Histologic proof of acalculous cholecystitis due to Cyclospora cayetanensis.

It is suspected that Cyclospora cayetanensis can infect the biliary tract in persons with human immunodeficiency virus infection, but histologic proof has never been published. We report a case of acalculous cholecystitis in a person with acquired immunodeficiency syndrome who required cholecystectomy and demonstrated C. cayetanensis in the gallbladder epithelium.

Gram stain method shows better sensitivity than clinical criteria for detection of bacterial vaginosis in surveillance of pregnant, low-income women in a clinical setting.

OBJECTIVE: The purpose of the study is to determine whether the Gram stain method is superior to the clinical criteria for the diagnosis of bacterial vaginosis in low-income pregnant women seen in a resident clinic setting. The clinical criteria is the current diagnostic method employed to diagnose bacterial vaginosis. STUDY DESIGN: In this study, 51 pregnant women with vaginal discharge were prospectively evaluated. All were screened using the clinical criteria, Gram stain method, and culture of the discharge. The modified scoring system instituted by Nugent et al. (J Clin Microbiol 29:297-301, 1991) was employed in reading the Gram stain smears. The clinical criteria were then compared with the Gram stain method. Isolation of moderate to many Gardnerella vaginalis growth by culture was used as the confirmatory finding. RESULTS: Sensitivity of the Gram stain method (91%) was significantly higher than that of the clinical criteria (46%), (sign test P = 0.0023, < 0.01). The Gram stain method also has both a low false-negative (4%) and high negative predictive value (96%), making it an ideal diagnostic test. CONCLUSION: The Gram stain method is a rapid and cost-effective test that is also highly reproducible and readily available in many laboratories. These features make the Gram stain method a more desirable screening procedure for bacterial vaginosis in a clinic population.

Microbial contamination of blood conservation devices during routine use in the critical care setting: results of a prospective, randomized trial.

OBJECTIVES: To compare microbial contamination of two different blood conservation devices; to determine if there was an association between contamination of the blood conservation devices and clinical infections; to determine if there was a significant user preference for either of the two devices. DESIGN: Prospective, randomized trial. SETTING: Medical, neurosurgical, and spinal cord intensive care units of an urban, university hospital. PATIENTS: Forty patients who required clinically indicated intrafierial catheters placed at new sites. INTERVENTIONS: The two most widely available blood conservation devices at the time of the study (Venous Arterial blood Management Protection system [VAMP], Baxter Edwards Critical-Care, Irvine, CA; and Safe Draw, Ohmeda, Madison, WI) were chosen for comparison. After the normal 48 to 72 hrs of device use, the blood conservation systems were removed and semi-quantitative and quantitative cultures were taken from comparable sites of the two devices. Positive cultures from the patients were recorded and correlated with cultures obtained from the devices. In order to assess preference for either device, a survey tool was administered to the nursing staff who participated in the study. MEASUREMENTS AND MAIN RESULTS: Quantitative cultures from all sites cultured in both groups demonstrated mean colony counts of < 10(3) colony-forming units (cfu)/mL. There were no statistically significant differences in the colony counts at any of the sites compared between the two groups. There were no statistically significant relationships between positive cultures and patient age, gender, duration of device utilization, frequency of device entry, or the intensive care unit in which the study was conducted. In no circumstance did positive cultures from any of the blood conservation devices correlate with positive culture results from any sites of clinical infection. The clinical survey demonstrated a statistically significant preference for the VAMP system, which persisted despite increased experience with the Safe Draw system. CONCLUSIONS: The levels of microbial contamination noted in these devices were not consistent with clinical infection (defined as 10(3) cfu/mL on quantitative cultures). There was no significant difference in degree or pattern of contamination between the two devices. When utilized and changed according to the Centers for Disease Control guidelines, blood conservation devices are not harbors of infection in the critical care setting. Blood conservation devices can be used as part of a comprehensive blood conservation program in the critical care setting without undue concern for exacerbating infectious processes.

The use and abuse of routine stool microbiology: a College of American Pathologists Q-probes study of 601 institutions.

