Filling the waiting time in the clinic with education about glaucoma.

The purpose of this study was to examine the effects of an educational intervention, designed to occupy the waiting time in an eye clinic, on learning about glaucoma and patient satisfaction. Subjects (N = 100) waiting in the eye clinic were randomly assigned to 2 groups: (1) educational intervention and (2) usual clinic care (no structured education during the waiting time in the clinic). Patients who were taught in the clinic had significant gains in knowledge about glaucoma from pretest to posttest and were more satisfied with the education received during the visit.

Use of a high-sensitivity rapid strep test without culture confirmation of negative results: 2 years' experience.

BACKGROUND: Optimal diagnostic management of patients with pharyngitis is controversial. In our study, we compared streptococcal complication rates at a large suburban medical center during 2 time periods: when pharyngitis patients were managed almost exclusively with throat culture and when they were managed primarily with a high-sensitivity antigen test without culture confirmation of negative results. METHODS: Using a combination of Current Procedural Terminology and International Classification of Diseases, Ninth Revision codes, we studied all patients seen for either pharyngitis or known streptococcal complications during a 4-year period. We then reviewed all available charts of patients with known streptococcal complications for coding accuracy. We compared streptococcal complication rates during each -time period. RESULTS: A total of 30,036 patients were seen for pharyngitis during the 4 years. A streptococcal diagnostic test was used in 66% of patient encounters. During the first 2 years (period 1), 99.9% of the tests ordered were blood agar plate throat cultures. During the second 2 years (period 2), 76.6% of tests ordered were high-sensitivity antigen tests without culture confirmation of negative results. Suppurative complications occurred in 37 patients in period 1 and 36 patients in period 2. There were no cases of acute rheumatic fever in either period. There was one case of poststreptococcal glomerulonephritis in period 2. CONCLUSIONS: Use of a high-sensitivity antigen test without culture confirmation of all negative results has not been associated with an increase in suppurative and nonsuppurative complications of group A beta-hemolytic streptococci.

Streptococcal pharyngitis: impact of a high-sensitivity antigen test on physician outcome.

The purpose of the present study was to determine whether the availability of results from a high-sensitivity, rapid test for group A streptococci (Strep A OIA; BioStar, Inc., Boulder, Colo.) improves physician outcome. The study population included 465 consecutive patients with symptoms of acute pharyngitis seen in two outpatient clinics in a large suburban medical center; one clinic, a walk-in clinic (WIC), primarily saw adult patients, and one clinic, a pediatric and adolescent medicine clinic (PED), primarily saw pediatric patients. We measured improvement in physician outcome by comparing physician intent for prescribing an antibiotic based on clinical impression with physician practice once the results of the Strep A OIA were known. Based upon intent, the physicians seeing WIC patients (WIC physicians) would have prescribed an appropriate antibiotic course for 42% of patients with cultures positive for group A beta-hemolytic streptococci (GABHS) and 61% of patients with cultures negative for GABHS. After receiving the results of the Strep A OIA, WIC physicians prescribed an appropriate antibiotic course for 81% of patients with positive cultures and 72% of patients with negative cultures. Based upon intent, the physicians seeing PED patients (PED physicians) would have prescribed an appropriate antibiotic course for 35% of patients with positive cultures and 77% of patients with negative cultures. After receiving the results of the Strep A OIA, PED physicians prescribed an appropriate antibiotic course for 90% of patients with positive cultures and 81% of patients with negative cultures. Based on a 14.5% prevalence of GABHS among WIC patients, Strep A OIA improved the overall WIC physician outcome from 58 to 74%. Based on a 31.5% prevalence of GABHS among PED patients, Strep A OIA improved the PED physician outcome from 64 to 84%. Had Strep A OIA alone guided therapeutic choice, physicians would have prescribed an appropriate antibiotic course for 95% of the patients at the time of the initial encounter. We conclude that the use of Strep A OIA improves physician outcome.

Postmarketing surveillance of oral terbinafine in the UK: report of a large cohort study.

