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Biomedical subjects

A B Bloch

Publications and source records attributed to A B Bloch.

At least 19 recordsLinked to original sources
PubMed1996

Management of an outbreak of tuberculosis in a small community.

OBJECTIVE: To investigate an outbreak of tuberculosis, determine the number of active cases and infections, and examine efforts to control the spread of disease. SETTING: A small town in Maine, in which no cases of tuberculosis had been reported in the previous 3 years. DESIGN: Epidemiologic investigation of an outbreak of tuberculosis infection and disease. MEASUREMENTS: A patient with an active case of tuberculosis was defined as a resident of the town or the surrounding area or an employee of the local shipyard who had a culture of sputum or tissue that was positive for Mycobacterium tuberculosis between June 1989 and May 1992. A case of tuberculous infection was defined as a positive tuberculin skin test result in a person with no previous positive test result. RESULTS: 21 active cases of tuberculosis occurred among shipyard workers and persons residing in the affected community between 1989 and 1992. One patient was the source of the outbreak; 8 months lapsed between the onset of this patient's illness and appropriate diagnosis and treatment. The M. tuberculosis strains isolated from this patient and from six other patients belonged to phage type I, auxiliary 14. All isolates were susceptible to drug treatment. Of 9898 persons who were tested, 697 (7%) were newly infected. Because isoniazid prophylaxis was not routinely offered to infected persons older than 35 years of age, only 341 (49%) infected persons completed isoniazid prophylaxis. CONCLUSIONS: Many secondary cases of tuberculosis occurred throughout this small Maine community because of delayed diagnosis and treatment of the source patient, delayed outbreak investigation, and failure to promote isoniazid prophylaxis to all persons infected during the outbreak. Aggressive efforts to identify persons with new infection are of limited value in controlling tuberculosis unless they are accompanied by an equally aggressive use of isoniazid prophylaxis.

Adult↗
PubMed1996

Predictors of survival in HIV-infected tuberculosis patients.

OBJECTIVE: To ascertain predictors of survival in HIV-infected tuberculosis (TB) patients. DESIGN: Retrospective cohort study. SETTING: New York City public hospital. PATIENTS: Fifty-four consecutive HIV-seropositive patients with newly diagnosed TB and no other AIDS-defining illnesses. MAIN OUTCOME MEASURES: CD4+ T-lymphocyte counts, completion of anti-TB therapy, repeat hospitalizations with TB, and survival. RESULTS: Forty-five (84%) of the 54 patients died a median of 15 months after TB diagnosis (range, 1-80 months), five (9%) were alive after a median of 81 months (range, 75-84 months), and four (7%) were lost to follow-up after a median of 42 months (range, 30-66 months). In univariate analyses, disseminated TB, intrathoracic adenopathy, oral candidiasis and CD4 count depletion were each associated with decreased survival. In a multivariate analysis, CD4 count depletion was the only independent predictor of decreased survival. Repeat hospitalization with TB occurred in 10 out of 15 patients who did not complete anti-TB therapy compared with one out of 21 patients who completed anti-TB therapy (P < 0.001). CONCLUSION: The clinical presentation of TB and CD4 count at TB diagnosis are each predictive of survival in HIV-seropositive TB patients. The CD4 count is the only independent predictor of survival.

Adult↗
PubMed1995

National trends in the concurrence of tuberculosis and acquired immunodeficiency syndrome.

BACKGROUND: Elucidation of the relationship between tuberculosis (TB) and the acquired immunodeficiency syndrome (AIDS) is needed to help predict the future course of these two epidemics. We examined nationwide trends in TB and AIDS occurring in the same individual. METHODS: Health departments in the 50 states, District of Columbia, Puerto Rico, and Guam matched their TB and AIDS case registries to determine the number of persons diagnosed with both TB and AIDS. The number of AIDS cases, TB cases, AIDS cases that matched with a TB case on the TB registry, and TB cases that matched with an AIDS case on the AIDS registry were reported to the Centers for Disease Control and Prevention, Atlanta, Ga. Data were analyzed for the period from 1981 through 1991. The number of matched TB-AIDS cases was compared with a modeled estimate of excess TB cases during the period from 1985 through 1990. RESULTS: From 1981 through 1991 there were 11,299 AIDS cases that matched with a TB case on the TB registry, representing 5.1% (geographic variation, 0% to 9.3%) of AIDS cases. The TB cases that matched with an AIDS case on the AIDS registry represent 4.3% (geographic variation, 0% to 15.1%) of TB cases from 1981 through 1991. Since 1981, matched TB and AIDS cases increased yearly through 1990. When examined by year of AIDS report, the percentage of AIDS cases that matched with a TB case increased from 1981 to 1982 (1.9% to 5.1%), remained fairly constant from 1983 through 1987 (range, 4.0% to 4.7%), increased in 1988 (5.4%) after extrapulmonary TB was added to the AIDS case definition, and increased slightly through 1990 (5.8%). When examined by year of TB report, the percentage of TB cases that matched with an AIDS case increased steadily from 1981 through 1990 (0.1% to 9.5%). The calculated fraction of excess TB cases during the period from 1985 through 1990 that could be accounted for by identified TB-AIDS cases was 30%. CONCLUSION: The risk of TB or AIDS among persons already diagnosed with one disease is much higher than among the general population. The percentage of persons with TB who are also diagnosed with AIDS has been increasing rapidly. Human immunodeficiency virus-induced immunosuppression is an important contributor to the TB epidemic and probably accounts for a minimum of 30% of excess TB cases during the period from 1985 through 1990.

