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.

Reduction of microorganisms in sewage effluent using hypochlorite and peracetic acid as disinfectants

A comparative study on peracetic acid and sodium hypochlorite in inactivating bacteria and viruses was carried out. Therefore the disinfection actions of peracetic acid, in comparison with sodium hypochlorite, was evaluated against the usual indicators of faecal contamination, the pathogen Salmonella, Pseudomonas spp., bacteriophages anti-Escherichia coli, F+/phage and the phage of Bactericides fragilis B40-8 and enteroviruses. Under the experimental conditions, no representative results were obtained for enteroviruses and phages because of their low concentration in the sewage effluent. On the other hand, the indicator organisms were reduced substantially by the sodium hypochlorite and peracetic acid concentrations, while more variable results were obtained against Pseudomonas and bacteriophages anti-Escherichia coli.

Genomic characterization of human and environmental polioviruses isolated in Albania

Between April and December 1996, a serious outbreak of poliomyelitis occurred in Albania; almost 140 subjects were involved, and the episode presented an unusually high mortality rate (12%). During the outbreak, water samples from the Lana River in Tirana, Albania, and stool samples from two cases of paralytic poliomyelitis were collected and analyzed for the presence of polioviruses. Six polioviruses were isolated from the environmental and human samples, according to standard methods. All the samples were characterized by partial genomic sequencing of 330 bases across the 5' untranslated region (5'-UTR) (nucleotide positions 200 to 530) and of 300 bases across the VP1 region (nucleotide positions 2474 to 2774). Comparison of these sequences with those present in data banks permitted the identification of environmental isolates Lana A and Lana B as, respectively, a Sabin-like type 2 poliovirus and an intertypic recombinant poliovirus (Sabin-like type 2/wild type 1), both bearing a G instead of an A at nucleotide position 481. The two other environmental polioviruses were similar to the isolates from the paralytic cases. They were characterized by a peculiar 5'-UTR and by a VP1 region showing 98% homology with the Albanian epidemic type 1 isolates reported by other authors. This study confirms the environmental circulation in Albania of recombinant poliovirus strains, likely sustained by a massive vaccination effort and by the presence in the environment of a type 1 poliovirus, as isolated from the Lana River in Tirana about 2 months before the first case of symptomatic acute flaccid paralysis was reported in this town.

HAV and HEV infection in hospitalised hepatitis patients in Alexandria, Egypt

A total of 202 serum and stool samples from acute hepatitis patients attending the Fever Hospital of Alexandria, Egypt, have been studied to reveal markers of hepatitis virus infection. Anti-HAV IgM were detected in 21 out of 202 sera (10.4%), whereas 201 sera (99.5%) had anti-HAV IgG. The first age attack was in the class-age 0-9 years with 64.7% of anti-HAV IgM positive sera. Among 202 patients, anti-hepatitis E IgG (sample/over cut off > 1.0) was identified in 90 patients (44.5%). The anti-HEV seropositivity ranged from 17.6% to 60.0% in the different age groups, with the highest level in the class-age 20 29 years. Anti-hepatitis E IgM were identified in 49 patients with the first age attack in the class-age 10-19 years (39.4%). HAV RNA was identified by nested PCR in 7 samples out of 15, whereas HEV RNA was present in 4 out of 75 stool samples. Direct DNA sequence of the latter PCR products confirmed the presence of the HEV genome; comparison of the sequences of the isolates from Egypt with those in data banks revealed the highest homology to the Burma strain. Our data confirm that HAV and HEV are common causes of acute sporadic hepatitis in Alexandria but with different peak age positivity. Occasionally, but not infrequently, dual infections (HAV-HEV and HEV-enteric viruses) were also found. The risk analysis indicates that patients living in rural areas are exposed to a higher risk of hepatitis E infection compared to the urban population, whereas the presence of anti-HEV IgG was significantly associated with consumption of common village water and use of indoor dry pit and oral therapy for schistosomiasis.

