Bollettino epidemiologico nazionale

Epidemic of Measles in the Local Health Authority of Campobasso

Giovanni di Giorgio, Health Observatory of the Local Health Authority of Campobasso and Sergio Rago, Operative Unit of Hygiene and Public Health, Local Health Authority of Campobasso.

The Local Health Authority of Campobasso consists of 51 communes subdivided in 5 health districts and covers a population of 131,231 residents, 14.6% of whom are between the ages of 0 and 14 years. After 6 years of low measles incidence, an increase was noted in 2002. Between January and July, the number of cases reported to the Department of Prevention increased progressively (Figure), reaching a total of 307 cases (23/10,000), compared with 40 cases reported over the past 5 years.

The majority of cases (269/307; 88%) occurred in children between the ages of 0 and 14 years. The highest incidence was in children between the ages of 5 and 9 years, followed by children 0-4 years. The rate in those 10-14 years of age was only slightly lower than that of the 0-4 year age group. Of the 307 cases, 13 (4%) were in vaccinated children and 270 (88%) in non-vaccinated children; for the remaining 24 (8%), data on vaccination status were not available.

The epidemic was not uniform across the local health authority, 8 of the 51 communes accounted for 82% of the cases (Table). In these communes, the observed incidence ranged between 55 per 10,000 in Campobasso (the regional capital) to 1,806 per 10,000 in the commune of Petrella. In the remaining communes, the levels were higher than those in Campobasso.

A review of hospitalizations demonstrated that during the study period of January to July 2002, 22 persons were hospitalized in the Cardarelli Hospital in Campobasso. The age of those hospitalized ranged from 1-37 years, uniformly distributed between the 0-4 age group (6 cases), those 5-9 years (5 cases), 10-14 years (4 cases and > 14 years (7 cases). Eight were residents of Campobasso, 4 of Ferrazzano, 2 of Boiano, and 1 in each of the remaining communes. Of the 22 who were hospitalized, 15 (68%) were discharged with uncomplicated measles, 5 had pulmonary complications (23%) and 2 had an encephalitis (9%). One six-year-old child died as a result of pulmonary and encephalic complications.

An analysis of the distribution of vaccine coverage shows that coverage varied among the affected districts. Overall, the coverage was 65%, with a range between 8% and 100% in the 8 districts (Table). Adjacent to districts with low coverage were others with much higher coverage.

A comparison of coverage data for 2001 with those from 2000 demonstrates that in some districts (Campobasso East, Riccia, e Trivento, there has been an increase in vaccination coverage (72% versus 75%, 70% versus 76%, 43% versus 53%), while in others the level has remained stable (27%) and Campobasso West, it actually declined (85% versus 69%). Within the districts, the same pattern of variable coverage was observed; even adjoining communes differed substantially in their levels of coverage.

The epidemic in the Campobasso local health authority has the characteristics of epidemics seen in areas of intermediate vaccination coverage. In this case, levels were sufficient to prolong the inter-epidemic period to 6 years from a previous interval of 3 when coverage levels were lower, but levels remained too low to interrupt disease spread.

Attempts were made to determine the causes of the uneven vaccination coverage in the local health authority. Two general hypotheses were developed:

• Insufficient information and lack of motivation of parents: lack of knowledge about the vaccine and concern about adverse reactions, lack of knowledge about where to take their children to be vaccinated, underestimation of the seriousness of the disease, and misunderstanding of contra-indications for vaccination.

• Problems with the vaccination centers: failure to disseminate information about the vaccine calendar, vaccines not available, inconvenient hours, delays in sending appointments for vaccinations, lack of attention to updating the vaccine registers, especially regarding changes in residence, and insufficient contact with pediatricians and general practitioners.

Each vaccination center, in fact, had its own problems. In some, the problem consisted of the small numbers of children to be vaccinated and sparse population density that make it difficult to reach the at-risk population, in others there were problems with establishing appointments and registering newborns in the vaccine registry, maintaining adequate vaccination supplies, etc. In addition, it is difficult for the public health and hygiene offices to gather data from the pediatricians and general practitioners, who do not always report the vaccines they have administered.

From the data gathered to date, it appears that there is a conflict between the need to offer optimal access but also offer quality services: the local communities and political leaders wish to have convenient local services; the district health staff, by contrast, wants to offer quality services based on motivated, specialized staff.

The epidemiologic study, in addition to quantifying the health damages caused by the epidemic, also provides suggestions on priority interventions needed to improve vaccine services, including the accreditation of vaccine centers and computerization of the vaccine registry.