AIDS-Related Opportunistic Infections↗
PubMed1994

Nationwide survey of drug-resistant tuberculosis in the United States.

OBJECTIVE: To determine antituberculosis drug resistance patterns, geographic distribution, demographic characteristics, and risk factors of reported tuberculosis (TB) patients in the United States. DESIGN: Survey of reported TB cases in the United States. For culture-positive cases reported to the Centers for Disease Control and Prevention, we asked health departments to provide drug susceptibility test results from initial Mycobacterium tuberculosis isolates. STUDY POPULATION: Culture-positive TB cases in the United States reported during the first quarter of 1991. MAIN OUTCOME MEASURES: Individual TB case reports submitted to the Centers for Disease Control and Prevention and drug susceptibility test results. RESULTS: Resistance to one or more antituberculosis drugs was found in 14.2% of cases. Resistance to isoniazid and/or rifampin was found in 9.5% of cases whose isolates were tested against one or both drugs; such cases were found in 107 counties in 33 states. Resistance to both isoniazid and rifampin (multidrug-resistant [MDR] TB) was found in 3.5% of cases whose isolates were tested against both drugs; such cases were found in 35 counties in 13 states. New York City accounted for 61.4% of the nation's MDR TB cases. The 3-month population-based incidence rate of MDR TB in New York City was 52.4 times (95% confidence interval [CI], 35.5 to 78.3) that of the rest of the nation (9.559 vs 0.182 cases per million population). Compared with the rate in non-Hispanic whites in the rest of the nation (0.032 cases per million), the relative risk of MDR TB in New York City non-Hispanic whites was 39.0 (95% CI, 8.1 to 164.5), 299.3 (95% CI, 112.5 to 927.1) in Hispanics, 420.9 (95% CI, 121.0 to 1515.8) in Asian/Pacific Islanders, and 701.0 (95% CI, 296.4 to 2018.1) in non-Hispanic blacks. CONCLUSIONS: With nearly 10% of TB patients resistant to isoniazid and/or rifampin, greater use of four-drug regimens and directly observed therapy is indicated. Aggressive intervention to prevent the further spread of MDR TB is needed to find every TB patient and to provide optimal patient management to ensure completion of chemotherapy.

Adolescent↗
PubMed1994

Risk factors for transmission of Mycobacterium tuberculosis in a primary school outbreak: lack of racial difference in susceptibility to infection.

Recent data have suggested that there are racial differences in the susceptibility to infection by Mycobacterium tuberculosis. An opportunity to test this suggestion was afforded by an outbreak of tuberculosis in a racially mixed elementary school in St. Louis County, Missouri. A physical education teacher was discovered to have cavitary pulmonary tuberculosis. Of 343 students in the school, 176 (51 percent) were found to be tuberculin skin test positive (> or = 5 mm induration by Mantoux method); 32 children had abnormal chest radiographs. More frequent contact with the physical education teacher was associated with infection (p < 0.001). Black children were no more likely to be infected than were white children (relative risk (RR) = 0.98, 95% confidence interval (CI) 0.78-1.22). However, black children who were tuberculin positive had larger skin reactions than did white children (mean, 18.9 vs. 16.6 mm, p < 0.001) and were more likely to have abnormal chest radiographs (RR = 2.76, 95% CI 1.44-5.27). Among tuberculin-positive children, low body mass index (less than 10th percentile) was associated with active disease (RR = 2.90, 95% CI 1.45-5.80). The analysis of race was unchanged after controlling for sex, body build, and level of contact with the physical education teacher. Widespread tuberculous infection resulted from contact with a highly infectious staff person. Thin body build was a risk factor for active disease. Black children were no more susceptible to infection than were white children, although they more commonly developed radiographic evidence of active disease.

