The microbiological profile of nosocomial infection in a respiratory intensive care unit

In 1987, in the Respiratory Intensive Care Unit of Santa Maria Hospital we developed a nosocomial surveillance program with specially created software that provides knowledge of NI in the ICU at any moment. The information gathered along the time is particularly useful in the correlation of the risk factors, the most frequent microorganisms and in the institution of empiric antibiotic therapy. Out of 2528 patients admitted in our ICU for the last 6 years (87/92), 10% had bacteriologically identified NI. Almost (93%) of them had occurred in mechanically ventilated patients, which corresponds to 20.7% NI in those patients. The gram-negative appeared in 63.37%, with the predominance of Enterobacteriaceae. From the gram-positives the most frequent were Staphylococcus spp. Their meticiline resistance was worrisome. NI patients had significantly higher severity and therapeutic intervention scores. Mechanical ventilation period was 4 fold higher and mortality 2.5 times higher in the patients with this complication.     

Reduction of nosocomial infection in a neonatal intensive care unit (NICU)

The aim of this study was to describe an outbreak of hepatitis A in a family group which extended to a day care center and to the families of the children attending the same and to determine the risk of acquiring the disease based on exposure to one or several sources of infection. The temporary distribution of the cases and the rate of hepatitis A in the population at risk were analyzed. The risk of acquiring hepatitis by exposure to one or more sources of infection was studied by logistic regression, calculating the odds ratio and the confidence interval of 95%. Initiation of the outbreak was in May 1996, in a 25-year-old male and finalized in November, having affected 63 people. The rate of global attack was of 12% and the risk of infection 18-fold greater (CI 95% = 5.4-61.8) in those exposed to more than one source of infection than in those exposed to only one source and 3.5-fold greater (CI 95% = 1.2-9.9) in the group from 15 to 29 years of age than in those under 14. The massive administration of immunoglobulin was useful to control the hepatitis in the day care center and in the school. The size of this epidemic of hepatitis A was due to its occurrence in a population little exposed to the virus. The greatest involvement was observed in young adults, with person to person transmission and the greater risk of acquiring hepatitis A on exposure to several sources of infection characterizing the outbreak. The possible usefulness of designing prevention strategies with the vaccine should be considered.     

Extended-spectrum beta-lactamase-producing Klebsiella pneumoniae strains causing nosocomial outbreaks of infection in the United Kingdom

Representative isolates from 10 distinct extended-spectrum beta-lactamase-producing strains of Klebsiella pneumoniae that caused hospital outbreaks in the United Kingdom from 1991 to 1994 were examined for relationships between their enzymes and plasmids. The beta-lactamases were identified by a combination of isoelectric focusing and gene sequencing. SHV-2 beta-lactamase was produced by isolates from four outbreaks, SHV-5 was involved in three, and SHV-4, TEM-15, and TEM-26 were involved in one outbreak each. All of the extended-spectrum beta-lactamases were encoded by self-transmissible plasmids, with sizes ranging from about 70 to 160 kb. No similarities between the restriction digest patterns of the extended-spectrum beta-lactamase-encoding plasmids were detected, except to some extent between those that produced TEM-15 and TEM-26. Thus, outbreaks of hospital infection with these organisms in the United Kingdom from 1991 to 1994 involved distinct organisms and resistance plasmids and appeared to be unrelated.     

Coagulase typing of Staphylococcus aureus in the geriatric wards after introduction of preventive measures of hospital infection

The study comprised 323 cryptorchidic boys, between 6 months and 14 years of age (mean age 5.68 years) with 440 maldescended testes. Testicular position was graded as inguinal low or prescrotal (I), inguinal middle (II), inguinal high (III), and abdominal testes (IV). Boys before 4 years of age received human chorionic gonadotropin (hCG) as intramuscular injections (I.M.), 500 IU twice a week for 5 weeks; and boys 4 or more years of age received hCG (IM), 1000 IU twice a week for 5 weeks. The objectives of this study were to evaluate the response of maldescended testes to treatment with hCG, and to investigate possible associations between the patients' ages and position of the testes with the response to hCG. Out of the 440 maldescended testes, 329 were in an inguinal location (75%) and 111 were abdominally located (25%). The overall response to hCG was 40%, and the inguinal testes response was 49%, with the highest success rates (72%) for the prescrotal testes. A positive correlation was found (p < .0001) between the rate of success and the testicular position. There was no association between the hCG response and the age at which treatment was initiated.     

