Anti-Phosphatidylserine, Anti-Prothrombin, and Anti-Annexin V Autoantibodies in Antiphospholipid Syndrome: A Real-Life Study.

The antiphospholipid antibodies (aPL) increase the risk of developing thrombotic events and may coexist with a variety of autoimmune diseases. They can be detected chronically or temporarily in patients with infectious diseases, during drug therapy, or in cases of cancer. A thrombotic event with aPL detection is known as antiphospholipid syndrome (APS) and the diagnostic criteria include the presence of lupus anticoagulant (LA), anticardiolipin (aCL) and ß2-glycoprotein-1(aß2GPI) antibodies. Other autoantigens recognized in APS are phosphatidylserine (aPS), prothrombin (aPT) and Annexin-5 (aA5). This real life study aimed to explore the connections between laboratory criteria and the prevalence of "non-criteria aPL" in APS. This study followed 300 patients with thrombosis and employed two phospholipid sensitivity assays for LA detection, chemiluminescence assays for aCL and aß2GPI and enzyme-linked immunoassays for aPS, aPT and aA5. A significant association was found between aPS and aCL (r = 0.76) as well as aß2GPI (r = 0.77), while the association with LA was less significant (r = 0.33). The results of the aPT and aA5 test did not correlate with criteria-antiphospholipid antibodies (r < 0.30). Since the risk of thrombotic complications increases with the intensity and the number of positive autoantibodies, measuring aPT and aA5 autoantibodies may be useful, particularly in aCL/aß2GPI-negative patients or in cases of isolated LA positivity.

Systemic sclerosis and primary biliary cholangitis share an antibody population with identical specificity.

Anti-centromere (ACA) and antimitochondrial antibodies (AMA) are specific for limited-cutaneous systemic sclerosis (lcSSc) and primary biliary cholangitis (PBC), respectively, and can coexist in up to 25 and 30% of SSc and PBC patients. Here, we evaluated whether anti-centromeric protein A (CENP-A) antibodies cross-react with mitochondrial antigens. To this end, sera from two lcSSc patients (pt1 and pt4), one of them (pt4) also affected by PBC, were used as the source of ACA, previously shown to recognize different groups of amino acids (motifs) in the CENP-A region spanning amino acids 1-17 (Ap1-17). Pt1 and pt4 Ap1-17-specific IgG were purified by affinity-chromatography on insolubilized Ap1-17-peptide column and tested by western blotting with nuclear and cytoplasmic protein extract from HeLa cells. Immunoreactive proteins were identified by mass spectrometry and validated by immunodot. The results showed that affinity-purified SSc/PBC pt4 anti-Ap1-17 and not SSc pt1 anti-Ap1-17 Ab, specifically cross-reacted with the E2 component of the mitochondrial pyruvate dehydrogenase complex (PDC-E2), the major mitochondrial autoantigen in PBC. Sequence homology analysis indicated that the motif A-x-x-P-x-A-P recognized by pt4 anti-Ap1-17 IgG and shared by CENP-A and PDC-E2, is also expressed by some members of the Human Herpesvirus family, suggesting that they may trigger the production of these cross-reacting antibodies.

Investigations on the Efficacy of Ozone as an Environmental Sanitizer in Large Supermarkets.

Awareness of the importance of the microbial contamination of air and surfaces has increased significantly during the COVID-19 pandemic. The aim of this study was to evaluate the presence of bacteria and fungi in the air and on surfaces within some critical areas of large supermarkets with and without an ozonation system. Surveys were conducted in four supermarkets belonging to the same commercial chain of an Apulian city in June 2021, of which two (A and B) were equipped with an ozonation system, and two (C and D) did not have any air-diffused remediation treatment. There was a statistically significant difference in the total bacterial count (TBC) and total fungal count (TFC) in the air between A/B and C/D supermarkets (p = 0.0042 and p = 0.0002, respectively). Regarding surfaces, a statistically significant difference in TBC emerged between A/B and C/D supermarkets (p = 0.0101). To the best of our knowledge, this is the first study evaluating the effect of ozone on commercial structures in Italy. Future investigations, supported by a multidisciplinary approach, will make it possible to deepen the knowledge on this method of sanitation, in light of any other epidemic/pandemic waves.

SARS-CoV-2 and Public Transport in Italy.

