Seroprevalence and incidence of Toxoplasma gondii infection in the Legnano area of Italy.

The decreasing prevalence of anti-Toxoplasma antibodies in Europe has re-opened the question of the appropriateness of serological screening during pregnancy. A study of 3426 pregnant women, resident in the Legnano area of Italy, revealed that the IgG seroprevalence according to ELISA was 21.5%, and that of IgM according to ELISA and enzyme-linked fluorescent assay was 1.2% and 0.9%, respectively. The incidence of infection, estimated on the basis of IgG avidity, was 0.9%. These results confirm a decrease in the prevalence of IgG, but indicate a high incidence of infection, thus suggesting that screening for anti-Toxoplasma antibodies during pregnancy should be maintained.

[From the Mailing List SIN: Epidemic of infections caused by 'aquatic' bacteria in patients undergoing hemodialysis via central venous catheters]. / Dalla Mailing-List soci SIN (ML-SIN). Epidemia di infezioni causate da batteri 'acquatici' in pazienti emodializzati tramite cateteri venosi centrali.

UNLABELLED: Bacteremia due to central venous catheter (CVC) infection is the most frequent complication of CVC use as vascular access for hemodialysis (HD). We report a case of an epidemic of CVC infections caused by 3 strains of unusual bacteria: Ralstonia pickettii (Rp), Leifsonia xyli/Leifsonia aquatica (Lxa), Tsuckamurella strandjordae (Ts). From 20/8/01 to 30/9/01, 23 of 35 patients dialyzed via CVCs experienced intra-HD pyrogenic reactions. Their hemocultures were positive for: Rp (14 pts), Lxa (3 pts), Rp+Lxa (5 pts) and Rp+Ts (1 pt). The hemocultures of 12/35 asymptomatic pts were positive for: Rp 2 pts, Lxa 2 pts, Rp+Lxa 2 pts, Ts 1 pt, Rp+Ts 1 pt. The epidemiological and microbiological analyses of environmental samples failed to identify the source of the epidemic. Actions taken were: a) replacement of the batches of disposable materials; b) removal of CVCs in cases where possible to prepare a different access; c) treatment of the infections with intra-CVC antibiotic lock therapy. No relapses were recorded until April 2002, when 8 pts had again pyrogenic reactions due to Rp. After quick substitution of the CVC and repetitions of the action a), no relapses of pyrogenic reactions were observed. CONCLUSIONS: 1) given the characteristics of Rp, Lxa and Ts, saprophytes of moist environments, the most plausible source of the epidemic was a low-charge contaminated solution that was not identified due to low sensitivity of environmental sample culturing methods; 2) antibiotic lock therapy is a viable option for the conservative treatment of CVC infections.

Use of simulated blood cultures for antibiotic effect on time to detection of the two blood culture systems BacT/ALERT and BACTEC 9240.

To avoid the influence of pre-analytical steps, this study was performed using sterile blood spiked with defined loads of microorganisms as inoculum. Time-to-Detection (TTD) was evaluated for the most frequently encountered bacteria comparing two commercially available blood culture systems, BD BACTEC 9240 (Becton Dickinson) and BacT/ALERT (Organon Teknika). The effect of the most widely used antibiotics on TTD was evaluated on both systems. TTD was measured with antibiotics at their trough and at increasing concentrations. The results show that the BACTEC PLUS system recovers more pathogens with shorter time to detection than the BacT/ALERT FAN system when beta-lactam antibiotics (Ampicillin, Cefotaxime) are present at their respective trough concentration corresponding to parenteral therapy. The two systems seem to be equally efficient when Gentamicin, Ciprofloxacin and Trimethoprim/sulfamethoxazole are used; in the case of Vancomycin, BACTEC seems more effective than BacT/ALERT.

Prevalence and drug susceptibility of pathogens causing bloodstream infections in northern Italy: a two-year study in 16 hospitals.

The epidemiology of bacterial pathogens causing bloodstream infection was studied in 16 hospitals in Lombardy (northern Italy) over a 2-year period (1999 and 2000). Overall, 2924 microorganisms causing significant bacteremia were collected. The most frequent isolates were Escherichia coli ( n=663; 22.7%), Staphylococcus aureus ( n=534; 18.3%), Staphylococcus epidermidis ( n=242; 8.2%), and Pseudomonas aeruginosa ( n=176; 6.0%). Unlike Escherichia coli, which was usually acquired from the community, Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa were usually acquired in hospitals. Rates of resistance to oxacillin and its associated traits were significantly higher among hospital-acquired staphylococci as compared to those of isolates from the community. Escherichia coli was highly susceptible to extended-spectrum cephalosporins, with a very low percentage of strains producing extended-spectrum ss-lactamases (ESBLs). On the contrary, production of ESBL appeared to be an important mechanism of resistance among nosocomial isolates of Klebsiella pneumoniae. Resistance to ciprofloxacin was widespread in several members of the family Enterobacteriaceae, with rates often exceeding 10%. Moreover, with regard to ciprofloxacin, there were no significant differences between rates of resistance among Enterobacteriaceae causing hospital-acquired infections versus those causing community-acquired infections. Multidrug resistance was commonly observed in Pseudomonas aeruginosa, indicating the need for new antimicrobial agents that are more active against nonfermentative gram-negative bacteria. In conclusion, epidemiological studies of the prevalence and antimicrobial susceptibility patterns of blood isolates in northern Italy appear to provide useful information for both empirical treatment of suspected infections and better management of patients.

