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Biomedical subjects

W A Cronin

Publications and source records attributed to W A Cronin.

10 recordsLinked to original sources

Delayed tuberculosis diagnosis and tuberculosis transmission.

SETTING: Tuberculosis (TB) patients and their close contacts reported to the Maryland Department of Health and Mental Hygiene from 1 June 2000 to 30 November 2001. OBJECTIVES: A recent prospective study found that 49% of pulmonary TB patients had total treatment delays > or = 90 days. This cohort was analyzed to determine the association between total treatment delay and TB transmission. DESIGN: TB patient data were collected as part of a prospective cohort study; contact data were collected from local health departments. RESULTS: Close contacts of 54 US-born patients (n = 310) and those of 70 foreign-born cases (n = 393) received tuberculin skin tests (TSTs). Among contacts of US-born patients with a total treatment delay of > or = 90 days, 40% had positive TSTs vs. 24% contacts of patients with shorter delays (aOR 2.34; P = 0.03). Other patient factors associated with TST positivity among contacts of US-born cases were black race (aOR 3.03; P = 0.05), sputum smear positive for AFB (aOR 3.29; P = 0.01) and chest radiograph with cavitation (aOR 3.11; P = 0.01). No associations were observed between foreign-born patients and risk of TST positivity among their contacts. CONCLUSION: Among US-born patients, delay in TB diagnosis is associated with greater transmission of infection to contacts and could be used independently of other index patient factors to identify contacts at greatest risk of TB infection.

Contact Tracing↗

Impact of empiric antibiotics and chest radiograph on delays in the diagnosis of tuberculosis.

SETTING: Maryland Department of Health and Mental Hygiene, Division of Tuberculosis (TB) Control. OBJECTIVES: To assess the implications of antibiotic treatment of presumed community-acquired pneumonia (CAP) on delays in the diagnosis of TB, and to assess the frequency with which chest radiographs (CXRs) were utilized before a diagnosis of pneumonia or pulmonary TB was made. DESIGN: A nested case-control study within a prospective study conducted to assess factors associated with delays in the diagnosis of TB. RESULTS: Cases (n = 85; 54%) were patients who received antibiotics for non-TB diagnoses/indications prior to TB diagnosis, and controls (n = 73; 46%) were patients who had initially received TB therapy. Median health care delay for cases was 39 days vs. 15 days (P < 0.01) for controls. Median antibiotic delay was similar among all antibiotic classes. Of 54 patients who did not have a CXR at their first health care visit, 41 (79%) received empiric antibiotics, compared to 44/105 (42%) who had a CXR (P < 0.01). Only 31/54 (57%) patients initially diagnosed with CAP had a CXR at the time of diagnosis. CONCLUSION: More widespread use of CXR when diagnosing CAP should reduce delays in diagnosing TB, and the unnecessary use of antibiotics.

Adult↗

Patient and health care system delays in pulmonary tuberculosis diagnosis in a low-incidence state.

SETTING: Tuberculosis (TB) patients reported to the Maryland Department of Health and Mental Hygiene from 1 June 2000 to 30 November 2001. OBJECTIVE: To determine the extent of delayed diagnosis of TB and to assess patient and provider factors associated with delays. DESIGN: A prospective cohort study. RESULTS: Median patient, health care and total delays were 32, 26 and 89 days, respectively, for 158 patients. Non-white (relative hazard [RH] 0.62; 95% CI 0.39-0.98) and less educated (RH 0.43; 95% CI 0.26-0.72) patients had longer patient delays. English-speaking patients (RH 0.40; 95% CI 0.24-0.68) had increased health care delays, as did patients who received a diagnosis of a respiratory illness and non-TB antibiotics (RH 0.69; 95% CI 0.49-0.96) prior to a TB diagnosis. Patients first presenting to a private physician (51 days) rather than a hospital emergency room (18 days; RH 1.87; 95% CI 1.05-3.33) or public health clinic (10 days; RH 1.79; 95% CI 1.21-2.63) had longer health care delays. When a TB diagnostic tool (chest radiograph or AFB culture) was utilized, a more rapid diagnosis of TB was made. CONCLUSION: Education of the patient population about TB symptoms might reduce delays. Increased physician awareness of the current epidemiology of TB and better use of available diagnostic tools will reduce delays and may reduce TB transmission.