Prevention of nosocomial infection in a pediatric intensive care unit (PICU) through the use of selective digestive decontamination

OBJECTIVE: To assess the effectiveness of selective digestive decontamination (SDD) on the control of nosocomial infection (NI) in critically ill pediatric patients. DESIGN: A prospective, randomized, non-blinded and controlled clinical microbiology study. SETTING: The pediatric intensive care unit (PICU) of a tertiary level pediatric university hospital. CRITERIA FOR INCLUSION: Patients 1 month to 14 years old, who underwent some kind of manipulation or instrumentation (mechanical ventilation, vascular cannulation, monitoring of intracranial pressure, thoracic or abdominal drainage, bladder catheterization, peritoneal dialysis, etc.) and/or presented a neurological coma requiring a stay in the PICU of 3 or more days. PATIENTS: Over a period of 2 years, 244 patients met the inclusion criteria; 18 patients were withdrawn because of protocol violation. The treatment group comprised 116 patients and the control group, 110 patients. INTERVENTION: The treatment group received a triple therapy of colimycin, tobramycin and nystatin administered orally or via nasogastric tube every 6 hours. All patients with mechanical ventilation or immune-depression received decontamination treatment of the oropharyngeal cavity with hexitidine (Oraldine 0.5 mg/ml) every 6-8 hours in accordance with the PICU's conventional protocol. METHOD: Up to 10 types of nosocomial infection were diagnosed following criteria of the Centers for Disease Control (CDC). The severity and manipulation of the patients on admission was assessed using the therapeutic intervention scoring system (TISS) and multi-organ system failure scores (MOSF). MEASUREMENTS AND MAIN RESULTS: UNIVARIANT ANALYSIS: SDD did not significantly reduce the incidence of NI, antibiotic use, the length of stay, or mortality; although a small percentage of respiratory and urinary tract infections was detected, catheter-related bacteremia was the most common infection. MULTIVARIANT ANALYSIS: Controlling the risk factors for each child through log regression showed that SDD acted as a protective factor for more than 90% of the sample with respect to the appearance of respiratory and urinary tract infections, reducing the risk of such infections to 1/5 and 1/3, respectively. CONCLUSIONS: SDD was effective in controlling respiratory and urinary tract infections in children admitted to the PICU, but it did not reduce the incidence of other types of nosocomial infection.     

The utilization of a paediatric emergency room in a general hospital in Kuwait

The objective of the study was to describe the ultrasonographic findings of urinary bladder urolithiasis and to determine the diagnostic value of the technique in feline lower urinary tract diseases (LUTD). Physical examination of the urinary system and routine clinicopathological analysis of the blood and urine were performed on 32 cats presented with clinical symptoms of LUTD. Cystosonography was done on all of the cats, while plain radiography was performed on 8 and double contrast cystography on 2 cats. Sonography of the bladder provided the following diagnoses: urolithiasis and chronic cystitis: 24 cases, chronic cystitis without urolithiasis: 4 cases, bladder neoplasm: 1 case, negative sonographic finding: 3 cases. Bladder calculi and/or plugs were diagnosed easily, up to a size of 2 mm, according to acoustic shadowing and/or reverberation and gravitation. When the bladder was empty, it was filled up with physiologic saline solution to visualise its contents more easily. Sonography proved to be a useful technique for diagnosing urinary bladder calculi and/or plugs even when they were radiolucent and for distinguishing among the different causes of LUTD. Although ultrasonography is a valuable diagnostic tool, radiography is still necessary to explore lower urinary tract diseases, especially when cystosonography provides negative results or urethral obstruction is suspected.     

Magnitude and prevention of nosocomial infections in the intensive care unit

Nosocomial infections among intensive care unit (ICU) patients usually are related to the use of invasive devices (e.g., mechanical ventilators, urinary catheters, or central venous catheters). This article discusses the impact of these devices and other risk factors for nosocomial infection in ICU patients. Data on etiologic pathogens and device-related infection rates from the National Nosocomial Infection Surveillance System are presented, general infection control guidelines for ICUs are reviewed, and special infection control problems encountered in ICUs are discussed.     

