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D A Enarson

Publications and source records attributed to D A Enarson.

At least 55 records · Page 3Linked to original sources
PubMed2003

Epidemiology of tuberculosis on Gran Canaria: a 4 year population study using traditional and molecular approaches.

BACKGROUND: In recent years several population based studies using restriction fragment length polymorphism (RFLP) analysis have shown a higher rate of recent transmission of tuberculosis than previously thought. This study was undertaken to determine the transmission patterns of tuberculosis and the potential causes of recent transmission on the island of Gran Canaria (Spain). METHODS: The strains of all patients diagnosed with tuberculosis confirmed by culture between 1 January 1993 and 31 December 1996 were typed by RFLP using the insertion sequence IS6110. A cluster was defined as two or more isolates with an identical RFLP pattern. Epidemiological linkage through contact tracing was investigated. RESULTS: Of the total of 719 patients, 153 (21.3%) were excluded because there was inadequate bacterial DNA for genotyping (n=129) or the isolates of Mycobacterium tuberculosis had less than five copies of IS6110 (n=24). The isolates from 409 patients (72.3%) were grouped into 78 different clusters with an estimated 58.5% of the cases being due to recent transmission. Young age was the only significant predictor of clustering. Only in 147 (35.9%) of the 409 patients belonging to a cluster could an epidemiological link be found. 111 patients (19.6%) were identified as having had previous contact with a tuberculosis patient and 81 of them (72.9%) belonged to a cluster. The three largest clusters included 75, 49 and 20 patients, respectively. CONCLUSION: Recent transmission is frequent among patients with tuberculosis on Gran Canaria and could be associated with certain aspects of control measures. Some of the clusters described in the study could be due to the prevalence of particular strains of M tuberculosis on the island.

Adult↗
PubMed2003

Risk factors for recent transmission of Mycobacterium tuberculosis.

In recent decades, the decline of tuberculosis has stopped in Western Europe, mainly due to increased immigration from high-prevalence countries. The objective of the current study was to identify risk factors for developing tuberculosis following recent infection, in order to better target interventions. Strains from 861 culture-positive cases, diagnosed in Norway in 1994-1999, were analysed by use of restriction fragment length polymorphism (RFLP). A cluster was defined as two or more isolates with identical RFLP patterns. Risk factors for being part of a cluster were identified by univariate and multivariate analysis. A total of 134 patients were part of a cluster. These constituted 5% Asian-born, 18% Norwegian-born, 24% European-born and 29% African-born patients. Four independent risk factors for being part of a cluster were identified: being born in Norway, being of young age, being infected with an isoniazid-resistant strain and being infected with a multidrug-resistant strain. Transmission of tuberculosis may be further reduced by improving case management, contact tracing, preventive treatment, screening of immigrants and access to health services for the foreign-born population.

Adolescent↗
PubMed2003

Tuberculosis transmission patterns in a high-incidence area: a spatial analysis.

SETTING: In the Cape Town suburbs of Ravensmead and Uitsig, tuberculosis has reached epidemic levels, with notifications of 1340/100,000 in 1996. These suburbs are characterised by overcrowding, high unemployment and poverty. It is traditionally believed that tuberculosis transmission takes place mainly in households after close contact with an infectious person. Studies have recently linked tuberculosis transmission to locations outside the household, and have associated these places with a particular high-risk lifestyle. Anthropological studies in some suburbs of Cape Town, in which a very high number of local drinking places (shebeens) were identified (17 per km2), have suggested that social drinking is part of such a lifestyle. OBJECTIVE: To investigate various risk factors and places of transmission of tuberculosis using a geographical information system (GIS). RESULTS AND CONCLUSION: The 1128 bacteriologically-proven cases of tuberculosis studied over the period 1993-1998 were investigated using spatial epidemiological techniques of exploratory disease mapping. Point pattern analysis and spatial statistics indicated clustering of cases in the areas of high incidence. Significant associations of tuberculosis notifications were found with unemployment, overcrowding and number of shebeens per enumerator sub-district. High tuberculosis notifications with unemployment and its associated poverty emerged as the strongest association.

