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Antibiotic therapy for abdominal infection.

Abdominal infections are treated by resuscitation, abdominal drainage, control of the source of infection, and antimicrobial agents. Ideally, antimicrobial therapy is active against expected pathogens, safe and effective in clinical trials, inexpensive, and unlikely to promote drug resistance. Numerous single-agent and combination-drug regimens have been efficacious in clinical trials, based on coverage of Escherichia coli and Bacteroides species, the predominant pathogens isolated. Whether expanded antimicrobial coverage is required, especially in hospital-acquired infections, is controversial. Candida infections should be treated with antifungal therapy in patients with recurrent abdominal infections, immunosuppressed patients, and those with candidal abscesses. Most agents have few serious adverse effects; aminoglycosides are the least expensive agents but cause nephro- and ototoxicity. There is little information on the promotion of drug resistance in this condition. Recent developments include the introduction of ticarcillin/clavulanic acid, ampicillin/ sulbactam, piperacillin/tazobactam, meropenem, aztreonam/clindamycin, and ciprofloxacin/metronidazole; success with once-daily aminoglycosides; evidence that antibiotics limit infectious complications of pancreatitis; controversy over the value of diagnostic cultures; the use of oral therapy; evidence in favor of shorter courses of treatment; and the introduction of pharmacoeconomic studies. Clinical investigators are challenged to improve drug trials by stratifying and controlling for the adequacy of surgical intervention.

Abdomen↗

Non-traumatic colon perforation in children: a 10-year review.

Colon perforation is an abdominal surgical emergency in the pediatric population, but is seldom reported when occurring from non-traumatic causes in children beyond the neonate. The goal of this study was to identify the clinical characteristics, management, and outcomes of non-traumatic colon perforation in children. Medical records for the 10-year period from September 1994 to September 2004 were reviewed for children beyond the neonate with non-traumatic colon perforation. Data gathered included age, gender, symptoms, duration of symptoms, physical findings, and length of postoperative hospital stay. Diagnostic information included laboratory data, radiographic imaging, and operative findings. Forty-four patients with non-traumatic colon perforation were recruited into this study. The mean age was 2.22 +/- 1.87 years; 91.4% of cases were younger than 5 years old. The most common presenting symptom was fever (97.7%); the most common sign was abdominal distention (93.1%). The mean duration of symptoms prior to admission was 6.19 days. Pneumoperitoneum was presented in 86.3% of patients by plain abdominal radiograph. Ascending and transverse colon were the most common perforation sites. Non-typhoid salmonella was the leading pathogen isolated, causing 20.4% of episodes. One case died due to Clostridium speticum infection. Non-traumatic colon perforation most commonly affects children younger than 5 years of age. It may be secondary to infection, especially non-typhoid salmonella. Plain abdominal radiograph can be an adjuvant tool for the high index of suspicion for colon perforation in children with abdominal distention and history of fever or diarrhea for more than 5 days.

Abdomen, Acute↗

Nosocomial postoperative endophthalmitis: a 14-year review.

BACKGROUND: The objective of this study was to evaluate the incidence, predisposing surgery, management and final visual outcome of postoperative endophthalmitis over a 14-year period at one institute. METHODS: This retrospective study reviewed all intraocular operations performed between 1 January 1991 and 31 August 2004 at Chang Gung Memorial Hospital, Kaohsiung Medical Center, to determine the incidence of nosocomial postoperative endophthalmitis and the characteristics of patients who developed this condition. RESULTS: The overall incidence of postoperative endophthalmitis after intraocular surgery was 0.19% (56 out of 30,219). Postoperative endophthalmitis developed in 56 eyes in 56 patients during the study period. The condition developed after cataract surgery in 46 eyes, after penetrating keratoplasty in 6 eyes, after filtering surgery in 2 eyes, after secondary intraocular lens implant in 1 eye, and after vitrectomy in 1 eye. Postoperative endophthalmitis was culture-positive in 31 cases (55%). The most frequent organism isolated was coagulase-negative Staphylococcus. Factors associated with better visual acuity outcomes included low virulence of isolated pathogen, initial visual acuity of counting fingers or better, and history of cataract surgery compared with other intraocular surgery. CONCLUSION: The overall incidence of endophthalmitis after intraocular surgery was 0.19%. The results of this 14-year review from a local medical center may serve as a source of comparison for other centers and future studies.

Adult↗

A 7-year study of bloodstream infections in an English children's hospital.

