One-year surveillance of legionellosis in burned patients and Legionella environmental monitoring.

Burned patients have a theoretically high risk of Legionella infection because burns produce a compromised immune system. Cutaneous surfaces are without protective barriers, and bathing tank water is frequently used for washing and caring. A one-year surveillance study was performed on 65 burned patients by antibody determination and by culture of bronchial aspirates. Environmental culturing for Legionella was done in the patients' care areas every four months during the same period. Low titers ranging from 8 to 32 were found in 30 (46.1%) subjects against 18 antigens including several Legionella species. No increase in antibody titers was shown in 193 patients' sera. Cultures of respiratory samples were negative. L. pneumophila serogroups 4, 5, 6 and 8 and L. rubrilucens were isolated from 55.5% of water samples. Despite no evidence of Legionella infection among patients included in this study, the authors believe it to be advisable to improve control measures in hospital water supplies, used by burned patients, to minimise the risk of legionellosis.

Microbiological investigations on a nosocomial case of Legionella pneumophila pneumonia associated with water birth and review of neonatal cases.

A case of Legionella pneumophila 1 pneumonia, confirmed by positive serology and urinary antigen, occurred in a 7-day old neonate after water birth in hospital. As respiratory samples were not available for culture, further microbiological investigations were performed in neonate and environment, in order to recognize the source of infection. The hospital water supply was contaminated by L. pneumophila 1 strains (300-2000 cfu/L) of two monoclonal subtypes of Pontiac subgroup. L. spiritensis (10-225 cfu/L) was isolated from cold tap water of the patient's home. PCR from tap and humidifiers water of the patient's home was positive for Legionella spp, but not for L. pneumophila. Because L. pneumophila 1, responsible of child infection, was only isolated from the hospital pool water for waterbirthing, we conclude that the infant acquired the nosocomial legionellosis by prolonged delivery in contaminated water, perhaps by aspiration. Infection control measures for waterbirthing are highly recommended. A review of neonatal case of legionellosis is also presented. As this rare infection may have a high fatality rate if unrecognized, pediatricians should be aware of the possibility of the legionellosis in newborns.

Designation of the European Working Group on Legionella Infection (EWGLI) amplified fragment length polymorphism types of Legionella pneumophila serogroup 1 and results of intercentre proficiency testing Using a standard protocol.

The utility of amplified fragment length polymorphism (AFLP) analysis as a genotyping method for the epidemiological typing of Legionella pneumophila serogroup 1 has been previously demonstrated. This study (i). reports recommendations for the designation of the European Working Group on Legionella Infections (EWGLI) AFLP types, (ii). describes the EWGLI AFLP types identified for the 130 strains in the EWGLI culture collection, and (iii). reports the results of a newly introduced international programme of proficiency testing. Following preliminary analysis of 20 epidemiologically unrelated isolates, 16 major AFLP types were identified. A coded proficiency panel, comprising 12 additional isolates representing 9 of these 16 AFLP types, was sent to 17 centres in 14 European countries where it was analysed following a previously determined standard protocol. The identity of each coded strain (recorded as AFLP type 001-016 or untypeable) was determined by participants with reference to these 16 AFLP types, either visually or using gel analysis software where available, and reported to the coordinating centre. Nine of the 12 strains, including an epidemiologically related pair and two pairs of unrelated isolates of the same type, were correctly identified to the correct AFLP type by all or all but one of the participants. Seven laboratories correctly identified all 12 isolates, and a further seven laboratories correctly identified 11. Type identification scores ranged from 75% (1 centre), 83% (2 centres), and 92% (7 centres) to 100% (7 centres). The AFLP method as described is robust and rapid and allows the genotypic comparison of isolates of Legionella pneumophila between different testing centres without the need for exchange of the strains studied.

Culture proven Legionella pneumophila pneumonia in a HIV-infected patient: case report and review.

