Occurrence of Legionella in showers at recreational facilities.

Critical environments, including water systems in recreational settings, represent an important source of Legionella pneumophila infection in humans. In order to assess the potential risk for legionellosis, we analyzed Legionella contamination of water distribution systems in 36 recreational facilities equipped with swimming pools. One hundred and sixty water samples were analyzed from shower heads or taps located in locker rooms or in bathrooms. By culture method and polymerase chain reaction, 41/160 samples were positive for Legionella from 12/36 recreational centers. Hotels (57.1%) and sports centers (41.2%) were the most contaminated. L. pneumophila serotypes 2-14 (25/41) were more frequently found than serotype 1 (10/41). Samples at temperature ≥30 °C were more frequently positive than samples at temperature <30 °C (n = 39 vs n = 2, p < 0.00001). The presence of L. pneumophila was investigated by comparison with heterotrophic plate count (HPC), an indicator of water quality. The presence of L. pneumophila was associated more frequently with high and intermediate HPC load at 37 °C, therefore should be considered a potential source when HPC at 37 °C is >10 CFU/mL. Maintenance, good hygiene practices, interventions on the hydraulic system and regular controls must be implemented to minimize exposure to L. pneumophila infection risk.

Analytical solution for the modeling of the natural time-dependent reduction of waterborne viruses injected into fractured aquifers.

We propose an analytical solution in order to explain the processes that determine the fate and behavior of the viruses during transport in a fractured aquifer at Salento (Italy). The calculations yield the efficiency of filtration in fractures at a site near Nardò (Southern Italy) in reducing the numbers of enteric viruses (i.e., Enteroviruses and Norovirus) in secondary municipal effluents that have been injected in the aquifer over the period 2006-2007. The model predicted, by a theoretical expression, the time-dependent rate of virus reduction, which was in good agreement with field data. The analytical solution yields the achievable "Log reduction credits" for virus reduction in wells located at the setback distances that are usually adopted in local drinking water regulations. The resulting new analytical formula for the time-dependent reduction of viruses during subsurface transport can easily be applied in health risk-based models used to forecast the spread of waterborne diseases and provides appropriate criteria (i.e., distances) needed to meet standards for the quality of drinking water derived from undisinfected groundwater.

[The birth of nanobiotechnologies: new nanomaterials, potential uses, toxic effects and implications for public health]. / La nascita delle nanobiotecnologie: I nuovi nanomateriali, i potenziali applicativi, gli effetti tossici e le implicazioni per la Sanità Pubblica.

Nanotechnologies hold considerable promise of advances in many sectors especially the biomedical field, since the materials used are of the appropriate dimensions to interact with important biological matter such as proteins, DNA and viruses. In this field the use of nanotechnologies will probably be second in importance only to biotechnologies. However many characteristics of nanomaterials that make them so promising from a technological point of view may also lead to negative effects on the environment and human health. It is important therefore that the environmental and work-related exposure effects to these materials be evaluated. In this article the potential uses, toxic effects and public health implications of nanobiotechnologies are discussed.

[Virus removal in conventional wastewater treatment process]. / Rimozione dei virus nei processi convenzionali di trattamento delle acque reflue.

Little has been published in the scientific literature on the distribution of pathogenic viruses and on their removal in the different treatment phases in wastewater treatment plants in Italy. Recent advances in molecular biology have reduced analytic costs and allowed the detection of virus directly in the environment. This study evaluates the presence of enteric viruses and their removal in three treatment plants of different sizes and which use different treatment methods. Overall 92 samples were collected during three seasonal campaigns (winter, spring-summer, and autumn). Samples were collected at different phases of the treatment process. Chemical and microbiological analyses were performed. Samples were concentrated by ultrafiltration and tested for the presence of hepatitis A virus, adenovirus, rotavirus, astrovirus, norovirus and enteroviruses. All viruses, excluding the Enteroviruses were detected through biomolecular testing. Enteroviruses, were isolated on BGM cells and subsequently genotyped at the VP1 region. Sixty-two of the 92 samples tested positive for viruses; of these, 21 tested positive for HAV, 4 for adenovirus, 9 for rotavirus, 21 for astrovirus, and 7 for norovirus. Enteroviruses were present on average in 44% of samples collected during the three sampling campaigns. Hepatitis A virus was isolated during the spring-summer period while Astroviruses were identified in all three sampling campaigns. Different enteroviruses were isolated, including four types of Coxsackie B virus variably isolated in all three campaigns, and type 1 Echovirus isolated in the second and third campaigns. All detected polioviruses were of the vaccine-type and were identified as types 1 and 3. Both viral genotypes of Norovirus were identified. Adenoviruses were only sporadically isolated and rotaviruses were identified as type A. As expected, results show a greater prevalence of Enteroviruses and this reflects viral circulation in the population. Regarding the efficacy of the different treatment stages, primary treatment was found to remove only small percentages of viruses, while activated sludge e subsequent sedimentation were found to be more effective.

Enteric viruses in molluscan shellfish.

