OBJECTIVETo explore the relative risk factors of adult measles in Qingdao city.

METHODSCase-control study was used to collect the information from 70 adult measles cases and 140 controls. Information would include general social and demographic characteristics, history and times regarding measles vaccination, demography of the study of population etc.

RESULTSThe case group had lower proportion of measles vaccination (chi2 = 26.88, P < 0.05, OR = 5.12, 95% CI: 2.69 - 9.73) than the control group with statistical significance. The vaccination frequencies were stratified as three ranks: 0, 1, > or = 2 times for analysis. When having 0 and 1 time measles vaccination, no statistical significance was found in these two groups (chi2 = 1.86, P = 0.173), but there were statistical significance between 0 and > or = 2 times (chi2 = 45.24, P = 0.000, OR = 13.35, 95% CI: 5.80 - 30.71), 1 and > or = 2 times (chi2 = 26.23, P = 0.000, OR = 7.91, 95% CI: 3.37 - 18.59) in the two groups. It was also found that the proportion of floating population was higher in case group than that of the control group (chi2 = 21.60, P < 0.01, OR = 4.06, 95% CI: 2.21 - 7.45). At the same time, statistically significant correlation was found between adult measles and average family incomes (chi2 = 2.23, P < 0.05, OR = 2.08, 95% CI: 1.15 - 3.76) by single-factor statistical analysis.

CONCLUSIONResults showed that 'without history of measles vaccination' was key relative risk factor for the adult measles while being a part of 'floating population' and those having lower incomes were among vulnerable groups.