting features were not different in those dying, in whom the diagnosis was made before, as compared with after, death. The most frequent mode of death due to tuberculosis was respiratory failure, followed by multiple organ system failure and haemoptysis. The case fatality rate was low (1.6%) and did not change over 10 years. One-half of patients whose death was due to tuberculosis were diagnosed only after death and this had not changed over 10 years. We conclude that death due to tuberculosis is uncommon in patients while on treatment and that the main reason for death due to tuberculosis is that some patients are not diagnosed, and therefore not treated, before they die of the disease.

Adult↗
PubMed1992

An estimate of the future size of the tuberculosis problem in sub-Saharan Africa resulting from HIV infection.

The impact of the human immunodeficiency virus (HIV) on tuberculosis is well documented. Its effect in populations with a high proportion of dually infected individuals is likely to be significant. Sub-Saharan Africa is one such region and to better document the effect of HIV infection on tuberculosis there we developed a mathematical model to predict the likely extra numbers of tuberculosis cases due to it. A mathematical model was developed using a variety of scenarios giving a range of risks for the period 1980-2000. The four scenarios included (1) a low rate of 1% risk of tuberculosis infection in year 0 (1980) with 45% tuberculosis infection prevalence, and an HIV prevalence of 2% in 1989; (2) a 2% risk of tuberculosis infection in year 0 with 60% tuberculosis infection prevalence, and a 2% HIV prevalence in 1989; (3) a 2% risk of tuberculosis infection in year 0 with 60% tuberculosis infection prevalence, and a 10% HIV prevalence in 1989; and (4) a 2% risk of tuberculosis infection in year 0 with 60% tuberculosis infection prevalence and a 20% HIV prevalence in 1989. Under scenarios 1 and 2, a 50-60% increase in smear-positive rates in the subpopulation (15-45 years old) is predicted for the year 2000, under scenario 3, smear-positive rates in the subpopulation in the year 2000 are expected to increase four-fold from the 1980 baseline. Under scenario 4, a 10-fold increase in smear-positive rates in 2000 is expected in the subpopulation. Under this scenario, total disease will have increased 12-fold in the subpopulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

A statistical chronicle of tuberculosis in Canada: Part I. From the era of sanatorium treatment to the present.

This report marks over 50 years of publication by Statistics Canada of annual reports on tuberculosis statistics. These years have witnessed what has been described as a conquest of tuberculosis in Canada. To quote George Jasper Wherrett in The Miracle of the Empty Beds: One hundred years ago the word consumption (as tuberculosis was then called) struck horror in human hearts. Today, in the western world, it barely evokes any emotion save a too easy surprise that it still exists. This statistical chronicle of tuberculosis in Canada is divided into two parts. Part I: From the Era of Sanatorium Treatment to the Present pulls together data from yellowed-with-age reports on tuberculosis and vital statistics, historical accounts and modern computer files, to document the changes in tuberculosis incidence and mortality over past decades to the present. Part II: Risk Today and Control takes a closer look at those most vulnerable to contracting tuberculosis. It also looks at the future, the need for maintaining and, indeed, strengthening vigilance, and the work yet to be done to eradicate tuberculosis in Canada. The fight against tuberculosis is far from over.

Adolescent↗
PubMed1992

A statistical chronicle of tuberculosis in Canada: Part II. Risk today and control.

This report marks over 50 years of publication by Statistics Canada of annual reports on Tuberculosis Statistics. These years have witnessed what has been described as a conquest of tuberculosis in Canada. To quote George Jasper Wherrett in the Miracle of the Empty Beds: One hundred years ago the word consumption (as tuberculosis was then called) struck horror in human hearts. Today, in the western world, it barely evokes any emotion save a too easy surprise that it still exists. This statistical chronicle of tuberculosis in Canada is divided into two parts. Part I: From the Era of Sanatorium Treatment to the Present pulls together data from yellowed-with-age reports on tuberculosis and vital statistics, historical accounts, and modern computer files, to document the changes in tuberculosis incidence and mortality over past decades to the present. Part II: Risk Today and Control takes a closer look at those most vulnerable to contracting tuberculosis. It also looks at the future, the need for maintaining and, indeed, strengthening vigilance, and the work yet to be done to eradicate tuberculosis in Canada. The fight against tuberculosis is far from over.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Tuberculosis in recent Asian immigrants to British Columbia, Canada: 1982-1985.