Use of a general surgical high dependency unit in a district general hospital: the first 10 years

The chemotherapy regimen of paclitaxel and carboplatin produces an objective response in 30%-60% of patients with non-small-cell lung cancer (NSCLC). In a prospective study, we administered paclitaxel 200 mg/m2 (by 1-3-hr infusion) and carboplatin at an area under the plasma concentration curve (AUC) of 5 (by the Calvert formula) every 3 weeks to 21 patients who had previously received predominantly platinum-based chemotherapy for NSCLC. We observed no objective responses. Patients received a median of 2 cycles before disease progression. Three of 5 patients who had received only single-agent treatment with a relatively inactive agent may have had modest clinical benefit. We conclude that the paclitaxel/carboplatin regimen has minimal activity in previously treated patients with NSCLC.     

Benefits to a regional neurosurgical unit following the introduction of a decentralised imaging facility

OBJECTIVE: To determine whether the establishment of a peripheral computed tomography (CT) facility has an influence on the central referral neurosurgical unit, and particularly whether unnecessary referrals are avoided. DESIGN: The outpatient records of all patients referred from Umtata General Hospital (UGH) to the neurosurgical unit at Wentworth Hospital, Durban, were retrospectively analysed over a 4-year period--2 years before and 2 after the introduction of CT facilities at UGH. SETTING: Wentworth Hospital, Durban, which houses the sole neurosurgical referral centre for the region. PATIENTS: Eight hundred and forty patients were referred to the neurosurgical unit from UGH during the 4-year study period--July 1990 to June 1994. MAIN OUTCOME MEASURES: 1. The number of referrals to the neurosurgical unit before and after introduction of peripheral CT facilities at UGH. 2. The admission rate of the above referrals during the same periods, indicating appropriate referrals. RESULTS: 1. There were 536 patients referred from UGH to the neurosurgical unit over a 2-year period before the introduction of peripheral CT facilities, and 304 patients during the subsequent 2-year period after introduction of CT facilities at UGH. This represented a 43.3% decrease in patient referrals during a period in which referrals from all other areas increased by 2.6%. 2. The admission rate of patients (indicating appropriate referrals) being referred from UGH increased from 46.3% before CT facilities to 79.9% after the introduction of peripheral CT facilities. The admission rate of patients from other areas, excluding UGH, during the same periods, decreased from 50.3% to 46.4%. CONCLUSION: This audit reveals that following the introduction of CT facilities at UGH, the number of referrals to Wentworth Hospital's neurosurgical unit decreased by almost half (43.3%). Furthermore, the patients referred after introduction of the peripheral CT facility were more likely to be appropriate referrals (79.9%) than before (46.4%). Therefore, the provision of CT facilities at peripheral hospitals may effectively serve to exclude those patients who would otherwise be referred unnecessarily, and enable earlier referral of those patients who require urgent care at a tertiary neurosurgical unit.     

The genetic typing of strains in the genus Francisella using universal probes

The determination of the genetic relationship of bacteria of the genus Francisella and their differentiation is one of the topical tasks of the epidemiology and infectology of F. tularensis, the causative agent of tularemia, belonging to this genus. To solve this task, investigation was carried out with a view to the determine the possibility of the genomic typing of Francisella. Genomic typing was based on the use of the hybridization of fragments of Francisella chromosomal DNA, split by restrictases EcoRI and Pstl, with DNA probes. As probes, "minisatellite" sequences of bacteriophage M13 DNA or Helicobacter pylori rDNA were used. The possibility of interspecific genomic typing of F. tularensis, F. novicida and F. philomiragia by the above-mentioned methods was established. The intraspecific typing of F. tularensis by the phenotypical sign of virulence was possible with the use of the hybridization of chromosomal DNA with bacteriophage M13 probe. The use of rDNA probe proved to be effective for the determination of subspecies of the causative agent of tularemia. The possibility of using the combination of these two methods for more complete characterization of the genomic polymorphism of Francisella, the determination of their genetic relationship and their differentiation is discussed.     

