OBJECTIVETo study the incidence of cases with rash and fever illness (RFIs) after measles vaccine (MV) inoculation.

METHODSDuring 1999 to 2002, 150 RFIs cases reported by the special measles surveillance system in Shandong province, China, were investigated and analyzed epidemiologically.

RESULTS7 674 690 ml MV were distributed during 1999 to 2002 and the annual average incidence of RFIs cases after MV inoculation was 0.20/10 000 ml (0.2 ml per dose). There was significant difference of incidences each year (chi(2) = 10.13, P < 0.05). All RFIs cases were sporadically distributed without epidemiological links. Clinical symptoms showed that 88.67% of the 150 RFIs cases having > 38.5 degrees C fever and 75.33% of all cases appeared typical rash after 4 to 11 days (the medium was 8 days) after MV inoculation. The order of rash onset among RFIs cases was consistent with that of regular measles cases caused by wild virus. 68.67% of the RFIs cases had first MV inoculation and 94.71% were 8 to 12 month-olds. IgM sera antibody test from RFIs cases were rubella negative and 45.65% positive for measles.

CONCLUSIONRFIs due to allergic reaction or measles vaccine virus infection might occur after MV inoculation. There seemed to be a correlation between RFIs incidence and the doses of MV. Measles virus genotype analysis needs to be carried out to confirm if the onset of some RFIs cases is aetiologically associated to MV vaccine virus infection.