1. The safety profile of terbinafine, the first orally active allylamine, was monitored in the UK in a post-marketing setting. The study recruited 10,361 patients, a number which is approximately 5% of the population who received oral terbinafine in the UK during the period of the study. 2. Follow-up data were available on 9,879 patients. During the course of the study 14.5% patients reported medical events. 49% were thought to be possibly or probably related to terbinafine treatment. Seventy-four of the events (< 1%) were classified as 'serious' and of these only five were assessed as possibly or probably related to treatment. 3. Taste disturbance occurred in 0.6% of the patients and emerged as the only new adverse reaction probably attributable to terbinafine: this was significantly commoner in females and reversible on stopping treatment, with a median time to recovery of 42 days. 4. The study approach successfully combined hospital based dermatology outpatient and general practice centres. Source data verification was conducted on 13% of the cohort selected randomly. 5. Overall, the denominator-based description of the safety profile in actual practice shows terbinafine to be well-tolerated against a wide background of age and coexisting illness.

Comparison of conventional stool concentration and preserved-smear methods with Merifluor Cryptosporidium/Giardia Direct Immunofluorescence Assay and ProSpecT Giardia EZ Microplate Assay for detection of Giardia lamblia.

Giardiasis is the most common parasitic infection in the United States. Variation in the numbers of cysts and/or trophozoites that are present along with the need for a skilled microscopist offer challenges in diagnosis. We compared the sediment wet preparation and permanent stained smear results (concentration in formalin-ethyl acetate and preparation of a smear prepared from a polyvinyl alcohol-preserved specimen) from 512 consecutive specimens with the results obtained by using the Merifluor Cryptosporidium/Giardia Direct Immunofluorescence Assay (DFA; Meridian Diagnostics, Inc., Cincinnati, Ohio) and the ProSpecT Giardia EZ Microplate Assay (EIA; Alexon, Inc., Sunnyvale, Calif.). The Merifluor DFA detected 33 of 33 positive specimens, and the ProSpecT EIA detected 32 of 33 positive specimens. The diagnostic sensitivities of the Merifluor DFA and the ProSpecT EIA were 100 and 97%, respectively. The specificities of the assays were 99.8%. The Merifluor DFA and the ProSpecT EIA appear to be equally sensitive, and both are more sensitive than conventional microscopy.

Cyclospora species as a gastrointestinal pathogen in immunocompetent hosts.

Previous reports of diarrhea resulting from Cyclospora species have been linked to travelers and immunocompromised patients. We conducted a prospective study of 1,042 formalin-ethyl acetate fecal concentrates collected from patients with diarrhea. Between May and November 1993, we identified three patients for whom studies were positive for nonrefractile spherical organisms measuring 10 microns in diameter and containing a cluster of refractile membrane-bound globules. The cysts exhibited variable acid fastness consistent with Cyclospora species. These three patients had no history of recent travel and presented with relapsing, watery, nonbloody diarrhea that lasted from 12 days to 8 weeks. No other parasitic or bacterial pathogens were identified in their stools. All three instances of diarrhea occurred in May or June. No common source of food or water was identified. None of these patients were immunosuppressed, and their diarrhea resolved spontaneously. We suggest that Cyclospora species should be considered in community-acquired diarrhea.

Evaluation of an enzyme-linked immunoassay employing a covalently bound capture antibody for direct detection of herpes simplex virus.

The FDL enzyme-linked immunosorbent assay (ELISA; Fairleigh Dickinson Laboratories, Inc., Abilene, Tex.) for the detection of herpes simplex virus (HSV) makes use of a covalently attached antibody. This assay was compared with viral isolation and with the Ortho HSV Antigen Detection ELISA (Ortho Diagnostic Systems, Inc., Raritan, N.J.). One hundred forty-eight specimens were tested. The FDL ELISA identified 66 of 104 specimens from which HSV was isolated, yielding a sensitivity of 63% and a specificity of 95%. These results compared favorably with those obtained by using the Ortho ELISA. The total test time was shorter and the washing step was simpler than that with the Ortho assay, making the FDL assay an attractive alternative to similar methodologies.

Minitek urea disk test, a sensitive and cost-effective method to screen for Campylobacter pylori in gastric biopsies.

One hundred fifty-five biopsy specimens from the gastric mucosa of 81 patients undergoing routine endoscopy procedures were tested for the presence of Campylobacter pylori by three methods: Gram stain, culture, and modified Minitek, a rapid urea disk test (BBL Microbiology Systems, Cockeysville, Md.). Twenty-nine patients were infected with C. pylori. Sensitivities and specificities of detection were 100 and 94% with the Minitek test and 93 and 100% with Gram stain, respectively. Rapid testing by the urea disk is a simple, cost-effective, and accurate method for detecting the presence of C. pylori in gastric biopsy specimens.

Haemophilus influenzae: antibiotic susceptibility.