We report the first culture proven case of Legionella pneumonia in a HIV-positive patient in Italy. The laboratory diagnosis was obtained by isolation of Legionella pneumophila serogroup 1, serology, urinary antigen detection and PCR. Culture first allowed diagnosis of the infection, that probably would have been unrecognized. Since Legionellosis in HIV-positive patients with respiratory symptoms is rare and difficult to confirm, we strongly suggest that all available laboratory tests, and particularly culture, should be performed. A review of literature on culture proven cases is also provided.

Evaluation of the efficacy of ultraviolet irradiation for disinfection of hospital water contaminated by Legionella.

We evaluated the efficacy of the ultraviolet irradiation on hospital water colonized by Legionella pneumophila serogroup 3, by inserting a lamp system on a hot water pipe supplying a small area. Cultures were performed for four months from 5L samples of water, collected before and after the ultraviolet treatment at the lamp unit and from two distal points. Irradiation was effective immediately after disinfection (<10 cfu/L), even when the incoming water was highly contaminated. One distal point showed little or no contamination (<10-20 cfu/L), while the other showed little to moderate contamination (<10(3) cfu/L). We conclude that ultraviolet irradiation is useful to protect the water system in small area; however, because of the lack of residual activity, it should be combined with other methods of disinfection. Maintenance of the water system is also necessary in order to reduce biofilm formation and Legionella recolonization.

Legionella pneumophila pneumonia in a newborn after water birth: a new mode of transmission.

We report a case of Legionella pneumophila pneumonia in a 7-day old neonate. Because the hospital water, and particularly the pool water for water birthing, was contaminated by L. pneumophila serogroup 1, the newborn was infected following prolonged delivery in contaminated water, perhaps by aspiration. This is the first case of nosocomial Legionella pneumonia in neonate after water birth.

Comparative evaluation of two commercially available antigen enzyme immunoassays (EIA) for the detection of Legionella pneumophila urinary antigen in frozen non-concentrated urine samples.

We evaluated two commercial enzyme immunoassay kits, Binax EIA (for detection of soluble antigen of Legionella pneumophila serogroup 1) and Biotest EIA (for detection of antigens of Legionella pneumophila serogroups and other Legionella spp.) in order to introduce this test routinely for the diagnosis of Legionnaires' disease (LD) in our Laboratory. Frozen non-concentrated urine samples belonging to 45 patients with and without LD were tested. The sensitivity of Binax EIA and Biotest EIA was 47.4% and 42.1% respectively, the specificity was 95% by both tests. Biotest did not detect antigen from a patient with culture-proven infection of L. pneumophila serogroup 6. The detection of urinary antigen by both EIA tests is a useful tool for rapid diagnosis of LD, especially when samples are unavailable for culture; the sensitivity may be increased if the assay is performed on unfrozen and concentrated samples.

Epidemiological trend of human leptospirosis in Italy between 1994 and 1996.

In the three-year period 1994 1996, 222 reports on human cases of leptospirosis were received by the Italian Ministry of Health. The average annual number of reports was 29.2% lower than in the preceding eight years. In all cases but two the infections were thought to have been acquired in Italy. As in previous years, the majority of cases was observed in the northern regions of the country (83.8%), mostly in males (88.9%). Cases occurred in all age groups, but were more common in the working-age population (15-64 years). There was no common-source outbreaks. The typical leptospiral seasonal course, with a peak in August, was observed. During 1994, leptospirosis was the reported cause of death in 19 patients. Mortality was higher among males than females. The overall fatality rate was 22.6%. During the study period, a total of 126 cases of leptospirosis were confirmed by the National Centre for Leptospirosis or one of the 12 Regional Leptospira Laboratories. Of the 103 patients for whom information on place of residence, contact with animals, occupational and recreational activities was available, 98 (95.1%) were people who live in rural areas or devote themselves to occupational or recreational activities at risk. The likely source of infection and the mode of exposure were known for 55 patients. Forty-five patients (81.8%) were likely infected by contaminating water (43 cases) or soil (2 cases), ten (18.2%) by direct contact with animals or animal urine. Both running (51.2%) and stagnant water (27.9%) have been reported as a source of infection. Rodents were implicated in 50.0% of the 10 cases involving animals. In comparison with the preceding eight-year period, the risk of contracting leptospirosis was found to have increased for recreational activities (from 34.7 to 38.2%) and decreased for occupational activities (from 45.8 to 32.7%). A large number of infections, however, was ascribed to accidental events (25.5%). As in the previous period, besides fever, the involvement of the liver was the most frequent clinical manifestation (70.8%). Influenza-like symptoms were the only signs of illness in 15.1% of cases. Infections by 9 different serogroups were detected. The most frequent antibodies were those against serovars icterohaemorrhagiae, poi, copenhageni and brattislava. The presence of co-agglutinins against serovars belonging to different serogroups prevented the identification of the presumptive infecting serogroup in 19.8% of subjects.

