OBJECTIVETo explore the spatial and temporal characteristics of measles patients younger than 1 year old in Shandong province.

METHODSA total of 5309 cases of measles, whose patients were younger than 1 year old in Shandong province between year 1999 and 2008 were collected. The epidemic features of measles were described, and the annual infant incidence was calculated. Software ArcGIS9.3 was applied to draw the spatial map of the disease, and the software GeoDa0.95i-beta was adopted to analyze the spatial autocorrelation.

RESULTSThe incidence among infants younger than 1 year old reported in Shandong province rose from 23.45/100 000 (206 cases) in 1999 to 269.60/100 000 (2791 cases) in 2008.5309 cases covered all month-aged infants under 1 year old, except 12 months old. Most patients (3494 cases) aged between 6 - 9 months old; especially the infants around 8 months old, accounting for 20.7% (1100/5309). The epidemic peak was between March and May, accounting for 45.5% (2414/5309). The spatial and temporal distribution features showed an up and down temporal trend and an increase from east to west in spatial trend. The global Moran's I values of measles incidence among infants in Shandong province were 0.346, 0.150, 0.396, 0.213, 0.477, 0.354 and 0.331 in year 1999, 2001 - 2002, 2005 - 2008 (P < 0.01) and 0.076 in year 2004 (P < 0.05). The local spatial autocorrelation analysis showed that southwest and northwest districts of Shandong were highly clustered districts of measles.

CONCLUSIONIn Shandong, the measles incidence among infants younger than 1 year old rose obviously; especially the infants aged between 6-9 months age. The epidemic peak was between March and May. A positive spatial correlation was found, the disease showed a distinct regional distribution feature, and a cluster district was found.