Female↗

Evaluation of an extensive tuberculosis contact investigation in an urban community and jail.

SETTING: Urban community and jail. OBJECTIVES/DESIGN: Evaluate outcome and process of an extensive tuberculosis contact investigation, including completion of treatment of latent TB infection (TLTBI). RESULTS: Between April 2000 and September 2001, 18 epidemiologically-linked tuberculosis cases were identified; 15 were culture-confirmed, all with a matching 14-band DNA fingerprint pattern. The source case had cavitary pulmonary disease and had been incarcerated 4 months prior to diagnosis. Sixty-six of 67 (99%) community contacts and 221/344 (64%) jail contacts were evaluated. The presumed new infection rate was 56% for community contacts (11 cases, 25 tuberculin skin test [TST] positive) and 20% for jail contacts (6 cases, 32 TST converters). Screening results for 113 (33%) jail contacts were obtained in the jail TST registry upon rearrest. All identified cases completed treatment. Of 22 community contacts initiating TLTBI, 11 completed (44% of infected, 50% of initiators). Of 32 infected jail contacts, 12 initiated TLTBI (all who remained incarcerated), and 10 completed (31% of infected, 83% of initiators). None of 20 additional in-fected jail contacts, all of whose TST conversions were identified with re-arrest data, were subsequently located. Two additional related cases have been identified as of October 2003. CONCLUSIONS: Close health department/corrections collaboration facilitated this extensive contact investigation, which identified high Mycobacterium tuberculosis transmission rates and controlled the outbreak. Numerous contacts were identified and screened, but rates of treatment completion for infected contacts were low. Novel strategies are needed to maximize the number of infected contacts who are not only identified and evaluated, but completely treated.

Adolescent↗

Transmission of Mycobacterium tuberculosis through casual contact with an infectious case.

BACKGROUND: An ongoing restriction fragment length polymorphism study of Mycobacterium tuberculosis isolates from tuberculosis cases showed an identical 12-band IS6110 pattern unique to 3 unrelated patients (Patients A-C) diagnosed as having tuberculosis within a 9-month period. METHODS: In an attempt to identify epidemiologic links between the 3 patients, we performed site visits to the retail business work site of patient A and conducted detailed interviews with all 3 patients and their contacts. RESULTS: Patient B had visited patient A's work site 3 times during patient A's infectious period, spending no more than 15 minutes each time. Patient C visited patient A's work site on 6 to 10 occasions during this period for no more than 45 minutes at any one time. There were no other epidemiologic links between these 3 cases other than the contact at the store. Contact investigation identified 4 tuberculin skin test conversions among 8 (50%) of patient A's coworkers, 6 positive tests among 15 household contacts (40%), and 8 positive tests among 16 identified customers who were casual contacts (50%). Patient B and patient C were most likely infected by patient A during one of their brief visits to patient A's work site. CONCLUSIONS: These data demonstrate that some tuberculosis is spread through casual contact not normally pursued in traditional contact investigations and that, in certain situations, M tuberculosis can be transmitted despite minimal duration of exposure. In addition, this outbreak emphasizes the importance of DNA fingerprinting data for identifying unusual transmission in unexpected settings.

Adult↗

Epidemiologic usefulness of spoligotyping for secondary typing of Mycobacterium tuberculosis isolates with low copy numbers of IS6110.

