Paul M. Arnow

Fever of unknown origin

ostensibly due to improved diagnostic imaging, but in a contemporaneous series the proportion was 24%. In our hospital neoplasia, in particular lymphoma, remains an important cause of FUO. The role of certain individual diseases has changed considerably. For example, rheumatic fever and systemic lupus erythematosus (SLE) were common in early series but are unusual today, probably because of the sharp decline in rheumatic fever in the developed world and the wide availability of accurate tests for SLE that permit early diagnosis. Infective endocarditis has decreased in frequency since the 1950s as blood culture techniques have improved, but new pathogens that are difficult to isolate (eg, Bartonella quintana) ensure that it will not disappear as a cause of FUO. A few diagnoses in recent series were unknown four decades ago, including Lyme disease, acute HIV infection, Sweet’s syndrome, and Bartonella endocarditis. Early series also failed to report drug fever as a cause of FUO.

Management of outbreaks of methicillin-resistant Staphylococcus aureus infection in the neonatal intensive care unit : A consensus statement

OBJECTIVE In 2002, the Chicago Department of Public Health (CDPH; Chicago, Illinois) convened the Chicago-Area Neonatal MRSA Working Group (CANMWG) to discuss and compare approaches aimed at control of methicillin-resistant Staphylococcus aureus (MRSA) in neonatal intensive care units (NICUs). To better understand these issues on a regional level, the CDPH and the Evanston Department of Health and Human Services (EDHHS; Evanston, Illinois) began an investigation. DESIGN Survey to collect demographic, clinical, microbiologic, and epidemiologic data on individual cases and clusters of MRSA infection; an additional survey collected data on infection control practices. SETTING Level III NICUs at Chicago-area hospitals. PARTICIPANTS Neonates and healthcare workers associated with the level III NICUs. METHODS From June 2001 through September 2002, the participating hospitals reported all clusters of MRSA infection in their respective level III NICUs to the CDPH and the EDHHS. RESULTS Thirteen clusters of MRSA infection were detected in level III NICUs, and 149 MRSA-positive infants were reported. Infection control surveys showed that hospitals took different approaches for controlling MRSA colonization and infection in NICUs. CONCLUSION The CANMWG developed recommendations for the prevention and control of MRSA colonization and infection in the NICU and agreed that recommendations should expand to include future data generated by further studies. Continuing partnerships between hospital infection control personnel and public health professionals will be crucial in honing appropriate guidelines for effective approaches to the management and control of MRSA colonization and infection in NICUs.

