Prevalence and Factors Associated with Intestinal Parasitic Infection among Children in an Urban Slum of Karachi Vikram Mehraj 1,2,3 , Juanita Hatcher 2 , Saeed Akhtar 2,4 , Ghazala Rafique 2 , Mohammad Asim Beg 1 * 1 Department of Pathology & Microbiology, Aga Khan University, Karachi, Pakistan, 2 Department of Community Health Sciences, Aga Khan University, Karachi, Pakistan, 3 Unite ´ Mixte de Recherche 6236, Centre National de la Recherche Scientifique, Faculte ´ de Me ´decine, Universite ´ de la Me ´diterrane ´e, Marseille, France, 4 Department of Community Medicine and Behavioral Sciences, Faculty of Medicine, Kuwait University, Safat, Kuwait Abstract Background: Intestinal parasitic infections are endemic worldwide and have been described as constituting the greatest single worldwide cause of illness and disease. Poverty, illiteracy, poor hygiene, lack of access to potable water and hot and humid tropical climate are the factors associated with intestinal parasitic infections. The study aimed to estimate prevalence and identify factors associated with intestinal parasitic infections among 1 to 5 years old children residing in an urban slum of Karachi Pakistan. Methods and Principal Findings: A cross sectional survey was conducted from February to June 2006 in Ghosia Colony Gulshan Town Karachi, Pakistan. A simple random sample of 350 children aged 1–5 years was collected. The study used structured pre-tested questionnaire, anthropometric tools and stool tests to obtain epidemiological and disease data. Data were analyzed using appropriate descriptive, univariate and multivariable logistic regression methods. The mean age of participants was 2.8 years and 53% were male. The proportions of wasted, stunted and underweight children were 10.4%, 58.9% and 32.7% respectively. The prevalence of Intestinal parasitic infections was estimated to be 52.8% (95% CI: 46.1; 59.4). Giardia lamblia was the most common parasite followed by Ascaris lumbricoides, Blastocystis hominis and Hymenolepis nana. About 43% children were infected with single parasite and 10% with multiple parasites. Age {Adjusted Odds Ratio (aOR) = 1.5; 95% CI: 1.1; 1.9}, living in rented households (aOR = 2.0; 95% CI: 1.0; 3.9) and history of excessive crying (aOR = 1.9; 95% CI: 1.0; 3.4) were significantly associated with intestinal parasitic infections. Conclusions: Intestinal parasites are highly prevalent in this setting and poverty was implicated as an important risk factor for infection. Effective poverty reduction programmes and promotion of deworming could reduce intestinal parasite carriage. There is a need for mass scale campaigns to create awareness about health and hygiene. Citation: Mehraj V, Hatcher J, Akhtar S, Rafique G, Beg MA (2008) Prevalence and Factors Associated with Intestinal Parasitic Infection among Children in an Urban Slum of Karachi. PLoS ONE 3(11): e3680. doi:10.1371/journal.pone.0003680 Editor: Colin J. Sutherland, London School of Hygiene & Tropical Medicine, United Kingdom Received April 18, 2008; Accepted October 18, 2008; Published November 10, 2008 Copyright: ß 2008 Mehraj et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: We acknowledge International Maternal and Child Health Research Training Program (FIC, NIH # 5 D43 TW05497-03) of Aga Khan University (AKU) and University of Alabama at Birmingham (UAB) for providing financial support in the development of this manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: masim.beg@aku.edu Introduction Intestinal parasitic infections (IPIs) are globally endemic and have been described as constituting the greatest single worldwide cause of illness and disease [1–3]. IPIs are linked to lack of sanitation, lack of access to safe water and improper hygiene; therefore they occur wherever there is poverty. IPIs deprive the poorest of the poor of health, contributing to economic instability and social marginaliza- tion. The poor people of under developed nations experience a cycle where under nutrition and repeated infections lead to excess morbidity that can continue from generation to generation. People of all ages are affected by this cycle of prevalent parasitic infections; however, children are the worst affected [1,2]. Ascaris lumbricoides, Trichuris trichiura and hookworms, collectively referred to as soil-transmitted helminths (STHs), are the most common intestinal parasites. [4]. Ascaris lumbricoides is the largest and the most common helminth parasitizing the human intestine and currently infects about 1 billion people worldwide [5]. Hymenolepis nana is the most common parasitic cestode prevalent globally [6]. Giardia duodenalis/Giardia intestinalis, previously known as Giardia lamblia, causing giardiasis, is the most prevalent protozoan parasite worldwide with about 200 million people being currently infected [6,7]. Another common intestinal protozoan is Blastocystis hominis whose parasitic status is under debate [5]. About one third of the world, more than two billion people, are infected with intestinal parasites [8,9]. Approximately 300 million people are severely ill with these worms and of those, at least 50% are school-age children [8]. IPIs rarely cause death but because of the size of the problem, the global number of related deaths is substantial [10]. About 39 million disability adjusted life years (DALYs) are attributed to IPIs and these infectious thus represent a substantial economic burden [11]. PLoS ONE | www.plosone.org 1 November 2008 | Volume 3 | Issue 11 | e3680