Guidelines for serological testing in the diagnosis of acute hepatitis A and B.

This study was performed to determine whether elevation of serum transaminases can be used to eliminate unnecessary serological tests to diagnose acute hepatitis A (HAV) and acute hepatitis B (HBV). Serum samples of 1226 patients were tested for HBsAg, anti-HBc (IgM), and anti-HAV (IgM). Acute hepatitis was diagnosed in 113 (9.2%) patients; 75 were serologically positive for HAV, 36 for HBV, and 2 patients for both HAV and HBV. Serum transaminase levels were elevated in 104 of 107 (97.2%) of seropositive patients in whom the results of biochemical tests were available. A review of the medical records of seropositive patients with normal transaminases revealed that each of the three HAV patients had a remote history of hepatitis. None of the seropositive patients with a recent history of acute viral hepatitis had normal transaminase levels. During this period, serological tests were ordered in 266 of 1054 (25.2%) seronegative patients with normal serum transaminases. We conclude that serum transaminase levels can be reliably used to screen sera for acute HAV and HBV infection.

Evaluation of cultures of percutaneous core needle biopsy specimens in the diagnosis of pulmonary nodules.

The value of cultures of tissue obtained by image-directed core needle biopsy of lung nodules has not been determined. Of the 250 biopsies performed during a 5-year period in an area endemic for coccidioidomycosis, 225 (90%) were diagnostic. Granulomas were identified in 75 specimens, whereas 3 specimens revealed abscess. Ziehl-Neelsen stain was positive for acid-fast bacilli (AFB) in 2 cases. Spherules of Coccidioides immitis were seen in 54 of the biopsy specimens with granulomas. Microbiologic cultures were positive for C immitis in 5 (9.6%) of 52 biopsy specimens. Both of the AFB-positive cases were negative by culture. Organisms were demonstrated in cases with abscess; however, the cultures submitted in 2 cases were negative. Cultures were uniformly negative in cases where special stains failed to reveal organisms. Cultures of core needle biopsy specimens are insensitive in the detection of specific microorganisms and need not be routinely performed.

Development and implementation of cost-effective guidelines in the laboratory investigation of diarrhea in a community hospital.

BACKGROUND: Fecal cultures are often inappropriately requested in the investigation of diarrhea. OBJECTIVES: To develop and determine the efficacy of practice guidelines for the ordering and processing of stool cultures that are submitted for the diagnosis of community-acquired diarrhea. METHODS: The results of stool cultures that were submitted to the microbiology laboratory of a tertiary care nonteaching community hospital were retrospectively reviewed. Following the implementation of guidelines, the efficacy was evaluated by comparison of fecal culture results in a prospective manner. RESULTS: Analysis of results of stool cultures that were obtained from 3072 patients during a 3-year period revealed that (1) the sensitivity (40%) and predictive value (20%) of finding neutrophils in smear preparations were too low to be clinically useful, (2) routine cultures from patients with nosocomial diarrhea were uniformly negative, and (3) multiple specimens from a patient rarely provided additional information. Based on these findings, new guidelines were developed and implemented with the cooperation of clinical staff. Three-month follow-up results showed that the total number of specimens, the number of specimens from patients with nosocomial diarrhea, and multiple specimens declined by 37.7%, 70.6%, and 50%, respectively. However, the isolation rate of pathogens increased from 11.7% to 18.7%. CONCLUSIONS: The application of practice guidelines that include elimination of smear examination of rectal swabs, exclusion of routine cultures from patients with nosocomial diarrhea, and rejection of repeated cultures can result in significant cost saving without adversely affecting patient care.

Pathology of the gallbladder in gallstone pancreatitis.

Although cholecystectomy is routinely performed as a part of treatment for gallstone pancreatitis, detailed histopathologic features of the gallbladder have not been described. In this study, the pathologic findings of 53 gallbladders from patients with clinical and laboratory evidence of gallstone pancreatitis are described. The presence of intraepithelial neutrophilic aggregates, a histologic finding associated with common bile duct obstruction, was identified in 32 (60.4%) cholecystectomy specimens and was the most common pathologic findings. Changes of acute cholecystitis and chronic cholecystitis were found in 15 (28.3%) and 6 (11.3%) gallbladders, respectively. Fat necrosis, which is characteristically associated with acute pancreatitis, was the most specific histologic change, but it was seen in the adventitia of only four gallbladders. The similarities of pathologic findings in gallstone pancreatitis and common bile duct obstruction emphasize the role of choledocholithiasis in the pathogenesis of pancreatitis associated with cholelithiasis.

