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.

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.

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.

PIP: The bacteriological virological parameters were evaluated on seawater samples taken at different points on the coast of Alexandria, Egypt. Samples were collected at 6 different points: Kayet Bay, El Shatby, Camp Cesar, Sporting, Beir Massoud, and El Max. A total of 24 samples were analyzed by estimation of the following parameters: Escherichia coli, total coliform and fecal streptococci, Yersinia, Shigella, Salmonella, bacteriophages, and enteric viruses. The virological analysis included the isolation and identification of cytopathogenic enteroviruses and three phages: somatic coliphage, F-specific, and B 40-8. The bacteriophage analysis was performed by the plaque assay method using the double-layer method, whereas the membrane filtration method was used to estimate bacterial populations in the samples. During the summer period no E. coli could be isolated from any point during the study, whereas in autumn E. coli were identified in all the points except for Sporting. E. coli was identified in 65% of the qualitative analyses. The limit was exceeded in 12 samples out of 24; for fecal streptococci, in 15 samples out of 24. The ratio over 4.4 relating to fecal coli and fecal streptococci indicated human fecal pollution. The El Max sample was positive for the presence of Salmonella; neither Shigella nor Yersinia were isolated from any of the analyzed points. In the El Max sample (autumn period), total coliform and fecal streptococci exceeded the European Community (EC) limit, whereas the ratio was 10, confirming human fecal pollution. 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, which was constantly high. Three samples were positive for the presence of enteric viruses: El Shatby, Beir Massoud, and Sporting. The enteric viruses were confirmed by a secondary passage on cell culture. The analysis of phages showed variable pollution values.