ABSTRACT Background: Schistosomosis and soil-transmitted helminths are labelled neglected diseases and affect exclusively the poor in rural and urban areas of developing countries. In many cases, these infections occur where malaria is endemic and pose a major public health problem resulting in polyparasitism. Objective:The present study was undertaken to investigate the prevalence, intensity and the distribution patterns of multiple infections with Plasmodium sp, soil-transmitted helminths and schistosomosis among schoolchildren in Kisumu Municipality, Western Kenya. Methodology: Three hundred and fifty six (356) children were randomly selected from four primary schools. Plasmodium species identification and quantification was done using thin and thick blood smears while Kato Katz method (WHO kit) was used to quantify intestinal helminth egg/gram of stool. Nuclear Pore Filtration technique analysis of urine was used to diagnose Schistosoma haematobium. Additionally, questionnaires were administered to the participants to determine pre-disposing factors for parasite infections. Results: Polyparasitism among the study population is common phenomenon with Plasmodium falciparum and Schistosoma mansoni as the main infections that occur in single or coinfection with other diagnosed parasites. Sixty two percent (62%) of the school age children harbour multiple parasites within them, infected with more than one parasite species and only 8.6% (N = 356) of the total children were negative to all parasites diagnosed. Conclusion: The high prevalence of parasites among the children (91.4%) is important factor for instituting regular de-worming of schoolchildren and possible integration into the National Malaria Control programmes. There is need for policy change in malaria parasitaemia management to include treatment of asymptomatic individuals to reduce human reservoir and continuous transmission in the community and continuous public education to create awareness on dangers of infectious parasitic diseases.. KEYWORDS: Plasmodium, Schistosoma, Soil-transmitted helminths, schoolchildren, Kisumu, Kenya INTRODUCTION Malaria mainly caused by Plasmodium falciparum places a huge burden on human life and it is one of the major causes of morbidity and mortality in tropical countries especially in the Sub-Saharan Africa. Annually, an estimated 300 – 500 million clinical cases of malaria are reported while 1.5 – 2.7 million deaths occur worldwide mostly among children (Snow et al., 1999). In Kenya, malaria is a major cause of morbidity and mortality and the leading cause of outpatient and inpatient mortality (Ministry of Health, 20002). Schistosomosis and soil-transmitted helminths (hookworms, Ascaris lumbricoides and Trichuris trichiura) on the other hand, are among the most neglected infections that affect mostly the poor in the rural and impoverished urban areas (Hotez et al., 2005). Cases of hookworm infection worldwide are estimated to be 740 million, with the highest prevalence occurring in sub-Saharan Africa and Eastern Asia (De Silva et al., 2003). It is also estimated that at least 200 million people are currently infected with schistosomosis, and its mortality is estimated to be 11,000 deaths per year, a burden that is responsible for about 1.7 million disability-adjusted life years (DALYs) lost per year (TDR/WHO 2002). The school going children are particularly vulnerable to helminth infections as a result of several factors including poor environmental sanitation, due to their high mobility and their incomplete physical development and immunological defence mechanisms (Montressor et al., 2002). Polyparasitism affects a considerable proportion of the population especially in developing countries hence poses a great toll on public health (Keiser et al., 2002). Helminth infections trigger immune responses that may drain the body’s ability to fight other infections hence make the infected individuals to be more susceptible to other co- infections which can be detrimental especially in HIV infected individual (Watkins and Pollitt, 1997). It has been found that helminth infections tend to exacerbate the effect of malaria parasites and increase the number of attack in an individual (Le Hesran et al., 2004). Hookworms and other soil-transmitted helminths (STHs) have been known to be responsible for extensive morbidity and mortality in sub- Saharan Africa (Handzel et al., 2003). In Kenya, infections with P. falciparum, schistosomiasis and STHs are common in some areas hence leading to increase in chances of polyparasitism. Infections with intestinal Science Journal of Medicine and Clinical Trial ISSN:2276-7487 http://www.sjpub.org/sjmct.html © Author(s) 2013. CC Attribution 3.0 License. Published By Science Journal Publication International Open Access Publisher Research Article The Burden of Multiple Infections with Plasmodium Falciparum, Schistosoma Mansoni and Soil-transmitted Helminths among School Going Children in Kisumu, Kenya 1. Department of Biological Sciences, Egerton University, Box 536, Egerton, Kenya 2. Medical Entomology, Kenya Medical Research Institute (KEMRI), Box 54840-00200, Nairobi, Kenya 3. Medical Parasitology, East and Southern Africa Centre of International Parasite Control (ESACIPAC), KEMRI, Box 54840, Nairobi, Kenya 4. Biomedical Engineering, Duke University, Durham NC 27708, USA 5. Biological Sciences, Laikipia University, Box 1100, Nyahururu, Kenya Volume 2013, Article ID sjmct-294,8 Pages, 2013. doi: 0.7237/sjmct/294 Accepted 10�� August, 2013 Corresponding Author: Emmily C. Ngetich Biological Sciences, Laikipia University, Box 1100, Nyahururu, Kenya Email:emyngetich@gmail.com Emmily C. Ngetich⁵*, Jimmy H. Kihara² , Rose O. Odhiambo¹ , Charles Mwandawiro², ³ and Prashant Swaminathan⁴