Risk of nosocomial infection in elderly patients admitted to a university hospital

BACKGROUND: A high percentage of current hospital visits are made by the elderly. The aim of this work is to quantify the risk of contracting a nosocomial infection among elderly patients admitted to a university hospital. METHODS: From the patients admitted from the emergency unit, outpatients and the waiting list, 6 patients of different age groups were chosen each day by a simple random sampling. The criteria of nosocomial infection were those of the CDC. The analysis of the information was made with the programme EPIINFO version 5. The chi 2 tests and Fisher's exact test were used to compare proportions. RESULTS: The rate of nosocomial infection in the group aged over 64 was 14.8%, showing statistically significant differences with respect to other age groups (p = 0.001). In this group the predominant infection was urinary, with an odds-ratio of 3.69, in comparison with the 25 to 44 age group. A prolonged hospital stay (> 15 days) has proved to be closely related to the risk of nosocomial infection in all age groups (p < 0.0001) in patients over 64. CONCLUSIONS: The greater risk of contracting nosocomial infections in the elderly makes it advisable to develop specific prevention programmes for this group, and the fitness of accommodations the length of stay to the care needs suitable to the hospital level.     

Management of patients with unstable angina in a general cardiology unit

AIMS: To review the clinical management of patients with unstable angina and to relate prospectively initial risk stratification, according to the Braunwald criteria, to subsequent cardiovascular events. METHODS: From February to April 1996 we performed a three month prospective review of all patients with a diagnosis of unstable angina admitted to the coronary care unit at Auckland Hospital. RESULTS: One hundred and four patients (61% male), with a mean age of 64 years, were classified as high (58%), intermediate (41%) or low risk (1%) for an adverse cardiac event. Twelve (12%) patients had a documented myocardial infarction, of whom 11 were in the high-risk group (p = 0.038). During hospitalisation there was one death. Twelve (12%) patients underwent inpatient exercise testing, five of whom proceeded to a coronary angiogram prior to hospital discharge. Twenty-two (21%) unstable patients underwent inpatient angiography without prior exercise testing. Twenty-one (20%) patients required revascularisation on the same admission: percutaneous coronary angioplasty (n = 14) or coronary artery bypass grafting (n = 7). Twelve of these 21 patients were in the high-risk group (p = 0.999, NS). CONCLUSION: Patients admitted with unstable angina had low inpatient mortality but a 12% rate of subsequent myocardial infarction. Braunwald low-risk unstable angina patients were not admitted to the coronary care unit. Braunwald high-risk patients were more likely to develop a subsequent myocardial infarction. Stratification of patients into intermediate or high-risk groups did not relate to initial medical management or subsequent revascularisation. Thus, while this method of risk stratification may predict cardiovascular events, it may be of limited clinical use in the New Zealand environment.     

Characterization of a membrane calcium pathway induced by rotavirus infection in cultured cells

Some viruses induce changes in membrane permeability during infection. We have shown previously that the porcine strain of rotavirus, OSU, induced an increase in the permeability to Na+, K+, and Ca2+ during replication in MA104 cells. In this work, we have characterized the divalent cation entry pathway by measuring intracellular Ca2+ in fura-2-loaded MA104 and HT29 cells in suspension. The permeability to Ca2+ and other cations was evaluated by the change of the intracellular concentration following an extracellular cation pulse. Rotavirus infection induced an increase in permeability to Ca2+, Ba2+, Sr2+, Mn2+, and Co2+. The rate of cation entry decreased over time as the intracellular concentration increased during the first 20 s. This indicates that regulatory mechanisms, including channel inactivation, are triggered. La3+ did not enter the cell and blocked the entry of the divalent cations in a dose-dependent manner. Metoxyverapamil (D600), a blocker of L-type voltage-gated channels, partially inhibited the entry of Ca2+ in virus-infected MA104 and HT29 cells. The results suggest that rotavirus infection of cultured cells activates a cation channel rather than nonspecific permeation through the plasma membrane. This activation involves the synthesis of viral proteins through mechanisms yet unknown. The increase in intracellular Ca2+ induced by the activation of this channel may be related to the increase in cytoplasmic and endoplasmic reticulum Ca2+ pools required for virus maturation and cell death.     

