PubMed Health⌕ Search

Biomedical subjects

Michael Giladi

Publications and source records attributed to Michael Giladi.

9 recordsLinked to original sources

Hospital-acquired infective endocarditis: should the definition be broadened?

Hospital-acquired infective endocarditis (IE) is a growing health-care problem. Hospital-acquired IE, according to the commonly used definition, is IE manifesting > or =72 h after admission to the hospital or within several weeks after a hospital-based invasive procedure. To assess the validity of this definition, we evaluated 87 episodes of IE, with special attention to recent hospitalizations. The incidence rate of IE in the 6-month period after discharge from the hospital was 27 cases per 100,000 person-years, compared with 1.1 cases per 100,000 person-years in a population with no recent hospitalizations. Furthermore, episodes of IE manifesting during this 6-month period were notable for a high proportion of typically hospital-acquired pathogens (26% vs. 0%; P=.001) and a low proportion of viridans streptococci (0% vs. 36%; P<.001), compared with community-acquired episodes that did not involve recent hospitalization. We conclude that characteristics of hospital-acquired IE extend to episodes arising within 6 months after discharge from the hospital and suggest that the definition of hospital-acquired IE be broadened to include these episodes.

Aged↗

Insight into the intrinsic sensitivity of the PCR assay used to detect CMV infection in amniotic fluid specimens.

BACKGROUND: PCR detection of human cytomegalovirus (HCMV) DNA in amniotic fluid (AF) is the most sensitive tool for diagnosis of fetal infection, but has sub-optimal sensitivity. It has been suggested that inhibition by AF reduces the sensitivity of this assay, however this assumption has never been thoroughly studied. Several PCR assays have been shown to improve sensitivity, but comparative studies are insufficient to choose the optimal approach. OBJECTIVES: To assess the effect of AF inhibition on PCR sensitivity and to determine the most sensitive assay for diagnosing fetal infection. STUDY DESIGN: Plasmid containing HCMV DNA was tested by PCR, in water and in non-infected AF, to assess the inhibitory effect of AF. Twenty-three AF-infected samples were tested by various PCR protocols. AF supernatant, with or without DNA extraction, and AF cells, were assayed by single-round and semi-nested PCR. Viral load was measured in the supernatant by a commercial quantitative PCR kit. RESULTS: The plasmid model demonstrated that single-round PCR was 2000-fold less sensitive in AF compared with water. Semi-nested PCR was only 10-fold less sensitive. Single-round PCR was 30% sensitive in HCMV-infected AF supernatants, and detected viral loads higher than 2.3 x 10(6) viral copies/ml. Extraction of DNA from the supernatant increased the sensitivity of this assay to 89% and the detection limit to 5.2 x 10(4) copies/ml. Semi-nested PCR performed on supernatant, with and without DNA extraction, was 96% and 100% sensitive, respectively, with a detection threshold of 3.8 x 10(3) copies/ml. Single-round and semi-nested PCR were 89% and 100% sensitive, respectively, in cells. The commercial quantitative PCR assay was 100% sensitive. CONCLUSIONS: AF supernatant is inhibitory to PCR. The two most sensitive assays were semi-nested PCR performed on DNA extracted from the supernatant and the commercial quantitative PCR kit. Of these two, the latter is standardized, non-labor-intensive, and allows minimal opportunity for contamination, thereby making it the preferred method for diagnosis.

Adult↗

Bartonella koehlerae, a new cat-associated agent of culture-negative human endocarditis.

Bartonella koehlerae is reported for the first time to be a human pathogen that causes culture-negative endocarditis. It is also shown that this species, isolated twice before from domestic cats, can be recovered as well from a stray cat population in Israel. This work follows a recent report of the same case in which the causative agent was misidentified as B. henselae, based on serology and PCR-restriction fragment length polymorphism (RFLP) analysis (A. Schattner, O. Zimhony, B. Avidor, and M. Gilad, Lancet 361:1786, 2003). B. koehlerae was identified in the valvular tissue of an endocarditis patient by DNA sequencing of the PCR products of two Bartonella genes: the genes for citrate synthase (gltA) and riboflavin synthase (ribC). The commonly used PCR-RFLP analysis of the TaqI-digested gltA PCR product did not distinguish between B. koehlerae and B. quintana or between B. elizabethae and B. clarridgeiae. PmlI digestion of the gltA amplification product failed to differentiate between B. quintana, B. clarridgeiae, and B. elizabethae. RFLP analysis of the heat shock protein (htrA) gene by TaqI digestion misidentified B. koehlerae as B. henselae. However, RFLP analysis of the ribC PCR product, digested with TaqI, was able to distinguish between the human endocarditis-associated Bartonella species tested, B. henselae, B. quintana, B. elizabethae, and B. koehlerae, as well as between the cat-associated Bartonella species, B. henselae and B. clarridgeiae. Given the expanding number of Bartonella species emerging as human pathogens, it is suggested that PCR-RFLP analysis for the diagnosis of Bartonella infections target several genes and be coupled with DNA sequencing to avoid species identification.