Although direct contact is considered the main mode of transmission of SARS-CoV-2, environmental factors play an important role. In this study, we evaluated the presence of SARS-CoV-2 on bus and train surfaces. From the buses, we took samples from the following areas: handrails used to enter or exit the bus, stop request buttons and handles next to the seats. From the trains, the sampled surfaces were handrails used to enter or exit the train, door open/close buttons, handles next to the seats, tables and toilet handles. SARS-CoV-2 was detected on 10.7% of the tested surfaces overall, 19.3% of bus surfaces and 2% of train surfaces (p < 0.0001). On the buses, the most contaminated surfaces were the handles near the seats (12.8%), followed by door open/close buttons (12.5%) and handrails (10.5%). Of the five analyzed transport companies, bus companies were the most contaminated, in particular, companies C (40%) and B (23.3%). A greater number of positive samples were found among those taken at 10:00 a.m. and 10:55 a.m. (45% and 40%, respectively). The presence of the virus on many bus surfaces highlights how the sanitation systems on public transport currently in use are not sufficient to limit the spread of SARS-CoV-2.

Potential Use of Untreated Wastewater for Assessing COVID-19 Trends in Southern Italy.

As a complement to clinical disease surveillance, the monitoring of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in wastewater can be used as an early warning system for impending epidemics. This study investigated the dynamics of SARS-CoV-2 in untreated wastewater with respect to the trend of coronavirus disease 2019 (COVID-19) prevalence in Southern Italy. A total of 210 wastewater samples were collected between May and November 2020 from 15 Apulian wastewater treatment plants (WWTP). The samples were concentrated in accordance with the standard of World Health Organization (WHO, Geneva, Switzerland) procedure for Poliovirus sewage surveillance, and molecular analysis was undertaken with real-time reverse-transcription quantitative PCR (RT-(q) PCR). Viral ribonucleic acid (RNA) was found in 12.4% (26/210) of the samples. The virus concentration in the positive samples ranged from 8.8 × 102 to 6.5 × 104 genome copies/L. The receiver operating characteristic (ROC) curve modeling showed that at least 11 cases/100,000 inhabitants would occur after a wastewater sample was found to be positive for SARS-CoV-2 (sensitivity = 80%, specificity = 80.9%). To our knowledge, this is the first study in Italy that has applied wastewater-based epidemiology to predict COVID-19 prevalence. Further studies regarding methods that include all variables (meteorological phenomena, characteristics of the WWTP, etc.) affecting this type of wastewater surveillance data would be useful to improve data interpretation.

A Possible Outbreak by Serratia marcescens: Genetic Relatedness between Clinical and Environmental Strains.

Serratia marcescens (SM) is a Gram-negative bacterium that is frequently found in the environment. Since 1913, when its pathogenicity was first demonstrated, the number of infections caused by SM has increased. There is ample evidence that SM causes nosocomial infections in immunocompromised or critically ill patients admitted to the intensive care units (ICUs), but also in newborns admitted to neonatal ICUs (NICUs). In this study, we evaluated the possible genetic correlation by PFGE between clinical and environmental SM strains from NICU and ICU and compared the genetic profile of clinical strains with strains isolated from patients admitted to other wards of the same hospital. We found distinct clonally related groups of SM strains circulating among different wards of a large university hospital. In particular, the clonal relationship between clinical and environmental strains in NICU and ICU 1 was highlighted. The identification of clonal relationships between clinical and environmental strains in the wards allowed identification of the epidemic and rapid implementation of adequate measures to stop the spread of SM.

Study on the In Vitro Activity of Five Disinfectants against Nosocomial Bacteria.

Nosocomial infections cause significant morbidity and mortality worldwide, and the pathogenic organisms responsible for such infections can develop resistance to antimicrobial agents. Understanding the activity of disinfectants against clinical and environmental bacterial isolates is therefore crucial. We analysed the in vitro activity of five antimicrobial products (phenolic compounds, didecyldimethylammonium chloride (DDAC), sodium hypochlorite, isopropanol + ammonium compounds (IACs), hydrogen peroxide) against 187 bacterial strains comprising clinical isolates, as well as 30 environmental isolates of Pseudomonas aeruginosa from hospital water samples. Disk diffusion assays were employed to assess antimicrobial activity. Hydrogen peroxide was significantly more active (p < 0.0001) than the other disinfectants against all P. aeruginosa, Klebsiella pneumoniae, Enterococcus faecalis and Staphylococcus aureus strains. It was also the only disinfectant with activity against both clinical and environmental strains of P. aeruginosa. DDAC and IAC-based disinfectants were ineffective against Gram-negative strains, but showed significant activity (particularly IACs, p < 0.0001) against the Gram-positive strains. Compared with IACs, DDAC was significantly more active on E. faecalis and less active on S. aureus (p < 0.0001). Sodium hypochlorite and phenol compounds, by contrast, were inactive against all bacterial strains. The development of disinfection procedures that are effective against all microorganisms is essential for limiting the spread of nosocomial infections.

