Bollettino epidemiologico nazionale

Epidemic of Measles in the Province of Benevento

Paolo D’Argenio, Annarita Citarella, Elena Fossi, and the Working Group of the Local Health Authority 1 of Benevento¹

In 1996, the Local Health Authority of Benevento adopted a strategy to eliminate measles.  This strategy included the vaccination of all infants at the age of 15-18 months and vaccination of 12 year olds. In 1996, following the directives of the Ministry of Health, the strategy was modified, with an initial vaccination at 12 months (at the time of the child’s third immunization visit), at 5-6 years of age (at the same time as the fourth dose of DTPa) for those who were vaccinated at 12 months or had never been vaccinated, and at 12 years for those children who had previously received only one dose or who had never been vaccinated.

In 2002, 23 family pediatricians working under contract with the Local Health Authority of Benevento collaborated in SPES, the Italian national sentinel surveillance system for vaccine-preventable diseases. Between January and August 2002, these pediatricians who cared for 17,732 children, notified 249 cases of measles, which per primarily concentrated during the months of May and June (Figure 1). A total of 18 persons were hospitalized for measles and measles-related complications; one was less than a year of age, 2 between 1 and 4 years, 8 between 5 and 9 years, and 7 between 10 and 14 years. No deaths occurred, and only one serious case of encephalitis occurred in a child who also had thalassemia.

The total incidence was 14.0 per 1000 patients. If we assume that the entire pediatric population between 0-14 years in the province had the same characteristics of those cared for by the pediatricians in the network, we can estimate that in the study period there were approximately 479 cases.

The epidemic did not uniformly involve the entire province. In one district, the rate was 53 per 1000, with 146 cases, representing 59% of the 249 notified cases.

All age groups were involved in the epidemic but the incidence increased with age, with the highest rate seen in the oldest age group (10-14 years). The age-specific rates were as follows: 3.1/100 for children less than one year, 5.2/1000 for those between 1-4 years, 18.5/1000 for those between 5 and 9 years, and 23.6/1000 for those between 10 and 14 years.

Vaccine coverage by birth cohort, measured before the epidemic (as of the 30^th of April 2002), varied substantially by age. Among those born after 1996, the coverage was higher than 80%; for those born in 1996, it dropped to 77%, for those born in 1995 it decreased further to 65%, and for those born prior to 1993, it was approximately 30%. As can be seen in Figure 2, there is an evident inverse relation between the vaccine coverage by age and the incidence of measles cases.

Beginning in May 2002, when the epidemic was identified, the Local Health Authority of Benevento decided to undertake a special vaccination campaign based on the following actions:

• Vaccination of all case contacts 6 months of age or older

• Active efforts to vaccinate all children under 12 years who had never been vaccinated

• Active efforts to re-vaccinate all children who had received only one prior dose

• Vaccination of adolescents between 13-18 years of age upon request

To facilitate identification of children needing vaccination, some districts conducted simple surveys in the elementary and middle schools, using a form sent home to thee parents asking whether their child had ever been vaccinated against measles. For those children who were not vaccinated, the parents were also asked to state whether they accepted or refused to have their children vaccinated.

Between May and July 2002, the vaccine centers of the province vaccinated nearly 9000 persons, including 27% of those who had never been vaccinated and 17% of those who had been vaccinated with only a single dose.

¹Working Group, ASL 1 Benevento:  Aversano Maria Pia, Bassi Rosa, Ferri Michela, Glielmo Nicla, Iglio Giovanni, Petroccia Clementina, Ragozzino Giovanna, Sacco Lea Arigliani Raffaele, Baldino Antonio, Caruso Vincenzo, Casani Antonella, Cicchella Nicola, Cioffi  Pasquale, Crisci Geppina, Insogna Marzio, Izzo Annamaria, Martucci Antonio G., Mascellaro Ornella, Massaro Claudio, Onofrio Elodia, Palumbo Renato M., Parente Carlo, Pezza Enrico, Ranieri Graziella, Rosa Federico, Sasso  Sara, Saviano M. Carmela, Simeone Claudio, Simeone Domenico, Sorice Nunziatina, Soricelli Maurizio, Vicario Valeria.