Occurrence and Genetic Diversity of Human Cosavirus in Sewage in Italy

Human Cosavirus (HCoSV) is a newly discovered virus whose role in human enteric diseases is still unknown. In Italy, the prevalence and genetic diversity of HCoSV are unexplored. One hundred forty-one raw sewage samples collected throughout Italy were screened for HCoSV by RT-nested PCR. HCoSV was detected in 25.5% of samples. Species A, C, and D, and a potentially new species were detected. Our results show a significant circulation and heterogeneity of HCoSV in Italy.

Frequent Detection and Genetic Diversity of Human Bocavirus in Urban Sewage Samples

The prevalence and genetic diversity of human bocaviruses (HBoVs) in sewage water samples are largely unknown. In this study, 134 raw sewage samples from 25 wastewater treatment plants (WTPs) in Italy were analyzed by nested PCR and sequencing using species-specific primer pairs and broad-range primer pairs targeting the capsid proteins VP1/VP2. A large number of samples (106, 79.1 %) were positive for HBoV. Out of these, 49 were classified as HBoV species 2, and 27 as species 3. For the remaining 30 samples, sequencing results showed mixed electropherograms. By cloning PCR amplicons and sequencing, we confirmed the copresence of species 2 and 3 in 29 samples and species 2 and 4 in only one sample. A real-time PCR assay was also performed, using a newly designed TaqMan assay, for quantification of HBoVs in sewage water samples. Viral load quantification ranged from 5.51E+03 to 1.84E+05 GC/L (mean value 4.70E+04 GC/L) for bocavirus 2 and from 1.89E+03 to 1.02E+05 GC/L (mean value 2.27E+04 GC/L) for bocavirus 3. The wide distribution of HBoV in sewages suggests that this virus is common in the population, and the most prevalent are the species 2 and 3. HBoV-4 was also found, representing the first detection of this species in Italy. Although there is no indication of waterborne transmission for HBoV, the significant presence in sewage waters suggests that HBoV may spread to other water environments, and therefore, a potential role of water in the HBoV transmission should not be neglected.

First outbreak of norovirus in Albania

AIMS

Noroviruses (NoVs) represent the most important enteric viruses responsible for acute gastroenteritis world-wide. This study objective is to characterize the first outbreak of NoV that occurred in Ballsh, a small city in Albania.

METHODS AND RESULTS

Stool specimens were collected from people attending to the hospital. Samples were also collected from the aqueduct for bacteriological and virological tests. Overall 33 stools and five drinking water samples were collected, respectively, from the hospital in Ballsh and from the municipal aqueduct. No water samples were scored positive whereas ten stool samples (30.3%) were scored GGII NoV positive. All the GGII isolates were identified as GGII·4 genotype, and no GGI was identified. The alignment and protein analysis were performed using, respectively, ClustalV and the mega 4 software.

CONCLUSIONS

This is the first report of NoV GGII·4 in Albania causing an outbreak. The genetic analysis showed several point mutations and amino acid substitutions with respect to the international strains.

SIGNIFICANCE AND IMPACT OF STUDY

Over the last decades, Albania has suffered from different outbreaks as cholera, poliomyelitis, hepatitis A and now, for the first time, it has been documented an outbreak of NoV.

Statistical correlation between enterovirus genome copy numbers and infectious viral particles in wastewater samples

AIMS

Classic virological tests are time consuming and labour-intensive; real-time RT-PCR has proven to be a fast method to detect and quantify enterovirus genomes in clinical and environmental samples. This method is unable to discriminate between infective and noninfective enterovirus particles; few clinical studies have compared real-time RT-PCR and viral culture. We wondered if the enterovirus genome quantification could be correlated to the infectivity.

METHODS AND RESULTS

We used the statistical approach to verify our hypotheses to correlate data, obtained by the standard method (most probable number of cytopathic units-MPNCU) and molecular test (real-time RT-PCR), on wastewater treatment plant samples. Chi-squared test was used, considering several cut-off values ('50'-'100'-'200' genome copy numbers), to determine statistical significance in comparison of the two methods. Chi-square value was not significant when cut-off of 50 (P = 0.103) and 100 (P = 0.178) was assumed but was significant with cut-off of 200 (P = 0.044).

CONCLUSION

This limit, 200 genome copy, could be used as cut-off value to indicate enterovirus survival in environmental monitoring.