Adult↗
PubMed2003

The effect of decentralisation on tuberculosis services in three states of Sudan.

SETTING: Referral hospitals and primary health care (PHC) facilities in Khartoum, Red Sea and Gadaref States. OBJECTIVES: To measure the effect of the decentralisation of the tuberculosis (TB) services on the clinical profile and treatment outcome of tuberculosis. DESIGN: A cohort study of case detection and treatment outcome using information routinely collected comparing patients attending PHC facilities and referral hospitals in selected locations in Sudan. RESULTS: Two-thirds of all TB patients were diagnosed in referral hospitals and one-third in PHC facilities. In PHC facilities, women represented 46% of notified cases, compared to 37.9% in referral hospitals (OR 1.398, 95%CI 1.343-1.455). Older age groups were more likely to prefer PHC facilities to referral hospitals. In referral hospitals, 38% were cured, 29.3% completed treatment without smear examination and 17.3% defaulted, while in PHC facilities 58% were cured, 17.8% completed treatment without smear examination and 11.6% defaulted. CONCLUSION: PHC facilities provide care for a higher proportion of women and older age groups of tuberculosis patients, suggesting a higher level of accessibility for these groups. A higher cure rate and a lower default rate were noted in PHC facilities, possibly reflecting better conditions for directly observed treatment and follow-up.

Adolescent↗
PubMed2003

Symptoms in patients attending services for diagnosis of pulmonary tuberculosis in Sudan.

OBJECTIVE: To describe the variation in clinical features of individuals presenting to a health facility with chest symptoms according to their ultimate diagnosis. METHODS: Of 16735 patients (52.6% males and 47.4% females) presenting at respiratory centres in seven states in Sudan, 5338 patients were identified with respiratory tract symptoms: 2917 (54.6%) men and 2421 (45.4%) women, with a mean age of 32 years. Those who had cough for more than 3 weeks that was not responsive to a course of antibiotics were screened by microscopy of two or three sputum specimens and chest radiography. RESULTS: A total of 504 (9.44%) were smear-positive, 259 (4.85%) were smear-negative, and 166 (3.11%) had extra-pulmonary tuberculosis, of whom 59 (1.11%) had pleural involvement; the remaining 4409 suspects (82.6%) were non-tuberculous. CONCLUSION: Tuberculosis patients had a constellation of presenting symptoms, with the principal symptom being cough for more than 3 weeks. The accompanying symptoms with greatest predicted significance were weight loss, tiredness and night sweats.

Adolescent↗
PubMed2003

Global elimination of tuberculosis: implementation, innovation, investigation.

The elimination of a public health menace such as tuberculosis is always an attractive proposition. Is it realistic to consider? Selecting elimination as a target engages commitment, identifies challenges and stimulates critical evaluation. Challenges are numerous, including the large pool of latent infection, the long incubation period, the inadequacy of present tools and strategies, poverty and its relation to tuberculosis, the dependence on declining health services, the negative impact of human immunodeficiency virus infection, and the long-term commitment required with present approaches. Although tuberculosis has a tragic impact in causing death and chronic illness, the target for elimination must remain preventing infection, and the aim to achieve a generation free of infection. Targeting decreased mortality or improved health will not be sufficient to guide the critical reflection required to eliminate the causative organism; this can only be achieved by focusing on preventing and eliminating infection. While we have an international consensus on the strategy for controlling tuberculosis, we must also keep in mind that it is not sufficient. We must improve the current strategy as well as develop new tools on which we can base a new strategy if we hope to achieve the objective of elimination of tuberculosis. Reaching the target will require commitment to implementing what we currently have, improving on it in every way possible and keeping our minds and imaginations open to new ways to approach the fight against tuberculosis.

Global Health↗
PubMed2003

Controlling tuberculosis: we can't do it if we don't find the cases.

The current international strategy for the control of tuberculosis emphasizes two different targets: a high success rate for the treatment of tuberculosis cases with an emphasis on positive sputum smear cases and a high case detection rate. Recent analyses indicate that while progress is being made towards successful treatment, targets for case-finding are not being achieved.

