Virological investigation on aerosol from waste depuration plants

Aerosol from activated mud decontamination plants used for the treatment of urban sewage can represent a vehicle for bacteria, virus and fungi. As a result, they become an infective hazard for plant personnel, the general population residing in the surrounding area and the occasional visitor. The present investigation focuses on the identification of enteric-type viruses in this kind of aerosol. The following methods were employed on 214 samples collected in the 1999-2000 period: cell culture (BGM, RD, Hep-2), electron microscopy, and polymerase chain reaction (PCR). Cytopathic effect was mild in 180 samples, and severe in 14, upon their first passage in culture. Virus identification was based on positivity to both electron microscopy (EM) and PCR. Thus, one positive sample was recognized to be of enteric-type virus and two positive samples were recognized as reovirus-type. All samples were negative for Norwalk-type virus or HAV. There was considerable discrepancy between electron microscopy and PCR concerning the number of enteric-type viruses recognized. A possible explanation is contamination with animal-type enterovirus.

Identification of cytopathogenic isolates from environmental matrices: application of analytical protocols

This work was aimed at studying cytopathogenic agents isolated from the environment by adopting, in parallel, various techniques currently used in clinical virology. The purpose of this research was not only to identify the viral species isolated but also to verify the most reliable protocols for environmental applications.

Reduction in 222radon concentration due to water treatment processes

In 40 samples of drinkable water taken from public fountains in the Province of Genoa determinations of 222Rn concentration were performed. The results were related to data obtained in a previous study on 222Rn concentration in spring water in the same areas, in order to assess a possible variation due to water treatment and to the aqueduct piping length. Radon concentration was also related to the main geographical areas in the Province and to the different geological formations. The average concentration was 0.92 +/- 0.86 Bq/l, and it can be related to equivalent dose to the population of 0.16 mSv/year. Our data show that water treatment processes cause a reduction in Radon concentration ranging between 58% and 93%, from picking up to utilization.

An electron microscopical investigation of small round viruses in non-bacterial gastroenteritis

Small round viruses implied in non-bacterial gastroenteritis were observed by electron microscope in stool specimens collected from 1993 to 1996. The specimens relative to 1981 were re-examined. The identified viruses are astroviruses (n = 6), caliciviruses (n = 7), Norwalk-like viruses (n = 34) and Parvoviruses (n = 6). Immunoelectron microscopy (IEM) and solid-phase immunoelectron microscopy (SPIEM) were used in order to verify serological differences existing among Norwalk-like viruses from different outbreaks. The results obtained suggest a possible circulation, in Liguria, of two serotypes of antigenically different viruses in the period considered.

[Status of tetanus immunity at the age of 10 years as a function of the introduction of compulsory vaccination: study of a sample of schoolchildren in Genoa]

Immunity to tetanus of 231 girls from Genoa, attending the last class of elementary school (average age 10) have been studied. According to the vaccination tables of the Public Health Service, these girls received a minimum of 4 to a maximum of 9 inoculations of vaccine (Diphtheria-Tetanus toxoid). The antitoxic antibodies have been titrated by passive-haemoagglutination method using antigen-coated lyophilized avian red cells. All subjects observed had high titer antitoxic antibodies. Comparing the antibodies titer with the time elapsed after the last vaccination, the result was that the average titer lowers progressively; the reduction becomes statistically significant after three years. All the 145 girls, who had 4 or 5 doses according to a regular calendar, had an antibody titer equal or major than 0.4 I.U./ml, after 5 years from the last dose.

[Prevalence of tetanus toxin antibodies in the population of Genoa in relation to age and sex]

Antitetanus toxin antibodies were measured, by means of the passive haemagglutination in the sera of 739 Genoese subjects, distributed in the following age classes: 1-5, 6-12, 13-20, 21-30, 31-40, 41-50, 51-60, 61-70 and greater than or equal to 71 years. It has been possible to verify that subjects of both sexes, aged less than 12 years, have high titer antibodies, particularly the female subjects show, in comparison with their male contemporaries, higher amounts of antitoxin. Besides the latter resulted at consolidated protection levels in 48% of the males, between 13 and 30 years, while for the male subjects, aged between 31 and 60 years this percentage dropped to 22 and, lastly, to 4 for those aged beyond 61 years. Furthermore for females older than 31 years, it was impossible, except exceptionally, to detect the presence of antibodies at titers greater than or equal to 0.1 I.U./ml.