Nonperinatal nosocomial transmission of Candida albicans in a neonatal intensive care unit: prospective study

BACKGROUND: The adventitial inversion technique obliterates the false lumen and converts a dissected aorta into a conduit with tough adventitia on the inside and outside. Dacron grafts can be anastomosed to the aorta with fine sutures, which hold without tears. METHODS: From August 1995 to March 1997, we treated 6 patients with acute dissecting aneurysms. Three aneurysms were type I (A) involving the entire aorta, two type II (A) involving the ascending aorta, and one type III (B) involving the thoracoabdominal aorta. Circulatory arrest was used in 3 patients, 1 with type I aneurysm (A), 1 type II (A), and 1 type III (B). RESULTS: All Dacron-aorta anastomoses held sutures well and did not bleed intraoperatively or postoperatively. One patient (type II [A]) died of intraoperative low cardiac output. In patients with type I (A) aneurysms, the false lumen was obliterated, but 1 patient required resection of a 6-cm abdominal aortic aneurysm. CONCLUSIONS: The adventitial inversion technique is a safe technique for the treatment of acute dissecting aneurysms, which facilitates operation and solves the problem of intraoperative or postoperative bleeding due to tissue friability.     

Insertion possibility of 16S-23S space amplification and random amplified polymorphic DNA analysis for typing of methicillin-resistant Staphylococcus aureus strains in the context of nosocomial infections

Within the scope of the present study n = 183 MRSA isolates from the extended area of Düsseldorf and n = 93 international MRSA strains from seven different countries were typed by pulsed-field gel electrophoresis and two PCR methods (RAPD and 16S-23S-spacer amplification). The isolates could be subdivided into 30 different types by PFGE, into 21 by means of RAPD and 18 by 16S-23S-spacer amplification. PFGE had the highest discriminatory potential, however, a combined use of the three typing methods allows a more detailed differentiation even of those isolates with identical PFGE pattern. Both amplification procedures were rapid, easy in handling with reproductable results. For a temporary epidemiological analysis within 24 hours, both amplification methods could be combined. In case the investigated isolates were still suspected of showing a "clonal identity", they should be analysed by additional PFGE (lasting about four days). Although the international isolates were chosen by random selection, several MRSA strains with identical pattern could be found in different countries of the world. Some RAPD-, spacer- and PFGE pattern were constant over many years. This reflects a high genetic stability of single strains.     

Overview of nosocomial infections in a neonatal intensive care unit (1989-1993)

Newborns admitted to any Intensive Care Unit (ICU) are more at risk for nosocomial infections. The author analyzed the incidence of nosocomial bacteriaemias occurred in the neonatal ICU of Trento, especially focusing on the relationship between weight at delivery, incidence of infections and mortality. The incidence of bacteriaemiae during the observation period (1.189-31.12.93) accounted for 3.5%, and 2.8% were classified as nosocomial. The most frequently involved organism was the Staphylococcus PCN (62% of bacteriaemiae). High risk newborns weighted < 1500 g; 10.7% were affected by nosocomial bactaeriaemia, representing the 56.1% of all the observed bacteriaemiae. A strong association (p < 0.05) was also observed between bactaeriaemiae and mortality, in newborns weighting less than 1000 g. Since low and very low birth weigh infants are particularly at risk for infections, special attention should be paid to the invasive techniques and a systematic reporting and documentation of epidemiology of infections, in order to monitor impact of modifications in caring techniques is warranted.     

Isolation of a serotype G6P11 bovine rotavirus showing two-way cross-neutralization with the serotype G10P11 virus

Four stains designated as OB94-1 to OB94-4 of group A bovine rotavirus (BRV) were isolated from 35 fecal samples of calves with diarrhea in sporadic outbreaks. In VP7 (G) and VP4 (P) serotyping of these isolates, OB94-1 to OB94-3 were determined as G6P5, G6P5 and G10P5, respectively, by cross neutralization (NT) test and the G- and P- serotyping polymerase chain reaction (PCR) analysis. OB94-4 showed a one-way antigenic relation with the Lincoln stain (G6P1) and a weak antigenic relationship with the KK3 strain (G10P11), and was determined as G6P11 by the PCR method. Thus, OB94-4 was shown to be a new G6 BRV with different antigenic properties from the others in the NT test.