SIGNIFICANT AND IMPACT OF THE STUDY

To introduce a fast procedure that is able to compensate for disadvantages of cell culture method for viral environmental analyses.

Presence and environmental circulation of enteric viruses in three different wastewater treatment plants

AIMS

The aim of the work was to evaluate the circulation of the viruses and to determine a correlation between faecal indicators and viruses.

METHODS AND RESULTS

Raw wastewater and effluent samples were collected from three wastewater treatment plants, during three sampling periods, and analysed, using cultural and molecular methods, to determine bacteria and virus presence. The results show a removal of bacterial indicators, but a limited reduction of the phages. The viral analysis displays the circulation of cultivable enteroviruses and differences in the seasonal-geographical distribution. Hepatitis A virus was found with only two genotypes: IA-IB. Rotavirus was present in 11.11%, 24.14%, 2.78% of the samples in the 1st, 2nd and 3rd sampling periods; Astrovirus in 33.33%, 6.9%, 25%; Adenovirus in 7.41%, 3.45%, 2.78%; Norovirus in 7.41%, 10.34%, 5.56% respectively. Adenovirus was never identified in plants B and C as Rotavirus in plant C.

CONCLUSIONS

The presence of faecal indicators was not predictive of the enteric virus presence, whereas a different circulation of Enteroviruses was found in the wastewater treatment plants.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study shows the importance and the usefulness of molecular methods to evaluate the virus circulation and the genetic variability of Enteroviruses.

Prevalence and genotyping of human isolates of Giardia duodenalis from Albania

Microscopical and PCR-based techniques were performed in order to investigate the prevalence of infection and the genotypes of Giardia duodenalis from 125 stool samples collected from children living in the urban and the rural areas of Tirana (Albania) and hospitalized with acute gastroenteritis. 7 out of 125 samples resulted positive for Giardia at the microscopic examination (5.6%). In 50 selected samples including the 7 samples positive for Giardia by microscopy, 3 and 15 additional positive samples were detected by immunofluorescence and PCR, respectively. Seasonality appeared as an important parameter to be evaluated in order to better understand the prevalence of infection. Sequence analysis revealed both human Assemblage A and B. This result represents the first data on G. duodenalis genotypes in Albania.

Use of armored RNA as a standard to construct a calibration curve for real-time RT-PCR

Armored Enterovirus RNA was used to standardize a real-time reverse transcription (RT)-PCR for environmental testing. Armored technology is a system to produce a robust and stable RNA standard, trapped into phage proteins, to be used as internal control. The Armored Enterovirus RNA protected sequence includes 263 bp of highly conserved sequences in 5' UTR region. During these tests, Armored RNA has been used to produce a calibration curve, comparing three different fluorogenic chemistry: TaqMan system, Syber Green I and Lux-primers. The effective evaluation of three amplifying commercial reagent kits, in use to carry out real-time RT-PCR, and several extraction procedures of protected viral RNA have been carried out. The highest Armored RNA recovery was obtained by heat treatment while chemical extraction may decrease the quantity of RNA. The best sensitivity and specificity was obtained using the Syber Green I technique since it is a reproducible test, easy to use and the cheapest one. TaqMan and Lux-primer assays provide good RT-PCR efficiency in relationship to the several extraction methods used, since labelled probe or primer request in these chemistry strategies, increases the cost of testing.

A large infantile gastroenteritis outbreak in Albania caused by multiple emerging rotavirus genotypes

By the end of December 2000, the epidemiological system 'Alert' of the Public Health Institute in Tirane reported an outbreak of acute gastroenteritis. The outbreak involved children in Tirane and in the rural area. In total, 2722 children were seen in Tirane Hospital and 982 (56.4%) were treated for acute gastroenteritis. The age group with the highest morbidity was 0-5 years (89.7%), followed by the 6-9 (6.2%) and 10-15 years age groups (4.1%). The distribution of acute gastroenteritis cases, which occurred along the same water distribution system, suggests a waterborne origin. The nucleic acid amplification confirmed the co-circulation of different genotypes of rotavirus, mainly P[8]G9 and P[8]G3, responsible for the outbreak. Other enteric viruses such as astrovirus serotype 1, adenovirus and Norovirus, genogroups I and II were detected. Co-infections with different rotavirus genotypes and even with different enteric viruses were detected in several samples.