Candidemia in the Neonatal Intensive Care Unit: A Retrospective, Observational Survey and Analysis of Literature Data.

We evaluated the epidemiology of Candida bloodstream infections in the neonatal intensive care unit (NICU) of an Italian university hospital during a 9-year period as a means of quantifying the burden of infection and identifying emerging trends. Clinical data were searched for in the microbiological laboratory database. For comparative purposes, we performed a review of NICU candidemia. Forty-one candidemia cases were reviewed (overall incidence, 3.0 per 100 admissions). Candida parapsilosis sensu stricto (58.5%) and C. albicans (34.1%) were the most common species recovered. A variable drift through years was observed; in 2015, 75% of the cases were caused by non-albicans species. The duration of NICU hospitalization of patients with non-albicans was significantly longer than in those with C. albicans (median days, 10 versus 12). Patients with non-albicans species were more likely to have parenteral nutrition than those with C. albicans (96.3% versus 71.4%). Candida albicans was the dominant species in Europe and America (median, 55% and 60%; resp.); non-albicans species predominate in Asia (75%). Significant geographic variation is evident among cases of candidemia in different parts of the world, recognizing the importance of epidemiological data to facilitate the treatment.

Enteric Viruses and Fecal Bacteria Indicators to Assess Groundwater Quality and Suitability for Irrigation.

According to Italian Ministerial Decree No. 185 of 12 June 2003, water is considered suitable for irrigation if levels of fecal bacteria (i.e., Escherichia coli and Salmonella) are within certain parameters. The detection of other microorganisms is not required. The aim of this study is to determine the bacteriological quality of groundwater used for irrigation and the occurrence of enteric viruses (Norovirus, Enterovirus, Rotavirus, Hepatovirus A), and to compare the presence of viruses with the fecal bacteria indicators. A total of 182 wells was analyzed. Widespread fecal contamination of Apulian aquifers was detected (141 wells; 77.5%) by the presence of fecal bacteria (i.e., E. coli, Salmonella, total coliforms, and enterococci). Considering bacteria included in Ministerial Decree No. 185, the water from 35 (19.2%) wells was unsuitable for irrigation purposes. Among 147 wells with water considered suitable, Norovirus, Rotavirus, and Enterovirus were detected in 23 (15.6%) wells. No Hepatovirus A was isolated. Consequently, 58 wells (31.9%) posed a potential infectious risk for irrigation use. This study revealed the inadequacy of fecal bacteria indicators to predict the occurrence of viruses in groundwater and it is the first in Italy to describe the presence of human rotaviruses in well water used for irrigation.

Serosurveillance of hepatitis A in a region which adopted the universal mass vaccination.

Hepatitis A is a common infectious disease worldwide that was endemic in many regions of Southern Italy, such as Apulia region. After a large hepatitis A outbreak occurred between 1996 and 1997, in Apulia an active-free immunization program that was targeted to new-borns and adolescents was started. The aim of this study is to investigate the hepatitis A seroprevalence in the adult Apulian population 18 years after the immunization program introduction, in order to evaluate the risk of new epidemics onset.The study was carried out from May 2011 to June 2012 among blood donors from Department of Transfusion Medicine and Blood Bank of Policlinico General Hospital in Bari. Participants signed a written consent and filled out a questionnaire including items on demographic characteristics, risk factors, disease memory, and raw food consumption. Serum samples, collected from each patient, were tested for anti-HAV using the chemiluminescent microparticle immunoassay. Vaccination status against hepatitis A was checked on Regional Digital Immunization Registry (GIAVA).In total 1827 donors agreed to participate (77.7% male) with a mean age of 38.4 ±â€Š11.7 years. However, 1172 (64.1%) donors were seropositive with no difference by sex. The highest proportion of seronegative subjects was in the 27 to 35 years age group. 91.8% of 1-dose vaccinated subjects (n = 190/207; 95%CI = 87.2-95.1) and 96.1% (n = 171/178; 95%CI = 92.1-98.1) of 2-doses vaccinated subjects were immune to the disease. Sensitivity of disease memory in unvaccinated subjects was 14.4% (95%CI = 12.2-16.7), specificity was 97.8% (95%CI = 96.3-98.8), positive predictive value was 91% (95%CI = 85.3-95), and negative predictive value was 42.6% (95%CI = 40-45.2). Raw seafood consumption in unvaccinated subjects was associated with the anti-HAV IgG positivity (OR = 2.1; 95%CI = 1.7-2.7; z = 7.4; P < 0.0001).The vaccination program seems to have changed the virus circulation pattern, with a higher seronegativity rate among subjects not included in the vaccination strategy: 67% of susceptible subjects were among younger people aged 27 to 35 years. Immunization program implementation with a catch-up strategy may be needed to avoid a possible increase of hepatitis A incidence and outbreaks in Apulia. Epidemiological surveillance should be continued and vaccination should actively be offer for free to all the cases contacts, in order to prevent new outbreaks onset.