UNLABELLED: Knowledge of the pattern of bloodstream infection (BSI) can help determine antibiotic prescribing policy and infection control procedures. Data on 2364 consecutive episodes of BSI at Birmingham Children's Hospital over 7 years were collected prospectively. A total of 1224 (51.8%) episodes were community-acquired, but only 281 (11.9%) were in previously healthy children. Intravascular devices (IVDs) were the most common source of infection, accounting for 48.9% of episodes. Gram-positive, gram-negative and anaerobic bacteria accounted for 66.2%, 31.3% and 0.4% of isolates, and 2.2% were yeasts. Coagulase-negative staphylococci, Staphylococcus aureus and enterococci accounted for over 50% of all isolates. Of these, only enterococci were predominantly hospital-acquired. Neisseria meningitidis was the most common cause of community-acquired BSI in previously healthy children. Of cases of meningococcaemia, 55.6% were diagnosed by PCR alone. Antibiotic resistance, especially in Enterobacteriaceae, S. aureus and enterococci, was more common than in earlier studies of BSI in children, and varied between specialties. The overall mortality rate directly attributable to infection was 2.4%, but was higher in neonates (6.2%) and in previously healthy children with community-acquired infections (5.3%). CONCLUSION: Intravascular devices have emerged as the commonest source of bloodstream infection in children, leading to marked similarities in the species distribution of blood culture isolates across specialties other than General Paediatrics, and explaining the low overall mortality rate. Antibiotic resistance was found frequently in most commonly isolated pathogens, but differences between specialties suggest the existence of local risk factors, some of which might be amenable to infection control interventions.

Bacteremia↗

First urinary tract infection in neonates, infants and young children: a comparative study.

In an attempt to evaluate first urinary tract infection (UTI) in neonates and infants, we estimated retrospectively in 296 patients (62 neonates and 234 infants) clinical and laboratory findings, occurrence of vesicoureteral reflux (VUR), urinary tract abnormalities and pyelonephritis. First UTI occurred more often in male than female neonates, whereas male and female infants/young children were affected at an equal rate. The pathogens isolated in urine cultures of neonates and infants did not statistically significantly differ (P>0.05); Escherichia coli predominated. Gram-negative bacteria other than E. coli affected boys more often than girls (P=0.0022). Fever was the most frequent symptom. Neonates had lower-grade fever of shorter duration than infants (P<0.05). The incidence of reflux and urinary tract abnormalities did not differ between neonates and infants, male and female neonates and infants (P>0.05). Pyelonephritis affected neonates and infants at an equal rate; it was more prevalent among female patients (P=0.038) and patients with VUR or urinary tract abnormalities other than VUR (P<0.0001). Neonates with reflux were more often affected by Gram-negative bacteria other than E. coli than were neonates without reflux (P=0.0008).

Child, Preschool↗

Prognostic significance of wound infections following major head and neck cancer surgery: an open non-comparative prospective study.

OBJECTIVE: We evaluated the incidence, risk factors and consequences of wound infection (WI) following major head and neck cancer surgery in an open non-comparative study. PATIENTS AND METHODS: The study group, comprising 95 patients who underwent clean-contaminated procedures with opening of the upper aerodigestive tract for biopsy-proven squamous cell cancer, were studied over a 1-year period. Antibiotic prophylaxis was amoxicillin and clavulanic acid. More than 20 variables were prospectively recorded for each patient. The mean follow-up was 30 months. MAIN RESULTS: The overall WI rate was 50.5% (48/95). Most pathogens isolated from samples were gram-negative rods. In univariate analysis, we found three risk factors for WI: alcohol consumption (P = 0.07), a hypopharyngeal location (P = 0.02) and laryngectomy stoma (P = 0.01). WI were associated with postoperative fever (P = l.5 x 10(-11)), postoperative antibiotic therapy (P = 1.5 x 10(-5)) and postoperative death (P = 0.043). Patients without WI had a median postoperative hospital stay of 15 days compared with 29 days for those with WI (P < 0.001). Healing of WI was achieved after a median time of 48 days. WI delayed postoperative radiation therapy in 21 out of 33 evaluable patients. But overall survival, and local and metastatic failures were similar with and without WI. CONCLUSIONS: WI are associated with a heavy postoperative morbidity, but have no prognostic impact on cancer control.

Amoxicillin↗

Subacute necrotizing fasciitis caused by gas-producing Staphylococcus aureus.