Restriction fragment length polymorphism (RFLP) analysis of IS6110 is commonly used to DNA fingerprint Mycobacterium tuberculosis. However, low-copy (< or =5) IS6110 M. tuberculosis strains are poorly differentiated, requiring secondary typing. When spoligotyping was used as the secondary method, only 13% of Maryland culture-positive tuberculosis (TB) patients with low-copy IS6110-spoligotyped clustered strains had epidemiologic linkages to another patient, compared to 48% of those with high-copy strains clustered by IS6110 alone (P < 0.01). Spoligotyping did not improve a population-based molecular epidemiologic study of recent TB transmission.

Aged↗

Transmission of Mycobacterium tuberculosis by a fiberoptic bronchoscope. Identification by DNA fingerprinting.

CONTEXT: An ongoing restriction fragment length polymorphism (RFLP) study of Mycobacterium tuberculosis isolates from tuberculosis (TB) cases revealed an identical 10-banded IS6110 RFLP pattern unique to 2 patients diagnosed as having TB 6 months apart. Their only identifiable link was care at the same hospital. OBJECTIVE: To determine if nosocomial transmission had occurred. DESIGN: Traditional and molecular epidemiologic investigation. MEASUREMENTS: We reviewed medical charts and bronchoscopic records, examined hospital locations visited by both patients, evaluated hospital ventilation systems, and observed cleaning and disinfection of bronchoscopes. RESULTS: A patient with cough, hoarseness, and fever underwent bronchoscopy and was diagnosed as having TB. A second patient with a mediastinal mass underwent bronchoscopy 2 days later and was diagnosed as having small cell carcinoma. Following 6 months of chemotherapy and radiation therapy, the second patient developed fever and an infiltrate of the right upper lobe of the lung. Bronchoscopic washings revealed acid-fast bacilli and were culture positive for M tuberculosis. Both patients had undergone bronchoscopy with the same instrument in the same operating room with no intervening bronchoscopies. Bronchoscope cleaning and disinfection procedures were inconsistent with national guidelines. CONCLUSIONS: A contaminated bronchoscope was the most likely source of M tuberculosis transmission between these 2 patients. The RFLP analysis of M tuberculosis isolates was responsible for detecting this nosocomial source of transmission and led to the implementation of public health measures to prevent further spread of infection and disease. This study emphasizes the need for continued vigilance in endoscope cleaning techniques.

Adult↗

Intravascular catheter colonization and related bloodstream infection in critically ill neonates.

Intravascular catheter tip colonization was prospectively evaluated in critically ill neonates to determine its relationship to the type of device used, duration of catheterization, insertion site and nosocomial bloodstream infection. Sixty-one percent (376 of 621) of all intravascular catheter tips were retrieved from 91 infants. Thirteen percent (41 of 310) of peripheral intravenous, 14% (6 of 42) of umbilical, 21% (3 of 11) of central venous, 36% (4 of 11) of peripheral arterial and 100% (2 of 2) of femoral catheters were colonized. Duration of catheterization was significantly longer for colonized lines (p less than .001). Eight of 26 (30.8%) peripheral intravenous catheters remaining in place for more than three days were colonized, compared with 33 of 284 (11.6%) at three days or less (p = 0.012). Coagulase-negative staphylococcus was the organism most frequently isolated from catheter tips and bloodstream infections. Catheter colonization rates in this population were higher than those found in adults. Heavily manipulated devices and those in place for longer periods of time were the most frequently colonized.

Age Factors↗

Obstetric infection control in a developing country.

In Ghana, infection has been identified as a major cause of birth-related mortality. Results of a 2-month observation of infection control practices among Ghanaian obstetric nurses and midwives indicated that most personnel did not practice basic rules of asepsis. Problems included frequent breaks in technique, inadequate sterilization and disinfection, and repeated exposure to large amounts of blood and vaginal secretions. Supplies were limited and, even when available, not always used appropriately. The situation in developing countries is different from that in the United States. Therefore, an observational needs assessment is essential to plan relevant and practical measures for change.

Cesarean Section↗