Evidence of hepatitis E virus replication on cell cultures

Several human and animal cell lines have been used to grow hepatitis E virus. The strain SAR-55 was adapted only on PLF/PLC/5 cell line without any visible cytopathic effect. The growth of the SAR-55 was monitored by examining the positive and the negative strands of HEV-RNA. Stool samples, obtained from hospitalised acute hepatitis patients at the Fever Hospital of Alexandria (Egypt), were used to confirm the susceptibility of PLF/PLC/5 cells. After more than one-week's cultivation, three stool samples out of 17 IgM anti-HEV positive and 1 from 52 IgG anti-HEV positive patients showed a specific RT-PCR amplification product. The nucleotide sequences of the methyltransferase region of the genome in the isolates revealed the maximum homology with Burma strain with several point mutations.

Serum antibodies to polioviruses in Alexandria, Egypt

Random sera, in a total of 192, were collected in the Fever Hospital of Alexandria, Egypt, and analysed for the presence of antibodies against polioviruses. The results show good antibody levels, only three sera (1.5%) were negative for poliovirus type 1, 5 (2.6%) for poliovirus type 2 and 10 (5.2%) for poliovirus type 3; one subject was completely negative.

Hepatitis A virus detection in wastewater by PCR and hybridization

Hepatitis A virus is a member of the Picornaviridae family and is a principal agent of acute hepatitis worldwide, causing from mild to severe illness. Although the incidence of hepatitis A is in decline, the risk of this disease is still high in the Mediterranean area. Detection of hepatitis A in the environment is difficult because this virus needs a prolonged incubation in cell culture, therefore we used an antigen capture PCR (AC-PCR) followed by a hybridization on membrane to identify HAV in wastewater samples. The raw sewage, concentrated by ultrafiltration, showed 8 positive samples out of 10 (80%), while after the oxidation step of the sewage, 2 out of 10 (20%) and 3 out of 10 (30%) were found positive respectively after concentration by electronegative (HAWP Millipore) and electropositive (1MDS Cuno-Div.) membranes. In the final effluent the positivity was 1 out of 10 (10%) for the electronegative membranes and 3 out of 10 (30%) for the electropositive membranes. Our results indicate: i) the possibility of HAV to cross the wastewater treatment plant and contaminate water and food (such as mussels); ii) PCR-hybridization as a rapid method for HAV identification in the environment.

Microbiological quality of coastal sea water of Alexandria, Egypt

The aim of the present study was to evaluate the quality of the seawater in Alexandria, Egypt. Samples were collected in 6 different points: Kayet Bay, El Shatby, Camp Cesar, Sporting, Beir Massoud and El Max. In total, 24 samples were analyzed. For each point the analysis included estimation of the following parameters: Esherichia coli, total coliform and fecal streptococci, Yersinia, Shigella, Salmonella, bacteriophages and enteric viruses. Just one sample (El Max) was positive for the presence of Salmonella, neither Shigella or Yersinia were isolated from any of the analyzed points. E. coli was identified in 10 samples while the ratio between total coliform and fecal streptococci showed variable results with the exception of El Max that resulted constantly high. Three samples were positive for the presence of enteric viruses: El Shatby, Beir Massoud and Sporting. The analysis of phages showed a variable pollution values.

Seroprevalence of HIV and HCV infections in Alexandria, Egypt

During the years 1992-1994, we tested 948 individuals from different population groups for HIV-1 and HIV-2 infections by ELISA and WB and for HCV infection by ELISA. Repeated ELISA reactivity for HIV was found in 2.12% of blood donors, 2.95% of fire brigade personnel and 1.61% of prisoners. Western blotting studies, however, showed that these samples were non-reactive or indeterminate to either HIV-1 or HIV-2. In contrast, anti-HCV antibodies were detected in 39% of fire brigade personnel, 31.4% of prisoners and 20.8% of blood donors. The analysis of risk factors for acquiring HCV infection showed a strong association between a past history of parenteral therapy for schistosomiasis and anti-HCV seropositivity (p < 0.0001). The implementation of preventive strategies is at the moment the mandatory choice to stop a further spread of the HCV infection. Meanwhile the same preventive measures could avoid spreading of the HIV disease.