Microbiological and hydrogeological assessment of groundwater in southern Italy.

This study represents the first investigation of microbiological groundwater pollution as a function of aquifer type and season for the Apulia region of southern Italy. Two hundred and seven wells were randomly selected from those monitored by the Regional Agency for Environmental Protection for emergency use. Both compulsory (Escherichia coli, Total Coliform, and Enterococci) and optional (Pseudomonas aeruginosa, Salmonella spp., Heterotrophic Plate Count at 37 and 22 °C) microbiological parameters were assessed regularly at these wells. Groundwater from only 18 of the 207 (8.7 %) wells was potable; these all draw from karst-fissured aquifers. The remaining 189 wells draw from karst-fissured (66.1 %) or porous (33.9 %) aquifers. Of these, 82 (43.4 %) tested negative for Salmonella spp. and P. aeruginosa, while 107 (56.6 %) tested positive for P. aeruginosa (75.7 %), Salmonella spp. (10.3 %), or for both Salmonella spp. and P. aeruginosa (14 %). A logistic regression model shows that the probability of potable groundwater depends on both season and aquifer type. Typically, water samples were more likely to be potable in autumn-winter than in spring-summer periods (odds ratio, OR = 2.1; 95 % confidence interval, 95 % CI = 1.6-2.7) and from karst-fissured rather than porous aquifers (OR = 5.8; 95 % CI = 4.4-7.8). Optional parameters only showed a seasonal pattern (OR = 2.6; 95 % CI = 1.7-3.9). Clearly, further investigation of groundwater microbiological aspects should be carried out to identify the risks of fecal contamination and to establish appropriate protection methods, which take into account the hydrogeological and climatic characteristics of this region.

Safety of shellfish and epidemiological pattern of enterically transmitted diseases in Italy.

In recent decades in South-Italy, drastic epidemiological changes in the pattern of the enterically transmitted diseases were recorded. This work aims to support the hypothesis that universal routine vaccination against hepatitis A started in Puglia in 1998 could be also effective in reducing contamination in seafood. Three studies on different samples of Mitylus edulis lamellibranch were conducted over 20 years. Microbiological analysis measured both the standard bacteriological indexes (faecal coliforms, Escherichia coli, Salmonella spp.) and the presence of hepatitis A, enterovirus, norovirus and rotavirus. Between 1989 and 2009, the highest number of hepatitis A cases was reported in 1996 and in 1997 (mean incidence rate of 130 per 100,000). Since 1999, the number of cases progressively decreased, reaching 29 cases in 2006 (incidence rate of 0.7 per 100,000). A progressive improvement in vaccination coverage of newborns was recorded ranging from 1997 (38.3%) to 2005 birth-cohorts (63.4%). Vaccination coverage of 12-year-old adolescents was 67.6% (95% CI: 58.4-76.8%). Hepatitis A was detected in 3.7% of samples in the 1987 study, in 18.3% of samples in the 1999-2000 study and it was absent in the 2007 study. The decreasing of HAV circulation in humans and in shellfish provides support for the link between vaccination efforts and the safety of molluscs.

The role of procalcitonin in neonatal intensive care unit patients with candidemia.