Clarithromycin and amoxicillin susceptibility of Helicobacter pylori strains isolated from adult patients with gastric or duodenal ulcer in Italy.

Helicobacter pylori strains, isolated from 100 gastric biopsies from 49 previously untreated adult patients with endoscopy and histology-confirmed gastric or duodenal ulcer, were tested for in vitro antimicrobial susceptibility. Strains were isolated from biopsies of 75.5% (37 of 49) patients before therapy and of 13.5% after therapy. Clarithromycin and amoxicillin susceptibility testing was performed on pretreatment and posttreatment strains by using the agar disk diffusion method and E-test, a quantitative technique for the minimal inhibitory concentration (MIC) determination. All strains (n = 53) were susceptible to amoxicillin by the two methods. Three strains of 34 (8.8%) patients were resistant to clarithromycin: two by both methods and one by E-test (MIC > 2 microg/ml). E-test, although more expensive than the disk diffusion method, is easy to perform and is a reliable method for testing H. pylori susceptibility to antimicrobial agents in the clinical microbiology laboratory.

Prevalence of Legionella pneumophila serogroup 1 antibodies in blood donors.

The prevalence of anti-Legionella pneumophila serogroup 1 antibodies in 777 blood donors of the Turin area was determined by the indirect immunofluorescence assay (IFA) and by the microagglutination test (MA). Low titers (IFA of 1/16 and MA of 1/8) were found in 0.3% of the subjects. A statistically significant difference was not observed by sex and by age for IFA titers, but was noted by sex for MA titers of > or = 1/4 (p < 0.05). The upper limit of normal titer was < 1/8 by IFA and < 1/4 by MA at 15% cutoff level and 1/8 by IFA and 1/4 by MA at 1% cutoff level. In conclusion, the prevalence of antibodies in the Turin area was very low; IFA titers of > or = 1/64 and MA titers of > 1/16 can be considered as presumptive of infection in a single serum specimen of a patient with pneumonia; no change in the epidemiology of the disease was observed in the recent years.

Prevalence of Yersinia antibodies in blood donors.

Agglutinins titers against Y. enterocolitica 0:3, 0:5, 0:9 and Y. pseudotuberculosis I were determined by the microagglutination method in 777 blood donor sera. Titers of < or = 1/10 were observed in 93.5% of the subjects for Y. enterocolitica 0:3, in 87.8% for Y. enterocolitica 0:9 and in 95.1% for Y. enterocolitica 0:5 and for Y. pseudotuberculosis I. Low level titers (1/10 - 1/20) were found in 11.4% to 23.1%. Titers of > or = 1/40 were observed in 1.7% for Y. enterocolitica 0:3, in 1.4% for Y. enterocolitica 0:5, in 5.1% for Y. enterocolitica 0:9 and in 1.2% for Y. pseudotuberculosis I. Titers of > or = 1/80 were seen in 0.2% for Y. enterocolitica 0:3, in 0.1% for Y. enterocolitica 0:5 and in 1.3% for Y. enterocolitica 0:9. Only in one donor's serum was a titer of 1/160 against Y. enterocolitica 0:9 found. The upper limit of normal titer at 15% cutoff level against Yersinia antigens, found in blood donor sera by the microagglutination test, was 1/10.