Bias↗
PubMed2002

Occupational and environmental risk factors for respiratory symptoms in rural Beijing, China.

The aim of the present study was to determine the effects of occupational and environmental exposure on respiratory symptoms in adults in rural Beijing, China. Thirty randomly selected villages in the counties of Shunyi and Tongxian, 50 km north and east, respectively, of the city of Beijing, China, participated in this study. Village doctors interviewed all residents aged > or = 15 yrs and completed the International Union Against Tuberculosis and Lung Disease Questionnaire on Bronchial Symptoms translated into Chinese with added questions on smoking and occupational and environmental exposure. Of the eligible population, 22,528 adults (98%) took part. The prevalence of all respiratory symptoms, i.e. asthma-like symptoms, asthma attacks in the last 12 months, chronic cough and chronic phlegm, was low. Significant determinants for respiratory symptoms were age, sex, smoking and county of residence. A dose-dependent relationship was found between cumulative cigarette consumption and prevalence of respiratory symptoms. After adjusting for these variables, exposure to insecticides and fertilisers significantly increased the risk of most of the respiratory symptoms, whereas exposure to indoor air pollution from domestic fuels did not. Exposure to chemicals such as insecticides and fertilisers contributed independently to the risk of respiratory symptoms in rural Beijing, China.

Adolescent↗
PubMed2002

The prevalence of asthma and asthma-like symptoms among adults in rural Beijing, China.

No data have been reported on the prevalence of asthma in rural areas of China. The objective of the present study was to determine the prevalence of asthma-like symptoms, reported asthma and reported asthma attacks in rural Beijing, China, and to compare the prevalence in 20-44-yr-old participants with those reported for Canada and the European Community Respiratory Health Survey (ECRHS). For a cross-sectional survey, 30 villages were randomly selected in the counties of Shunyi and Tongxian, 50 km north and east respectively of the city of Beijing and within the municipality of Beijing. The International Union Against Tuberculosis and Lung Disease questionnaire on bronchial symptoms translated into Chinese was completed by village doctors for each individual of >15 yrs. The survey was completed by 22,561 individuals, representing 98% of the eligible population. The prevalence of asthma-like symptoms and reported asthma attacks was higher in females than in males and increased with age. Smoking significantly increased the prevalence of symptoms; the effect in females was greater than in males. Among the 20-44-yr-olds, the prevalence of reported asthma attacks in the previous 12 months was 0.67% in rural Beijing, very much lower than that reported in ECRHS centres (3.1%), urban Canada (6.9%) and semirural Canada (5.1%), after adjusting for age and sex. The prevalence of asthma-like symptoms was also very low in rural Beijing compared with ECRHS centres and Canada. It is concluded that the prevalence of asthma-like symptoms and reported asthma was low in rural China compared with other countries, consistent with reports of the relative scarcity of asthma in farms and the "hygiene hypothesis".

Adolescent↗
PubMed2002

Epidemiology of tuberculosis in Kuwait from 1965 to 1999.

BACKGROUND: After several decades of continuous decline, the incidence of tuberculosis (TB) has increased over the last 10 years in several regions of the world. No reports have been published describing the epidemiology of TB in Kuwait. OBJECTIVES: To examine the trend of TB in Kuwait from 1965 to 1999 and analyse the factors associated with this trend. METHODS: Annual reports of the Kuwait central TB unit were examined. Tuberculosis registers recommended by the World Health Organization (WHO) and the International Union Against Tuberculosis and Lung Disease (IUATLD), which were available for the years 1998 and 1999, were also examined. RESULTS: The notification rate of TB for the whole population has declined from 259 per 100000 in 1965 to 24/100000 in 1999. There has been a steeper decline among Kuwaiti nationals, from 355/100 000 in 1965 to 14/100000 in 1999. The average annual rate of decline in all cases of TB among Kuwaiti nationals was 11.9% from 1965 to 1976, and 11.0% from 1976 to 1989, but there was a slight rise of 4.3% per year from 1989 to 1999. The average annual rate of decline in all cases of TB among non-nationals was 6.3% from 1965 to 1976, and 8.3% from 1976 to 1989, but there was a rise of 2.3% per year from 1989 to 1999. CONCLUSION: Tuberculosis in Kuwait declined steadily from 1965 to 1989. Since 1989 there has been a slight rise in TB incidence in Kuwait among both Kuwaiti nationals and non-nationals.