Candidemia is a major infectious complication in neonatal patients. The isolation of yeasts from blood is still the "gold standard" for its diagnosis, but other laboratory markers (i.e., circulating antigens) have been studied with varying specificities and sensitivities. The aim of this study was to evaluate the role of procalcitonin for the diagnosis of candidemia in neonatal patients at high risk. To verify if the use of different commercial methods can highlight dissimilar results of sensitivity and/or specificity, the determination of procalcitonin serum levels was estimated by two systems. Overall, 90 patients from a Neonatal Intensive Care Units were enrolled, of whom six developed Candida bloodstream infection. Four of six infants with candidemia had slight increase of procalcitonin values (0.5-1 ng/mL). Only one baby showed very high levels but he had fungal and bacterial sepsis at the same time, while no elevation was observed in the sixth patient. No statistically significant difference was observed between two different methods at the time of monitoring (p>0.643). Both methods showed a sensitivity of 83.3 % at diagnosis, while the specificity was 73.8 and 63.1 % by methods A and B, respectively. In the light of the low sensibility and specificity of this assay, we can assume that the determination of procalcitonin would not seem to play a significant role in the diagnosis of fungal infection in neonatal patients.

Increase in interleukin-8 production from circulating neutrophils upon antibiotic therapy in cystic fibrosis patients.

BACKGROUND: It is not known whether antibiotic therapy for lung disease in cystic fibrosis (CF) has an influence on circulating polymorphonuclear neutrophil (PMN) function and apoptosis. PATIENTS AND METHODS: Blood PMNs were obtained from 14 CF patients before and after antibiotic treatment for an acute exacerbation, and from 10 healthy controls. PMNs were evaluated for production of reactive oxygen species (ROS) by spectrophotometry, of cytokines in the conditioned medium by ELISA, and apoptotic response by cytofluorimetry. RESULTS: ROS and interleukin (IL)-8 were produced at higher levels by CF PMNs pre-therapy than control PMNs under basal conditions. IL-8 levels further increased after therapy. Early apoptotic response was higher in CF PMNs pre-therapy than in control PMNs, and this pattern did not change after antibiotic treatment. CONCLUSIONS: Circulating PMNs are primed in CF acute patients. Further studies are needed to consider PMN-produced IL-8 as a biomarker to evaluate response to antibiotic therapy in CF patients.

[The history of cholera in the Puglia region (Italy), 1836-1994]. / Cholera-Morbus: storia del colera in Terra di Bari, 1836-1994.

Historians and epidemiologists agree that seven pandemics of cholera have occurred from 1817 to the present time. However they do not always agree on the date of onset and extinction of several of the pandemics. Cholera appeared for the first time in Europe and therefore in Italy in the first half of the 19th century. In this context, the population of the Puglia region (Italy) was first affected by cholera starting in 1836, during the second pandemic, and then again during the following pandemics and in more recent local outbreaks in 1973 and 1994. This article describes the impact of the disease in the Puglia region, not only in terms of morbidity and mortality but also in terms of collective behaviour and public health interventions. Information was obtained from documents held by the State Archives of the city of Bari and from local documents. This historical analysis highlights the great progress made in this Region in terms of environmental rehabilitation and control of infectious diseases.

Legionella spp. and legionellosis in southeastern Italy: disease epidemiology and environmental surveillance in community and health care facilities.

BACKGROUND: Following the publication of the Italian Guidelines for the control and prevention of legionellosis an environmental and clinical surveillance has been carried out in Southeastern Italy. The aim of the study is to identify the risk factors for the disease, so allowing better programming of the necessary prevention measures. METHODS: During the period January 2000 - December 2009 the environmental surveillance was carried out by water sampling of 129 health care facilities (73 public and 56 private hospitals) and 533 buildings within the community (63 private apartments, 305 hotels, 19 offices, 4 churches, 116 gyms, 3 swimming pools and 23 schools). Water sampling and microbiological analysis were carried out following the Italian Guidelines. From January 2005, all facilities were subject to risk analysis through the use of a standardized report; the results were classified as good (G), medium (M) and bad (B). As well, all the clinical surveillance forms for legionellosis, which must be compiled by physicians and sent to the Regional Centre for Epidemiology (OER), were analyzed. RESULTS: Legionella spp. was found in 102 (79.1%) health care facilities and in 238 (44.7%) community buildings. The percentages for the contamination levels < 1,000, 1,000-10,000, > 10,000 cfu/L were respectively 33.1%, 53.4% and 13.5% for samples from health care facilities and 33.5%, 43.3% and 23.2% for samples from the community. Both in hospital and community environments, Legionella pneumophila serogroup (L. pn sg) 2-14 was the most frequently isolate (respectively 54.8% and 40.8% of positive samples), followed by L. pn sg 1 (respectively 31.3% and 33%). The study showed a significant association between M or B score at the risk analysis and Legionella spp. positive microbiological test results (p < 0.001). From clinical surveillance, during the period January 2001 - August 2009, 97 cases of legionellosis were reported to the OER: 88 of community origin and 9 nosocomial. The most frequent symptoms were: fever (93.8%), cough (70.1%), dyspnea (58.8%), shivering (56.7%). Radiological evidence of pneumonia was reported in 68%. The laboratory diagnostic methods used were: urinary antigen (54.3%), single antibody titer (19.8%), only seroconversion (11.1%), other diagnostic methods (14.8%). CONCLUSIONS: Our experience suggests that risk analysis and environmental microbiological surveillance should be carried out more frequently to control the environmental spread of Legionella spp. Furthermore, the laboratory diagnosis of legionellosis cannot be excluded only on the basis of a single negative test: some patients were positive to only one of the diagnostic tests.

