A new study from Columbia University shows that measles cases around the world surged 140% from 2010 to 2019, with declining vaccination rates in 59 of 194 nations fueled by socioeconomic factors in some low-resourced countries and vaccine reluctance in wealthier nations.
The researchers analyzed data on measles incidence, vaccine uptake, and socioeconomic, demographic, and environmental influences from 2010 to 2019 in the 194 World Health Organization (WHO) member countries using country-level linear regression models.
The results were published yesterday in the International Journal of Infectious Diseases.
"Measles cases and deaths increased globally following the disruptions to health services caused by the COVID-19 pandemic," the researchers noted. "Even before the pandemic, measles cases were on the rise, including in countries that had previously eliminated the disease."
High birth rates tied to rising incidence
During the study period, global measles cases per 1 million people varied, declining from 2010 to 2016 but rising about 140% in 2019. "Out of 184 countries reporting measles incidence data, the trend analysis indicates that only 6 countries experienced a clear decreasing trend in measles incidence and 12 experienced an increasing trend," the study authors wrote.
Of the 10 socioeconomic factors considered in measles incidence, effective vaccine coverage, higher gross national per-capita income, greater proportion of urban population, migration, and political stability/absence of violence had significant negative correlations with lower rates.
High birth rates, however, were positively correlated.
"These factors likely reflect the quality of public health infrastructure (e.g., access to vaccines), particularly in low- and middle-income countries (LMIC)," the researchers said. "In addition, stratified analysis suggests vaccine hesitancy likely contributed to measles case increases in high- and upper-middle income countries (HIC & UMIC)."
Better healthcare access needed in LMICs
While overall measles vaccine uptake increased, reaching 86% and 71% for first and second doses by 2019, it dropped in 37 countries and likely dropped in 22, according to model estimates. At the same time, vaccine coverage rose in 72 nations and likely rose in 20, and the trend was uncertain or stable in the other 43.
Combating measles requires not only improving healthcare access but also addressing vaccine hesitancy through tailored campaigns to ensure continued progress in the fight against measles.
"The decline in vaccination coverage was most pronounced in the European region (18 countries experienced downward trend, followed by the African region (7 countries) and the American region (5 countries)," the researchers wrote. "These regional differences highlight the challenges in achieving widespread immunization against measles globally."
The results underscore the need for more public health resources, especially in LMICs, the authors said.
"The identified significant association of measles incidence with political stability has important implications in light of the ongoing conflicts," they wrote. "The risk of measles outbreaks could further increase in the conflict-afflicted regions due to disruptions to public health, particularly timely vaccinations and healthcare access."
"Combating measles requires not only improving healthcare access but also addressing vaccine hesitancy through tailored campaigns to ensure continued progress in the fight against measles," they concluded.
