HIV counseling and testing in tuberculosis contact investigations in the United States and Canada.

BACKGROUND: Determining the human immunodeficiency virus (HIV) status of tuberculosis (TB) patients and contacts is important. Despite existing guidelines, not all patients are tested, and testing of contacts is rarely performed. METHODS: In a study conducted at nine US/Canadian sites, we introduced formal procedures for offering HIV testing to TB patients and contacts. Data were collected via interviews and medical record review. Characteristics associated with offering and accepting HIV testing were examined. RESULTS: Of 651 TB patients, 601 (92%) were offered testing, 511 (85%) accepted, and 51 (10%) were HIV-infected. Of 4152 contacts, 3099 (75%) were offered testing, 1202 (39%) accepted, and 24 (2%) were HIV-infected. Contacts aged 15-64 years, non-Whites, foreign-born persons, smokers, those with positive TB screening, and household contacts were more likely to be offered testing, whereas contacts exposed to HIV-negative patients were less likely to be offered testing. Contacts aged 15-64 years, smokers, drug/alcohol users, diabetics, and those with positive TB screening were more likely to accept testing. Foreign-born persons, Blacks, Hispanics, and contacts exposed to HIV-positive patients were less likely to accept testing. CONCLUSIONS: High rates of HIV were detected among patients and contacts. Despite structured procedures to offer HIV testing, some patients and most contacts did not accept testing. Strategies are needed to improve testing acceptance rates.

Cardiovascular parameters in a mixed-sex swine study of severe decompression sickness treated with the emulsified perfluorocarbon Oxycyte.

Intravenous perfluorocarbons (PFC) have reduced the effects of decompression sickness (DCS) and improved mortality rates in animal models. However, concerns for the physiological effects of DCS combined with PFC therapy have not been examined in a balanced mixed-sex population. Thirty-two (16 male, 16 female) instrumented and sedated juvenile Yorkshire swine were exposed to 200 feet of seawater (fsw) for 31 min of hyperbaric air. Pulmonary artery pressure (PAP), cardiac output (CO), and systemic arterial pressure (SAP) were monitored before (control) and after exposure. Animals were randomized to treatment with Oxycyte (5 ml/kg; Oxygen Biotherapeutics, Inc., Morrisville, NC) vs. saline (control) with 100% oxygen administered upon DCS onset; animals were observed for 90 min. Parameters recorded and analyzed included PAP, CO, and SAP. In all animals PAP began to rise prior to cutis marmorata (CM) onset, the first sign of clinical DCS, generally peaking after CM onset. Female swine, compared with castrated males, had a more rapid onset of CM (7.30 vs. 11.46 min postsurfacing) and earlier onset to maximal PAP (6.41 vs. 9.69 min post-CM onset). Oxycyte therapy was associated with a sustained PAP elevation above controls in both sexes (33.41 vs. 25.78 mmHg). Significant pattern differences in PAP, CO, and SAP were noted between sexes and between therapeutic groups. There were no statistically significant differences in survival or paralysis between the PFC and control groups during the 48-h observation period. In conclusion, Oxycyte therapy for DCS is associated with a prolonged PAP increase in swine. These species and sex differences warrant further exploration.

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.

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.

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.

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.

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.

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.

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.

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.

PIP: In the summer of 1991, a project director, codirector, and a US nursing student observed infection control practices of obstetric nurse and midwives before, during, and after vaginal deliveries and Cesarean sections at 12 health facilities in the North and South Birim districts in rural eastern Ghana to gather baseline data which the Ministry would use to design intervention strategies to reduce puerperal infections. Most of the midwives and obstetric nurses did not use aseptic techniques. They did not wash lancets for hemoglobin testing between uses and stored them in small glass containers or in disinfectant, but the disinfectant was often moldy. Reusable instruments were washed with a bar of soap rather than with detergent. The predominant disinfection technique was boiling, but the staff did not time the boiling or fully immerse the equipment. They often used Dettol to disinfect equipment, yet this is ineffective. The hospital had an autoclave, but it was often used incorrectly. The facilities had an inadequate supply of needles, syringes, and gloves. Staff reused needles and syringes and did not wear gloves when they were available. Even though 81% knew that exposure to blood placed them at risk of hepatitis B virus and HIV, just 69% thought that they should wear gloves. Physicians prescribed antibiotic prophylaxis too late and too long for Cesarean section patients. 47% of the women in the area place herbs or spices in the vagina within a week after delivery, but the health workers did not tell the discharged mothers not to insert anything into the vagina. The nurses and midwives did not give the women adequate discharge instructions about umbilical cord stump care, yet most women did not bring their newborns back to the facility for such care.

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.