Risk factors for central venous catheter-related infections in surgical and intensive care units. The Central Venous Catheter-Related Infections Study Group.

OBJECTIVE: To identify avoidable risk factors for central venous catheter (CVC) infections in patients undergoing short-term catheterization. DESIGN: Prospective multicenter cohort study. SETTING: Two university teaching hospitals and five large nonteaching hospitals. PATIENTS: Patients admitted to intensive care units or surgical units and exposed to short-term CVCs. RESULTS: Of 623 catheterization episodes, 9.3% were associated with catheter-related infections (CRI). The skin at the catheter site was frequently colonized (16.2%) and was the potential source of infection in 56.1% of the cases, mostly local infections. The hub was colonized less frequently (3.5%) but was responsible for systemic infections more frequently. The following variables were independently associated with CRI: duration of catheterization (for 7 to 14 days, odds ratio [OR], 3.9; 95% confidence interval [CI]95, 1.4 to 10.7; and for > 14 days, OR, 5.1; CI95, 1.7 to 15.4), coronary care unit service (OR, 6.7; CI95, 1.1 to 42.9) or surgery service (OR, 4.4; CI95, 1.03 to 18.5), second episode of catheterization (OR, 7.6; CI95, 1.8 to 32.3), skin colonization at the insertion site (OR, 56.5; CI95, 10.8 to 296), and hub colonization (OR, 17.9; CI95, 2.4 to 132). The risk associated with skin colonization varied with use of jugular access or simultaneous colonization of the hub. When only symptomatic CRI was considered, the risk associated with hub colonization was consistently higher (OR, 36.6; CI95, 7 to 190) than that associated with skin colonization (OR, 3.2; CI95, 0.7 to 14). Age, transparent dressing, jugular insertion, male gender, duration of catheterization, and hub colonization were independent risk factors for skin colonization. The effect of age varied by type of dressing and vice versa; the effect of jugular access varied by sex; and the effect of transparent dressing varied by length of catheterization and vice versa. Total parenteral nutrition and skin colonization were independently associated with an increased risk of hub colonization. CONCLUSIONS: Skin and hub colonization are the two major determinants for endemic CRIs; colonization of the hub, however, is more frequently associated with more severe infections. In order to reduce CRIs, more efforts should be focused on understanding which factors increase the risk of colonization both of the skin and of the hub.

Central venous catheter-related infections in pediatric hematology-oncology patients: role of home and hospital management.

In a 61-month period, 135 single-lumen central venous catheters (CVCs) were positioned in 125 children with mainly hematological malignancies. We retrospectively investigated the different role of home and hospital CVC management in development of CVC-related infections (CI) during different hematological conditions (presence or absence of neutropenia). Forty-nine percent of the children presented at least one CI, for a total of 109 episodes, during the 20,558 days a CVC remained in situ. CVC hospital management was safer and more reliable than CVC home management in both neutropenic and nonneutropenic patients. None of the CI was life threatening and only in 11% of the cases was it necessary to remove the catheter. Analysis of the microorganisms involved showed that they were mainly gram-positive with CVC home management and gram-negative with CVC hospital management. Careful evaluation of our retrospective survey study suggests that a better training of parents in the care of the CVC and more careful measures of asepsis in hospital could further decrease the incidence of CI, thus improving patients' quality of life.

Central venous catheter-related complications after bone marrow transplantation in children with hematological malignancies.

We studied infectious and mechanical complications occurring with 55 central venous catheters (CVCs) managed in hospital and at home, in 53 children with hematological malignancies who underwent bone marrow transplantation (BMT). The total catheter life span was 6906 days (median 111), 2359 days (median 40) in hospital and 4547 days (median 78.5) at home. Duration of neutropenia was 1241 days (median 20), mostly in hospital. We observed 21 CVC-related infections from 17/55 CVCs (31%): 0.30 episodes/100 days of CVC use with 0.55/100 days in hospital vs 0.17/100 days at home. Antibiotic treatment resolved 72% of infections without CVC removal, which was required in six instances. There were 14 mechanical complications (0.20 episodes/100 days of CVC use) in 6/55 CVCs (11%), with three removals. Interventions to resolve mechanical problems included catheter declotting by urokinase, repair and replacement. We conclude that CVC is an essential component of care of children with cancer undergoing BMT and that it has a relatively low complication rate. Most complications can be resolved by an appropriate CVC handling and by a multidisciplinary intervention in the critical post-BMT phase.

Sulbactam/ampicillin versus cefotetan in the treatment of obstetric and gynecologic infections.

