Seroepidemiology of Rubella in Mozambique, 2006-2014: Implications for Rubella Immunization in Settings With High Fertility Rates

ABSTRACT

Background: Rubella and congenital rubella syndrome are highly underreported and neglected in most sub-Saharan countries and vaccination has not yet been incorporated into their national immunization schedules. In this study, we investigated the frequency of immunoglobulin M antibodies against rubella and examined correlations with fertility rates during the period from 2006 to 2014 in Mozambique. Methods: We conducted a retrospective analysis of data collected through the routine case-based surveillance system for measles in Mozambique. Results: A total of 7312 serum samples from suspected cases of measles were tested between 2006 and 2014. The median age was 4 years (interquartile range 1-8 years). Of these, 1331 (18.2%) were positive for immunoglobulin M anti-rubella. The highest frequency of rubella was observed within the 5-9-year-old age group (32.6%). The frequency in the age groups <1 years old, 1-4, 10-14, 15-19, 20-29 and ≥30 were 4.5%, 13.1%, 28.7%,18.7%, 5.2% and 5.1%, respectively. Conclusion: Our data show that rubella is frequent among women of childbearing age in Mozambique. Considering that early pregnancy is common in Mozambique, this suggests that, in settings such as ours, the introduction of routine rubella vaccination in children should be accompanied by repeated vaccination campaigns targeting older children and adolescents.