Ampicillin resistance was first reported among clinical isolates of Haemophilus influenzae in 1972. Reports of chloramphenicol resistance followed shortly thereafter. The principal mechanism of resistance to these two antibiotics is enzymatic. Although other mechanisms have been described, they are found in comparatively few strains. The genetic information for the inactivating enzymes is plasmid mediated and therefore readily transmissible to susceptible strains. Consequently, effective therapy for invasive disease caused by this pathogen has been seriously compromised. As antibiotic susceptibility became less predictable, in vitro testing became increasingly important. Unfortunately, the standardization of methods for laboratory testing has been slow and complicated by the fastidious nature of the organisms. This review traces the development of antibiotic resistance in H. influenzae, discusses the mechanisms which appear to be important in mediating resistance, explores newer antimicrobial agents which might be useful in the treatment of infection, and analyzes the various approaches to in vitro testing.

Rapid detection methods in microbiology: are they right for your office?

This article discusses some of the direct test methods for diagnosing Group A streptococcal pharyngitis, urinary tract infection, and the three most common sexually transmitted diseases: gonorrhea, Chlamydia, and Herpes simplex virus infection. Emphasis is placed on their practicality for the office setting as well as the limitations of the test methods in various patient populations.

Ampicillin resistance and penicillin-binding proteins of Haemophilus influenzae.

Penicillin-binding protein (PBP) alterations have been associated with non-beta-lactamase-mediated ampicillin resistance in Haemophilus influenzae. We evaluated the PBP profiles of several ampicillin-susceptible and -resistant clinical isolates of H. influenzae to determine how consistently the described alterations occurred, and to document the reproducibility of the PBP profiles for this species. The MIC of ampicillin ranged from 0.06 to 0.13 microgram ml-1 for the susceptible isolates at an inoculum of 100,000 c.f.u. when tested by broth dilution, and was 0.5 microgram ml-1 for all four isolates when tested by agar dilution. The MIC for the resistant isolates ranged from 4 to 8 micrograms ml-1 when tested by broth dilution, and from 1.5 to 16 micrograms ml-1 when tested by agar dilution. At least eight distinct PBPs with molecular masses ranging from 27 to 90 kDa were detected both in cell membrane preparations and whole cell (in vivo) binding assays done on cells in the exponential growth phase. PBP variability was evident both in the ampicillin-susceptible and -resistant isolates; however, much greater variability existed within the four resistant strains. The differences in PBP patterns included (1) electrophoretic mobility, (2) binding capacity for the antibiotic and (3) the presence of additional PBPs in two of the resistant isolates. However, decreased binding capacity was consistently demonstrated in PBP 5 (56 kDa) of all of the resistant isolates. Saturation curves with both penicillin and ampicillin indicated that PBP 5 had decreased affinity for the antibiotics.(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid methods in microbiology for in-office testing.

There are now a variety of rapid test methods available to assist in the diagnosis of the three most common infectious diseases seen in ambulatory medicine: pharyngitis, urinary tract infection, and venereal disease. Before choosing to implement any of these methods, several aspects should be carefully considered. The objectives met by onsite testing should be clearly identified and the appropriate test chosen to meet those objectives. For example, if the goal is to establish a diagnosis while the patient is still available in the office, a test method that requires more than 20 to 30 minutes to perform will not fulfill the objective. Similarly, if tests must be batched for maximum efficiency, timeliness of results will be compromised. The prevalence of the specific agent or disease in the patient population should be established, as prevalence will significantly influence the predictive value of a diagnostic test. The lower the prevalence of a disease, the lower the predictive value of a positive result and the higher the predictive value of a negative result. Conversely, the higher the prevalence, the higher the positive predictive value and the lower the negative predictive value. Thus, in one setting a test may serve best as a screen to rule out disease and, in another setting, as a confirmatory test to establish a diagnosis. The impact of false-positive and/or false-negative results must be clearly appreciated to avoid diagnostic errors. The technical features of a test method should be carefully appraised. How difficult is the test to perform and what skill level is necessary to ensure the validity of results? How much quality control is necessary? How much additional equipment is needed to perform the assay, and does the equipment have multiple applications or just a single application? Finally, does the cost-benefit ratio of providing on-site testing exceed that of referring the specimens to a reference laboratory?

In vitro susceptibilities of isolates from patients with Branhamella catarrhalis pneumonia compared with those of colonizing strains.