One hundred and thirty-seven bivalves were collected for environmental monitoring and the market; all the samples were analysed by RT-PCR test. Bacteriological counts meeting the European Union shellfish criteria were reached by 69.5% of all the samples, whereas the overall positive values for enteric virus presence were: 25.5%, 18.2%, 8.0% and 2.1% for Rotavirus, Astrovirus, Enteroviruses, Norovirus, respectively. Mussels appear to be the most contaminated bivalves, with 64.8% of positive samples, 55.7% and 22.7% respectively for clams and oysters, whereas in the bivalves collected for human consumption 50.7% were enteric virus positive, as compared to 56.4% of the samples collected for growing-area classification. The overall positive sample was 54.0%.

Influence of enteric viruses on gastroenteritis in Albania: epidemiological and molecular analysis.

Gastroenteritis is one of the most important diseases in developing country and viral infections are well documented. To understand better the epidemiological aspect of gastroenteritis in Albania and especially viral gastroenteritis, one-year study was carried out with the cooperation of physicians working in the Paediatric Hospital in University Hospital Center "Mother Thereza" in Tirana. Three hundred thirteen stool samples were collected from children with diarrhoea and a questionnaire was filled by the health personnel for each child. Analysis of the questionnaires revealed that overcrowding families and the limited availability of drinking water at home were risk factors for gastroenteritis. All the tests for enteroviruses were carried out using the molecular methods. One hundred and forty-seven out of three hundred thirteen stool samples showed a specific amplification band for one of the enteric viruses: astrovirus, adenovirus, rotavirus, and norovirus with an overall positive specimen rate of 46.9%. Rotavirus was the most frequent virus identified in 105 out of 147 samples (71.4%), astrovirus in 5 (3.4%), norovirus in 19 (12.9%), and enteric adenovirus in 18 (12.3%) samples. Double infection was present only in 14 samples (9.5%). The data suggest an evident circulation of viruses involved in gastroenteritis with a higher prevalence of rotavirus.

Identification and sequence analysis of hepatitis A virus detected in market and environmental bivalve molluscs.

In Italy in 1998, hepatitis A virus (HAV) was responsible for an infectious disease transmitted by contaminated bivalve molluscs. To determine the presence of HAV in the bivalves collected during a 1-year follow-up study, hepatitis A RNA was extracted and amplified by a nested reverse transcriptase-PCR method overlapping the VP1/2A region. The HAV genome was detected in 24 (14.1%) of 170 samples: 19 clams (Tapes decussates and Tapes semidecussatus), 1 oyster (Crossostea gigas), and 4 mussels (Mytillus galloprovincialis). Eleven positive samples were collected from marketing areas, and 13 positive samples were collected from growing areas. Seventeen of the 24 positive samples had been taken from domestic products, and 7 had been imported. Sequence analysis showed the presence of genotypes IA and IB. Our results suggest significant presence of HAV in bivalves from both marketing (public consumption) and environmental (growing) areas.

Nucleotide correlation between HAV isolates from human patients and environmental samples.

Hepatitis A disease is endemic in Albania even though records from the Medical Authority show outbreaks involving only limited numbers of people. In the city of Lac, 200 people became ill following an outbreak of hepatitis A started on November 2002. The age distribution of the cases shows a peak in the age group 5-9 (43.5%) followed by the age group 10-14 (28%) and the age group 1-4 (18%). No cases were recorded in the age group 0-1. Drinking water and sewage samples were collected, using electropositive cartridges, during the outbreak. Rotavirus was identified by RT-PCR in two out of five drinking water samples; however, all the samples tested negative for HAV and astrovirus. Rotavirus was also identified in three out of five sewage samples from which four were HAV positive. HAV-RNA was identified in 28 (62.2%) out of 45 IgM anti-HAV positive sera collected during the outbreak. Genotype IA was expressed from all the amplified samples. Sequence analysis of the overlapping VP1-2A region shows 97-99% homology with three Italian strains IT-SCH-00, IT-ZAM-01, and IT-CAP-00 and one Spanish strain (Sa 30/06/95), whereas the phylogenetic tree built from the 168 bp sequence of the VP1-2A shows four clusters, one including 24 out of 28 RT-PCR positive sera. Considering the deduced amino acid sequence, only one substitution was identified and reported previously for genotype IB.

Hepatitis in Albanian children: molecular analysis of hepatitis A virus isolates.

Hepatitis A is a common disease in developing countries and Albania has a high prevalence of this disease associated to young age. In spite of the occurrence of a unique serotype there are different genotypes classified from I to VII. Genotype characterisation of HAV isolates circulating in Albania has been undertaken, as well as the study of the occurrence of antigenic variants in the proteins VP3 and VP1. To evaluate the genetic variability of the Albanian hepatitis A virus (HAV) isolates, samples were collected from 12 different cities, and the VP1/2A junction amplified and sequenced. These sequences were aligned and a phylogenetic analysis performed. Additionally, the amino half sequence of the protein VP3 and the complete sequence of the VP1 was determined. Anti-HAV IgM were present in 66.2% of all the sera. Fifty HAV isolates were amplified and the analysis revealed that all the isolates were sub-genotype IA with only limited mutations. When the deduced amino acid sequences were obtained, the alignment showed only two amino acids substitutions at positions 22 and 34 of the 2A protein. A higher genomic stability of the VP1/2A region, in contrast with what occurs in other parts of the world could be observed, indicating high endemicity of HAV in Albania. In addition, two potential antigenic variants were detected. The first at position 46 of VP3 in seven isolates and the second at position 23 of VP1 in six isolates.