Presented here is a case of necrotizing fasciitis that developed bilaterally on the thighs of a 54-year-old diabetic woman following subcutaneous insulin injection. Severe localized pain was the presenting symptom; later, soft-tissue gas appeared. Incisional biopsy, performed on day 10 following admission, confirmed the diagnosis. Staphylococcus aureus was the only pathogen isolated. The disease had a slowly progressive course despite appropriate medical treatment, and recovery of the patient was achieved only after fasciotomy, drainage, and debridement of necrotic tissue was undertaken 4 weeks following admission. Staphylococcus aureus may cause subacute necrotizing fasciitis, and infection with this organism should be considered in cases of soft-tissue infection with gas formation in diabetics. The development of soft-tissue infection at the site of insulin injection should alert physicians to the possibility of infection with Staphylococcus aureus.

Anti-Bacterial Agents↗

Cavitating pneumonia after treatment with infliximab and prednisone.

Tumor necrosis factor (TNF)-alpha antagonists constitute a novel class of immunomodulating drugs that are used for the treatment of an increasing number of inflammatory disorders. These agents are associated with an increased risk of tuberculosis, but the risk of other infections is less clear. Reported here is the case of a patient who developed cavitary pneumonia after treatment with infliximab (monoclonal TNF-alpha antibodies) and corticosteroids for rheumatoid arthritis. Cryptococcus neoformans was the only pathogen isolated from bronchoalveolar lavage fluid. The patient responded well to fluconazole. The risk of infection after treatment with TNF-alpha antagonists and the possible causative microorganisms are discussed.

Antibodies, Monoclonal↗

Nosocomial lower respiratory tract infections: prevalence and risk factors in 14 Greek hospitals.

Nosocomial lower respiratory tract infections (NLRTIs) are associated with significant morbidity and mortality. The aim of this study was to investigate the epidemiological features of NLRTIs in Greece, where knowledge about these infections is limited. Two point-prevalence studies of hospital-acquired infections were carried out in 14 Greek hospitals located throughout the country, one in 1999 and one in 2000. NLRTIs were diagnosed in accordance with the Centers for Disease Control and Prevention (CDC) definitions. Among the 7,120 hospitalized patients registered during the two studies, 610 (8.6%) cases of hospital-acquired infections were identified, of which 200 (32.8%) were NLRTIs. Sixty-nine (34.5%) patients had pneumonia, and the remaining 131 (65.5%) patients had bronchitis. The greatest prevalence of NLRTI was found in the adult ICUs (30.4%). Male gender, age >65 years, mechanical ventilation, tracheostomy, an intravenous central line, and an indwelling urethral catheter were the main risk factors. There was no significant difference in the incidence of NLRTI among hospital-acquired infections between the 1999 study and the 2000 study. The causative microorganism was identified in 78 of 200 (39%) cases, and 103 strains were isolated. The majority of strains (67%) were gram-negative bacteria. The most frequently isolated microorganisms were Pseudomonas aeruginosa (22.3%), Acinetobacter spp. (19.4%), Klebsiella pneumoniae (12.6%), and Staphylococcus aureus (10.7%). There was no difference between the two prevalence studies in the frequency of isolation of the microorganisms. NLRTI was the leading cause of morbidity and mortality among hospitalized patients with hospital-acquired infections in Greek hospitals. Gram-negative microorganisms were the most frequently isolated pathogens.

Aged↗

Analysis of risk factors for ventilator-associated pneumonia in a multidisciplinary intensive care unit.

A prospective study was conducted to determine the incidence, risk factors and pathogens of ventilator-associated pneumonia (VAP) in 198 patients requiring mechanical ventilation for more than 48 hours. VAP occurred in 67 (33.8%) patients. Risk factors associated with VAP were admission APACHE II score >20 (odds ratio [OR] 4.77, 95% confidence interval [CI] 2.04-11.27, P<0.001), mechanical ventilation > 10 days (OR 44.4, 95% CI 2.16-26.7, P< 0.0001), ICU length of stay >10 days (OR 9.4, 95% CI 3.55-25.65, P< 0.0001), and admission PaO2/FiO2 ratio <200mmHg (OR 3.4, 95% CI 1.00-11.41, P<0.05). Logistic regression analysis showed a relationship between VAP and length of stay in ICU, duration of fever and presence of catheter-related infection. The pathogens isolated were predominantly gram-negative bacteria (83.2%), with a high proportion of Acinetobacter spp. (35%) resistant to commonly used antimicrobial agents. The mortality rate was not influenced by VAP.

