Malaria in Middle Childhood and Adolescence

Excerpt

The age distribution of cases of malaria is influenced by the intensity of transmission. In areas where the population has low exposure to infection, malaria occurs in all age groups. In high transmission areas, in contrast, the main burden of malaria, including nearly all malaria-related deaths, is borne by young children (figure 14.1). These different age patterns are seen because exposure to repeated malaria infections induces some protection against subsequent attacks; but protection is rarely complete.

The age pattern of clinical malaria is determined by the level of transmission and the consequent level of acquired immunity, so it is sensitive to changes in the level of transmission (Carneiro and others 2010; Snow and others 1997). In many malaria-endemic areas, successful control programs have reduced the level of transmission substantially (Noor and others 2014; O’Meara and others 2010; WHO 2015). Consequently, in such communities, the peak age of clinical attacks of malaria is shifting from very young to older children. In The Gambia, the peak age of hospital admission for severe malaria increased from 3.9 years in 1999–2003 to 5.6 years in 2005–07 (Ceesay and others 2008); similar changes have been seen in Kenya (O’Meara and others 2008).

If the financial support for malaria control continues, further decreases in the intensity of transmission can be anticipated in many highly endemic areas; these decreases will increase the incidence of clinical attacks of malaria, including severe attacks, in school-age children (ages 5–14 years). However, the epidemiology and management of malaria in school-age children has, until recently, received little attention. This chapter reviews the current burden of malaria in school-age children, its clinical consequences, and approaches to controlling the disease in this increasingly vulnerable group. The review focuses largely on Sub-Saharan Africa, in part because this region has the greatest burden of malaria in school-age children, but also because of the lack of information on the impact of malaria in school-age children in other parts of the world, including those where Plasmodium vivax is the dominant malaria parasite. An earlier version of the review has been published (Nankabirwa, Brooker, and others 2014). Definitions of age groupings and age-specific terminology used in this volume can be found in chapter 1 (Bundy, de Silva, and others 2017).