OBJECTIVE: To examine the efficiency with which physicians use routine stool microbiology tests. DESIGN: Questionnaire and structured review of 100 consecutive stool bacteriology and parasitology examinations at each participating institution. SETTING: Six hundred one institutions enrolled in the College of American Pathologists Q-probes Program. RESULTS: Of 59500 bacteriology specimens, 3808 (6.4%) contained a pathogen. The vast majority (99%) of bacterial pathogens were detected in either the first or second specimen submitted. Almost 40% of inpatient specimens were collected after the third day of hospitalization, but only 0.6% of these specimens were positive for enteric pathogens that had not been previously recovered. More than half of the laboratories reported having no limits on the number of bacteriology specimens per patient that could be submitted for testing, and fewer than 8% of laboratories rejected specimens from inpatients after a certain number of days in the hospital. The frequency with which laboratories performed tests for Clostridium difficile varied widely. Of 58500 parasitology specimens, 1463 (2.5%) contained a pathogen; 97.6% of pathogens were detected by the second stool specimen, and 99.8% were detected by the third specimen. Only 0.7% of specimens from inpatients hospitalized more than 4 days contained a new pathogen. CONCLUSIONS: We recommend that no more than two bacteriology specimens and no more that two or three parasitology specimens be processed per patient without consultation. Standard stool examination for a bacterial pathogens has a low yield and should not be performed after 3 days of hospitalization. Likewise, parasitology examinations should not be performed after 4 days of hospitalization.

The laboratory diagnosis of pneumonia. The role of the community hospital pathologist.

Pneumonia is one of the most serious infections seen in community hospital practice, with virulent bacteria and viruses producing infections in the healthy host and a variety of opportunistic organisms capable of causing disease in the immunocompromised patient. Accurate laboratory diagnosis is extremely important for correct clinical management of pneumonia, and the community hospital pathologist can take an active role in daily review of respiratory tract specimens to optimize and coordinate this important laboratory testing. This article discusses strategies for improving sputum Gram stain interpretation and for the use of both routine and supplementary cultures in community-acquired pneumonias and outlines a comprehensive consultative approach for rapid and reliable pneumonia diagnosis in the compromised patient.

Relationship of the inguinal ligament to pelvic radiographic landmarks: anatomic correlation and its role in femoral arteriography.

PURPOSE: Because of the known risks of suprainguinal catheterization, an anatomic study of the inguinal ligament was performed in 10 cadavers. MATERIALS AND METHODS: The position of the inguinal ligament as estimated by means of palpation and use of anatomic landmarks was compared with the actual ligament position as determined by means of groin dissection. Infrainguinal contrast material injections were also performed to assess competence of the inguinal ligament against spread of hematomas. RESULTS: The radiographically determined position was an average of 15.2 mm superior to the actual ligament position (range, 3 mm below to 24 mm above). The palpated position of the ligament was an average of 7.8 mm superior to its actual position (range, 7 mm below to 23 mm above). Contrast material injections demonstrated the inability of the inguinal ligament to contain blood or fluid, with formation of retroperitoneal hematomas. CONCLUSION: Puncture of the femoral vessels should be positioned in the midportion of the femoral head, as determined with fluoroscopy for maximum safety during catheterizations.

The efficacy of image-guided stereotactic brain biopsy in neurologically symptomatic acquired immunodeficiency syndrome patients.

A prospective series of 50 neurologically symptomatic human immunodeficiency infected patients with intracranial lesions who underwent image-guided stereotactic brain biopsy is presented. Patients were diagnosed with primary central nervous system lymphoma (14 patients), progressive multifocal leukoencephalopathy (14 patients), toxoplasmosis (13 patients), human immunodeficiency virus encephalitis (3 patients), infarction (2 patients), and 1 patient each with metastatic adenocarcinoma, metastatic melanoma, cryptococcoma, and atypical mycobacterial infection. Two of the patients with toxoplasmosis had a second intracranial abnormality. Two biopsies resulted in either descriptive diagnosis only or were nondiagnostic; the definitive diagnostic efficacy of image-guided stereotactic biopsy was thus 96%. No deaths were incurred as a result of biopsy. Four intraoperative or postoperative hemorrhages occurred; in only 1 patient was there a residual neurological deficit related to the surgery. Image-guided stereotactic biopsy may thus be considered both safe and effective in this patient population.

An autopsy-based study of diagnostic errors in geriatric and nongeriatric adult patients.

One hundred sixty-two consecutive adult autopsies (87 of subjects over age 65 years and 75 of subjects aged 23 to 64 years) performed at a university hospital were studied retrospectively by six internists to determine (1) if diagnostic errors were quantitatively or qualitatively different between the two age groups; (2) if the underlying causes of error (divided into nine categories) were different or age related in any way between the two groups; and (3) any aspects of care that related age to clinical outcome. We found the frequency of major clinical/autopsy discrepancies to be similar to those in previous studies (35%), but in only 7% of cases were these likely to have affected therapy/outcome. Ther was no difference in the frequency of major discrepancies between age groups. There were significantly more "unexpected" minor discrepancies in the older patients, probably related to the multiplicity and complexity of their problems, but these would have affected therapy/outcome in only 1 (3%) of 37 cases. The most common causes of 136 clinical "errors" in 151 autopsies were, in order of frequency: a diagnostic "blind spot," a conscious decision not to pursue a clinical finding (not a real "error"), failure to account for a symptom or sign, atypical presentations, and inadequate follow-up of abnormal laboratory findings. There were no differences between the geriatric and adult groups in terms of frequency or cause of the errors. We conclude that (1) there is no difference in the diagnostic accuracy regarding cause of death between geriatric and nongeriatric patients in the acute hospital environment, and (2) closer attention to basic knowledge and clinical skills and a special focus on judgment and reasoning skills, utilizing autopsy findings among other things, will lead to even further improvement in clinical care at all ages.

