Risk factors for transmission of measles during an outbreak: matched case-control study

Area of Science:

• Epidemiology
• Infectious Disease Control
• Public Health

Background:

• A significant measles outbreak occurred in Merseyside, UK, in 2012, with 359 confirmed cases.
• Many infected individuals reported recent visits to healthcare and social settings.

Purpose of the Study:

• To determine the risk factors contributing to measles transmission during the 2012 Merseyside outbreak.
• To identify key epidemiological factors associated with measles infection.

Main Methods:

• A retrospective, matched case-control study was conducted in April 2012.
• Fifty-five confirmed measles cases were matched 1:1 with 55 community controls based on age and geography.
• Data on exposures, including healthcare visits, were collected via telephone interviews, followed by univariate and multivariate analyses.

Main Results:

• Incomplete vaccination for age was strongly associated with measles infection (adjusted odds ratio [aOR] 22.1).
• Being under the routine vaccination age also increased risk (aOR 20.4).
• Hospital admission was independently associated with measles infection (aOR 20.2).

Conclusions:

• Incomplete vaccination, being too young for routine immunization, and hospital admission are significant risk factors for measles infection.
• The findings underscore the importance of prompt vaccination, early diagnosis, and isolation of cases.
• Strict infection control measures in healthcare settings are vital to prevent measles spread.