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Biomedical subjects

D E Snider

Publications and source records attributed to D E Snider.

At least 73 records · Page 4Linked to original sources
PubMed1985

Isoniazid-resistant tuberculosis. A community outbreak and report of a rifampin prophylaxis failure.

The choice of effective preventive treatment for persons exposed to Mycobacterium tuberculosis resistant to isoniazid is uncertain. Although no data document the efficacy of any drug other than isoniazid for preventive treatment of tuberculosis, rifampin, with or without ethambutol, has been used for prophylaxis in contacts of cases with known isoniazid-resistant organisms. This report describes a community outbreak of isoniazid-resistant tuberculosis infection and a case of rifampin prophylaxis failure with acquired rifampin resistance. This raises concern about the efficacy of rifampin for the preventive treatment of contacts exposed to isoniazid-resistant tuberculosis.

Adult↗
PubMed1985

Variations in national health care practices and behaviours and their influence on international research.

Multinational clinical trials are valuable to the understanding of global health problems, but they pose special problems. Our experience with a multinational trial of isoniazid (INH) preventive therapy for tuberculosis revealed marked variation among the seven participating countries in the amount of tuberculosis screening prior to the trial; this variation contributed to the observed differences in the risk of tuberculosis among the countries. The incidence of 'uncooperativeness' and drug side-effects, and the proportion of participants who complied with and completed treatment also varied significantly from country to country. These differences in completion and compliance served to differentially alter the expected risk of tuberculosis among the three regimens being studied. For all factors investigated, variation from country to country was greater than variation from dispensary to dispensary within a country. This suggests that cultural and other national characteristics are more potent determinants of health care practices and behaviours than patient and health care practitioner characteristics.

Clinical Trials as Topic↗
PubMed1985

Infection and disease among contacts of tuberculosis cases with drug-resistant and drug-susceptible bacilli.

Three hundred ninety-eight tuberculosis patients with tubercle bacilli resistant to isoniazid and/or streptomycin were matched by age, race, sex, and geographic area to an equal number of patients with tubercle bacilli susceptible to 9 drugs, including isoniazid and streptomycin, in an effort to determine whether the risk of infection and disease among contacts of patients with resistant bacilli is different from the risk among contacts to patients with susceptible bacilli. The risk of infection among contacts of previously untreated patients was not significantly different, regardless of whether the bacilli were drug-resistant or susceptible. However, the risk of infection increased if the index patient with resistant bacilli had been previously treated. We found no evidence of a lower risk of infection among contacts exposed to bacilli resistant to the highest concentration of isoniazid tested or among contacts exposed to bacilli resistant to both isoniazid and streptomycin. There was a strong association between infection risk among contacts and the age of the index case; younger patients were more infectious. Index cases tended to infect most (or all) or few (or none) of their contacts. The investigation of contacts of patients excreting drug-resistant bacilli should be given high priority.

Adolescent↗
PubMed1984

Tuberculin skin testing of hospital employees: infection, "boosting," and two-step testing.

The prevalence of tuberculous infection (i.e., reactions greater than or equal to 10 mm to 5 tuberculin units of purified protein derivative; Mantoux skin test) was determined among employees of 10 hospitals located throughout the United States. The risk of infection was strongly associated with age and race/ethnicity; nonwhites and older individuals were at higher risk. The prevalence of infection among hospitals varied threefold, from 7.0% to 21.4%. After adjusting for differences in the characteristics of employee groups (e.g., age, race/ethnicity, and sex), twofold differences among hospitals were still observed. The occurrence of "boosting" on retest was also studied. Among the different hospitals, the rate varied from 0% to nearly 10%. Race/ethnicity and age were the characteristics most closely associated with boosting. From our data and other data in the literature, we conclude that all hospitals should use two-step testing at least on a pilot basis. Our calculations suggest that two-step testing for employees over 35 years of age could be cost effective if the booster rate is greater than 1% of the employees retested.