The prevalence and incidence of active tuberculosis among 21,959 recently arrived (1982-1985) immigrants from 7 selected Asian countries into British Columbia (BC), Canada, were reviewed. Among these newly arrived immigrants, 1173 (5.3%) were judged to have inactive tuberculosis at the immigration examination in their country of origin. In this subgroup, 14 of 932 (1.5%) were found to have active tuberculosis at the initial examination after arrival in Canada. Subsequently, 7 further cases arose in this group of inactive cases giving an average annual incidence rate of 0.33% over the 4-year period of study. Only 3 of these 21 cases had had previous antituberculosis chemotherapy. The remaining 20,786 recent immigrants with normal X-rays at the immigration examination contributed 30 cases during the next 4 years--an average annual incidence rate of 0.08% or 8 times the comparable rate for BC (0.01%). The limitations of the immigration screening process are illustrated and the value of early surveillance of immigrants designated as having inactive tuberculosis is underlined. The apparent failure to exclude active disease prior to the arrival of these immigrants is one factor elevating the incidence of active tuberculosis in the first few years after arrival in the host country. Other factors include the relatively high prevalence of inactive tuberculosis among the immigrants from certain countries and their high rate of early relapse after entry, especially in those not previously treated. Such immigrants should be considered for chemoprophylaxis immediately after entry.

Asia↗
PubMed1991

Natural history of tuberculosis. Epidemiology.

This Symposium honours the achievements of Dr Karel Styblo. In this presentation, specific epidemiologic insights are reviewed. Studies of the epidemiology of tuberculosis in Eskimos showed a picture of tuberculosis at the height of the epidemic. Very high incidence was observed in young people who experienced a high fatality rate. Application of specific control measures were accompanied by rapid decline in rates, greater than observed in any other human population, demonstrating that tuberculosis could be brought under control by specific intervention. Studies of the natural trend of tuberculosis in South India showed that, even in the absence of intervention, a decline was observed in the rates of this disease. In the absence of chemotherapy, 50 per cent of cases die within 5 years, 30 per cent recover spontaneously and 20 per cent remain sputum positive. Studies of the efficacy of BCG in Madras, enabled to study the impact of efficient case-finding associated with poor treatment results showing that such a situation multiplies the number of surviving, infectious cases in the community and, thus, actually deteriorates the epidemiological situation. These various basic studies have shown both how to create success and how to create failure in tuberculosis programmes.

Alaska↗
PubMed1989

Tuberculosis in British Columbia among immigrants from five Asian countries, 1982-85.

The influence of immigration from six selected Asian countries--Japan, Korea, Philippines, India, China and Hong Kong--on the incidence of tuberculosis in British Columbia has been examined. During the period 1982-1985 the average annual incidence of bacillary tuberculosis in these immigrants was more than six times as great as the overall British Columbia rate and contributed a quarter of the cases of active bacillary tuberculosis in this province whereas the immigrants from these countries represented only 3.7% of the total population. The clinical patterns of active tuberculosis by birthplace were analysed. A high proportion of cases of lymphadenitis was seen among all immigrants from Asia, particularly those from the Philippines. Both primary and secondary drug resistance was substantially higher than in Canadian-born patients. The frequency of primary drug resistance was higher among patients aged less than 40 years than those aged 40 or more.

British Columbia↗
PubMed1988

Respiratory health in chrysotile asbestos miners in British Columbia: a longitudinal study.

A respiratory survey was undertaken in chrysotile asbestos miners in British Columbia consisting of a questionnaire, spirometry, chest radiography, and physical examination. The tests were performed in 1977 and again in 1983. The population groups studied included 63 "exposed" (working in the plant more than nine years), 52 "controls" (working in the plant less than five years), and 38 residents of the village at the minesite. A subset of 39 was identified with high exposure (worked in the mill more than five years). Measured levels of environmental particulates were similar over the entire period of operation of the plant (1.4 to 14.0 million particles per cubic foot and 0.7-88.0 fibres/cc in the mill; 0.2 to 2.7 mpcf and 0.6 to 9.3 f/cc in the mine). The exposed groups were more likely to report cough and breathlessness than the two other groups and were also more likely to have abnormal FVC and chest x ray films (the latter not significant, p greater than 0.05) and to be more likely to have a combination of these abnormalities. There was no trend to progression in the combination of abnormalities associated with exposure on follow up. The heavily exposed group showed a significantly worse trend in FVC. This adverse trend was confined to those with initial abnormalities. Tobacco smoking did not increase the trend to progression in this group.

Adult↗
PubMed1987

An analysis of pulmonary tuberculosis data in Taiwan and Korea.

An analysis is carried out on pulmonary tuberculosis survey data from Taiwan and Korea. A mathematical model based on a Markov process is developed and used to estimate transition rates between various disease states, as well as certain 'infection parameters', which measure the strength of the relative contributions of different disease states and of endogenous reactivation to the incidence of tuberculosis in the population. It is found that endogenous reactivation plays a primary role in generating cases, followed by chronic sources of infection, particularly those with drug-sensitive organisms. Some recommendations are made with regard to optimizing treatment regimens. The methodology can easily be applied to other countries.