"In vitro" and in animal model studies on a double virus-inactivated factor VIII concentrate

To improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100 degrees C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (S/D) method during the manufacturing process. The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

Complete nucleotide sequence of a cytopathic hepatitis A virus strain isolated in Italy

The molecular basis of the cytopathic effect induced in cell culture by some hepatitis A virus (HAV) strains and variants has not been determined. In order to assess the molecular mechanism(s) underlying this particular phenotype the genome of an Italian cytopathic isolate (strain FG) was sequenced from cDNAs obtained by RT-PCR. Sequence analysis revealed the presence of mutations common to either adapted or cytopathic variants of HAV. In particular, amino acid deletions in proteins VP1 and 3A were detected. Expression of protein 3A in E. coli showed that the N-terminal deletion renders this protein toxic to bacteria.

Mutations in the 3A genomic region of two cytopathic strains of hepatitis A virus isolated in Italy

Two strains of hepatitis A virus (HAV) were isolated in cell culture and found to induce a cytopathic effect at early passages. The nucleotide sequences of the 5' non-translated region (5'NTR) and of genes 2B, 2C, 3A and 3B were determined for these strains and found to contain mutations similar to those detected in cell-culture adapted variants of HAV strain HM175. In addition, gene 3A shows a deletion of three aspartic acid residues near the N-terminus of the polypeptide. In combination with variations in the 5'NTR and in genes 2B and 2C, the absence of an aspartic acid residue in position 4 of gene 3A of three cytopathic clones of HM175 suggests a possible role of the 3A protein in determining the cytopathic phenotype.

Detection of hepatitis A virus in concentrated river water by polymerase chain reaction

Sensitive and specific techniques are needed to detect Hepatitis A virus in environmental samples. PCR was used on concentrated river samples. In the analysis of 13 samples, two were positive by Elisa (15.3%), three were positive on cell culture (23%), five were positive by hybridization (38.4%) and height with PCR (67%).

Hepatitis A virus identification in an outbreak by enzymatic amplification

From April 28th to May 22nd, 1987, the Medical Authority identified 13 cases (6 symptomatic cases) of hepatitis A (HA) in a school and in a college of Rome. The principal risk factor was determined to be "full-time presence at the State school and boarders at the college". The distribution of HA cases suggested a person to person contact; anti-hepatitis A virus IgM were identified in 12 out of 13 cases with high levels of transaminases. During the disease epidemic, water samples were taken from the well of the college for bacteriological and virological analyses. The water was classified as undrinkable due to the presence of 16 total coliforms/100 ml and 35 total bacteria count at 36 degrees C. Fecal coliforms, fecal streptococci and sulfite reducing clostridia were absent. Two water samples of 100 liters were collected and concentrated by adsorption-elution method on electropositive membranes or by ultrafiltration using a Millipore apparatus. Infectious Hepatitis A virus was only isolated from samples concentrated by adsorption-elution method on electropositive membranes using tissue culture methods and subsequently HA virus was identified by other traditional methods (Elisa and immunofluorescence). In contrast, PCR test performed on the concentrated samples, was positive only for the ultraconcentrated sample. The positivity of the PCR test confirmed the presence of the Hepatitis A virus in the well water.

Methisoprinol-effect on the replication cycle of human hepatitis A virus

The antiviral activity of methisoprinol was investigated under different conditions using a strain of hepatitis A virus (HAV), that shows a strong cytopathic effect on the Frp/3 cell line 7-9 days post-infection. Treatment of Frp/3 at a dose range of 125-1200 micrograms/ml had no toxic effect and showed a dose dependent inhibition of the HAV replication cycle. At the methisoprinol dose of 500 micrograms/ml the cytopathic effect was completely abolished and HAV antigen production reduced by 50% as measured by indirect immunofluorescence (IIF) and commercial enzyme-linked assay (ELISA). The virus yield was virtually abolished at the highest dose employed (1000 micrograms/ml).