An Outbreak of Fatal Fluoride Intoxication in a Long-Term Hemodialysis Unit

Long-term hemodialysis is the most common treatment for end-stage renal disease in the United States and was administered to more than 155 000 patients in 1991 [1]. Technologic developments in dialyzer membranes, dialysis machines, and vascular access have made hemodialysis routine, but the procedure remains potentially hazardous because of mechanical malfunctions and human error [2]. Serious adverse reactions have resulted, particularly from microbiological or chemical contamination of hemodialyzers and dialysate solutions [2-7]. Municipal water used to prepare dialysate must be purified to ensure that no contaminants remain that would be toxic to patients receiving dialysis. Reverse osmosis is the most common procedure to remove ions, but deionization systems, alone or after reverse osmosis, were used by nearly one half of the hemodialysis centers in the United States in 1991 [1]. Paradoxically, these deionization systems pose an additional hazard. When their ion exchange resin becomes exhausted, toxic ions previously removed from municipal water and bound to the resin may be displaced into the effluent stream of purified water [5, 6]. Johnson and Taves [8] found that high concentrations of fluoride could be released in this manner into effluent, but no cases of acute fluoride intoxication attributable to this mechanism have been reported. We recently investigated in a hemodialysis unit an outbreak of acute illness and death caused by fluoride intoxication. We describe the epidemiologic characteristics of the outbreak and the pattern of deionization system use that resulted in massive fluoride efflux from an exhausted resin. The Outbreak On 16 July 1993, several patients treated at a long-term hemodialysis unit became ill during or soon after hemodialysis. The predominant symptoms were severe pruritus, headache, nausea, and chest or back pain. One patient had cardiac arrest immediately after completion of dialysis. Patients continued to receive dialysis treatment until that afternoon, when the unit was notified that two other patients had had cardiac arrests after leaving the unit. Dialysis treatments were stopped during the third shift of patients, and patients who had received hemodialysis on 16 July were brought to the University of Chicago Hospital for evaluation. Those who had any symptoms were admitted to the hospital, and patients whose scheduled treatment had been interrupted resumed dialysis at the hospitals acute care dialysis unit. An investigation was then initiated. Methods Clinical and Epidemiologic Characteristics of the Patients We interviewed patients who received long-term hemodialysis treatment in the unit and reviewed their records to identify symptoms during the period 26 April to 16 July 1993, when a temporary water purification system was used. We considered that patients had severe hemodialysis-associated illness if within 5 hours after the start of dialysis either severe pruritus developed or cardiac arrest ensued, or if at least three of the following symptoms developed: burning or feverish feeling; headache; nausea or vomiting; syncope or near syncope; pain in the chest, back, or abdomen; or diarrhea. We reviewed medical and dialysis unit records to determine patient age, sex, primary underlying illness, results of physical examination and clinical laboratory tests, number of years of long-term hemodialysis, duration of the hemodialysis session on 15 or 16 July, hemodialysis blood flow rate, type of dialyzer, and dialyzer reuse. We considered that patients had cardiac disease if they had coronary artery disease, cardiomyopathy, valvular heart disease, or clinically significant electrocardiographic abnormalities such as bundle-branch block. For statistical analysis, we compared each continuous variable using the t-test and the Wilcoxon test, and proportions were compared using the Fisher exact test [9]. Dialysis Unit Design and Water Supply We surveyed the municipal water supply, dialysis water purification systems, types of dialyzers and dialysis machines, dialysate preparation, and dialyzer reprocessing procedures. We also reviewed records of daily municipal water treatment and periodic chemical analyses by the City of Chicago Department of Water during 7 June to 16 July 1993. Sample Collection and Analysis Blood specimens were collected on 16 July from all surviving patients who had had hemodialysis treatment that day. Complete blood count and routine blood chemistry testing were done. A portion of each sample was stored at 70C and later assayed for fluoride. Samples of purified water used for dialysate preparation were collected on 16 July 1993 for analysis of 18 chemicals for which maximum allowable levels were established by the Association for the Advancement of Medical Instrumentation [10]. Samples of municipal water, purified water used to prepare dialysate, acid concentrate, bicarbonate concentrate, and bicarbonate dialysate also