Adult↗
PubMed1993

Tuberculosis in a correctional facility.

BACKGROUND: After the identification of five suspected cases of tuberculosis (TB) in a Nassau County (New York) jail during a 3-week period, an epidemiologic investigation was begun to document the number of cases of TB infection and disease associated with the jail, the characteristics of current or former inmates with TB disease, and the factors contributing to TB transmission in the jail. METHODS: The county TB register was matched against the inmate files of the jail. Medical records from hospitals, the health department, and the jail were then reviewed. All inmates in the jail were skin tested during a mass screening. RESULTS: From January 1, 1988, through March 16, 1990, of 205 TB cases in the county, 49 (24%) were associated with the jail. Forty of the cases occurred among current or former inmates, one in a corrections officer, and eight among community contacts of inmates. The 40 inmates with TB were predominantly nonwhite (75%), unmarried (80%) men (90%), with a median age of 32 years. Twenty-three (58%) had a history of injecting drug use, and 14 (35%) were known to be seropositive for the human immunodeficiency virus. Thirty (75%) of the inmates had culture-confirmed pulmonary TB. Five (29%) of 17 Mycobacterium tuberculosis isolates had the same phage type and DNA fingerprint, which was consistent with transmission of infection within the jail. The mass screening revealed that 374 (20%) of 1855 inmates were tuberculin positive. CONCLUSIONS: Without an effective program of TB control, jails can act as reservoirs of disease for inmates and staff, and for the community into which the inmates are released.

Adult↗
PubMed1992

Nosocomial transmission of tuberculosis in a hospital unit for HIV-infected patients.

OBJECTIVE: To assess nosocomial transmission of tuberculosis (TB). DESIGN: A historical cohort study of hospitalized patients with the human immunodeficiency virus (HIV) and a purified protein derivative (PPD) tuberculin skin test survey of health care workers (HCWs). SETTING: A large public teaching hospital in San Juan, Puerto Rico. PATIENTS: For the cohort study, a case patient was defined as any patient in the HIV unit at the hospital who developed culture-positive TB from 31 days or more after admission through December 31, 1989. For the PPD survey, of 1420 HCWs from the hospital, 908 agreed to participate and had sufficient data for analysis. MAIN OUTCOME MEASURES: For the cohort study, to compare the risk of developing active TB among patients who were exposed to hospital roommates with infectious TB and the risk among nonexposed patients. For the HCW PPD survey, to determine the prevalence of and risk factors for tuberculous infection. RESULTS: Eight of 48 (9.7/10,000 person-days) exposed case patients vs four of 192 (0.8/10,000 person-days) nonexposed case patients developed active TB (relative risk [RR] = 11; 95% confidence interval [CI], 2.3, 50.3). Positive PPDs (greater than or equal to 10 mm of induration) in HCWs were associated with older age (P = .0001) and with history of community TB exposure (P = .0002). In a multivariable logistic model that adjusted for these variables, HIV unit nurses (nine of 19) and nurses in the internal medicine ward (45 of 90) had a higher proportion of positive PPDs than the reference group (clerical personnel on other floors: 35 of 188, P = .0005). CONCLUSIONS: These data suggest that patient-to-patient transmission of TB in HIV units can occur and that HCWs are at risk of acquiring TB infection.

Adolescent↗
PubMed1991

Tuberculosis diagnosed at death in the United States.

From 1985 through 1988, 5.1 percent of TB cases reported in the United States were diagnosed at death. Differences in the proportions diagnosed at death by race/ethnicity, sex, and place of birth (United States vs foreign-born) were relatively small. The proportion of cases diagnosed at death increased with age, from 0.7 percent in patients less than 5 years old to 18.6 percent among patients 85 years and older. Only 26.0 percent of cases diagnosed alive were among those 65 years and older, but 60.3 percent of those diagnosed at death were in this age group. Eighteen percent of cases with miliary, meningeal and peritoneal TB were diagnosed at death, compared with 4.8 percent among those with pulmonary TB. These data indicate that TB too often remains unrecognized and that, to prevent continuing deaths from this curable disease, a high index of suspicion of TB remains important, particularly among the elderly and among persons with extrapulmonary sites of disease.

Adolescent↗
PubMed1990

Nosocomial transmission of tuberculosis associated with a draining abscess.