Preparation of bacteriologically safe bicarbonate concentrate for hemodialysis.

To determine whether bacteriologic hazards associated with bicarbonate concentrate may be reduced or prevented, evaluation of a system consisting of a mixing tank supplied with R.O. water and two separate storage tanks was undertaken. Bicarbonate was mixed on a schedule specific to usage and dispensed to the storage tanks from which it was drawn off into 2.5 gallon jugs for each treatment. The mixing tank was disinfected with hypochlorite solution (200 ppm) before each use. Storage tanks and 2.5 gallon jugs were disinfected weekly and sampled immediately before scheduled disinfection and after the longest storage time. The mixing tank was sampled for corresponding batches. A 1 ml inoculum of concentrate was plated onto tryptic soy sheep blood agar, incubated for 48 hours at 35 degrees C and colony counts/ml recorded. A total of 225 batches on a 10% sampling schedule were monitored. All cultures have grown less than 50 cfu/ml, which is less than AAMI standards for maximum allowable level for water and dialysate. Bacteriologically safe bicarbonate concentrate can be reliably produced using R.O. water, controlled storage times, and rigid disinfection schedules.

Detection of AIDS virus in macrophages in brain tissue from AIDS patients with encephalopathy.

One of the common neurological complications in patients with the acquired immune deficiency syndrome (AIDS) is a subacute encephalopathy with progressive dementia. By using the techniques of cocultivation for virus isolation, in situ hybridization, immunocytochemistry, and transmission electron microscopy, the identity of an important cell type that supports replication of the AIDS retrovirus in brain tissue was determined in two affected individuals. These cells were mononucleated and multinucleated macrophages that actively synthesized viral RNA and produced progeny virions in the brains of the patients. Infected brain macrophages may serve as a reservoir for virus and as a vehicle for viral dissemination in the infected host.

The role of fiberoptic bronchoscopy in the evaluation of immunocompromised hosts with diffuse pulmonary infiltrates.

To define the utility of fiberoptic bronchoscopy in the evaluation of immunocompromised patients with diffuse pulmonary infiltrates, we reviewed our experience between January 1980, and January 1983, with 50 such patients with a wide variety of underlying diseases. Of these, 35 patients underwent bronchoscopy, including brushings, alveolar lavage, and transbronchial biopsy, and 15 underwent open lung biopsy; 8 patients underwent both procedures. All patients with a nondiagnostic bronchoscopy either recovered without specific antibiotic therapy or underwent an open procedure. A diagnosis was made in 29 patients (58%). An infectious process was found in 20 patients (40%). A diagnosis was made bronchoscopically in 19 patients including 18 infections. Transbronchial biopsy was rarely diagnostic of infection when brushings were negative. For all diagnoses, bronchoscopy had a sensitivity of 76.9%. For all pulmonary infections, bronchoscopy had a sensitivity of 90%. Given a negative bronchoscopy, the probability that an infection was not present (i.e., predictive value negative) was 94.4%. Unfortunately, making a specific diagnosis did not appear to greatly improve survival. We conclude that in this setting: (1) fiberoptic bronchoscopy is an extremely sensitive procedure for diagnosing pulmonary infections, (2) bronchial brushings are as useful as transbronchial biopsies for diagnosing nonfungal infections, (3) these procedures are less useful for diagnosing noninfectious conditions, and (4) in the face of a negative bronchoscopic procedure, there is a very low probability that an infectious process will be found with an open biopsy.

Legionella pneumophila serogroup six: isolation from cases of legionellosis, identification by immunofluorescence staining, and immunological response to infection.

Isolates of Legionella pneumophila that are serologically different from strains of serogroups 1 through 5 were obtained from lung biopsy tissue or pleural fluid from three renal transplant recipients in Chicago, Ill. These strains were placed in a newly designated L. pneumophila serogroup, serogroup 6, on the basis of fluorescent-antibody staining characteristics. An L. pneumophila strain obtained from Bethesda, Md., one from Houston, Tex., and one from Oxford, England, also belong to this new serogroup. L. pneumophila serogroup 6 appears to be widely distributed geographically.