[Hygienic aspects of the Tiber river: presence of pathogenic protozoa and correlation with microbiological and physico-chemical parameters]

An investigation on the hygienic quality of the Tiber river was conducted with the aim both to enumerate Giardia cysts and Cryptosporidium oocysts in the water and to determine possible correlations between them and bacterial indicators, pathogens and physico-chemical parameters. A low hygienic water quality was evidenced, with high counts of microorganisms. Furthermore, variable concentrations of Giardia and Cryptosporidium were observed. No correlation was found between the protozoa concentrations and that of the other microorganisms, whilst a significant correlation with redox potential and Giardia cysts was calculated.

[Enteric viruses and bacteriological parameters in molluscs]

Eighty-seven samples of shellfish were collected considering: type of mollusc, origin, growing area, monitoring or for human purpose. The bacteriological parameters were: Fecal Coliforms, Escherichia coli, and Salmonella; whereas the virological parameters included: Hepatitis A and E virus, Rotavirus, Astrovirus and Enterovirus. In total, 63.2% of samples had normal bacteria values, only one sample was Salmonella positive. The percentage of positive samples for Hepatitis A virus was 5.7%, Rotavirus 29.9%, Astrovirus 27.6%, Enterovirus 10.3%. The recovery of hepatitis E virus was always negative, whereas 13 samples (14.9%) were positive for two viruses.

Waterborne gastroenteritis outbreak in Albania

Three different studies are reported concerning the environmental pollution caused by viruses in Albania. The first study describes an outbreak of gastroenteritis in the capital city, involving 2,722 children attending the Paediatric Unit of Tirana Hospital. The age group with the highest morbidity was 0-5 years, with 89.5%; no fatalities were recorded during the outbreak. Rotavirus was detected in 26/28 faecal samples by RT-PCR, although astrovirus, adenovirus and calicivirus were also present. The second study describes an outbreak of hepatitis A virus involving the city of Lac. Two hundred cases were recorded, with the highest incidence in the age-group 5-9 years. Phylogenetic analysis of the VP1/2A region showed the presence of a unique sequence: genotype IA. Rotavirus was identified in drinking-water samples collected during the outbreak. The third study describes the prevalence of HAV and HEV in 202 sera randomly collected from 12 different cities in Albania. HAV showed a high incidence (66.2%), whereas none was positive for HEV. The genomic analysis of the VP1/2A junction revealed the presence of only one genotype (IA) with few point mutations and just two amino acid substitutions at codons 22 and 34. Additionally, two potential antigenic variants were detected, the first at position 46 of VP3 and the second at position 23 of VP1.

[Health-related behaviour and HCV prevalence among elderly and younger adults in an isolated community close to Rome (Italy)]

The aim of this study has been to investigate the differences in the health-related behaviour by means of a questionnaire in a sample of elderly (>54 years, 1st generation) and younger adults (<54 years, 2nd generation, all of them sons/daughters of HCV positive subjects), given the high difference in HCV positive prevalence among the two groups (19.4% vs. 2.1%). Most (53.4% vs. 0.0%) of the 1st generation subjects used glass syringes while all the 2nd generation subjects used disposable syringes. Among the elderly, the frequency of hospitalisation (70% vs. 50%), transfusions (11.8% vs. 2.9%) and dental therapy by false dentists (52% vs. 0%) were higher. These results show that the use of non recyclable syringes is the main responsible for the drastic reduction of HCV circulation in the present community, and the consequent decrease in the risk for infection in younger subjects. Moreover, dental therapy was not related to an increased risk for infection, providing that the treatment has been made by a "true" dentist. Finally, the intrafamiliar transmission was not supported by the present data.

[Virus transmission in drinking water]

Several epidemiological data confirm the presence of enteric viruses in drinking water. The present paper deals with several problems tied to the virological analysis, such as the concentration of the samples, the isolation and the identification of enteric viruses.