Nine secondary cases of tuberculosis and 59 tuberculin skin test conversions occurred after exposure to a hospitalized patient with a large tuberculous abscess of the hip and thigh. Among 442 tuberculin-negative hospital employees, the relative risk of skin test conversion associated with recalled exposure to the patient was 14.0 (95% confidence limits, 6.8, 28.7). Four of 5 surgical suite employees who assisted with incision and debridement of the abscess had skin test conversions, as did 85% of 33 employees on a general medical floor who recalled exposure to the patient and 30% of 20 intensive care unit employees who recalled exposure. The prevalence of tuberculin reactivity in visitors and other patients on two floors also showed a strong association with exposure to the patient. A high concentration of Mycobacterium tuberculosis in the abscessed tissue, disturbance of the surface of liquid drainage from the abscess by irrigations and by the agitated behavior of the patient, and positive air pressure in the patient's room are factors that appear to have contributed to the high risk of tuberculosis transmission.

Abscess↗
PubMed1990

Recovery of hepatitis A virus from a water supply responsible for a common source outbreak of hepatitis A.

An outbreak of hepatitis A occurred in a north Georgia trailer park served by a private well. Of 18 residents who were serosusceptible to hepatitis A virus (HAV), 16 (89%) developed hepatitis A. Well water samples were collected 3 months after illness onset in the index case and 28 days after illness onset in the last trailer park resident. Hepatitis A virus antigen (HAVAg) was detected in the samples by enzyme immunoassay from three of the five cell lines following two 30-day passages and from a fourth cell line following a third passage of 21 days.

Adult↗
PubMed1990

Acquired immunodeficiency syndrome and extrapulmonary tuberculosis in the United States.

Of 48,712 acquired immunodeficiency syndrome (AIDS) cases reported to the Centers for Disease Control from October 1987 through March 1989, 1239 (2.5%) were diagnosed with extrapulmonary tuberculosis. Extrapulmonary tuberculosis was diagnosed in 1013 (2.3%) of the US-born persons with AIDS, compared with 26 (8%) of the Mexican-born, 82 (13%) of the Haitian-born, and 4 (1%) of the Cuban-born. Patients with AIDS with and without extrapulmonary tuberculosis were similar in age, except that extrapulmonary tuberculosis was relatively rare in patients with AIDS under the age 10. Compared with white homosexual/bisexual men, black race (odds ratio, 2.7), intravenous drug use (odds ratio, 2.0), heterosexual AIDS transmission category (odds ratio, 1.9), and Hispanic ethnicity (odds ratio, 1.6) were independently associated with extrapulmonary tuberculosis. In 1988, extrapulmonary tuberculosis in persons known to be human immunodeficiency virus seropositive represented 21% of national extrapulmonary tuberculosis morbidity.

Acquired Immunodeficiency Syndrome↗
PubMed1989

An outbreak of tuberculosis in rural Delaware.

A total of 35 patients diagnosed with tuberculosis in 1976-1984 were identified as part of a sustained outbreak involving five communities located in southern Delaware. The index case, a 25-year-old black female with sputum smear-positive, cavitary pulmonary tuberculosis, was a sexual partner of three other persons with cavitary pulmonary tuberculosis and a close contact of 10 other persons with tuberculosis. The median age of the 35 patients was 23 years (range 15 months to 77 years), and 13 (37%) were less than 15 years of age. Sixteen patients (46%) were male, and 34 (97%) were black. Pulmonary parenchymal disease was noted in 18 cases (51%), including nine (26%) with cavitary lesions; 11 (31%) had lymphatic disease (hilar and/or mediastinal); five (14%) had pleural disease; and one (3%) had a normal chest radiograph. Infection prevalence (per 100 tested) was 44.7 for close contacts of cases and 18.3 for other than close contacts, and disease prevalence (per 100 tested) was 8.9 and 1.4 for those two groups, respectively. This outbreak highlights several points: Outbreaks of tuberculosis may go undetected for several years; aggressive and complete surveillance and containment efforts are needed to control tuberculosis; and tuberculosis in children and minorities is still a problem in the United States.

Adolescent↗
PubMed1989

The epidemiology of tuberculosis in the United States. Implications for diagnosis and treatment.

Tuberculosis in the United States is primarily and increasingly a disease of minorities and the foreign-born. Tuberculosis among non-Hispanic whites is predominantly a disease of the elderly, whereas among minorities and the foreign-born, it is primarily concentrated in young adults. In the past few years, tuberculosis has increased among young adults, especially those who are black or Hispanic. Available data support the hypothesis that the spread of human immunodeficiency virus infection has increased the risk of tuberculosis. A substantial proportion of tuberculosis in the United States is potentially preventable through the administration of preventive therapy to high-risk populations.

Acquired Immunodeficiency Syndrome↗