were collected on 16 July and assayed for fluoride concentration using an ion-selective electrode system (Orion Research, Cambridge, Massachusetts) [11]. Additional samples of purified water from each of the two sets of deionization tanks in the room (room 1) where sick patients had received hemodialysis treatment were collected on 17 July after approximately 1000 L of water had flowed through the systems when the dialysis machines were tested. These samples and dialysate collected from room 1 on 16 July were assayed by the Illinois Department of Public Health for fluoride and for toxic organic compounds by gas chromatography-mass spectrometry and by ultraviolet spectrometry. Postmortem serum specimens were obtained and assayed for fluoride by the Cook County Medical Examiners Office. Model Deionization System To confirm that sustained high levels of fluoride in effluent from the deionization system in the dialysis unit could have been released by operating the system after the resin was exhausted, a laboratory model of the system was constructed. An activated carbon tank and four newly regenerated deionization tanks were supplied by the water treatment contractor who maintained the system in the dialysis unit. The four tanks were arranged in series as follows: first, a cation resin tank containing sulfonated polystyrene (Amberlite IR-120 Plus, Rohm and Haas, Philadelphia, Pennsylvania) in position 1; next, an anion resin tank containing a type II quaternary ammonium resin (Amberlite IRA-410) in position 2; then two mixed-bed tanks containing both cation and anion resins in positions 3 and 4. This system was used to treat 27 500 L of municipal water, a volume estimated to be the same as that which flowed through each of the two sets of deionization tanks in room 1 from 26 April to 7 June 1993. A second deionization system was then constructed with newly regenerated tanks in positions 1, 2, and 4; the mixed-bed tank from position 4 in the first deionization system was moved into position 3, as had been done in the dialysis unit. The second deionization system was operated beyond exhaustion of the resins to simulate use from 7 June to 16 July 1993. During operation of the two model deionization systems, effluent was collected to measure fluoride concentration and resistivity, which decreases as electrolyte concentration increases. Results Clinical and Epidemiologic Characteristics of the Patients At the time of the outbreak, 56 patients were receiving long-term, high-flux hemodialysis. One half of the patients were treated on Monday, Wednesday, and Friday, and the other half were treated on Tuesday, Thursday, and Saturday. Twenty-one patients received at least a portion of their scheduled dialysis on 16 July before treatments were stopped. Nine of the 21 patients treated on 16 July and 3 of the 25 patients treated on 15 July were classified as cases. Review of dialysis unit records for the previous 12 weeks identified only 1 additional patient who met the case definition. That patient, who had a cardiac arrest on 9 June, was not considered to be part of this outbreak and thus we did not include him as a case-patient. Table 1 summarizes the characteristics of both the 12 patients classified as case-patients and the 20 patients not considered cases who were treated during the same shifts. Symptoms other than cardiac arrest began 1 to 3 hours after the start of hemodialysis in all cases and resolved by the next morning. Case-patients who reported pruritus described it as the most severe they had ever experienced. Diphenhydramine hydrochloride was taken by 5 patients, none of whom noted any relief. Pruritus lasted more than 6 hours in the surviving patients who became ill on 16 July and less than 3 hours in the three patients who became ill on 15 July. Table 1. Demographic Characteristics and Clinical Features of Patients Receiving Long-Term Hemodialysis Cardiac arrests occurred 4 to 6.5 hours after hemodialysis began. Antecedent symptoms were pruritus, vomiting, and/or chest pain in two patients and leg pain in the third. Emergency medical care records showed fatal ventricular fibrillation in all three patients; one was restored briefly to sinus rhythm by electrical cardioversion. All three had preexisting cardiac abnormalities: left bundle-branch block, right bundle-branch block and coronary artery disease, or mitral stenosis with atrial fibrillation. All six surviving patients who became ill on 16 July were hospitalized that evening. None had new abnormal findings on physical examination or complete blood count, and none had hyperkalemia. Three patients had low serum calcium concentrations of 7.8 to 8.3 mg/dL (1.95 to 2.54 mmol/L). Patients in the dialysis unit received high-flux dialysis in two treatment rooms using individual self-proportioning, volumetrically controlled ultrafiltration machines (COBE Centrysystem 3, COBE Laboratories, Lakewood, Colorado). The 12 patients who became ill received dialysis treatment for a mean of 2.8 0.7 hours (ra