Fate of bacterial indicators, viruses and protozoan parasites in a wastewater multi-component treatment system

The extent of reduction in selected microrganisms was tested at a multi-component wastewater treatment plant that treats sewage for a potential re-use in agriculture. The aim of the investigation was to evaluate possible reciprocal correlation among the different microrganisms and to compare the removal of two encysted pathogenic protozoa with that of microbial indicators, Clostridium perfringens spores, enteroviruses and bacteriophages. Samples collected included the raw wastewater, the chlorinated effluent and the effluent after an ultraviolet light treatment. All of the raw sewage samples were positive for Cryptosporidium oocysts and Giardia cysts, as well as for the other microorganisms tested but the bacteriophage B40-8. The data obtained confirm the removal efficiency of the entire process for indicator bacteria but also show the low and variable removal efficiency for the other microbial parameters, such as Giardia and Cryptosporidium, enteroviruses and Clostridium perfringens spores. Reciprocal correlation between Cryptosporidium and Giardia (oo)cysts and the other microbial groups was not demonstrated. The results confirm the resistance of Clostridium perfringens spores, enteroviruses and protozoa to chlorination and demonstrate the relative persistence of these organisms in the effluents even during the ultraviolet light treatment. The yields also emphasise the influence of the analytical method for the determination of protozoan parasites.

Tirane, Albania: survey on drinking water quality and facilities

To develop a realistic model of the situation, a study was carried out in four different socioeconomic and hygienic areas of Tirane, namely in the modern and historical centre as well as in the intermediate and peripheral areas. In each area interviewers from the city's Public Health Directorate, contacted randomly, door-to-door, the residents, submitting a questionnaire and collecting water samples at the same time. Our data show relevant differences regarding distribution and quality of drinking water between the centre and peripheral areas. One third of water samples revealed the presence of microorganisms, whereas one fifth had no residual chlorine. Altogether more than 200,000 people in the peripheral areas of Tirane live under low level hygienic conditions. The recent outbreaks of cholera, poliomyelitis and the hyperendemic hepatitis A disease are the dramatic results of the low quality drinking water.

Determination of enteroviruses, hepatitis A virus, bacteriophages and Escherichia coli in Adriatic Sea mussels

The aim of the present study was to evaluate the incidence of enteric viruses in mussels and to verify the possibility of using phages as indirect indicators of mussel viral contamination. Mussels (36 samples) collected from three different areas of the Adriatic Sea were analysed to determine the following parameters: Escherichia coli, somatic coliphage (T6 phage), F-Plus (MS2 phage), B40-8 (phage of Bacteroides fragilis), enteroviruses and hepatitis A virus. Most of the results of the bacteriological analysis (most probable number (MPN) ml-1) were in accordance with the bacteriological limits established by European law, with the exception of seven samples. The bacteriophage analyses were always negative for F-Plus and B40-8, with the exception of a few samples, whereas the somatic coliphages were generally between 0 and 20 MPN g-1, with the exception of two samples (110 MPN g-1). The virological analysis showed five samples positive for the presence of enteroviruses and 13 for the presence of hepatitis A virus (in three samples both viruses were present). Most of these samples presented acceptable bacteriological parameters and the bacteriophages were absent or their value was generally very low. The results show that the detection of E. coli and phages does not seem to be a good indicator of viral contamination.

Concomitant poliovirus infection during an outbreak of hepatitis A

AIM OF THE STUDY

The present study was designed to evaluate the possible co-infection, with other enteric viruses, during an outbreak of hepatitis A (HA).

MATERIAL AND METHODS

Forty-two stool samples and sera were collected during an outbreak of hepatitis A. Sera were analysed by the Abbott test for IgG-IgM anti-HAV antibodies. Stool samples were used to identify the presence of enteric viruses. HAV genome was identified by a RT-PCR test, other enteric viruses were identified, after cell passage and seroneutralization test on BGM cells, by RT-PCR and RFLP assay.

RESULTS

The samples were obtained from 27 employees of an industrial plant, nine household contacts and six non-employee controls. The attack rate was 12.5%, whereas the overall prevalence was 63%. In the employee group, 12 out of 27 stool samples were positive for the presence of HAV by reverse transcriptase polymerase chair reaction (RT-PCR). All the other samples (30) were negative. Five samples from employees, three from household contacts and one from non-employees were also found positive for enteroviruses. These viruses were classified by seroneutralization as poliovirus and RFLP assay as Sabin poliovirus type 1. Four samples were positive both for HAV and poliovirus.

CONCLUSIONS

This study confirms co-infection with different enteric viruses may occur and also emphasizes the wide circulation of HAV and the existence of silent infection with poliovirus.