In an open, randomized clinical study, the safety and efficacy of sulbactam/ampicillin was compared to that of cefotetan in 95 hospital patients with gynecologic or obstetric infections. Sulbactam/ampicillin (1 g:2 g), was administered intravenously every 8 h to 46 patients, and cefotetan (2 g) was administered intravenously every 12 h to 49 patients. All 23 patients with obstetric infections and 18 of the 23 patients with gynecologic infections treated with sulbactam/ampicillin were evaluated as cured. All 21 patients with obstetric infections and 23 of the 28 patients with gynecologic infections treated with cefotetan were evaluated as cured. No side effects requiring discontinuation of therapy or reduction of the dose administered, were observed.

A family cluster of Legionella pneumophila infections.

Three members of one single family of 4, the father, a son and a daughter, showed seroconversion against Legionella pneumophila serogroup 1 (Lp SG1). The son had a severe pneumonia, whereas the father and the daughter did not develop any other illness than mild and transient fever. A fourth member, the mother, remained seronegative. Lp SG1 was detected by a direct immunofluorescence test in water samples from the shower at home, in tap water in the family's butcher shop, and in condensation water from the ventilator of refrigerator cells in the shop. Two different sources of infection appear to have occurred: showering at home and an aerosol of contaminated condensation water. Reports of more than one case of legionella infection within a family seem to be extremely rare and have not been found in the literature.

[Comparative study of 2 latex tests (rubalex and rubascan) with an immunoenzyme test (enzygnost-rubella) and a hemagglutination inhibition test for the study of anti-rubella antibodies]. / Studio comparativo di due tests al lattice (rubalex e rubascan) con un test immunoenzimatico (enzygnost-rubella) ed un test di inibizione dell' emoagglutinazione per la ricerca di anticorpi anti-rosolia.

Four different assays for detection of rubella IgG antibodies, two latex agglutination (Rubalex and Rubascan), one hemagglutination inhibition (HAI) and one enzyme-linked immunosorbent assay (ELISA IgG), were used to test 372 human serum samples. All samples were also tested with a rubella ELISA IgM test and all of them were found negative. The results obtained in 358 (96.2%) out of 372 samples tested were identical with all procedures. Inconclusive results were obtained in 14 (3.8%) specimens, in that there were positive and negative results for the different assays. These 14 specimens were sent to the Institute of Virology in Turku (Finland) and tested by using a hemolysis in gel and a non commercially-available ELISA IgG test. Results obtained with the two last tests were considered definitive. The two latex tests were found equal or better than HAI and ELISA IgG for sensitivity and specificity. Furthermore they were also cost effective and more simple to perform.

[IgM ISAGA test in the diagnosis of acute acquired Toxoplasma infections]. / Il test IgM ISAGA nella diagnosi di infezione toxoplasmica acuta acquista.

An immunoglobulin M immunosorbent agglutination assay (IgM ISAGA) was tested in 1804 outpatients' samples. The test was negative in all 1091 sera from individual negative in the total indirect immunofluorescence antibody (IFA tot) test and in the passive hemagglutination (HA) test and in 15 sera with inconclusive results in these two tests. The 698 sera positive in the IFA tot and HA tests were also tested with direct IgM enzyme-linked immunosorbent assay (IgM ELISA). The 74 sera positive in the IgM ISAGA and/or IgM ELISA were also tested in the IgM immunofluorescent (IgM IFA) test. These sera belong to 42 individuals, 26 of whom were followed for previous positive results in the IgM ELISA test. 51 samples (68.9%) were found positive in both IgM ISAGA and IgM ELISA tests. Only 13 (25.5%) of these 51 samples were found positive in the IgM IFA. 9 samples (12.2%) were positive only in the IgM ISAGA test. Conversely another 9 samples (12.2%) were positive only in the IgM ELISA test, performed on serum as well as on chromatographic IgM fraction. Finally five samples (6.7%) yielded false positive results in the IgM ELISA test, and three of them were found false positive also in the IgM IFA test. All these five samples in fact were found negative on IgM chromatographic fraction in both tests. In conclusion, IgM ISAGA appears to be more specific than direct IgM ELISA or IgM IFA test for the detection of Toxoplasma gondii IgM. Sensitivity of IgM ISAGA test seems to be as good as in the direct IgM ELISA and better than in the IgM IFA test for the diagnosis of acute acquired toxoplasma infection.

[The Sceptor system: relation of results from antibiograms in diffusion agar to MIC]. / Sistema Sceptor: confronto dei risultati degli antibiogrammi in agar diffusione rispetto alla MIC.

The Sceptor system and the susceptibility of Gram-positive cocci and Gram-negative rods to several antibiotics were presented. The accuracy of methicillin and gentamicin MIC of Staphylococcus aureus was determined. The MIC of methicillin-resistant strain was less than 8 mg/l. Finally the MIC accuracy to 29 Pseudomonas aeruginosa strains was compared with the results obtained by the standard disk diffusion method.