An Outbreak of Gram-Negative Bacteremia Traced to Contaminated O-Rings in Reprocessed Dialyzers

Reprocessing of hemodialyzers has become a common practice in the United States because of decreased costs, improved biocompatibility, and fewer patient symptoms [1-3]. Reuse generally has been safe, but pyrogenic reactions and bacteremia occasionally have occurred [4-11]. These problems have been attributed to improper disinfection procedures [4, 7, 9] or inadequate potency of the solution used to disinfect the dialyzer [5-7, 9]. Treated water used to prepare dialysate and rinse dialyzers has been implicated as the reservoir for organisms causing bacteremia [4, 9, 11], but the exact means by which bacteria from the treated water reach the bloodstream of patients has not been elucidated. We investigated a cluster of cases of gram-negative bacteremia in patients receiving long-term hemodialysis at our institution. Using epidemiologic and laboratory studies, we identified the mechanism by which bacteria were transmitted from treated water to the bloodstream of patients receiving hemodialysis treatment. Methods Hemodialysis Unit The outpatient hemodialysis unit at the University of Chicago Hospital was opened in July 1985 in a building separate from the hospital. At the time of the outbreak, approximately 130 patients were receiving long-term hemodialysis treatment there. The unit operated three shifts per day, 6 days per week, and administered approximately 390 hemodialysis treatments per week. In September 1987, the center introduced high-flux dialysis, and in October 1987 the unit began a program of dialyzer reuse. Reprocessing was done by an automated procedure (Renatron; Minntech, Minneapolis, Minnesota) using a hydrogen peroxide-peracetic acid germicide (Renalin, Minntech). The long-term hemodialysis unit has two rooms for patient treatment and a separate room for the water treatment system, supplies, and dialyzer reprocessing. The main treatment room contains 16 stations, and the other treatment room (annex) contains 3 stations. The use of high-flux dialysis increased dramatically during March 1988, so that at the time of the investigation in July 1988, approximately 50% of all patients at the center were receiving high-flux dialysis. Recovery of Pseudomonas cepacia from blood culture specimens taken during dialysis on 30 June 1988 from 2 patients receiving long-term hemodialysis prompted an investigation that continued from July 1988 to April 1989. Case Definition and Case Detection A case was defined as an episode of primary gram-negative bacteremia occurring in a patient receiving long-term hemodialysis. To detect cases, results of all blood culture specimens from patients receiving long-term hemodialysis were reviewed retrospectively for the period 1 July 1987 to 30 June 1988 and then prospectively through April 1989. Blood Cultures Specimens for blood culture were obtained during hemodialysis from the venous return port after it was wiped with an iodophor antiseptic and then with 70% alcohol. Specimens were inoculated into an enrichment medium (Bactec, NR660; Becton-Dickinson Diagnostic Instrument Systems, Towson, Maryland). All organisms isolated were identified by an automated method (AutoMicrobic Systems; Vitek, Hazelwood, Missouri), confirmed by conventional biochemical methods, and tested for susceptibility to antimicrobial agents using a broth microdilution method. Matched-Pair Study We did a casecontrol study to identify risk factors for the development of primary gram-negative bacteremia. For each case, a matched control of the same sex and closest age was selected from among patients having outpatient hemodialysis on the same day who did not have signs or symptoms of gram-negative bacteremia. Medical records were reviewed to identify underlying renal disease; years on long-term dialysis; type of dialyzer (high-flux or conventional); type of vascular access; dialysis shift, station number, and location; dialysis machine; number of times dialyzer had been reused; dialyzer reprocessing technician; and recent antibiotic use. Data were analyzed using the McNemar chi-square test and the Wilcoxon signed-rank test. Evaluation of the Hemodialysis Unit and Hemodialyzers Techniques used to disinfect water-distribution lines and hemodialysis machines, to reprocess dialyzers, and to dialyze patients were observed to determine compliance with written procedures. The results of cultures routinely done each month to monitor treated water were reviewed, and, during the first 3 months of the investigation, additional 100-mL samples of treated water were cultured weekly from seven sites throughout the water-distribution system. Total bacterial counts were determined using a standard membrane filter technique [12]. On 7 July 1988 and 18 October 1988, cultures were taken of moist environmental surfaces and of antiseptics and solutions used in the dialysis unit for hemodialysis and dialyzer reprocessing. Serial volumes (1, 0.1, and 0.01 mL) of solution were plated