摘要:Aim: To analyze the reasons for epidemic outbreaks of measles, mumps and viral hepatitis A and to propose measures to prevent them in future. Materials and methods: Тhe incidence of measles, mumps and hepatitis A in Plovdiv region was studied for the period 2006-2010. An analysis of the age structure of the patients was made, while taking into account the time for routine immunization performed against measles and mumps (first and second dose). Results: In 2006-2009 single cases of measles were found occasionally, but in 2010 they were 2787 (incidence 395/100,000). Most of them (51%) were for ages 13 months-12years, 27%-0-13 months and 11%-13 to 18 years. The incidence of mumps for 2006-2010 varied widely, and has increased significantly in 2007 (130/100,000) and 2008 (169/100,000). The majority of patients (over 34%) during the epidemics were aged 13 months-12years, and over 26% of them-13-19 years. For the period 2006-2010 the incidence of hepatitis A ranged from 2.98/100, 000 (2009) to 426/100,000 (2006). Over 50% of the cases involved children aged up to 9 years. For the three diseases over 80% of patients were individuals of Roma origin. Conclusions: 1. Epidemic spread of measles in 2010 was mainly due to shortcomings in the routine immunization carried as a prevention of the disease. 2. There are two reasons for the outbreak of mumps: А) Failure to administer the second vaccine dose at 12 years in Bulgaria until 2001. B) Shortcomings in routinely performed immunization. 3. The extremely high incidence of hepatitis A in 2006 (and in the rest of the years) is due to the lack of routine immunization. 4. Essential for the outbreaks in all three diseases are the poor hygienic living conditions, the low social status and the lack of health promotion of the population at risk 5. To prevent future outbreaks of the diseases hereby in question, we suggest it is appropriate: А) To introduce compulsory immunization against hepatitis A; B) To carry out periodic catch-up vaccination campaigns against measles and mumps.