[Observations on the diffusion of hepatitis A and B virus during an epidemic in a Sicilian town with a high rate of infection]. / Osservazioni sulla diffusione di virus epatitici A e B durante una epidemia in un comune Siciliano con alta prevalenza di infezioni.

Epidemiological investigations were carried out during a viral hepatitis outbreak occurring in a Sicilian town of 30,000 inhabitants with poor sanitary standards, with the aim to study the mode of spread of HAV and HBV in conditions of high incidence of infections. HBsAg, anti HBs, anti HAV (RIA), HBeAg, anti HBe and anti HBc were investigated in serum samples from patients, their family contacts and from healthy individuals of different age groups. Morbidity was inferred from case notifications; search of unreported cases among school children, through the study of absenteeism, did not reveal further cases. In all 148 cases, occurred from August 1976 through July 1977 with a peak in January, 44% were under 5 and 93% under 10 years of age. All but 8 of 59 cases in which laboratory data were available were due to HAV. Anti HAV antibodies were highly prevalent in serum samples obtained in February through April 1977: 62% were positive in the 1 to 3 years age group, and more than 90% among school children. Prevalence of HBsAg was age and sex dependent, ranging from 4% to 15%; anti HBs was present in 8% of the children 1-10 years and in 30% or more in age groups 30-41 and over. It is suggested that direct contact between very young children was the main mode of spread of HAV, and inapparent cases the main source of infection, although ambient diffusion through water contamination could not ruled out. HBV was probably propagated mostly by intrafamilial spread with little overt pathology.

[Epidemiological surveillance of influenza in western Sicily in 1976-1977]. / Sorveglianza epidemiological sull'influenza nella Sicilia occidentale negli anni 1976-1977.

Two strains of influenza virus A/H3N2 antigenically similar to A/Victoria/3/75 have been isolated in Palermo in February 1977; a peak of extramortality has been observed in the same month, and a rise of HAI antibodies for A/H3N2 viruses in human serum samples, taken from apparently healthy subjects living Palermo, has been demonstrated between October 1976 and February 1977. Similar rise of antibody titers has also taken place in serum samples from two communities in Western Sicily (Favara, 30,000 inhabitants, Favignana, 3,000 inhabitants). Serum samples obtained in June 1977 showed a slight fall of antibody level in Palermo and in Favignana, whereas in Favara a further rise, in comparison to February, is consistent with the hypothesis of a delayed circulation of virus in that community. Reduction of HAI titers for H3N2 viruses was even more pronounced in October 1977 in all groups of serum samples tested. The importance of local surveillance of influenza and the assessment of herd immunity level is discussed.

[Studies of influenza in Palermo, 1970-75]. / Indagini sull'influenza a Palermo, 1970-75.

Epidemiological surveillance of influenza was carried out in Palermo betwen 1970 and 1975. Antigenic structure of viral strains A/H3N2 isolated from influenza patients during winter outbreaks was studied in comparison with reference strains circulating in the same periods in other parts of the world. Antigenic drift of hemagglutinin, of neuraminidase, or of both, was observed in Palermo isolates, which were progressively different from Hong Kong/68 strain; 1973 and 1975 isolates were similar to A/England/72 and A/Port Chalmers/73. HI antibodies against Palermo isolates were titered in serum samples obtained from adults living in Palermo. Seronegativity for each strain progressively decreased from 1971 to 1975.

[Studies of diseases caused by hepatitis B virus on the island of Favignana]. / Indagini sulle affezioni da HBV nell'isola di Favignana.

731 serum samples were drawn from inhabitants of Favignana (Egadi Islands, total population 3,000). Presence of HBsAg and anti HBs was tested by R.I.A. Although only two cases of B Virus Hepatitis had been observed in the last 3 years, the overall positivity for HBsAg was 4.8% and for anti HBs 31.6%, showing a distribution by age and sex comparable to that observed in similar studies. The rather high prevalence of HBsAg in males over 70 deserves further investigations.