Age-specific occurrence rates of measles in urban, peri-urban, and rural environments: implications for time of vaccination.

Measles vaccination is unsatisfactory in infants less than 8 months old. To find out what proportion of children with measles in the developing world fall within this age range, a survey was conducted in Natal/Kwa Zulu. Data were collected from urban (community-based survey, infectious diseases hospital data, referral centre date), peri-urban (regional hospital and clinics), and rural (3 local hospitals and their peripheral clinics) populations. There was a positive association between population density and the percentage of measles cases aged 8 months or less. 20-45% of measles patients in urban areas, 15% in the peri-urban zone, and 6-12% in rural Kwa Zulu had the disease at or below 8 months of age. The mortality rate for measles in this age group at the referral centre was 26%. There is an urgent need for effective methods of immunizing the very young against measles in high-density regions of developing countries.