A cross-sectional study to describe and explore factors associated with measles immunisation and recording among cases linked to an outbreak, South West England, 2016

Following an outbreak of measles across South West England in 2016, the multi-agency outbreak control team suggested that immunisation history records collected for the health protection response may not be reliable. We undertook a cross-sectional study to compare measles immunisation records collected from outbreak cases on the case management system HPZone by the Health Protection Team with the full primary care record. A total of 122 cases were reported. We identified 86.9% cases were not fully immunised and 5.7% had an unknown immunisation status. There were 14 cases whose primary care records did not match HPZone and 18 cases where primary care records were available and immunisation status was not documented in HPZone. Complex, non-linear associations were found between age and socioeconomic deprivation status of each case and having an incorrect HPZone record. Cases who resided in postcode areas of greater socioeconomic deprivation had statistically significantly higher odds of having been fully immunised. Only 13.3% of partially or unimmunised cases received an MMR immunisation following their onset of measles infection. Collecting immunisation status from the full primary care record during acute management of measles cases may support improvements in control and prevention of further cases.