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Biomedical subjects

L B Lefkowitz

Publications and source records attributed to L B Lefkowitz.

At least 19 recordsLinked to original sources
PubMed2001

Nosocomial transmission of Mycobacterium tuberculosis from an extrapulmonary site.

OBJECTIVE: To assess the extent of nosocomial transmission and risk factors associated with tuberculin skin test (TST) conversions among healthcare workers (HCWs) exposed to a patient with genitourinary Mycobacterium tuberculosis. DESIGN: Retrospective cohort study of exposed HCWs. SETTING: A 275-bed community hospital in Middle Tennessee. PARTICIPANTS: A total of 128 exposed HCWs and the index patient, who required drainage of a prostatic abscess and bilateral orchiectomy and expired after a 27-day hospitalization. Disseminated tuberculosis was diagnosed at autopsy. METHODS: Contact tracing was performed on exposed HCWs. Logistic regression was used to identify independent risk factors associated with TST conversion. RESULTS: A total of 128 HCWs were exposed to the index patient. There was no evidence of active pulmonary tuberculosis throughout the patient's hospitalization; TST conversions occurred only among HCWs who were exposed to the patient during or after his surgical procedures. A total of 12 (13%) of 95 exposed HCWs who were previously nonreactive had newly positive TST: 6 of 28 nurses, 3 of 3 autopsy personnel, 2 of 17 respiratory therapists, and 1 of 12 surgical staff. By logistic regression, irrigation or packing of the surgical site was the only independent risk factor associated with TST conversion among nurses (odds ratio, 9; 95% confidence interval, 1.2-67; P=.03). CONCLUSION: Manipulation of infected tissues of the genitourinary tract can result in nosocomial transmission of tuberculosis.

Adult↗
PubMed2000

Group B streptococcal disease in the era of intrapartum antibiotic prophylaxis.

BACKGROUND: Group B streptococcal infections are a leading cause of neonatal mortality, and they also affect pregnant women and the elderly. Many cases of the disease in newborns can be prevented by the administration of prophylactic intrapartum antibiotics. In the 1990s, prevention efforts increased. In 1996, consensus guidelines recommended use of either a risk-based or a screening-based approach to identify candidates for intrapartum antibiotics. To assess the effects of the preventive efforts, we analyzed trends in the incidence of group B streptococcal disease from 1993 to 1998. METHODS: Active, population-based surveillance was conducted in selected counties of eight states. A case was defined by the isolation of group B streptococci from a normally sterile site. Census and live-birth data were used to calculate the race-specific incidence of disease; national projections were adjusted for race. RESULTS: Disease in infants less than seven days old accounted for 20 percent of all 7867 group B streptococcal infections. The incidence of early-onset neonatal infections decreased by 65 percent, from 1.7 per 1000 live births in 1993 to 0.6 per 1000 in 1998. The excess incidence of early-onset disease in black infants, as compared with white infants, decreased by 75 percent. Projecting our findings to the entire United States, we estimate that 3900 early-onset infections and 200 neonatal deaths were prevented in 1998 by the use of intrapartum antibiotics. Among pregnant girls and women, the incidence of invasive group B streptococcal disease declined by 21 percent. The incidence among nonpregnant adults did not decline. CONCLUSIONS: Over a six-year period, there has been a substantial decline in the incidence of group B streptococcal disease in newborns, including a major reduction in the excess incidence of these infections in black infants. These improvements coincide with the efforts to prevent perinatal disease by the wider use of prophylactic intrapartum antibiotics.

Adolescent↗
PubMed1995

The reporting of communicable diseases: a controlled study of Neisseria meningitidis and Haemophilus influenzae infections.

Surveillance systems for communicable diseases in the United States are primarily passive. We compared the passive reporting system for invasive disease caused by Neisseria meningitidis and Haemophilus influenzae with a concurrent, active laboratory-based system in the four metropolitan counties of Tennessee. The passive reporting system identified approximately 50% of all cases that were identified by the active system and accurately reflected trends in disease occurrence during the study period. Of all reported cases, physicians contributed fewer than 4%. Nearly 40% of all hospitals in the study area did not participate in the passive system. This lack of participation resulted in disproportionately increased reporting of disease among blacks. Inconsistencies in case definition within the state also contributed substantially to underreporting and lack of demographic representativeness of reported cases. The median reporting interval (the time from the onset of disease to transmission of the case report to the Centers for Disease Control and Prevention) was 24 days (range, 5-157 days). Efforts to improve surveillance of those infections for which isolation of a pathogen is tantamount to a diagnosis should concentrate on laboratory-based reporting and the use of currently available computer telecommunication systems.

Centers for Disease Control and Prevention, U.S.↗
PubMed1992

Increased incidence of syphilis in Tennessee during the 1980s: challenges for a new decade.

Although recent increases in the incidence of syphilis are well known to public health officials, the general medical community is less well informed regarding the dramatic rise in cases. We present trend data from Nashville and Tennessee over the past decade. These statistics emphasize specific factors, such as drug abuse, that contribute to new difficulties in controlling this sexually transmitted disease.

Contact Tracing↗
PubMed1991

Homotypic antibody responses to fresh clinical isolates of human immunodeficiency virus.