Pathology of the gallbladder in common bile duct obstruction: the concept of ascending cholecystitis.

The presence of intraepithelial aggregates of neutrophils in the gallbladder mucosa is proposed as a specific histologic marker of common bile duct obstruction. Medical records of 334 patients who underwent cholecystectomy over a 14-month period were reviewed. Based on clinical, laboratory, radiologic, and operative findings, 48 patients with common duct obstruction were identified. Pathologic changes of acute cholecystitis were found in eight patients. In the remaining 40 patients the proposed pathognomonic changes of biliary obstruction were observed. Sensitivity and specificity of the histologic criterion were 83.3% and 97.4%, respectively. On a pathophysiologic basis, the characteristic inflammatory response in the gallbladder mucosa is believed to be analogous to the reaction seen in the wall of the common bile duct and liver, and a part of the process of ascending cholangitis. In the absence of usual changes of acute cholecystitis, a pathologist may suggest the possibility of common duct obstruction if intraepithelial neutrophilic aggregates are seen on examination of the gallbladder.

Clinicopathologic study of changes in prolapsed intervertebral disks.

To study the various factors that might influence the detection of edge neovascularization that is seen in prolapsed intervertebral disks, clinical features of 112 patients were reviewed. Edge neovascularization, which was seen in nearly one half of surgical specimens, was identified more frequently in lumbar disks (61.2%) than in cervical disks (3.8%). Although the characteristic change was more likely to be found in entirely than partially submitted specimens, the difference was not statistically significant. There was a direct relationship between neovascularization and the duration of symptoms. The frequency of finding the specific change increased from 12.5% in patients with disease for less than a month to 82% of patients who had symptoms for 6 months or more. Specific changes in prolapsed disks probably reflect a reparative phenomenon that is influenced by the degree and duration of mechanical forces.

Endogenous and exogenous infection with Pseudomonas aeruginosa in a burns unit.

Twenty patients who were admitted to the Burns Unit from December, 1969 through October, 1970 were studies to determine the sources of infection caused by Pseudomonas aeruginosa. The pyocine typing method was employed for finger printing of 383 isolates recovered from wounds and 67 isolates from environmental cultures of nurses' hands, sinks, floors, bed rails, walls and baths. In addition, cultures of moist rectal swabs were carried out daily for the first six days of hospitalization to assess the importance of endogenous infection. In six patients, the rectum was identified as the source of infection. However, in these patients, pyocine types of Ps. aeruginosa which were not obtained from rectal cultures, were also recovered. Pyocine types 1b, 10 and 31 were isolated more frequently than others. Clustering of common pyocine types suggests cross-contamination. Sinks were found to be consistently contaminated with Ps. aeruginosa. Amongst the environmental sources, positive cultures were occasionally obtained from floors, bed rails and nurses' hands. It is suggested that sinks are probably the most important reservoir of Pseudomonas infection in burns.

Fluorescent Vi antibody test in the screening of typhoid carriers.

The comparative efficacies of direct bacterial agglutination and immunofluorescent antibody for the estimation of serum Vi antibody were determined in the detection of typhoid carriers. Sera from all 12 typhoid carriers gave significant titers of 1/10 or more in the direct bacterial agglutination test; however, 26 of 119 (21.8%) sera from culture-negative individuals were also falsely positive. In the fluorescent Vi antibody test, 11 of 12 typhoid carriers showed significant serum antibody levels, while only two of 119 (1.7%) culture-negative subjects had significant antibody titers. In view of the much lower false-positive rate, the immunofluorescent Vi antibody test is considered to be superior to the direct bacterial agglutination test in the screening of typhoid carriers.

Serum immunoglobulins after surgical operations.

Serum concentrations of IgG, IgM and IgA were determined before and after surgery in 38 patients Eighteen patients who were anesthetized for less than 2.5 hours showed a slight decrease of serum IgG levels on the first and third postoperative days. The fall in serum levels of IgG on the first and third postoperative days was significant in 20 patients who underwent surgical operations which lasted more than 2.5 hours. Serum IgM increased on the third and seventh postoperative days. Alterations of IgA levels were minimal. The incidence of postoperative surgical infection was much higher in the group of patients which had lengthier operations. Though the number of patients was small for statistical evaluation, a correlation was observed between serum levels of IgG and IgM and the risk of developing surgical infection. Possible mechanisms underlying these changes in serum immunoglobulins are briefly discussed. We suggest that the duration of exposure to an anesthetic agent may be more important than the severity of surgical trauma in causing alterations of serum immunoglobulins.