Is mortality among under-five children in Nairobi slums seasonal?

To investigate the seasonal pattern of overall mortality among children aged below 5 years living in two informal settlements in Nairobi City.

We used data collected from January 2003 to December 2005 in the Nairobi Urban Health and Demographic Surveillance System on demographic events (birth, death, and migration). Analyses of seasonal effects on under-five mortality are based on Poisson regression controlling for sex, age, study site and calendar year.

During the study period, there were 17 878 children below 5 years in the study sites. Overall 436 under-five deaths were recorded. The overall death rate for the under-five children was 19.95 per 1,000 person years. There is a significant seasonal variation of under-five mortality. The mortality risk was significantly higher in the second and third quarters of year than in the fourth quarter (RR = 1.6, CI: 1.3-2.2 and RR = 1.5, CI: 1.1-2.0).

This paper demonstrates that overall mortality among under-five children in the urban poor is seasonal. Overall during the second quarter of the year, the death rate increases by nearly twofold. This evidence generated here may help to support well targeted interventions in reducing under-five mortality in the slums.