Measles outbreak in Bulgaria among children: Poor maternal educational attainment as a risk factor

An eight-year era of interrupted indigenous measles transmission in Bulgaria came to an end in April 2009 when an outbreak erupted that would eventually claim 24,253 cases and 24 deaths; infants, children and young adults of the Roma community were disproportionally affected.

In order to disentangle the contribution of underlying drivers of the outbreak, we collected a number of ecologic variables of the outbreak. We also reviewed outbreak charts of 434 measles cases in three regions of Bulgaria: Montana, Burgas and Razgrad. We conducted a logit regression analysis of data from individuals with medical complications from measles infections with 293 of respondents.

Maternal education was protective against medical complications from measles in our study population, with an odds ratio (OR) of 0.54 (95% CI: 0.333 - 0.867). The probability of developing medical complications from a measles infection decreased with age of the child (OR=0.90; 95% CI: 0.855 - 0.960); the number of household members (OR=0.76; 95% CI: 0.642 - 0.904); and households with declared income (OR=0.90; 95% CI: 0.519 - 1.549).

Complications from measles infection, and possibly the associated high case-fatality rate, can in part be explained by maternal educational attainment. Mother's education is a function of a number of factors such as improved knowledge of children's health and higher income. Low vaccination coverage and concentration of risk factors, characterized by lack of resources among the Roma community, can diminish herd immunity and be a crucial conduit for rapid disease transmission in society at large.