Catheters, Indwelling↗

Randomized, multicentre study of the efficacy and tolerance of azithromycin versus clarithromycin in the treatment of adults with mild to moderate community-acquired pneumonia. Azithromycin Study Group.

Adults with mild to moderate community-acquired pneumonia were treated with azithromycin (500 mg once daily for 3 days) or clarithromycin (250 mg twice daily for 10 days) and clinically assessed between days 3 and 7 and days 12 and 16. Patients classified as improved at the day 12-16 visit were also evaluated between days 19 and 23. Two hundred three patients were treated (101 with azithromycin, 102 with clarithromycin). A satisfactory clinical response was recorded at the end of therapy in 83 of 88 (94%) evaluable azithromycin-treated and 84 of 88 (95%) evaluable clarithromycin-treated patients (P=0.518). At day 19-23, only one patient in each treatment group had relapsed. Thirty-one of 32 (97%) pathogens isolated from patients in the azithromycin group were eradicated, compared with 32 of 35 (91%) isolated from clarithromycin patients. In all patients with atypical pneumonia, the clinical response was satisfactory at follow-up. Incidences of treatment-related adverse events were similar for the two groups (P=0.815). Two (2%) clarithromycin patients discontinued therapy due to severe treatment-related adverse events; none in the azithromycin group did. This study shows that a 3-day, once-daily course of azithromycin is as clinically effective and well tolerated as a 10-day, twice-daily course of clarithromycin in the treatment of mild to moderate community-acquired pneumonia.

Adolescent↗

Candidemia in HIV-infected subjects.

The epidemiological features of 37 episodes of candidemia in HIV-infected subjects were analysed in a retrospective matched case-control study conducted over an 8-year period (1990-1997). Univariate analysis identified eight risk factors that were significantly associated with candidemia (P<0.05): i) use of central venous catheters; ii) administration of total parenteral nutrition; iii) previous antifungal therapy; iv) previous therapy with glycopeptides; v) presence of oral/ esophageal candidiasis; vi) concomitant bacterial infections; vii) neutropenia; and viii) concomitant AIDS dementia complex. Stepwise logistic regression analysis revealed that the only independent risk factor for developing candidemia was the use of central venous catheters (P = 0.0001). Candida albicans was the most frequently isolated pathogen, accounting for 18 (48%) episodes of candidemia, followed by Candida tropicalis (19%) and Candida glabrata (11%). The crude mortality rate was 62%. On univariate analysis concomitant opportunistic infections, presence of non-Candida albicans species of Candida and neutropenia were shown to be predictive of death. Multivariate analysis revealed that the presence of non-Candida albicans strains of Candida was the only significant factor associated with a worse prognosis (P = 0.001). In conclusion, candidemia appears to be more common in patients with advanced HIV disease. Of the factors which influenced the onset of candidemia, use of central venous catheters seemed to be the most important one.

AIDS-Related Opportunistic Infections↗

Assessment of laboratory methods for evaluating cassava genotypes for resistance to root rot disease.

Field evaluation of six cassava genotypes for resistance to root rot disease was compared with three rapid laboratory methods (whole root inoculation, root slice inoculation, and stem inoculation) for resistance screening. Both the field evaluation and the three laboratory methods separated the varieties into resistant and susceptible groups. Genotypes 30572 and 91/02324 were resistant while 92/0247, 92/0057 and TME-1 were susceptible. One genotype (30001) was not consistent in its reaction between field evaluation and laboratory assays. In the laboratory assays with three fungal pathogens, different pathogens varied in their levels of virulence on host genotypes. With the most virulent pathogen (Botryodiplodia theobromae), the majority of the genotypes reacted in the same way across trials with the root slice and whole root assays. Due to the good correlation between the whole root assay and the field results, we recommend this for the routine assessment of cassava resistance to root rot disease and for the analysis of virulence of pathogen isolates. However, because of the advantages in terms of economy of labour, space, time, quantity of root and inoculum required, the root slice assay could be used for the preliminary screening of large cassava accessions. The selected genotypes can then be further screened with the whole root inoculation method.

Agriculture↗

Sporadic tuberculous meningoencephalitis.

Tuberculous meningoencephalitis in a 24-month-old boy is reported. He contracted the infection from his apparently healthy grandfather with unnoticed pulmonary tuberculosis, as suggested by restriction fragment length polymorphism analysis of the isolated pathogen.