on blood agar and incubated for 48 hours at 35 C, and growth was assessed quantitatively. Swab samples were plated on blood agar and assessed semi-quantitatively. All isolated organisms were identified using a commercially available kit (API test-strips; Analylab Products, Inc., Plainview, New York) or by conventional biochemical methods. When available, hemodialyzers (associated with patients who had bacteremia) were examined and cultured. Dialysis and blood pathway fluids were cultured using standard membrane filter techniques and were assayed for the presence of Renalin using Renalin residual test strips (Renal Systems, Inc.; Minneapolis, Minnesota). Screw-top headers (when present) were removed, and the fiber-bundle ends and header O-rings were cultured by impression onto blood agar. During 7 July to 6 September, 47 dialyzers used in patients without bacteremia were similarly cultured and assayed for Renalin concentration. O-Ring Contamination To determine whether O-rings were adequately decontaminated during reprocessing, O-rings from Hemoflow F-80 hemodialyzers (Fresenius AG; Bad Homburg, Germany) Figure 1 were deliberately contaminated by being dipped in a bacterial suspension and were then replaced in dialyzers that were reprocessed. Strains of bacteria used in these experiments were the isolates of P. cepacia, Xanthomonas maltophilia, Citrobacter freundii, Enterobacter cloacae, and Acinetobacter calcoaceticus var. anitratus from patients receiving hemodialysis who had gram-negative bacteremia. Bacterial concentrations ranged from 102 to 105 colony-forming units (CFU)/mL. After the dialyzers had been disinfected with Renalin and stored for 48 hours, sterile saline was flushed through the blood and dialysis compartments and was then cultured quantitatively by plating 0.1-, 1.0-, and 10-mL aliquots onto blood agar. Also, O-rings were removed and cultured by impression onto blood agar. Growth was assessed semi-quantitatively at 48 hours as light when a faint or partial outline of a ring was visible, moderate when a complete circle was present with bleeding onto the surrounding agar, and heavy when a lawn of growth was present. Dialyzers showing persistent bacterial contamination after initial disinfection were processed a second time using the standard method. Several dialyzers with positive cultures after a second attempted disinfection were disinfected a third time with the additional step of removing the O-rings, dipping them in Renalin, and replacing them in the header before reuse. Figure 1. Schematic representation of the Hemoflow F-80 dialyzer. Simulated Dialysis Simulated hemodialysis was done after F-80 dialyzer O-rings were contaminated by dipping them in a suspension of 104 to 105 CFU/mL of bacteria. Dialyzers were reprocessed and stored at room temperature for 48 hours. To simulate dialysis, each dialyzer was connected to a dialysis machine, and 800 mL of sterile saline was circulated through the blood compartment, whereas 600 mL of bicarbonate solution was circulated through the dialysis compartment. This simulation was continued for approximately 20 minutes for each dialyzer. The saline circulating through the blood pathway was cultured, the dialyzers were then disconnected, and the O-rings were cultured. Next, these dialyzers were reprocessed with the additional step of removing the O-ring and dipping it in Renalin before automated reprocessed. The O-rings were replaced, and the dialyzer was reprocessed by the automated method. After storage at room temperature for 48 hours, the dialyzers again were used for simulated dialysis, and cultures were repeated. Results Description of Cases During January to October 1988, 12 episodes of primary gram-negative bacteremia were identified in 11 patients receiving long-term hemodialysis (Table 1). One episode was caused by two different organisms, and the pathogens in the 12 episodes were P. cepacia (6 episodes), X. maltophilia (4 episodes), C. freundii (1 episode), Acinetobacter calcoaceticus var. anitratus (1 episode), and E. cloacae (1 episode). During the course of the outbreak, gram-negative bacteremia occurred at a rate of about 0.77 episodes per 1000 hemodialysis sessions. Table 1. Characteristics of Patients Receiving Long-Term Hemodialysis in Whom Primary Gram-Negative Bacteremia Developed The most common clinical manifestations of bacteremia were chills (11 episodes) and temperature greater than 37.5 C (8 episodes). In 11 episodes, symptoms began about 30 minutes to 3 hours after the start of treatment. In the remaining episode, chills began shortly after the patient had completed treatment and left the dialysis unit. Intravenous antibiotic treatment was administered for 11 episodes, and 3 episodes required that the patient be admitted to the hospital. All of the patients recovered, including one who received no treatment for X. maltophilia bacteremia. One patient had bacteremia first with C. freundii and then 6 weeks later with P. cepacia. Pseudomonas cepacia bacteremia was documented