Adult↗
PubMed1984

Rapid radiometric methods to detect and differentiate Mycobacterium tuberculosis/M. bovis from other mycobacterial species.

Rapid methods for the differentiation of Mycobacterium tuberculosis/M. bovis (TB complex) from other mycobacteria (MOTT bacilli) were developed and evaluated in a three-phase study. In the first phase, techniques for identification of Mycobacterium species were developed by using radiometric technology and BACTEC Middlebrook 7H12 liquid medium. Based on 14CO2 evolution, characteristic growth patterns were established for 13 commonly encountered mycobacterial species. Mycobacteria belonging to the TB complex were differentiated from other mycobacteria by cellular morphology and rate of 14CO2 evolution. For further differentiation, radiometric tests for niacin production and inhibition by Q-nitro-alpha-acetyl amino-beta-hydroxy-propiophenone (NAP) were developed. In the second phase, 100 coded specimens on Lowenstein-Jensen medium were identified as members of the TB complex, MOTT bacilli, bacteria other than mycobacteria, or "no viable organisms" within 3 to 12 (average 6.4) days of receipt from the Centers for Disease Control. Isolation and identification of mycobacteria from 20 simulated sputum specimens were carried out in phase III. Out of 20 sputum specimens, 16 contained culturable mycobacteria, and all of the positives were detected by the BACTEC method in an average of 7.3 days. The positive mycobacterial cultures were isolated and identified as TB complex or MOTT bacilli in an average of 12.8 days. The radiometric NAP test was found to be highly sensitive and specific for a rapid identification of TB complex, whereas the radiometric niacin test was found to have some inherent problems. Radiometric BACTEC and conventional methodologies were in complete agreement in Phase II as well as in Phase III.

Cells, Cultured↗
PubMed1984

Supervised six-months treatment of newly diagnosed pulmonary tuberculosis using isoniazid, rifampin, and pyrazinamide with and without streptomycin.

In a previous study, we have shown that a 6-month regimen consisting of 2 months of isoniazid, rifampin, pyrazinamide, and streptomycin administered daily (2IRSZ) followed by 4 months of isoniazid and rifampin administered twice weekly (4I2R2) yielded no relapses after 30 months of follow-up. In order to assess the contribution of streptomycin to this treatment regimen, 213 patients with newly detected smear-positive pulmonary tuberculosis were randomly assigned to the following two 6-month treatment regimens: 2IRZ/4I2R2 and 2IRSZ/4I2R2. One hundred seventy-two of the 213 patients (81%) completed therapy, i.e., 116 of 135 patients (86%) treated with 2IRZ/4I2R2 and 56 of 78 patients (72%) treated with 2IRSZ/4I2R2. Adverse reactions requiring withdrawal of drugs for 7 days or longer were observed in 4.2% of patients (3.7% receiving the 2IRZ/4I2R2 regimen and 5.1% receiving the 2IRSZ/4I2R2 regimen). At the end of treatment, all patients in the 2IRZ/I2R2 series had negative smears and cultures. Two of the 116 patients (1.7%) in the 2IRZ/I2R2 series developed isoniazid resistance in the fourth month of treatment and remained sputum positive at the end of treatment. In the follow-up period, 4 patients (3.4%) treated with 2IRZ/4I2R2 relapsed and 1 (1.8%) treated with 2IRSZ/4I2R2 relapsed. The only significant difference between the 2 regimens was the higher dropout rate among those assigned to the 2IRSZ/4I2R2 regimen.

Adolescent↗
PubMed1984

The usefulness of phage typing Mycobacterium tuberculosis isolates.

Mycobacteriophage typing of Mycobacterium tuberculosis isolates was used as an epidemiologic aid in investigating the transmission of tuberculosis in community, industrial, and institutional outbreaks. The technique was also useful in other situations, e.g., documenting congenital transmission of infection and distinguishing exogenous reinfection from endogenous reactivation. Additional studies are indicated to further explore the value of phage typing for tracking the transmission of tuberculosis in the community.