Adolescent↗
PubMed2002

The impact of national health insurance on the notification of tuberculosis in Taiwan.

SETTING: General notification of tuberculosis in Taiwan. OBJECTIVES: To ensure the completeness of notification of tuberculosis (TB) in Taiwan, the Bureau of National Health Insurance (NHI) introduced two policies in 1997: 1) the no-notification-no-reimbursement (NNNR) policy, and 2) the notification-fee (NF) policy. The goals of this study were to investigate the impact of the NNNR and NF policies on notification of TB. DESIGN: Review of all cases notified to the National TB Register from 1995 to 1999 to determine calendar trend, type of case and source of notification. RESULTS: There were 11,453 and 13,612 reported cases in 1995 and 1996, respectively. Following the implementation of the NHI policies, there was a 47% increase in 1997, with 20 021 reported cases. Quarterly reporting of cases reached a historic peak in the third quarter of 1997. The increase in reported cases was mainly from general hospitals/clinics. Since 1998, the number of reported cases has declined steadily, at a rate of 7% and 3% in 1998 and 1999, respectively. CONCLUSIONS: The NNNR and NF policies had a significant impact on notification of TB in Taiwan. These policies substantially improved completeness of reporting, an observation with implications for surveillance of other reported diseases.

Disease Notification↗
PubMed2002

Treatment results of DOTS in 1797 Sudanese tuberculosis patients with or without HIV co-infection.

SETTING: Consecutive new tuberculosis (TB) patients, from eight states in Sudan, who had never been previously treated for as much as 1 month between 1998 and 2000. OBJECTIVE: To determine the impact of human immunodeficiency virus (HIV) co-infection on tuberculosis treatment outcome. DESIGN: All patients presenting with symptoms suggestive of tuberculosis underwent sputum microscopy for acid-fast bacilli (AFB). Treatment is free of charge, and directly observed for all smear-positive patients. Treatment outcomes were those defined by the World Health Organization. All patients were tested anonymously for human immunodeficiency virus (HIV) using the Bionor test. RESULTS: Of 10 494 patients suspected of TB and referred for sputum microscopy, 1797 were TB cases; 983 had smear-positive pulmonary tuberculosis, 521 smear-negative pulmonary tuberculosis, and 293 extra-pulmonary tuberculosis. Smear-positive cases showed a cure rate of 77.2% and a failure rate of 1%. Smear-negative and extra-pulmonary patients had a completion rate of 79.4%. Cure rates for the smear-positive cases were 68.3% for HIV-positive and 77.6% for HIV-negative patients (P = 0.164). Case fatality was significantly higher among HIV-positive (12%) than among HIV-negative cases (1.8%) (OR 7.7, 95% CI 3.51-16.8). CONCLUSION: To date, a relatively low proportion of tuberculosis patients in Sudan also have HIV infection. These patients are substantially more likely to die while on treatment for their tuberculosis, a fact that underlines their need for more comprehensive care if their lives are to be prolonged. In addition, every effort is required to diminish the transmission of HIV infection to prevent the tragedy this infection represents to the community.

Adolescent↗
PubMed2001

Epidemiological evidence of the spread of a Mycobacterium tuberculosis strain of the Beijing genotype on Gran Canaria Island.