Growth of Yersinia species in artificially contaminated blood bags.

Transfusion blood bags were inoculated with less than 0.1 colony-forming units (CFU) of Yersinia enterocolitica (serotypes O:3, O:5, and O:9) and Yersinia pseudotuberculosis I per mL and stored at 4 degrees C for 41 days. During storage, samples were collected periodically and colony counts of serial dilutions were performed by plating on tryptic soy agar. After a lag-phase, the growth of Yersinia species from less than 0.1 CFU per mL to 10(9) CFU per mL was observed in 3 of 10 bags. The data showed that prolonged storage of contaminated blood bags allows Y. enterocolitica and Y. pseudotuberculosis to multiply to high levels.

Endemicity of Legionella pneumophila serogroup 3 in a hospital water supply.

A microbiological and epidemiological investigation at the Infectious Diseases Hospital in Turin, Italy, demonstrated Legionella pneumophila serogroup 3 at 10(2) to greater than 4 X 10(3) cfu l-1 from 24 of 32 hot water samples collected from hand-basins in six separate buildings. A sample taken from the public water supply, and a hot water sample (80 degrees C) collected from hot water tanks, did not yield legionellas. Legionella pneumophila serogroup 3 was found in samples taken at the first point of mixed hot and cold water (50 degrees C) at 3 X 10(2) cfu l-1. 12 of 26 samples from the shower-heads yielded 10(3) to 2.5 X 10(5) cfu l-1 and one of 12 water samples from oxygen bubble humidifiers tested yielded 1.6 X 10(4) cfu l-1. No other legionellas species or serogroups of Legionella pneumophila were isolated during the study. No cases of nosocomial pneumonia were detected among 3653 patients' records, nor was there serological evidence of Legionella infection in the 180 patients tested.

[Yersinia and infantile gastroenteritis]. / Yersinia e gastroenteriti infantili.

Fecal samples and intestinal mucosal biopsies of 16 patients in paediatric age, with protracted diarrhoea with blood and mucus, were examined for intestinal pathogens including Yersinia. Yersinia enterocolitica 1/5/XZ and Yersinia intermedia 1/18/XZ were isolated from fecal samples of two patients. In another child, Yersinia enterocolitica, 1/5/XZ was isolated from fecal sample, while Yersinia enterocolitica 1/self-agglutinable/XZ from colon biopsy. The other intestinal pathogens were absent; Aeromonas hydrophila however was isolated from two fecal samples. The Yersinia strains isolated are not frequently found in human infections.

Attempt of Yersinia enterocolitica isolation from human feces in Senegal.

One-hundred-eight stool samples, collected in a fishing village of Senegal from 72 apparently healthy subjects and from 36 patients with gastrointestinal disorders, were examined for the presence of Y. enterocolitica. After 1, 2, 3 weeks of cold enrichment with PBS 1/15M, pH 7.6, plating was performed on MacConkey Agar after use of the alkali method. No Yersinia strains were isolated.

Fungal colonization in patients with cancer of the upper respiratory tract.

Fungal opportunistic infections are a danger for immunocompromised hosts, such as patients with malignancies, especially in a hospital environment. We studied a group of patients with solid tumors of the respiratory tract on admission and after twenty days of hospitalization. Colonization by moulds and/or yeasts was frequently found. Preventive measures should be applied to avoid colonization inside the hospital. The importance of overcrowding, sanitation and diet is pointed out.

[Identification of staphylococcal enterotoxins]. / L'identificazione delle enterotossine stafilococciche.

The important problem of the staphylococcal enterotoxins identification from cultures of Staphylococcus aureus and from foods is discussed in this work. The usefulness and reliability both of the media and methods for the enterotoxins production and of the techniques of identification are examined. For practical purposes is very important to use simple, sensitive, reliable and rapid methods for the identification of staphylococcal enterotoxins.