Molecular identification of streptomycin monoresistant Mycobacterium tuberculosis related to multidrug-resistant W strain.

A distinct branch of the Mycobacterium tuberculosis W phylogenetic lineage (W14 group) has been identified and characterized by various genotyping techniques. The W14 group comprises three strain variants: W14, W23, and W26, which accounted for 26 clinical isolates from the New York City metropolitan area. The W14 group shares a unique IS6110 hybridizing banding motif as well as distinct polymorphic GC-rich repetitive sequence and variable number tandem repeat patterns. All W14 group members have high levels of streptomycin resistance. When the streptomycin resistance rpsL target gene was sequenced, all members of this strain family had an identical mutation in codon 43. Patients infected with the W14 group were primarily of non- Hispanic black origin (77%); all were US-born. Including HIV positivity, 84% of the patients had at least one known risk factor for tuberculosis.

Use of spoligotype analysis to detect laboratory cross-contamination.

Spoligotype analysis identified false-positive isolates of Mycobacterium tuberculosis caused by laboratory cross-contamination. Spoligotyping is faster, is less expensive than DNA fingerprinting, and can be used with a variety of media. Patients were reevaluated and had medications discontinued as a result of this investigation. Months of unnecessary patient follow-up and treatment were avoided.

Cross-contamination with Mycobacterium tuberculosis: an epidemiological and laboratory investigation.

OBJECTIVE: To investigate possible cross-contamination of laboratory specimens, as suggested by an increased incidence of newly diagnosed patients with tuberculosis, many of whom had all negative smears for acid-fast bacilli and only one positive Mycobacterium tuberculosis culture referred to as "negative smears, one positive" or NSOP. METHODS: Medical-record reviews were performed for all patients with NSOP results diagnosed at this facility within a 9-month period. Laboratory logbooks were reviewed for all isolates processed; DNA fingerprinting was performed on available isolates. RESULTS: Of 80 patients with NSOP results, 45 (56%) were found to have false-positive cultures resulting from laboratory contamination with H37Ra, an avirulent stock strain of Mycobacterium tuberculosis. CONCLUSION: Laboratory cross-contamination resulted in the false diagnosis of tuberculosis in at least 45 individuals. Use of the Mycobacteria Growth Indicator Tube may have contributed to these contamination incidents by detecting small numbers of contaminating mycobacteria that may not have been detected with less sensitive media.

A continuing outbreak of multidrug-resistant tuberculosis, with transmission in a hospital nursery.

We investigated an increase in cases of multidrug-resistant tuberculosis (MDRTB) at a large urban facility where a prior nosocomial outbreak of MDRTB had occurred. Nosocomial transmission appeared to account for this outbreak as well, including a cluster of cases in a newborn nursery. Seven of 24 patients (29%) described in this investigation may have been exposed in the hospital nursery during an approximately 2-week period. We believe this to be the first documented outbreak of MDRTB in a hospital nursery. The transmission in the nursery demonstrates that the possibility of exposure to unrecognized active tuberculosis in nursery and hospital personnel is always present. Infection and active disease in the infants developed after a relatively short period of exposure. These findings underscore the need for adherence to published infection control guidelines in health care settings.

A multi-institutional outbreak of highly drug-resistant tuberculosis: epidemiology and clinical outcomes.

OBJECTIVE: To investigate a multi-institutional outbreak of highly resistant tuberculosis and evaluate patient outcome. DESIGN: Epidemiologic investigation of every tuberculosis case reported in New York City. SETTING: Patients cared for at all public and nonpublic institutions from January 1, 1990, to August 1, 1993 (43 months). PATIENTS: We reviewed medical and public health records and conducted clinical, epidemiologic, drug susceptibility, and restriction fragment length polymorphism (RFLP) analyses. A case was defined as tuberculosis in a patient with an isolate resistant to isoniazid, rifampin, ethambutol hydrochloride, and streptomycin (and rifabutin, if sensitivity testing included it), and, if RFLP testing was done, a pattern identical to or closely related to strain W. MAIN OUTCOME MEASURES: Patient survival and the conversion of sputum cultures from positive to negative. RESULTS: Of the 357 patients who met the case definition, 267 had identical or nearly identical RFLP patterns; isolates from the other 90 patients were not available for RFLP testing. Among these 267 patients, 86% were human immunodeficiency virus (HIV)-infected, 7% were HIV-negative, and 7% had unknown HIV status. All-cause mortality was 83%. Epidemiologic linkages were identified for 70% of patients, of whom 96% likely had nosocomially acquired disease at 11 hospitals. Survival was prolonged among patients who received medications to which their isolate was susceptible, especially capreomycin sulfate, and among patients with a CD4+ T-lymphocyte count greater than 0.200 x 10(9)/L (200/microL). Treatment with isoniazid and a fluoroquinolone antibiotic was also independently associated with longer survival. CONCLUSIONS: This outbreak accounted for nearly one fourth of the cases of multidrug-resistant tuberculosis in the United States during a 43-month period. Most patients had nosocomially acquired disease, were infected with HIV, and unless promptly and appropriately treated, died rapidly. With appropriate directly observed treatment, especially combinations including an injectable medication, even severely immunocompromised patients had culture conversion and prolonged, tuberculosis-free survival.

Gathering information about vasectomy in Honduras.

PIP: To understand the barriers to vasectomy in Honduras, an operations research project is being conducted. 2 separate research activities composed the initial phase of the project. The 1st activity was a series of focus-group discussions to determine male attitudes and beliefs about vasectomy. The 2nd activity was a knowledge, attitude, and practice survey which studied a larger and more representative sample of the population. In the groups, the men frequently said that they should be more responsible for family planning. Although a few men could explain vasectomy, most of them knew little about the procedure. Preliminary findings from the survey indicate that more than 2/3 of the sample had never heard of vasectomy. Misconceptions regarding vasectomy were widespread. More than 80% believed that the woman should be sterilized. Only 5% believed that the man should be sterilized. 58% agreed that information regarding vasectomy should be provided in their communities. These preliminary results clearly demonstrate a need for a widespread educational campaign concerning the nature of vasectomy and its benefits and risks.^ieng