Branhamella catarrhalis has recently been recognized as an opportunistic respiratory pathogen. We tested 10 isolates recovered from patients with documented B. catarrhalis pneumonia and 15 colonizing isolates for their susceptibility to 19 antimicrobial agents and for their ability to produce beta-lactamase. Eight of ten disease isolates and 12 of 15 colonizing isolates produced a detectable beta-lactamase. The isolates that were negative for beta-lactamase were susceptible to all agents tested, including penicillin G. Although all strains were found to be susceptible to the majority of the newer agents by broth dilution testing, the most active new semisynthetic penicillin was azlocillin (MIC that inhibited 90% of strains, 0.5 micrograms/ml), and moxalactam had the greatest potency among the cephalosporins (MIC that inhibited 90% of strains, 0.06 micrograms/ml). Members of the first- and second-generation cephalosporins had only moderate activity. All disease isolates were susceptible to the aminoglycosides and to trimethoprim-sulfamethoxazole and resistant to vancomycin. The antibiotic susceptibilities of the disease isolates were not different from those of the colonizing strains. The results of standardized disk diffusion testing did not correlate well with those of dilution testing for penicillin or ampicillin. However, disk diffusion testing did predict susceptibility adequately for the remainder of the antibiotics tested.

Proteolytic activity of Candida albicans and other yeasts.

Clinical isolates of C. albicans (75 strains) and other yeasts (20 strains) were evaluated for their ability to produce a carboxyl acid proteinase in an effort to assess its potential role as a virulence factor. Yeasts were categorized as to the infectious process present in the patient: (1) isolates from patients with invasive disease, (2) isolates from patients with possible invasive disease, (3) isolates from superficially infected patients and (4) isolates from noninfected, colonized patients. Yeasts were grown for 7 days in medium containing bovine serum albumin (BSA) as the sole nitrogen source. The amount of extracellular proteinase was measured at pH 3.2, using BSA as substrate. The majority (97%) of C. albicans isolates produced a detectable proteinase. Some non-C. albicans isolates produced proteinase; however, the amount of activity was generally less than for C. albicans. No correlation was found between the amount of proteolytic activity and the degree of invasiveness of the strains.

Incidence, adherence, and antibiotic resistance of coagulase-negative Staphylococcus species causing human disease.

Fifty-two isolates of coagulase-negative Staphylococcus species recovered from the blood or intravenous catheters of patients with clinically significant disease were compared to 60 similar isolates from patients who were presumably colonized. All isolates were identified and evaluated for ability to adhere to smooth surfaces, and resistance to anti-staphylococcal penicillins. S. epidermidis, S. hominis, and S. haemolyticus were the most frequently occurring species, representing 65%, 15%, and 10%, respectively, of disease isolates and 57%, 25%, and 8% of colonizers. The seven other species recovered accounted for only 10% of the total in both groups. Differences in isolation rates of each species within the two groups were not significant and were reflective of their reported incidence in the normal flora. All species of coagulase-negative Staphylococcus (except S. capitis and S. cohnii, which were isolated in very small numbers) were capable of adhering to smooth surfaces. S. hominis disease isolates were all capable of adherence, and the difference between the disease isolates and colonizers was statistically significant (p less than 0.02). This was not true for any other species that was analyzed nor for all isolates considered as a whole. Resistance to anti-staphylococcal penicillins was documented for all coagulase-negative Staphylococcus species, and was more frequent in S. epidermidis disease isolates than colonizers (p less than 0.05). No correlation was found between resistance to antistaphylococcal penicillins and ability to adhere.

Analysis of the fecal microflora and its enzymatic activity in individuals genetically predisposed to colon cancer.

The role of the fecal microflora in the induction of colon cancer was investigated in individuals believed to be genetically predisposed to colon cancer. Subjects were members of families with increased occurrence of colon and endometrial carcinomas characteristic of the cancer family syndrome. Group 1 consisted of 5 cancer family syndrome individuals previously diagnosed with colon cancer. Group 2 consisted of 6 cancer family syndrome individuals previously diagnosed with endometrial cancer but free of colon cancer. An environmental control group (Group 3) consisted of 8 spouses of subjects in Groups 1 and 2. Quantitative bacterial cultures and assays of beta-glucuronidase and 7 alpha-dehydroxylase activity were performed on fecal samples. No differences in bacterial quantities or levels of beta-glucuronidase or 7 alpha-dehydroxylase activity were found among Groups 1, 2, and 3 or between spouse pairs. The results fail to associate quantities or enzymatic activity of the intestinal flora to colon cancer in individuals believed to be genetically predisposed to colon cancer.