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Biomedical subjects

J J Weems

Publications and source records attributed to J J Weems.

18 recordsLinked to original sources
PubMed2001

The many faces of Staphylococcus aureus infection. Recognizing and managing its life-threatening manifestations.

Serious infections caused by S aureus, particularly those associated with bloodstream infection, are rapidly increasing in frequency, likely as a result of the proliferation of invasive procedures, the increasing severity of illness of hospitalized patients, suboptimal adherence to infection control practices, selection of resistant strains by antibiotic use, high rates of injecting drug use, and diabetes mellitus. In many cases, being aware of the clinical manifestations and treatment of S aureus can help to decrease the incidence of these infections and promote better care for patients who have been--or could be--exposed to the pathogen.

Anti-Bacterial Agents↗
PubMed1998

A viral gastroenteritis outbreak associated with person-to-person spread among hospital staff.

OBJECTIVE: To identify the etiologic agent and risk factors associated with a hospital ward outbreak of gastroenteritis. SETTING: A regional referral hospital in upstate South Carolina. METHODS: We reviewed patient charts, surveyed staff, and tested stool from acutely ill persons. A case was defined as diarrhea and vomiting in a staff member or patient from January 5 to 13, 1996. RESULTS: The initial case occurred on January 5 in a staff nurse who subsequently was hospitalized on the ward and visited by many staff colleagues. The staff were at a significantly greater risk for gastroenteritis than were patients (28/89 [31%] vs 10/91 [11%]; relative risk [RR], 2.9; 95% confidence interval [CI95], 1.5-5.5). All 10 case-patients had been exposed to case-nurses (assigned nurses who were primary caretakers), and eight had documented exposure to case-nurses 1 to 2 days before their illness. Patients exposed to case-nurses had a significantly increased risk of illness (8/57 [14%] vs 0/32; RR, >4.5; CI95, undefined). Neither staff nor patients had significantly increased risk from food, water, ice, or exposure to case-patients. Electron microscopy identified small round-structured viruses (SRSVs) in nine of nine stool samples. CONCLUSION: This nosocomial outbreak of gastroenteritis was likely caused by SRSVs introduced by a staff member and spread via person-to-person transmission from and among staff. The potential for spread of SRSV-associated gastroenteritis from and among staff should be considered in developing strategies to prevent similar outbreaks in hospital settings.

Adult↗
PubMed1993

Nosocomial outbreak of Pseudomonas cepacia associated with contamination of reusable electronic ventilator temperature probes.

OBJECTIVE: The investigation and control of an outbreak of nosocomial Pseudomonas cepacia respiratory tract colonization and infection. DESIGN: Epidemiologic investigation based on infection control surveillance data, including definition and characterization of case patients, environmental cultures based on epidemiologic information, and institution of control measures based on study results. SETTING: A 1,171-bed, university-affiliated tertiary care hospital. RESULTS: Between January 1, 1988, and June 30, 1989, 127 patients were culture-positive for P cepacia, 117 (92%) of whom were culture-positive from sputum and were treated in the intensive care unit. Review of respiratory care procedures revealed that when mechanical ventilators were serviced between patients, the electronic temperature probes used with servo-controlled humidifiers were wiped with the same odor-counteractant cleaning solution used on ventilator cabinets. P cepacia was isolated from nine of 12 in-use temperature probe tips, three of which were from patients with negative sputum cultures for P cepacia, one of whom subsequently developed culture positivity for P cepacia. P cepacia also was isolated from the diluted odor-counteractant solution. Following the institution of a disinfection procedure for temperature probe tips, the incidence of P cepacia sputum culture positivity in ICU patients fell significantly compared to the outbreak period (138 of 5,225 discharges versus 52 of 3,678 discharges, P < 0.01). CONCLUSIONS: This investigation identified contamination of reusable electronic temperature probes as a source of nosocomial respiratory infection due to P cepacia and emphasizes the need to carefully evaluate disinfection practices for reusable patient care equipment.