Bartonella↗

Long-term serological analysis and clinical follow-up of patients with cat scratch disease.

A highly specific enzyme immunoassay (EIA) was recently described for use in the diagnosis of cat scratch disease (CSD). However, data regarding EIA antibody kinetics or its correlation with long-term clinical follow-up data are lacking. The association between antibody kinetics, clinical spectrum, and disease duration were studied in 98 patients with CSD. The median duration of follow-up was 35.3 weeks (range, 2-211.3 weeks). Results of EIA testing for detection of anti-Bartonella henselae immunoglobulin M (IgM) antibodies (detected in 53% of the patients) remained positive for < or =3 months. Therefore, the presence of IgM indicated acute infection. Titers of immunoglobulin G (IgG) also decreased over time; 25% of the patients remained seropositive for >1 year after the onset of CSD. Onset of CSD in patients with an IgG titer with an optical density of > or =1.0 occurred within the prior 12 months. No association was found between antibody titers or their kinetics and the clinical manifestations or duration of disease. EIA allows for the identification of atypical manifestations of CSD that were unrecognized before the use of serological assays. Complete recovery from these manifestations may take months. Results of this study provide additional data supporting the utility of EIA in the serodiagnosis of CSD.

Adolescent↗

Isolated splenic cat scratch disease in an immunocompetent adult woman.

We report a case of isolated splenic cat scratch disease in an immunocompetent woman. The clinical presentation of prolonged fever, night sweats, weakness, and intrasplenic lesions was highly suggestive of lymphoma. This is the second reported case of isolated splenic cat scratch disease in an adult and the first in a healthy adult.

Adult↗

Asthma in adventure travelers: a prospective study evaluating the occurrence and risk factors for acute exacerbations.

BACKGROUND: Exacerbation of asthma during travel to remote regions may lead to devastating consequences. The course of asthma in travelers and the risk factors for disease exacerbation during travel have not been studied. METHODS: We screened 5835 consecutive travelers and identified 203 patients with asthma. Before travel, all enrollees were assessed for presumed risk factors for asthma exacerbation by means of an interview and an exercise test combined with spirometry. After travel, data regarding travel characteristics and asthma severity were recorded by means of a structured telephone interview. RESULTS: The 203 enrollees visited 56 countries for a median duration of 13 weeks, 147 were engaged in high-altitude trekking, and 88 had asthma attacks. Among these, 40 reported worsening asthma during travel, 32 experienced the worst asthma attack ever, and 11 reported a life-threatening asthma attack. Two independent risk factors for attacks during travel were identified: frequent use (> or = 3 times weekly) of inhaled bronchodilators before travel (relative risk [RR], 3.35; 95% confidence interval [CI], 1.75-6.39) and participation in intensive physical exertion during treks (RR, 2.04; 95% CI, 1.04-3.98). When both risk factors were present, the RR for asthma attacks increased to 5.52 (95% CI, 2.81-10.84). CONCLUSIONS: Asthma frequently worsens during travel and should not be ignored as a potentially life-threatening condition requiring pretravel consideration. Asthmatic travelers who frequently use inhaled bronchodilators before travel or participate in intensive trekking during travel are at increased risk to develop asthma attacks. Therapy should be intensified to achieve better disease control; intensive trekking should be discouraged.

Acute Disease↗

Reappraisal of community-acquired bacteremia: a proposal of a new classification for the spectrum of acquisition of bacteremia.

In recent years, dramatic changes in health care systems have shifted much of the care of sick individuals from hospitals to the community. Consequently, infections traditionally classified as community-acquired or hospital-acquired infections cannot now be readily classified into either category. We thus propose a new classification based on a wider spectrum of acquisition. A total of 1028 episodes of bloodstream infection (BSI) were divided into 5 categories: true community-acquired infections (370 episodes [36%]), infections in recently discharged patients (110 [11%]), infections associated with invasive procedures performed just before or at the time of admission (56 [5%]), infections in patients admitted from nursing homes (68 [7%]), and hospital-acquired infections (424 [41%]). Thus, 234 (39%) of the 604 bloodstream infections traditionally defined as community acquired were reclassified into 3 newly defined groups, each of which has distinct epidemiologic, clinical, and bacteriologic characteristics, as well as distinct antimicrobial susceptibility profiles. There is a conceptual and practical need for such a new classification.

Aged↗

The right answer.

Explore the source record for details and available documents.

Bartonella↗