Epidemiology and clinical consequences of vancomycin-resistant enterococci in liver transplant patients.

BACKGROUND Vancomycin-resistant enterococci (VRE) are increasingly important as pathogens in liver transplant patients. To guide control efforts, we conducted an epidemiological study of the frequency, source, and modes of transmission of VRE at our center. METHODS During September 1998 through August 1999, we obtained weekly surveillance cultures from consenting liver transplant patients and surfaces in their rooms. Pooled handwash specimens from personnel also were obtained. Specimens were processed on selective media to detect VRE, and isolates were typed by pulsed field gel electrophoresis. Information was collected from patient records concerning in-hospital treatment and clinical course. RESULTS Serial cultures were obtained during 33 admissions of 29 patients. VRE were detected in initial specimens from 6 admissions, and nosocomial acquisition of VRE occurred in 12 (44%) of the remaining 27 admissions. Seven different strain types of VRE were detected. The initial site of acquisition was stool in all cases; bile became culture-positive in only two patients. Overall, 16 (55%) of the 29 patients became colonized, usually after transplantation. VRE were detected in environmental cultures during 10 admissions and in 2 of 21 pooled handwashes. No statistically significant differences in clinical status or treatment were found when colonized patients were compared to noncolonized controls. The only VRE infection resulted from a choledochojejunostomy anastomotic leak. CONCLUSION Alimentary tract colonization by VRE occurred commonly in liver transplant patients, probably by cross-transmission. The clinical consequences were modest in the patients studied, but colonized transplant patients provide a substantial reservoir for continued VRE transmission in hospitals.

Multicenter, randomized trial of ciprofloxacin plus azlocillin versus ceftrazidime plus amikacin for empiric treatment of febrile neutropenic patients

In a multicenter, randomized clinical trial, the efficacy of ciprofloxacin plus azlocillin was compared with that of a standard regimen of ceftazidime plus amikacin for the initial empiric treatment of fever in neutropenic cancer patients. In addition, the efficacy of early conversion from intravenous therapy to orally administered ciprofloxacin was compared with that of continued ceftazidime plus amikacin. Seventy-one oncology patients with 79 episodes of fever and neutropenia were randomly assigned to receive initial empiric antibiotic therapy with either intravenously administered ciprofloxacin and azlocillin followed by orally administered ciprofloxacin (regimen 1, 25 episodes); ceftazidime and amikacin (regimen 2, 30 episodes); or ceftazidime and amikacin followed by oral ciprofloxacin (regimen 3, 24 episodes). Microbiologically documented infections were the cause of fever in 10 (40 percent), seven (23 percent), and nine (38 percent) episodes in regimens 1, 2, and 3, respectively, including six, five, and four episodes of bacteremia. Patient survival was 90 to 92 percent in each regimen; however, some modification of antimicrobial therapy occurred in 65, 44, and 41 percent of surviving patients in regimens 1, 2, and 3, respectively. The rate of clearance of initial bacteremia was 67 percent (four of six) in regimen 1, 100 percent (five of five) in regimen 2 and 50 percent (two of four) in regimen 3. Patients in regimens 1 and 3 were able to convert to orally administered ciprofloxacin in 32 (65 percent) of 49 episodes after a mean of six days of intravenous therapy. Superinfections occurred in 24, 10, and 12 percent of patients receiving regimens 1, 2, and 3, respectively, and occurred similarly for patients receiving orally administered ciprofloxacin, 12 percent (four of 32), and intravenous therapy, 17 percent (eight of 47). Parenteral ciprofloxacin was generally well tolerated. One (4 percent) of 25 patients receiving regimen 1 experienced oto- or nephrotoxicity, compared with eight (15 percent) of 54 patients receiving regimens 1, 2, and 3 (p = 0.15), including three patients who required premature termination of aminoglycoside therapy. Our data suggest that the combination of ciprofloxacin and azlocillin is an effective alternative to ceftazidime and amikacin for the initial empiric therapy of febrile neutropenic patients, is generally well tolerated, and avoids the oto- and nephrotoxicity associated with aminoglycoside use. In addition, a majority of patients could change to orally administered ciprofloxacin alone after six days of parenteral therapy.

