Carlo Maria Avio

Cost-benefit analysis of tetanus prophylaxis by a mathematical model

A mathematical model has been developed which allows estimation of the epidemiological and economic effects of different tetanus vaccination strategies. The model was used to simulate the epidemiology of tetanus in Italy from 1955 to 1982, and then applied to a district of Tuscany by utilizing data obtained from a seroepidemiological survey carried out in the same area. For this district we simulated vaccination programmes designed to reach, within 1 or 10 years, coverages of 60 or 90% of the population aged over 10 years who had not been exposed to the neonatal vaccination programme. The most effective strategy, from both the epidemiological and economic point of view, seems to be 90% coverage reached in 1 years time. Benefits would be increased by improving the reliability of vaccinal anamnesis.

HIV serology among Italian male military recruits at entrance and discharge

To evaluate the usefulness of anti-HIV mass screenings, we examined 662 new military recruits and 1353 soldiers being discharged. None of the former and only one of the latter (0.07%) resulted seropositive on repeated ELISA and Western-blot. For comparison we also report the results of routine anti-HIV antibody testing in our diagnostic laboratory: the highest proportion of seropositive subjects was found among symptomatic patients (79%), followed by haemophiliac patients (31%), drug addicts (24%), sexual partners of seropositive subjects (21%), prisoners (5%) and homosexual men (5%). Health care personnel and prison guards were all negative. These data confirm that in Italy HIV infection is still relatively confined to the classic risk groups. While generalized screening during military service seems to be excessive, periodic sample surveys could be very useful to follow the evolution of HIV epidemiology.