Antipoliomyelitis immunity status among a population that was regularly vaccinated 11-12 years before

A study of poliomyelitis neutralizing antibodies was carried out on 165 samples of blood serum drawn from subjects aged 14-15 years who had completed vaccination with OPV 11 or 12 years ago. Two different methods of incubation of the serum-virus mixtures (1 hour at 37 degrees C; 6 hours at 37 degrees C and then 18 hours at 4 degrees C, respectively) and two different cell lines (RC-37 and Hep-2) for the inoculation of these mixtures were employed. The results were also evaluated in relation to different initial dilutions of the sera (from 1:4 to 1:1). With the 1:4 initial serum dilution the highest frequencies of sero-negativity were observed utilizing the short incubation time and inoculation in Hep-2 (42% for polio 1, 10% for polio 2, 32% for polio 3). These frequencies diminish significantly utilizing the RC-37 cell line and the long incubation respectively. Under all the experimental conditions the results were better when the 1:2 initial serum dilutions were employed and even better when undiluted sera were used. Neutralizing antibodies against the 3 types of poliovirus were detected in the undiluted sera of all the subjects utilizing the long incubation and inoculation in either the RC-37 or the Hep-2 cell lines. In three subjects lacking detectable antibodies at the 1:4 dilution of the sera, the administration of a dose of IPV produced after 5-7 days a high response which remained almost unchanged 30 days later.

Poliomyelitis immunity status at different intervals from vaccination

Research on neutralizing antibodies against the 3 serotypes of poliovirus was carried out on 441 blood specimens drawn from children and young people living in Parma, a town of about 200,000 inhabitants, where the vaccination services were well organized. From June 1983 to June 1984 blood samples were taken from different groups of subjects at different stages of vaccination (before vaccination, and after 1, 2, 3, and 4 doses of trivalent balanced OPV). In addition, groups of children and young people vaccinated from 2 to more than 14 years earlier were bled. Ten per cent of unvaccinated babies (aged 1-3 months) were lacking in neutralizing antibodies for types 1 and 3 and five per cent for type 2; among children aged 4-5 months vaccinated by one dose of OPV a residual 5% of subjects without antibodies for type 1 was also found. All subjects who received two, three, or four doses, had antibodies against all serotypes of poliovirus. As for the number of administered doses, significant differences among GMTs of antibodies were recorded only for type 1, when the group given 3 doses, was compared with the group which received two and one dose, respectively. At different intervals from completion of vaccination (2-14 years), all groups we examined still had antibodies against all three serotypes. For poliovirus type 1 antibody, GMTs were not significantly different in the examined groups. For types 2 and 3 significant decreases were observed in the groups vaccinated from 2 to 5 years. The high levels of immunity observed earlier in Parma were not found throughout the entire territory.(ABSTRACT TRUNCATED AT 250 WORDS)

[Acute respiratory syndromes caused by viruses in a pediatric department. Clinical and epidemiological studies of a series of cases admitted in the period from February to May, 1979]

In the period between February and May 1979, in concomitance with a sharp increase in admittance to the pediatric Division of the Parma General Hospital for acute respiratory infections, we carried out a virologic and serologic investigation on hospitalized children aged 21 days-12 years. The investigation was carried out on 137 patients with respiratory diseases: 33 with bronchiolitis, which occurred mainly (32/33) between February and March in children that were prevalently (30/33) in the first year of life; 27 with upper respiratory tract infections; 54 with mid respiratory tract infections; 23 with pneumonia. Forty-eight controls (without respiratory infections) were also investigated. In the months of February and March there was a high circulation of respiratory syncytial virus (RSV): throughout the entire period there was a lower incidence of Adenovirus infections and more uniformly distributed.

[Virological research in acute respiratory diseases in 1976--1977 (author's transl)]

From October 1976 to June 1977 virological researches have been carried out on 5 subjects with influenza, on 302 children hospitalized in pediatric departments for respiratory illness and 94 children hospitalized in the same departments for other (non respiratory) diseases. The incidence of influenza was moderate and restricted to small epidemic episodes in school and preschool children. The isolated viruses resulted of A type, substantially similar to the prototype strains appeared from 1972 to 1975. Among children hospitalized for respiratory diseases Adenoviruses (6.8%) and, with decreasing frequency, Enteroviruses, paraifluenza viruses and RS have been also isolated. The incidence of isolation of RS virus is significantly related to bronchopneumonia cases in infants under on year of age. The incidence of significant increases of FC antibodies against influenza (A and B) viruses, RS and Myc. pneumoniae in children with bronchitis and broncho-pneumonia is also considerable. The drawing of pharyngeal swabs at different intervals from the entry to the hospital has shown that the shedding of respiratory viruses is generally very short and that hospital cross-infections may occur.

[Detection of Salmonella in surface waters]

After a detailed description of some of the methods used for the research of Salmonella in superficial waters, the AA. examine some problems relative to the collection of the samples and to the culture of these bacteria. Results obtained in the Po river and its affluents are also briefly presented; the high incidence of samples positive for Salmonella is stressed and some aspects of an epidemiological nature are considered.

[Epidemic due to group B Coxsackie viruses in a newborn infants' department (author's transl)]

Virological and clinical researches have been done on hospitalized newborn infants' with various infectious diseases (respiratory infections, aseptic meningitis, serious generalized disease). Initially from some newborn children Coxsackie B5 virus has been isolated and later from other patients Coxsackie B3 virus. The pathological findings, in those newborn who died as a result of serious generalized disease were dominated by hemorragic lesions in different organs.