Endemic Contamination of Clinical Specimens by Mycobacterium gordonae

Contamination of clinical specimens by Mycobacterium gordonae is a significant endemic problem in many laboratories. To investigate this problem, 84 cases at 1 hospital were retrospectively identified during 20 months. The overall rate of specimen contamination was 2. 4%, and 72 of the contaminated specimens were respiratory. A case-control comparison showed that the risk of respiratory specimen contamination was significantly increased if the specimen was expectorated (odds ratio [OR], 3.62; 95% confidence interval [CI], 1. 36-9.50) or if the patient consumed fluids within 2 days before specimen collection (OR, 8.92; 95% CI, 1.40-71.20). Cultures of tap water, ice, and iced drinking water all yielded M. gordonae at 10(-2)-10(0) cfu/mL. A culture survey of consenting patients showed contamination of 8 (24%) of 34 sputum specimens collected immediately after a tap water mouth rinse. These findings demonstrate that endemic specimen contamination arises from mycobacteria in hospital tap water and provide a foundation for control efforts.

Safety of peripheral intravenous catheters in children.

OBJECTIVES To determine the overall and per-day risk of complications of short peripheral intravenous (PIV) catheters placed for indefinite periods. DESIGN During 5 months, general pediatric patients receiving intravenous therapy through short PIV catheters were monitored. Patient and catheter characteristics were recorded, complications were noted, and rolled semiquantitative cultures of removed catheters were performed. Major endpoints were infection and phlebitis. Per-day risk of complications and catheter colonization (>15 colony-forming units) were calculated. SETTING University childrens hospital. PATIENTS General pediatric ward inpatients with PIV. RESULTS We studied 642 Teflon catheters in place >24 hours (mean, 3.7 days) in 525 patients. There were no cases of catheter sepsis (0%; 95% confidence interval [CI95], 0%-0.6%), one possible insertion-site infection (0.2%; CI95, 0.004%-0.9%), and seven cases of phlebitis (1.1%; CI95, 0.4%-2.3%). Catheter colonization occurred in 92 (26%) of 348 catheters cultured. Neither the per-day risk of phlebitis nor of catheter colonization increased significantly with placement >3 days. CONCLUSION Current guidelines recommend replacement of PIV catheters in adults within 2 to 3 days; no recommendations are made for children. Our findings and those of others indicate that the overall risk of PIV catheter complications in children is extremely low and would not be reduced substantially by routine catheter replacement.

Early detection of hypersensitivity pneumonitis in office workers

Symptoms of hypersensitivity pneumonitis in three employees in an office building led to an investigation of their work environment. An open spray water air cooling system was implicated when inhalation challenge with the spray water caused acute illness in one of them. A questionnaire survey of the 4,023 co-workers identified 48 other suspect cases, and laboaratory studies confirmed hypersensitivity pneumonitis in three additional workers of this group. A significant change in pulmonary function, occurring only after exposure to the work environment, was the most useful laboratory finding and was found in five workers with no other pulmonary abnormalities, but not is asymptomatic workers or controls, since five of the six patients with hypersensitivy pneumonitis worked in offices cooled by the spray water system and since three had positive responses to inhalation challenge, use of the spray water system was discontinued. The affected workers improved after they were removed from the office complex.

Pseudomonas fluorescens bacteremia from blood transfusion

In October 1980, two units of blood contaminated with Pseudomonas fluorescens caused septic transfusion reactions in two recipients at a Chicago hospital; one patient died. Both units had been purchased from the same blood center. Investigation at the blood center and at other hospitals it supplied revealed another fatal case of P. fluorescens sepsis that had occurred one year earlier. Despite extensive environmental culturing at the blood center, the source of P. fluorescens was not identified. However, comparison of the interval between collection and administration of contaminated and non-contaminated units indicated that prolonged storage was a risk factor that may have caused clustering of cases in one hospital. Laboratory studies showed that small inocula of P. fluorescens proliferated in refrigerated fresh whole blood and reached 10(6) to 10(7) colony-forming units per milliliter seven days after incubation. These data suggest that prolonged storage of blood may be an important risk factor for the development of transfusion-related sepsis.