Burkholderia cepacia↗
PubMed1992

Typhlitis and HIV.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Candida parapsilosis: epidemiology, pathogenicity, clinical manifestations, and antimicrobial susceptibility.

Early reports associated Candida parapsilosis with endocarditis in intravenous narcotic addicts. More recently, this species has emerged as an important nosocomial pathogen, with clinical manifestations including fungemia, endocarditis, endophthalmitis, septic arthritis, and peritonitis, all of which usually occur in association with invasive procedures or prosthetic devices. Outbreaks of C. parapsilosis infections have been caused by contamination of hyperalimentation solutions, intravascular pressure monitoring devices, and ophthalmic irrigating solution. Experimental studies have generally shown that C. parapsilosis is less virulent than Candida albicans or Candida tropicalis. However, characteristics of C. parapsilosis that may relate to its increasing occurrence in nosocomial settings include frequent colonization of the skin, particularly the subungual space, and an ability to proliferate in glucose-containing solutions, with a resultant increase in adherence to synthetic materials. Recently developed molecular techniques may facilitate the continued exploration of the epidemiology and pathogenesis of C. parapsilosis infections.

Animals↗
PubMed1991

Cavitary Pneumocystis carinii pneumonia in patients receiving aerosol pentamidine prophylaxis.

We have described two patients with AIDS who had cavitary Pneumocystis carinii pneumonia while receiving aerosolized pentamidine prophylaxis. This is the first report of this complication. Neither patient showed a clinical response to subsequent use of pentamidine either intravenously or by aerosol followed by intravenous use. Clinicians should be aware of the possibility that cavitary pneumonia in patients receiving aerosolized pentamidine may be due to P carinii.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Use of low-dose trimethoprim-sulfamethoxazole thrice weekly for primary and secondary prophylaxis of Pneumocystis carinii pneumonia in human immunodeficiency virus-infected patients.

We conducted an open prospective clinical trial to evaluate the efficacy and toxicity of trimethoprim-sulfamethoxazole given as one double-strength tablet thrice weekly for primary and secondary prophylaxis of Pneumocystis carinii pneumonia (PCP) in human immunodeficiency virus-infected (HIV+) patients. A total of 104 HIV+ patients were evaluated, with 74 being in the primary prophylaxis group and 30 being in the secondary prophylaxis group. All except six patients received concomitant zidovudine; five patients on primary prophylaxis and one patient on secondary prophylaxis refused zidovudine. There were 70 patients evaluated for the efficacy of primary prophylaxis. The mean CD4 count was 124.4 +/- 110.1 cells per microliter. The mean follow-up time was 11.8 +/- 5.8 months (median, 12 months; range, 1 to 32 months). Two noncompliant patients developed PCP after 1 and 3 months of chemoprophylaxis. The failure rate (under the intention to treat principle) was 2 of 70 patients (2.9%; 95% confidence interval, 0.35 to 10%), or 1 per 413 patient-months of observation. There were 27 patients evaluated for the efficacy of secondary prophylaxis. The mean follow-up time was 12.4 +/- 7.2 months (median, 11 months; range, 1 to 29 months). Two patients, one of whom was noncompliant, were treatment failures, developing PCP after 14 and 15 months of chemoprophylaxis; this gave a failure rate of 2 of 27 patients (7.4%; 95% confidence interval, 0.9 to 24.3%), or 1 per 167 patient-months of observation. Adverse reactions sufficient to permanently terminate therapy occurred in 9 of 104 patients (8.7%; 95% confidence interval, 4 to 15.7%) overall. The serum trimethoprim, sulfamethoxazole, and N4-acetyl-sulfamethoxazole concentrations measured by high-pressure liquid chromatography were uniformly low. One double-strength tablet of trimethoprim-sulfamethoxazole taken weekly on Monday, Wednesday, and Friday appeared to be well tolerated and efficacious for the prophylaxis of PCP in HIV+ patients at high risk and deserves further investigation.

