Abstract
BACKGROUND: Measles remains a major public health burden worldwide. Parents often hesitate to vaccinate children with chronic diseases. We investigated the association between the percentage of vaccination and chronic diseases and explore hospital infections' role in the 2017-2019 measles outbreak across northern Vietnam provinces. METHODS: A total of 2,064 children aged 0-15 years old admitted for measles to the National Children's Hospital during the outbreak were included in the study. Demographic information, clinical characteristics, vaccination statuses and laboratory examination were extracted from electronic medical records, vaccination records, or interviews with parents when other sources were unavailable. RESULTS: The incidence rate that provincial hospitals sent to the National Children's Hospital was proportional to the population density of their provinces of residence. Early nosocomial transmission of measles was observed before community-acquired cases emerged in many provinces. Among patients aged over 18 months, those with chronic diseases had a proportion of vaccination of 9.4%, lower than patients without chronic diseases at 32.4%. Unvaccinated patients had a higher proportion of hospital-acquired infections with aOR = 2.42 (1.65-3.65), p < 0.001 relative to vaccinated patients. The proportion of hospital-acquired infections was higher among children with chronic diseases compared to those without, with aOR = 3.81 (2.90-5.02), p < 0.001. CONCLUSION: Measles spread in healthcare settings prior to community cases that occurred in several provinces. We recommend enhancing hospital infection control by increasing staff training and improving early detection and isolation during non-outbreak periods. Measles patients with chronic diseases exhibited lower proportions of vaccination and faced a higher risk of hospital-acquired infections. It is crucial to establish comprehensive vaccination guidelines and enhance parental awareness regarding the significance and safety of measles vaccination to protect these vulnerable individuals.