Infectious Disease and School-Age Children
A range of infectious diseases affect school-age children.
Helminth Infections
Between 25 and 35 percent of school-age children are estimated to be infected with one or more of the major species of worms (Bundy 1997; see also chapter 24). The most common and important infections are caused by geohelminths (the roundworm Ascaris, the whipworm Trichuris, and the two species of hookworms Ancylostoma and Necator) and by the schistosomes (Schistosoma spp.), which give rise to a wide range of chronic but largely nonspecific symptoms. The most intense worm infections and related illnesses occur at school age (Partnership for Child Development 1998b, 1999) and account for some 12 percent of the total disease burden and 20 percent of the loss of disability-adjusted life years (DALYs) from communicable disease among schoolchildren (World Bank 1993).
Infected schoolchildren perform poorly in tests of cognitive function; when they are treated, immediate educational and cognitive benefits are apparent only for children with heavy worm burdens or with concurrent nutritional deficits. Treatment alone cannot reverse the cumulative effects of lifelong infection or compensate for years of missed learning, but studies suggest that children are more ready to learn after treatment for worm infections and may be able to catch up if this learning potential is exploited effectively in the classroom (Grigorenko and others, forthcoming). In Kenya, treatment reduced absenteeism by one-fourth, with the largest gains for the youngest children who suffered the most ill health (Miguel and Kremer 2004).
Malaria
Up to 5 percent of children infected with malaria early in life have residual neurological sequelae (Snow 1999). In areas of unstable transmission, malaria accounts for 10 to 20 percent of all-cause mortality among school-age children (Bundy and others 2000), and those who have suffered repeated attacks have poorer cognitive abilities. In Kenya, primary school students miss 11 percent of school days because of malaria, equivalent to 4 million to 10 million days per year (Brooker and others 2000).
Oral antimalarial treatment reduced school absenteeism by 50 percent in Ghana (Colbourne 1955); the use of insecticide-treated bednets in Tanzania reduced malaria and increased attendance (Shiff and others 1996). Girls in The Gambia were more than twice as likely to enroll in primary school if they had received malaria prophylaxis in early childhood (Jukes and others submitted).
HIV/AIDS
Although school-age children have the lowest infection prevalence of any age group (figure 58.2), an estimated 3.8 million children under 15 years of age have been infected with HIV and more than two-thirds have died (UNAIDS 2002). Even uninfected children suffer physically, socially, and psychologically through death or illness in their family (World Bank 2002). The proportion of orphans, most of whom are of school age, has risen from 2 to 15 percent in some African countries, with AIDS accounting for 50 percent of this increase. The number of orphans is expected to reach more than 25 million by 2010.
[Figure
58.2]
School-age children with HIV infections have lower IQ levels and poorer academic achievement, language, and visual motor functioning. These deficits can be reduced or reversed with antiretroviral therapy. The improvement is greater for children of school age than for younger children.
Acute Respiratory Infection
Acute respiratory infection, the most common acute infection in school-age children globally, is a significant cause of absenteeism. Research in industrial countries (Cohen and Smith 1996) finds that flu infection affects attention and reaction time; colds primarily affect hand-eye coordination, as well as reduce the ability to tolerate high levels of noise and other distractions common to the classroom.