Streptococcus pneumoniae modulates the respiratory burst response in human neutrophils.

The gram-positive pathogen Streptococcus pneumoniae is the most common cause of community-acquired pneumonia and is responsible for high morbidity and mortality worldwide. A major feature of pneumococcal pneumonia is an abundant neutrophil infiltration. In this work we observed that the R6 nonencapsulated S. pneumoniae strain induced a higher oxidative burst in neutrophils compared with its capsulated progenitor D39, by triggering neutrophil NADPH oxidase to produce more reactive oxygen intermediates (ROI) and by interfering with the neutrophil kinase signalling pathway. In addition, we evaluated the possibility that the capsule, lacking in R6 but present in D39, could modulate the S. pneumoniae-induced neutrophil respiratory burst. In this respect, three knock-out isogenic mutants (D39ΔCPS2E, D39ΔCPS-R6 and R6ΔCPS-R6) that were unable to synthesize the capsule, were tested for their capability of inducing the release of neutrophil-ROIs. The results indicate that the mutants behaved similarly to their wild-type parental strains in enhancing respiratory burst activity, suggesting that the capsule itself is not directly involved in modulating the neutrophil oxidative burst induced by S. pneumoniae, but that other genetic differences between D39 and R6 present elsewhere in the genome could be responsible for these mechanisms.

Occurrence of aflatoxin M(1) in dairy products in southern Italy.

A screening survey of the presence of aflatoxin M(1) (AFM(1)) was carried out on 265 samples of cheese made from cow, buffalo, goat, sheep, sheep-goat milk collected in the Apulia region (Southern Italy). Selected samples included unripened, medium and long-term ripened cheeses. AFM(1) was found in 16.6% of the analyzed samples. The highest positive incidence was for medium and long-term ripened cheeses, especially those made from sheep-goat milk, while buffalo cheeses tested consistently negative. Our results show that the level of contamination by AFM(1) in dairy products from Apulia Region are lower than in other Italian and European regions. Moreover, it is important to underline that a common European norm concerning the AFM(1) threshold limits for dairy products is still lacking.

Clinical-environmental surveillance of legionellosis: an experience in Southern Italy.

In Italy, although the number of cases of legionellosis notified to the health authorities has significantly increased in recent years, the incidence is still believed to be underestimated. To verify the true frequency and identify the sources of infection, an active clinical-environmental surveillance program was instituted in three hospital facilities in Southern Italy. Between January 2001 and March 2005, a total of 1000 patients admitted to the three hospitals with a diagnosis of pneumonia were enrolled. The urinary antigen and anti-Legionella antibody titre were assayed in each subject, and direct searches for the microorganism were made in biological specimens. Legionellosis was found to be present in 5.9% of the patients. For each of the cases of legionellosis, microbiological surveys were made of the water supply in the public and/or private facilities involved. Overall, 197 water samples of hospital origin and 218 of community origin were analysed: Legionella spp was isolated in 44.2 and 36.7% of the cases, respectively. Comparison of our data with those of the routine surveillance system for the same area (only 7 cases during the period 1997-2000), showed that the frequency of legionellosis is grossly underestimated in Southern Italy. It is therefore necessary to set up more rigorous controls in both hospital and community facilities, so that timely preventive measures can be taken to avoid any further spread of the disease.