Adolescent↗
PubMed1984

Current tuberculosis screening practices.

Health department officials in all 50 states and 14 major cities responded to a survey questionnaire designed to obtain information about current tuberculosis screening practices. Persons being screened fell into the groups designated as high risk by the American Thoracic Society (ATS) and the Centers for Disease Control (CDC). The methods used for screening were generally those advocated by ATS, CDC, and the Food and Drug Administration (FDA), although chest radiographs continue to be overused. Screening in about one-half of the groups is mandated by law or regulation. There appears to be some confusion about the circumstances in which "two-step" tuberculin testing should be used. Data on the productivity and costs of screening activities were very limited. We encourage those responsible for tuberculosis screening programs to evaluate them, discontinue those which are unproductive, and intensify those which are productive.

Female↗
PubMed1984

Tuberculosis, atypical mycobacteriosis, and the acquired immunodeficiency syndrome among Haitian and non-Haitian patients in south Florida.

To study the association between mycobacterial disease and the acquired immunodeficiency syndrome, we reviewed the records of all cases of tuberculosis and all cases of the syndrome reported in Dade County, Florida, from January 1980 through June 1983. Tuberculosis was diagnosed in 27 of 45 Haitians with the syndrome, but in only 1 of 37 non-Haitians with the syndrome (p less than 0.001). Among the 27 Haitians with the syndrome and tuberculosis, 19 had extrapulmonary tuberculosis, whereas among 286 Haitian patients with tuberculosis without the syndrome, only 56 had extrapulmonary tuberculosis (p less than 0.001). Tuberculosis preceded the syndrome by 1 to 17 months (mean, 6) in 22 patients. In 10 patients with the syndrome and positive sputum cultures who were treated with conventional antituberculosis drugs, the cultures became negative within 1 to 4 months and tuberculosis did not recur. The frequency of disseminated atypical mycobacteriosis or positive sputum cultures for atypical mycobacteria was not significantly different between Haitian (11.3%) and non-Haitian (8.3%) patients with the syndrome.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Should women taking antituberculosis drugs breast-feed?

Most of the commonly used antituberculosis drugs are excreted in the breast milk of nursing mothers. However, only a small fraction of the adult dose appears in breast milk, and we estimate that breast-fed infants would receive no more than 20% of the usual therapeutic dose for infants for any of these drugs. Based on these considerations, we believe the risk of toxic reactions to drugs in infants of nursing mothers receiving antituberculosis drugs is very low. Nevertheless, the decision to breast-feed while taking antituberculosis drugs must be an individual one that takes into account the known facts, professional opinion, and the patient's values and preferences.

Antitubercular Agents↗
PubMed1984

Six-months isoniazid-rifampin therapy for pulmonary tuberculosis. Report of a United States Public Health Service Cooperative Trial.

In a multicenter trial of 2 regimens for treatment of pulmonary tuberculosis, all patients received 300 mg of isoniazid (INH) and 600 mg of rifampin (RIF) daily for 6 months (the Initial Phase). During the next 9 months (the Maintenance Phase) patients received either daily INH (300 mg) and ethambutol (EMB) (15 mg per kg body weight) or matching placebos. Of the 672 patients who met the admission criteria, only 309 (46%) completed the Initial and Maintenance Phases. Approximately 20% of the patients failed to keep their appointments. Adverse drug reaction, most commonly hepatotoxicity, accounted for the withdrawal of 37 patients (5.5%). No visual toxicity caused by EMB was observed. During the Maintenance Phase, 3 patients who were taking INH and EMB, and 16 who were taking placebos, developed relapses, i.e., 2 or more positive cultures. The significant difference in relapse rate between regimens (Fisher's exact test, p less than 0.001) demonstrates the inadequacy of INH-RIF given alone for only 6 months.

Adult↗