Topic:

Epidemiology and public health

Abstract No.:

ISE.491

Title:

Vaccine-preventable diseases prevalence in Bolivian children. Results from BOLKID study, 2010

Author(s):

C. Masuet Aumatell¹, J. M. Ramon Torrell¹, R. Dávalos², S. L. Montaño Rodriguez³; ¹Hospital Universitari de Bellvitge, International Health Unit, Preventive Medicine, L'Hospitalet de Llobregat/ES, ²Universidad Mayor de San Simón, Research Unit, Cochabamba/BO, ³Universidad Mayor de San Simón, Research unit, Cochabamba/BO

Abstract:

Background: Since 1974, the World Health Organization's Expanded Programme on Immunization (EPI) has targeted in Bolivia some vaccine-preventable diseases. However some historical differences have occurred between immunization coverage reported and described by survey. We undertook a study to assess seroprevalence of vaccine-preventable diseases in 5 to 16 years old Bolivian children from the Cochabamba region.
Methods: A population-based cross-sectional survey (n=441) was undertaken in 2010. A parental-administered questionnaire about socio-demographic information was gathered and a blood sample obtained from each participant with parental informed consent. Vaccine-preventable diseases prevalence as hepatitis A, hepatitis B, measles, and varicella were estimated as well as their 95% confidence intervals. A descriptive and bivariate analysis using Student T test or Mann-Withney U test to according to normality distribution and Chi-squared test or Fisher exact test when needed, were performed.
Results: The global prevalence of hepatitis A was 94.33% (CI95% 92.17-96.49), hepatitis B 12.70% (CI95% 9.60-15.81), varicella 77.32% (CI95% 73.41-81.23), and measles 69.61% (CI95% 65.32-73.90). Hepatitis B prevalence showed a negative relationship with age group (p<0.001), decreasing its prevalence by age, on the contrary, measles showed a positive relationship (p=0.010), increasing its prevalence by age group.
Conclusion: This study identifies a high prevalence of measles probably due to high coverage of inmunization, but a low prevalence of hepatitis B, even it is increasing in younger birth cohorts. On the other hand a high prevalence of hepatitis A and varicella were obtained by natural infection. Therefore susceptibility of different vaccine-preventable diseases in Bolivia is still of concern.