Human immunodeficiency virus type 1 (HIV-1) exhibits extensive genomic and antigenic diversity, which is thought to contribute to the failure of the host's immune response to control infection and prevent clinical progression. Part of this failure may be due to utilization by the virus of antigenic variation as a means to escape protective immune responses. Antibody-escape variants of HIV-1 were studied here using fresh clinical isolates and autologous plasmas. HIV-1 was isolated from the plasma of seven people who were all seropositive for at least 2 years, and symptomatic sometime during that period. Isolated viruses were confirmed as HIV-1 by the presence of reverse transcriptase activity in infected culture supernatants, and by positive immunofluorescence using human monoclonal antibody to HIV-1 core protein. Plasma from these people were positive by Western immunoblot (DuPont) for most major HIV-1 (strain IIIB) antigens. These plasmas neutralized three laboratory strains of HIV-1 (i.e., IIIB, RF, and MN) but did not neutralize the homotypic strain in five cases, and had greatly reduced neutralizing titers against the homotypic strain in two cases. Homotypic neutralizing antibodies were absent in autologous plasma obtained 3 months later. When antibody titers were measured by fixed-cell indirect immunofluorescence assays (IFAs), high titers of IgG (1:6400 to 1:25,600) were detected against HIV-1 IIIB, while low titers of only 1:20 to 1:160 were detected against homotypic viral antigens at the time of virus isolation, and remained low 12 and 16 weeks later. No class IgA, IgD, IgE, or IgM antibodies to homotypic viral antigens, as possible IgG-blocking antibodies, were detected by fixed-cell IFAs. Cross-reactions with heterologous donor's plasmas were observed in some cases, and in these cases the cross-reactions were unidirectional. Live-cell IFAs detected IgG in patient's plasma to HIV-1 IIIB-infected cells but not to cells infected with homotypic isolates. These results suggest that it is common for neutralization-resistant HIV-1 variants to appear during the course of infection, and that all or most antigens of these variants are capable of escaping antibody recognition.

AIDS-Related Complex↗
PubMed1991

Absence of a clinical correlation for complement-mediated, infection-enhancing antibodies in plasma or sera from HIV-1-infected individuals. Multicenter AIDS Cohort Study Group.

Neutralizing and complement-mediated infection-enhancing antibodies to HIV-1 were measured in sera or plasma from 54 HIV-1-positive individuals at various stages of disease, and from an additional 36 HIV-1-positive individuals for whom no clinical data were available. Antibodies were measured in microtiter infection assays utilizing MT-2 cells and the IIIB strain of HIV-1. The frequency of detection of both types of antibodies was identical, being 77 out of 90 cases (86%). Neutralizing and infection-enhancing antibodies were not always found together, and in four cases both were undetectable. No correlation was found between titers of either type of antibody and stage of disease. Furthermore, titers of infection-enhancing antibodies at early stages of disease did not predict rate of disease progression.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Septic shock and acute respiratory distress syndrome after salpingitis caused by Streptococcus pyogenes group A.

A 32-year-old woman with acute salpingitis had signs and symptoms of sepsis, with hypotension, renal failure, acute respiratory distress syndrome, and disseminated intravascular coagulation. Streptococcus pyogenes group A was grown from blood cultures taken at the onset of illness, and salpingitis was confirmed at laparotomy. The patient recovered after appropriate antimicrobial and intensive supportive therapy.

Adult↗
PubMed1985

Falsely elevated serum creatinine levels secondary to the presence of 5-fluorocytosine.

The Kodak Ektachem (Eastman Kodak Co., Rochester, NY) is a new clinical chemistry analyzer that uses an enzymatic method to measure creatinine. The authors report the case of a patient with falsely elevated creatinine levels that were caused by the presence of 5-fluorocytosine. A review of the literature confirmed that this can occur, but well documented reports are not found. In order to determine the magnitude of this interference, the authors plotted creatinine levels versus 5-FC concentration. Significant interference is seen with therapeutic levels of 5-FC. Both clinicians and pathologists should be aware of this phenomenon.

Aged↗
PubMed1977

Recurrences and sequelae of rheumatic fever in Nashville. A follow-up study.

A follow-up study of 311 patients who acquired rheumatic fever in Nashville, Tenn, during the period from 1963 to 1969 showed that 53% took penicillin prophylaxis regularly, 36% did not take it as recommended, and 11% did not take it at all. There were no recurrences among those who received prophylaxis by injection regularly, six recurrences among those who took oral prophylaxis regularly, and no recurrences among 45 subjects who did not take prophylaxis. Among these 45, however, were 29 for whom prophylaxis was not recommended by their physicians. The original study indicated that the incidence of acute rheumatic fever among blacks was twice as high as among whites. In the present study, incidence of rheumatic heart disease and recurrences was substantially higher among blacks than among whites.

Administration, Oral↗
PubMed1975

Gestational exposure to rubella vaccinees: a population surveillance study.

Over a two-year period an attempt was made to identify instances of transmission of rubella vaccine virus from rubella vaccinees to pregnant women in Nashville-Davidson County, Tennessee. Approximately 24,000 children were immunized in a mass campaign at the outset of the study. Several prospective surveillance methods of 11,635 women and their new babies were employed. Attempts were made to recover rubella virus from throat swabs of 10,951 newborns. No rubella vaccine virus was recovered. Wild rubella virus was isolated from a single infant with the congenital rubella syndrome whose mother had natural rubella during the first month of pregnancy. Rubella virus was not isolated from the products of 240 abortions. There were no seroconversions among 3990 women who had paired sera available for study. Clinical and serologic follow-ups of infants judged to be a high risk because of intimate maternal exposure to vaccine virus revealed no late manifestations of congenital rubella infection. A history of close maternal contact with vaccinees during the three months before and the three months following conception was not associated with an increased incidence of congenital anomalies or clinical features seen with congenital rubella infection. Thus, no evidence of vaccine virus transmission was found, providing further evidence of the safety of rubella vaccine under field conditions. A seroepidemiologic study of 8824 pregnant women revealed the expected decline in rubella susceptibility with increasing age. When age was controlled, the variables of race, parity, and educational achievement produced no major influence on immunity.

Antibodies, Viral↗