The number of measles cases reported worldwide has increased in recent
years, and in 2015, there was a measles outbreak in Xi’an, China.
However, the epidemiology of measles and the seroepidemiology of healthy
people after 2015 have not been fully understood. We collected fingertip
blood samples from healthy people around each suspected measles case in
Xi’an in 2016-2018 and tested IgG using ELISA. Eighty measles cases were
reported in Xi’an in 2016–2018, with an average annual incidence of
0.29 per 100,000 persons. Children aged ≤ 5 years and adults aged 25-29
accounted for a large proportion of measles cases. More than half of the
cases in the 0-year group were under 8 months. A total of 5476 blood
samples from healthy people were collected. Apart from 1-4 years and
over 40, other age groups’ seroprevalence was 93%. Our findings suggest
that the first vaccine shot should be administered at 6 months or
earlier, the second at 12 months, and the third at 10 years, and couples
should be vaccinated with another dose. The findings may provide novel
insights into measles elimination.