Adult↗
PubMed1987

Inner-city survey for tuberculosis: evaluation of diagnostic methods.

A total of 1,271 persons living in a socially and economically depressed, inner-city area of Vancouver, British Columbia, voluntarily attended a tuberculosis case-finding campaign. Chest x-ray, on-the-spot specimen of sputum, and tuberculin skin test were offered at the time of the first attendance. All 3 diagnostic methods were found to be well accepted, with 93% of the participants having an x-ray, over 95% producing a sputum specimen, and almost 95% having a tuberculin test (a quarter of these did not, however, report for reading of the test). Eight cases of bacteriologically confirmed pulmonary tuberculosis were found: 6 suspected on x-ray (the remaining 2 films were abnormal but not diagnostic of tuberculosis), and 6 being positive on smear and/or culture of the initial on-the-spot sputum specimen. Examination of a second specimen of sputum diagnosed all of the 8 active cases identified by the survey. These results suggest that, in this particular setting, a chest radiogram taken by a transportable chest x-ray apparatus or examination of 2 sputum specimens might be equally successful at detecting all cases of active pulmonary tuberculosis within the time required for sputum culture. Examination of the sputum smear immediately identifies all the more infectious cases of pulmonary tuberculosis. The prevalence rate of 629 per 100,000 among those presenting themselves to this campaign illustrates the high-yield which might be achieved by active case-finding projects in known high-incidence segments of a generally low-incidence population.

Adult↗
PubMed1987

Significance of the tuberculin test in the elderly.

Nine hundred thirty-three persons over 65 years of age, residing in long-term or extended-care facilities in Vancouver, Canada, had tuberculin tests. In addition to PPD-tuberculin, 5 TU and 250 TU, we used PPD-Battey, Candida albicans, mumps, and Trichophyton antigens. Twenty-five percent reacted to 5 TU of tuberculin with reactions of 10 mm or more. There was a progressive, substantial loss of reactivity with advancing age. Reactions to PPD-Battey greater than to PPD-T 5 TU were infrequent, suggesting that atypical mycobacterial infections were uncommon and that positive reactions to PPD-T, 250 TU, were predominantly caused by infections with Mycobacterium tuberculosis. Based on the results of both 5 TU and 250 TU, the prevalence of tuberculous infection exceeded 60 percent. Waning of tuberculin sensitivity appears to be an integral part of the aging process. Testing with nonmycobacterial antigens used in this study shed no further light on the problem of anergy in the elderly, as the number of reactors was smaller than that obtained with PPD-tuberculin.

Aged↗
PubMed1986

Incidence of active tuberculosis in the native population of Canada.

We analysed the incidence rates of active tuberculosis reported between 1970 and 1981 in three groups of people born in Canada: Inuit, registered Indians and others (mainly of European origin). While the rates of tuberculosis were quite low in the last group, which constitutes about 82% of the population of Canada, they were 16 times higher among Indians and 24 times higher among Inuit. Some 20 to 30 years ago the Inuit had the highest recorded rate of tuberculosis in the world; with an intensive program the rate decreased sharply. Such a program has not been implemented among the Indian population, and the incidence rate has not decreased as rapidly. A major effort is required to satisfactorily control tuberculosis among Indians. In addition, we must not allow our efforts to slacken in the control of tuberculosis among the Inuit.

BCG Vaccine↗
PubMed1985

Grain dust and respiratory health.

Exposure to grain dust gives rise to many respiratory problems. Since the growing, transporting and processing of grain are major Canadian industries, the number of individuals who might be affected by such exposure is sizeable. This paper describes clinical syndromes related to grain dust exposure, together with predisposing host factors, in an attempt to determine what levels of exposure are "safe" for workers and what areas still require extensive research.

Airway Resistance↗
PubMed1985

Isolation and geographic distribution of Mycobacterium other than M. tuberculosis in British Columbia, 1972-81.

It has been suggested that the incidence of infection with mycobacteria other than typical tubercle (MOTT) bacilli is increasing. Laboratory and epidemiologic information relating to MOTT infection in British Columbia between 1972 and 1981 was analysed. Patient records for 1960-81 were also analysed. Of the 313 661 laboratory specimens 13 474 yielded Mycobacterium tuberculosis isolates and 3172, MOTT isolates. Over the 10 years the number of M. tuberculosis isolates declined, whereas the absolute and relative numbers of MOTT isolates increased. Members of the highly drug-resistant MAIS complex (M. avium-intracellulare, M. scrofulaceum and M. simiae) accounted for 73.3% of the 1778 potentially pathogenic MOTT isolates. MAIS isolation rates varied geographically. Analysis of patient records revealed 217 MOTT infections, of which 152 (70%) were due to MAIS organisms. Further studies are needed to determine the source of MAIS organisms in order that the infection and the disease may be more clearly understood.

British Columbia↗