Influence of polyions on the early steps of enterovirus infection

The influence of electric charged molecules on the early phases of enterovirus infection was studied in order to select antiviral compounds able to prevent viral attachment. The effect of different polyelectrolytes on the multiplication of coxsackie virus B3, echovirus 6 and hepatitis A virus was investigated in susceptible cells by adding the drug before, during or after the viral adsorption period. Among polyanions, the polysaccharides heparin and dextran sulfate inhibited viral infectivity, dextran sulfate being the most effective mainly towards hepatitis A virus infection. DEAE-dextran and protamine sulfate, generally recognized as enhancers of infectivity of naked and enveloped viruses, exhibited an inhibitory effect towards the three picornaviruses tested. Only in the case of hepatitis A did DEAE-dextran slightly improve viral antigen synthesis. The inhibitory effect shown by compounds belonging to positive and negative polyions suggests that the electric charge is not sufficient by itself to explain the antiviral activity of these drugs.

An outbreak of hepatitis A in young adults in central Italy

Between September, 1988 and January, 1989 a common source outbreak of 47 cases of serologically confirmed hepatitis A occurred in a town of central Italy. Thirty-eight cases were primary, three co-primary and six secondary. The highest age-specific attack rate was seen in subjects aged 15-24 years (120 per 100,000); the mean age of cases was 24.6 years and the median age was 22 years. A matched triplet case-control study showed significant association between the disease and consumption of either raw mussels (41% of cases, compared with 10% of controls; P less than 0.0001) or a single brand of mineral water (63% of cases, compared with 41% of controls; P less than 0.05). The mean age of the cases reflects the shift in primary susceptibility to the infection from younger to older age groups, a finding which has recently been demonstrated by several seroepidemiological surveys in Italy.

Susceptibility of mammalian, avian, fish, and mosquito cell lines to rabies virus infection

The relationship between plasma membrane receptor organization and cell susceptibility in vitro was investigated in mammalian, avian, fish, and arthropod cell lines infected with fixed rabies virus. IMR32, HeLa, CER, and EPC cells were widely susceptible to infection with CVS virus, whereas a lower level of specific viral antigens was detectable in A. albopictus cells. In spite of these differences, the amount of infectious virus particles bound to the various cell surfaces was similar. Competition experiments carried out with plasma membranes extracted from ability of these components to bind the virus and to prevent infection. The different cellular permissiveness to rabies infection described here did not correlate with significant differences in number or in chemical structure of the receptor binding sites, but more likely with events following virus adsorption.

Characterization by T1-oligonucleotide fingerprinting of three strains of human hepatitis A virus isolated in Italy

Three human hepatitis A virus strains, all of them isolated in Italy but one acquired abroad, were analyzed by T1-RNAase oligonucleotide mapping and by monoclonal antibody neutralization. The variation among their genomes according to T1-maps was calculated to be about 9%, thus confirming the poor genomic variation assessed by nucleotide sequencing (1-10%). However T1-maps of these Italian isolates were different from those reported in the literature (Weitz and Siegl, 1985). Neutralization by monoclonal antibody caused a reduction in titres of 2-25 log10. This genomic stability, if confirmed, is important with a view to a valuable vaccine.

Effect of inhibitors of cytoplasmic structures and functions on rabies virus infection in vitro

The effect in vitro of some cytoplasmic structure and function inhibitors on the different stages of rabies virus infection was investigated. Treatment of fibroblasts (CER) and human neuroblastoma cells (IMR-32) with substances acting on low pH intracellular compartments (methylamine and monensin) prevented rabies virus genome delivery in the cytosol. An early inhibition of viral infection was also obtained in the presence of B and D cytochalasins and trifluoperazine which interact with microfilament structures. Treatment with colchicine and vinblastine did not affect rabies multiplication, suggesting that microtubules are not involved in this process. However, the multiplication of prebound virions did not take place in the presence of inhibitors of oxidative phosphorylation (sodium azide and CCCP) and of glycolysis (2-deoxy-D-glucose) indicating that rabies virus replication is largely energy-dependent in both host cells examined.