Representativeness of suspected measles cases reported in a southern district of Nigeria

To compare the characteristics of suspected measles cases at the health facilities and to determine the representativeness of the data.

We visited 25 hospitals in the Aniocha Local Government Area (LGA) of Delta State, Nigeria, from which information on reportable diseases was collected. In particular, the suspected measles cases in their registries between January 1, 2007, and June 30, 2008, were reviewed. We compared the characteristics, including age, sex, location, and month of reporting, of the suspected cases with the LGA surveillance records.

In the LGA records, 10% cases involved individuals older than 14 years, compared with 20% in the same age group in the health facility records. Based on geographic location, 53% of the measles cases among the hospital records came from a single location, in contrast to only 30% of the cases among the LGA records. An analysis considering time revealed that 30% of the cases in the LGA records occurred in August 2007, whereas 20% of hospital cases were reported in February and May 2008 combined.

The two record types differed considerably in all of the characteristics used in this comparison.