Adult↗
PubMed1989

Molecular epidemiology of nosocomial, multiply aminoglycoside resistant Enterococcus faecalis.

The prevalence of high-level aminoglycoside resistance among Enterococcus faecalis at the Memphis VA Medical Center was 23.6% (59 of 250 isolates) from October to December 1986. Hybridization to a probe cloned from Ent. faecalis pIP1800 for 6' acetyltransferase-2" phosphotransferase (AAC6'-APH2") was observed in 55 (93.2%) of the resistant isolates and was associated with gentamicin resistance. Hybridization to a probe cloned from Ent. faecalis pJH1 for 3', 5" phosphotransferase type III (APH3', 5" III) was observed in 28 (47.4%) and was associated with streptomycin resistance. Twenty-five of the 32 isolates which were resistant to both gentamicin and streptomycin hybridized to both probes. Cell mating in conjunction with hybridization indicated that the AAC6'-APH2" gene is transferred separately from that for APH3', 5" (III), and the streptomycin resistant gene is cotransferred with the latter. The gentamicin-streptomycin resistant isolates therefore contain genes from two Ent. faecalis plasmids, and resistance to these two antibiotics appears to transfer separately. The genetic homogeneity of these isolates suggests nosocomial transmission of enterococci.

Aminoglycosides↗
PubMed1988

Phenotypic selection of small-colony variant forms of Staphylococcus epidermidis in the rat model of endocarditis.

Four pathogenic strains of Staphylococcus epidermidis (sensu strictu)-EC, RP62A, LW, and HBSN--exhibited a mixed population of colony phenotypes when plated onto a high-salt, low-glucose agar ("Memphis agar"). When compared with challenge inocula, significant shifts in colony populations to the small-colony variant forms occurred for all four strains for isolates recovered from infected vegetations of rats with catheter-induced endocarditis. Various colony phenotypes of the HBSN strain were compared in virulence studies by using the rat model of endocarditis. The infectivity rate of the small-colony variant forms was significantly less than that of either the normal parent form (P less than .05) or the mixed phenotypic inoculum (P less than .05). These data indicate that the small-colony variant forms may be selected for, once endocardial infections are established, and that the small-colony variant forms alone are much less able to initiate and/or sustain intracardiac infections in experimental endocarditis.

Animals↗
PubMed1988

Pneumocystis carinii antigenemia in acquired immunodeficiency syndrome.

The present study was conducted to determine the prevalence and significance of Pneumocystis carinii antigenemia in patients with acquired immunodeficiency syndrome (AIDS) and clinically or invasively diagnosed P. carinii pneumonitis. Single serum specimens from 20 AIDS patients invasively examined for P. carinii organisms and 106 AIDS patients with a clinical diagnosis only of P. carinii pneumonitis were blindly tested for P. carinii antigenemia by a counterimmunoelectrophoresis assay. In the 20 specimen-documented cases, the antigen test demonstrated a sensitivity of 75% and a specificity of 90%. The positive predictive value of the test was 90%, while the negative predictive value was 70%. In AIDS patients with specimen-documented P. carinii pneumonitis, the prevalence of P. carinii antigenemia coincided almost exactly with the prevalence of positive invasively obtained specimens (60 and 59%, respectively). In patients with a clinical diagnosis only of P. carinii pneumonitis, half as many (30%) were found to exhibit antigenemia. Sequential P. carinii antigen titers determined by a new latex agglutination technique on three AIDS patients with specimen-documented P. carinii pneumonitis demonstrated the influence of specific therapy upon P. carinii antigenemia and its potential prognostic application.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Construction activity: an independent risk factor for invasive aspergillosis and zygomycosis in patients with hematologic malignancy.

