PREVALENCE AND SEVERITY OF MALNUTRITION IN PRE-SCHOOL CHILDREN IN A RURAL AREA OF WESTERN KENYA ARTHUR M. KWENA, DIANNE J. TERLOUW, SAKE J. DE VLAS, PENELOPE A. PHILLIPS-HOWARD, WILLIAM A. HAWLEY, JENNIFER F. FRIEDMAN, JOHN M. VULULE, BERNARD L. NAHLEN, ROBERT W. SAUERWEIN, AND FEIKO O. TER KUILE Centre for Vector Biology and Control Research, Kenya Medical Research Institute, Kisumu, Kenya; Division of Parasitic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia; Department of Medical Biochemistry, Faculty of Health Sciences, Moi University, Eldoret, Kenya; Department of Medical Microbiology, University Medical Center, St. Radboud, Nijmegen, The Netherlands; Department of Public Health, Erasmus University, Rotterdam, The Netherlands; Department of Infectious Diseases, Tropical Medicine & AIDS, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Roll Back Malaria, World Health Organization, Geneva, Switzerland Abstract. We determined the nutritional status of children less than five years of age in an area in rural western Kenya with intense malaria transmission, a high prevalence of severe anemia and human immunodeficiency virus, and high infant and under-five mortality (176/1,000 and 259/1,000). No information is available on the prevalence of mal- nutrition in this area. Three cross-sectional surveys were conducted between 1996 and 1998 to monitor the effect of insecticide-treated bed nets on child morbidity. Anthropometric indices are presented for 2,103 children collected prior to and during intervention (controls only). The prevalence of stunting (Z-scores for height-for-age [HAZ] <-2), wasting (Z-scores for weight-for-height [WHZ] <-2) and being underweight (Z-scores for weight-for-age [WAZ] <-2) was 30%, 4%, and 20%, respectively. This was severe (Z-score <-3) in 12% (stunting), 1% (wasting), and 5% (underweight) of the children. Few children less than three months of age were malnourished (<2%), but height-for-age and weight-for- age deficits increased rapidly in children 3-18 months of age, and were greatest in children 18-23 months old (44% stunted and 34% underweight). While the mean HAZ and WAZ stabilized from 24 months of age onwards, they still remained substantially below the reference median with no evidence of catch-up growth. Malnutrition is likely to interact with infectious diseases, placing children 3-24 months of age at high risk of premature death in this area. INTRODUCTION The fourth report on global nutrition showed that the scope of malnutrition is still unacceptably high and progress to re- duce it in most regions of the world is slow. 1 It was estimated that in the year 2000, 182 million pre-school children, or one- third of children less than five years old in developing coun- tries were stunted, reflecting long-term cumulative inadequa- cies of health and/or nutrition. 2 Approximately 27% were estimated to be underweight. 1 While the overall trend in nu- tritional status in developing countries over the last 20 years is one of improvement, and is expected to continue, the United Nations region of eastern Africa (which includes Kenya, but also higher-risk countries such Djibouti and Ethiopia) is the only region where the trend has been in the opposite direction. The prevalence of stunting and being un- derweight among pre-school children in this region are now estimated at 48% and 36% and are expected to increase fur- ther over the next decade. 1 In Kenya, the prevalence of stunted and underweight chil- dren remained stable throughout the 1990s, as did the gross national product per capita, while the less than five mortality rate increased slightly from 105/1,000 to 112/1,000. 3 The Ken- yan National Council for Population and Development’s es- timates of the prevalence of malnutrition in 1997-1998 in children less than five years of age showed a large variation by province, reflecting the considerable variability in environ- mental and socioeconomic risk factors. These estimates were approximately 33.0% (stunting), 22.1% (underweight), and 6.1% (wasting) for Nyanza Province in western Kenya. 4 It is unknown whether these statistics apply to our study area in Asembo, where malaria studies have been undertaken over the past 20 years. This poor rural area located in Nyanza province in western Kenya has intense malaria transmission and a high prevalence of human immunodeficiency virus (HIV). Both malaria and HIV are perceived as the main contributors to the very high infant and less than five mor- tality (176/1,000 and 259/1,000) in this area, which is con- siderably higher than in other parts of Kenya. 5 We have previously shown that the main burden of malaria in this area is in a relatively narrow range between 3 and 16 months of age, after which children who survived have acquired sufficient clinical immunity to be protected from severe ma- laria. 6 This period of highest risk overlaps with the main risk period for iron deficiency anemia (4-6 to 24 months). 7 Furthermore, approximately 35-45% of HIV-1-infected children are estimated to die within the first 24 months of life. 8,9 While public perception assumes that children in this area are prone to malnutrition, no data have been available to support this, or to make comparisons with other populations. As part of a large, randomized, controlled intervention study of insecticide (permethrin)-treated bed nets (ITNs), we moni- tored all-cause morbidity and standard parameters of malnu- trition in a series of cross-sectional surveys involving a ran- dom selection of pre-school children. 10 The aim of this report is to describe the nutritional status of these children and to determine the main age groups at risk of malnutrition. Only data collected prior to the introduction of ITNs, and subsequent data from control villages are used for this analy- sis. MATERIALS AND METHODS Details of the ITN trial site and methods have been de- scribed in detail elsewhere. 11,12 Briefly, the study site is in Asembo, located on the shores of Lake Victoria, in Bondo district of western Kenya. The population is ethnically homo- geneous; more than 95% are members of the Luo tribe. The main occupations are subsistence farming (mainly maize, sor- Am. J. Trop. Med. Hyg., 68(Suppl 4), 2003, pp. 94–99 Copyright © 2003 by The American Society of Tropical Medicine and Hygiene 94