title: Prevalence and risk factors of intestinal parasitism among two indigenous sub-ethnic groups in Peninsular Malaysia.
abstract: BACKGROUND
  Intestinal parasitic infections (IPIs) among indigenous people have been widely documented in Malaysia, however, the prevalence of these infections remains high. In the past, most studies have focused on specific species of parasites but polyparasitism has received limited attention. In addition, epidemiology studies on indigenous people tend to consider them as a homogenous group, whereas in reality different sub-ethnic groups have different cultural and living practices. Variations in living habits such as personal hygiene practices may predispose different groups to different parasitic infections. To better understand prevalence and risk factors of intestinal parasitism among different sub-ethnic groups, the present study was conducted among two sub-ethnic groups of indigenous people (Temuan and Mah Meri) residing in Selangor state, Malaysia.
  
  
  METHODS
  A cross-sectional study that focused on two distinct sub-ethnic groups was carried out from February to September 2014. Faecal samples were collected from 186 participants and examined using the formalin-ether sedimentation technique. A molecular approach was adopted to conduct a genetic characterisation of the parasites. Additionally, questionnaires were administered to obtain information on the demographics, socio-economic backgrounds and behavioural risks relating to the participants, as well as information about their environments. Statistical analyses (i.e. binary and multivariate logistic regression analyses) were performed to measure risk factors.
  
  
  RESULTS
  For Temuan communities, trichuriasis (64.2 %) was the most common infection found, preceding hookworm infection (34 %), ascariasis (7.5 %), giardiasis (14.2 %) and amoebiasis (7.5 %). As for the Mah Meri communities, trichuriasis (77.5 %) prevailed over ascariasis (21.3 %), hookworm (15 %), giardiasis (7.5 %) and amoebiasis (3.8 %). Significant differences in proportions of trichuriasis, ascariasis and hookworm infections were observed between the Temuan and Mah Meri sub-ethnic groups. Polyparasitism was more common among the Temuan sub-ethnic group (41.5 %) compared to the Mah Meri sub-ethnic group (32.5 %), with the majority of participants harbouring two parasites concurrently (Temuan: 33 %, Mah Meri: 20 %). Trichuris trichiura and Ascaris lumbricoides co-infections were most prevalent (10 %) among the Mah Meri communities, while a co-infection of T. trichiura with hookworm (19.8 %) was most common among the Temuan communities. Multivariate analyses showed that being unemployed, having a large family and drinking unboiled water were found to be significantly associated with intestinal parasitism.
  
  
  CONCLUSIONS
  The present study highlights substantial polyparasitism and risk factors for infections in the Temuan and Mah Meri sub-ethnic groups. The high prevalence of IPIs among these two sub-ethnic groups indicates that parasitic infections are important health issues in these communities. Hence, it is imperative to implement sound intervention strategies such as periodic preventive chemotherapy coupled with health education in order to reduce and eradicate these infections.
authors.affiliation: Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Yuee Teng
authors.initials: YT
authors.lastname: Chin
authors.affiliation: Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia. limailian@um.edu.my.
authors.forename: Yvonne Ai Lian
authors.initials: YA
authors.lastname: Lim
authors.affiliation: Department of Life Sciences, School of Pharmacy, International Medical University, 57000, Kuala Lumpur, Malaysia.
authors.forename: Chun Wie
authors.initials: CW
authors.lastname: Chong
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Cindy Shuan Ju
authors.initials: CS
authors.lastname: Teh
authors.affiliation: Department of Life Sciences, School of Pharmacy, International Medical University, 57000, Kuala Lumpur, Malaysia.
authors.forename: Ivan Kok Seng
authors.initials: IK
authors.lastname: Yap
authors.affiliation: Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Soo Ching
authors.initials: SC
authors.lastname: Lee
authors.affiliation: Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Mian Zi
authors.initials: MZ
authors.lastname: Tee
authors.affiliation: Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Vinnie Wei Yin
authors.initials: VW
authors.lastname: Siow
authors.affiliation: Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia. khchua@um.edu.my.
authors.forename: Kek Heng
authors.initials: KH
authors.lastname: Chua
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D060085:Coinfection / Q000453:epidemiology* / Q000469:parasitology; D003430:Cross-Sectional Studies; D005243:Feces / Q000469:parasitology; D005260:Female; D006373:Helminthiasis / Q000453:epidemiology* / Q000469:parasitology; D006801:Humans; D007411:Intestinal Diseases, Parasitic / Q000453:epidemiology* / Q000469:parasitology; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D044382:Population Groups; D015995:Prevalence; D011528:Protozoan Infections / Q000453:epidemiology* / Q000469:parasitology; D012307:Risk Factors; D055815:Young Adult
keywords: Indigenous people; Intestinal parasites; Intestinal parasitism; Mah Meri sub-ethnic group; Peninsular Malaysia; Prevalence; Risk factors; Sub-ethnic group; Temuan sub-ethnic group