Between November 1982 and July 1984, five patients at a 110-bed pediatric hospital were diagnosed with invasive filamentous fungal infection; three had invasive aspergillosis (IA) and two had invasive zygomycosis (IZ). All five had underlying hematologic malignancy (HM). In a case-control study, these five HM patients (cases) were compared to 10 autopsied HM patients without evidence of aspergillosis or zygomycosis (controls). Cases and controls did not differ in underlying disease or in the degree of immunosuppression, as measured by duration of granulocytopenia and number of platelet transfusions. However, case-patients were more likely than controls to have been hospitalized during the construction of a hospital addition (p less than 0.02, Fisher's exact test [FET]). Four (80%) of five HM patients autopsied during the period of construction had IA or IZ compared with one (5%) of 21 autopsied before construction began (p = 0.001, FET). These findings suggest that, in a population of comparably immunosuppressed patients, construction activity may represent an independent risk factor for IA or IZ. Hospitals caring for such patients should take precautions which minimize exposure of these patients to construction or renovation activity.

Adolescent↗
PubMed1987

Candida parapsilosis fungemia associated with parenteral nutrition and contaminated blood pressure transducers.

During the period September 1983 through May 1985, Candida parapsilosis was isolated from intravascular sites (blood or vascular catheter tips) in 12 patients at a pediatric hospital. Of 205 patients with cultures of any site positive for Candida species, 32 (16%) had cultures positive for C. parapsilosis. In contrast, of 23 patients with intravascular cultures positive for Candida species, 12 (51%) had cultures positive for C. parapsilosis (P less than 0.001, Fisher's exact test). The 12 patients with intravascular cultures positive for C. parapsilosis were more likely to have received central venous nutrition therapy (10 of 12 versus 7 of 23; P less than 0.01, Mantel-Haenzel chi-square test) and had a longer duration of exposure to blood pressure transducers (P less than 0.08, paired t test) than the 23 ward- and age-matched controls. C. parapsilosis was isolated from 11 (32%) of 34 in-use and stored blood pressure transducers. After ethylene oxide sterilization of blood pressure transducers was begun, in-use pressure transducers showed no growth of C. parapsilosis. This study emphasizes the role of C. parapsilosis as a nosocomial pathogen associated with invasive devices and parenteral nutrition; it also emphasizes the importance of adhering to recommended procedures for sterilizing blood pressure transducers.

Adolescent↗
PubMed1987

Pseudoepidemic of aspergillosis after development of pulmonary infiltrates in a group of bone marrow transplant patients.

During February and March 1985, seven patients in the pediatric bone marrow transplant unit (PBMTU) of a 350-bed cancer hospital developed pulmonary infiltrates. Five of the patients had Aspergillus spp. isolated from the respiratory tract, and two of these patients had histologic evidence of aspergillosis. Between 26 February and 22 April, Aspergillus spp. were isolated in a total of 70 cultures from 39 hospitalized patients. Of the 70 cultures, 14 (group 1) were from respiratory specimens of PBMTU patients with pulmonary infiltrates and were submitted to the laboratory intermittently over the 56-day period. However, of the other 56 Aspergillus-positive cultures (group 2), 41 (73%) were submitted on six days during this period (P less than 0.001, chi-square goodness of fit), including 8 blood cultures submitted on one day. When Aspergillus sp. was recovered from group 1 cultures early during this period, the isolates were stored in the culture-processing room. Aspergillus isolates were not handled in a biological safety cabinet, and blood cultures were done by using a system which requires opening of an evacuated bottle to room air. The presence of stored Aspergillus isolates was associated with a markedly elevated concentration of airborne fungi in the culture-processing room. After removal of the stored Aspergillus isolates from the culture-processing room, the concentration of airborne fungi returned to background level and there were no further Aspergillus-positive cultures. These findings suggested that group 2 cultures had been contaminated by stored Aspergillus isolates. No evidence for a common source of infection was found in the PBMTU patients with pulmonary infiltrates.

Air Microbiology↗