Cerebrospinal Fluid↗

Risk of endocarditis in transesophageal echocardiography.

The risk of endocarditis associated with transesophageal echocardiography was studied in 101 patients. To evaluate possible bacteremia, blood cultures were performed on samples from consecutive patients who did not have clinical or laboratory evidence of infection. The broth blood culture Signal system was used in all patients, and additionally, the lysis-centrifugation technique was performed in a subgroup of 40 patients to further ameliorate recovery of rapidly phagocytosed germs. Comprehensive criteria for differentiation between true bacteremia and possible contamination were provided by means of simultaneous blood sampling from two separate venipuncture sites and skin specimens from the venipuncture area. Oropharyngeal specimens were cultured for evaluation of possible association of oropharyngeal flora with positive blood culture findings. They revealed facultative pathogenic isolates, as well as physiologic residental flora, in 15 patients. All blood isolates that were recovered simultaneously 6 minutes after the procedure were found to be sterile. Correspondingly, clinical follow-up for 2 weeks was uneventful with regard to episodes of infection. These results indicate that the risk of bacteremia associated with transesophageal echocardiography is extremely low. Thus endocarditis prophylaxis is not required for this procedure.

Adolescent↗

Cardiac conduction abnormalities complicating native valve active infective endocarditis.

Two hundred eleven episodes of native valve active infective endocarditis treated at the Massachusetts General Hospital between 1975 and 1983 were reviewed. The aortic (36%) and mitral (33%) valves were most frequently involved, but in 21% of the cases the site of infection could not be localized. Streptococcal (50%) and staphylococcal (35%) species were the most frequently isolated pathogens. New or changing ("unstable") conduction abnormalities developed in 9% of the patients, while an additional 7% had conduction abnormalities of "indeterminate" age. Unstable conduction block was more likely to develop in patients with aortic valve infective endocarditis than in those with mitral infection. Surgery was performed in 23% of the patients. Unstable conduction abnormalities were significantly associated with valve replacement, but in a multivariate analysis, this effect could be explained by the site of valvular infection. The mortality rate was 20%. Patients with unstable conduction abnormalities had a significantly higher mortality rate, even after other significant predictors of death (age, type of causative organism) were taken into account. Patients whose conduction changes persisted had a worse prognosis than those with transient conduction abnormalities. Although more hemodynamically compromised, patients with unstable conduction block who underwent valve replacement did at least as well as those given medical therapy alone. Patients with native valve active infective endocarditis in whom persistent, unstable conduction abnormalities develop without other identifiable cause, especially in the presence of aortic valve infection, should be considered for valve replacement.

Adolescent↗

Potential of imipenem as single-agent empiric antibiotic therapy of febrile neutropenic patients with cancer.

Infection remains a major cause of morbidity and mortality for the patient with cancer who experiences episodes of severe granulocytopenia. The search continues for new antimicrobial agents with improved efficacy and lower incidence of toxicity. Imipenem is a new carbapenem antibiotic which possesses a broad antibacterial spectrum with excellent activity against Pseudomonas aeruginosa and the other commonly recovered enteric gram-negative bacilli that infect the granulocytopenic patient with cancer. The combination of imipenem plus an aminoglycoside has shown in vitro synergy against P. aeruginosa and Staphylococcus aureus whereas the combination of imipenem plus piperacillin or the extended spectrum cephalosporins have frequently shown antagonism when tested against P. aeruginosa and Serratia marcescens. The use of a P. aeruginosa-infected neutropenic rat model has provided an in vivo system to evaluate the activity of new antibiotics or antibiotic combinations. Monotherapy with imipenem is as effective in this model as any of the currently available synergistic antibiotic combinations. This degree of activity has not been found with other broad-spectrum antibiotics when used alone. Imipenem provides serum bactericidal activity well above a 1:8 dilution for the four most commonly isolated pathogens: P. aeruginosa, Escherichia coli, Klebsiella species, and S. aureus. In addition, imipenem's post-antibiotic effect against P. aeruginosa may be pertinent. Imipenem is a unique antibiotic, with properties that make it well suited for study as monotherapy for fever and suspected infection in granulocytopenic patients with cancer. A prospective randomized, double-blind study comparing imipenem with a control regimen of piperacillin plus amikacin as empiric antibiotic therapy of febrile granulocytopenic patients with cancer is currently underway at the University of Maryland Cancer Center.

Agranulocytosis↗