Low Seroprevalence of Measles-Specific IgG in Children of Three Ethnic Groups from Mexico: Influence of Age, Sex, Malnutrition and Family Size

Abstract

Background: The reemergence of measles represents a public health problem. The aim of the study was to determine the seroprevalence of IgG antibodies against measles in children of three ethnic groups in southern Mexico and the nutritional status and demographic risk factors associated. Methods: A cross-sectional study in 416 school-age children, 207 belonging to the Tlapaneco ethnic group, 101 to the Mixteco group and 108 were considered Mestizo. Sociodemographic data were collected, an anthropometric evaluation of the children was performed and a fasting blood sample was obtained from each child for the measurement of measles IgG antibodies by Enzyme-Linked Immunosorbent Assay (ELISA). Results: From the total sample, 59% of the children were seropositive for IgG antibodies against measles; in contrast, 41% lacked IgG antibodies. Measles antibody seropositivity was higher in girls (64%). 90.5% of 6-year-old children had higher antibodies seroprevalence, compared to the children between 10 and 13 years old (45.5%). In the three ethnic groups, age was negatively correlated with the index standard ratio (ISR) of measles antibody levels and the families with ≥8 members showed less seropositivity. According to the antibodies levels, most of the positive cases remained around 1 Standard Deviation (SD) of the ISR values and no underweight children had antibody levels above 2 SD. Conclusions: The Anti-Measles serological coverage is low in children of three ethnic groups from Southern Mexico and the age, sex, malnutrition and family size are associated factors. Therefore, it is important to strengthen immunization campaigns, principally in vulnerable groups.

Reduced Prevalence of Measles Antibodies in a Cohort of Brazilian Children under 15 Years of Age

“…Similar measles seronegativity data were also observed in children by other authors, including Gupta et al [ 23 ], where 60% of children between 5 and 10 years of age in India lacked protective immunity against measles, and Sánchez-Alemán et al [ 24 ], where 59% of Mexican children aged 6–13 years of age lacked MeV antibodies. Data reported by the WHO indicate that measles immunization coverage in the Americas has been approximately 69.2% over the past 20 years, with rates slightly higher after 2014; rates well below the threshold of herd immunity.…”

Low Measles Seropositivity Rate among Thai Adolescents in the Thai National Immunization Program

“…Our study showed that older age and an uncertain history of measles vaccination were associated with a lower measles seropositivity rate. Published studies in China and Mexico also reported that lower measles seropositivity rates were associated with older age [21,22]. In terms of seroprevalence of MMR, the lower measles seropositivity found in this study is comparable to the previous study, which found that rubella and mumps seropositivity levels were lower among adolescents [23,24].…”

Resurgence of measles infection among children: findings from a surveillance-based population study

“…35 Several studies have also found a discrepancy between ethnicity and measles infection. [36][37][38] A study showed that ethnicity and cultural background were strong predictors of MMR vaccine uptake. 36 These findings differed from our own, in that we found no link between ethnicity and laboratory-confirmed measles.…”