Molecular epidemiological studies suggest that particular Mycobacterium tuberculosis strains have an enhanced capacity to spread within a community. One strain, the Beijing genotype, has been associated with outbreaks in a number of communities throughout the world. IS6110 restriction fragment length polymorphism (RFLP) analysis was performed on M. tuberculosis isolates from 566 of the 721 patients (78.5%) diagnosed with tuberculosis (TB) on Gran Canaria Island from 1993 to 1996, as well as 35% of isolates from 1991-1992 (85 strains). RFLP identification of the family of strains of the Beijing genotype was confirmed by spoligotyping. Medical records of all patients were reviewed and epidemiological links were identified. Of 566 M. tuberculosis isolates from 1993 to 1996 with RFLP available, 72% belonged to clusters. The largest contained 75 cases and was caused by a strain of the Beijing genotype that was introduced to the island in 1993. It was found in 10 patients in 1993 (5.5%), 12 in 1994 (8.1%), 18 in 1995 (16.4%), and 35 in 1996 (27.1%). Epidemiological linkage was confirmed for 68% of cases. This study has demonstrated rapid dissemination of this strain of the Beijing genotype. This genotype might play an important role in the future of the worldwide tuberculosis epidemic.

Adolescent↗
PubMed2001

The tuberculosis pandemic today: routes of transmission and new target groups.

Tuberculosis, a disease that has been with us since the dawn of time, shows little sign of disappearing. Declines in death rates observed for several centuries prior to 1960 have been reversed in recent decades. This is in spite of the fact that efficient means of controlling the disease have been available during this period. This article reviews experience in 3 communities: among the Inuit, who live in the region of the North Pole; in the Beijing Municipality in the People's Republic of China; and in a socially isolated community in South Africa. In the first 2 communities, dramatic declines in the burden of disease have been observed: in the Inuit community, this occurred after substantial intervention; in the Beijing Municipality it was done with limited resources. The third community in South Africa illustrates an alarming trend, with tuberculosis being seen in a variety of locations but in the absence of external agents such as HIV infection. Clearly we need to refocus our efforts to control this disease, making use of the new tools that are rapidly becoming available. This must be done without delay, before influences such as HIV infection put the possibility of control completely out of reach.

Arctic Regions↗
PubMed2001

Analysis for a limited number of gene codons can predict drug resistance of Mycobacterium tuberculosis in a high-incidence community.

Correct and rapid diagnosis is essential in the management of multidrug-resistant tuberculosis (MDR-TB). In this population-based study of 61 patients with drug-resistant tuberculosis, we evaluated the frequency of mutations and compared the performance of genotypic (mutation analysis by dot blot hybridization) and phenotypic (indirect proportion method) drug resistance tests. Three selected codons (rpoB531, rpoB526, and katG315) allowed identification of 90% of MDR-TB cases. Ninety percent of rifampin, streptomycin, and ethambutol resistance and 75% of isoniazid resistance were detected by screening for six codons: rpoB531, rpoB526, rrs-513, rpsL43, embB306, and katG315. The performance (reproducibility, sensitivity, and specificity) of the genotypic method was superior to that of the routine phenotypic method, with the exception of sensitivity for isoniazid resistance. A commercialized molecular genetic test for a limited number of target loci might be a good alternative for a drug resistance screening test in the context of an MDR "DOTS-plus" strategy.

Bacterial Proteins↗
PubMed2001

Exogenous reinfection with tuberculosis on a European island with a moderate incidence of disease.

The frequency and determinants of exogenous reinfection and of endogenous reactivation of tuberculosis in patients previously treated are poorly understood. In Gran Canaria Island, Spain, between 1991 and 1996, 962 tuberculosis cases were confirmed by culture. Drug susceptibility testing was performed on available bacterial isolates and IS6110-based RFLP genotyping was carried out. Twenty-three patients (2.4%) had two positive cultures separated by at least 12 mo, 18 of whom had bacterial DNA available for genotypic analysis. The initial and final isolates from eight (44%) were different genotypes, indicating exogenous reinfection. Six of them were retreated after cure and two retreated after default. Six were HIV seronegative and two were HIV seropositive. Endogenous reactivation was seen in the remaining 10 patients of whom eight were retreated after default and two after cure. Three of the eight (38%) being retreated after default developed multidrug resistance. One genotype was responsible for a second episode of tuberculosis in five cases, three exogenous reinfections and two endogenous reactivations. In the context of a moderate incidence of tuberculosis, exogenous reinfection is an important cause of TB recurrence, even in HIV-seronegative patients.

Adult↗