Predominance of Blastocystis sp. Infection among School Children in Peninsular Malaysia

RESEARCH ARTICLE Predominance of Blastocystis sp. Infection among School Children in Peninsular Malaysia Kalimuthu Nithyamathi1, Samudi Chandramathi2, Suresh Kumar1* 1 Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia, 2 Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia * a11111 Abstract Background OPEN ACCESS Citation: Nithyamathi K, Chandramathi S, Kumar S (2016) Predominance of Blastocystis sp. Infection among School Children in Peninsular Malaysia. PLoS ONE 11(2): e0136709. doi:10.1371/journal. pone.0136709 Editor: Henk D. F. H. Schallig, Royal Tropical Institute, NETHERLANDS Received: August 12, 2014 Accepted: August 8, 2015 Published: February 25, 2016 Copyright: © 2016 Nithyamathi 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. Data Availability Statement: All relevant data are available in the paper. Funding: This research was supported by High Impact Research (HIR) Grant – Ministry of High Education (MOHE) - (Project UM.C/625/1/HIR/044) and Postgraduate Research Grant (PPP), Institute Graduate Studies, University Malaya - (PV1332012A). One of the largest cross-sectional study in recent years was carried out to investigate the prevalence of intestinal parasitic infections among urban and rural school children from five states namely Selangor, Perak, Pahang, Kedah and Johor in Peninsula Malaysia. This information would be vital for school authorities to influence strategies for providing better health especially in terms of reducing intestinal parasitism. Methods and Principal Findings A total of 3776 stool cups was distributed to 26 schools throughout the country. 1760 (46.61%) responded. The overall prevalence of intestinal parasitic infection in both rural and urban areas was 13.3%, with Blastocystis sp (10.6%) being the most predominant, followed by Trichuris trichiura (3.4%), Ascaris lumbricoides (1.5%) and hook worm infection (0.9%). Only rural school children had helminthic infection. In general Perak had the highest infection (37.2%, total, n = 317), followed by Selangor (10.4%, total, n = 729), Pahang (8.6%, total, n = 221), Kedah (6.2%, total, n = 195) and Johor (3.4%, total, n = 298). School children from rural schools had higher infection (13.7%, total, n = 922) than urban school children (7.2%, total, n = 838). Subtype (ST) 3 (54.3%) is the most predominant ST with persons infected with only ST1 and ST3 showing symptoms. Blastocystis sp infection significantly associated with low household income, low parent’s education and presence of symptoms (p<0.05). Conclusion It is critical that we institute deworming and treatment to eradicate the parasite especially in rural school children. Competing Interests: The authors have declared that no competing interests exist. PLOS ONE | DOI:10.1371/journal.pone.0136709 February 25, 2016 1 / 14 Blastocystis in Rural School Children Introduction Intestinal parasitic infection (IPI) is common with an estimation of 3 billion people infected worldwide. It is a major public health problem in Southeast Asia particularly among poor children living in urban squats and rural communities. In Malaysia, intestinal parasitic infection is endemic among Orang Asli communities [1,2]. High infection rates are associated with high human population density, low socio-economic status, inadequate supplies of clean water, insanitary disposal of feces and larger families [2]. Infection distribution in a community follows a negative binomial pattern, although everybody is susceptible, most individuals are uninfected or have low infection intensity, whilst only a small proportion carry a heavy parasitic load [3]. Epidemiological studies carried out previously showed that the socioeconomic situation can be one of the major contributors to disease transmission caused by parasitic diseases. Blastocystis sp. have been shown to be the commonest intestinal parasite found in most stool surveys[4]. Most of the prevalence studies carried out in Malaysia focused on aborigines [1,5,6], HIV infected patients or immunocompromised patients[7], closed communities namely high-rise flat dwellers [8,9], patients diagnosed with gastrointestinal disorders such as Irritable Bowel Syndrome (IBS) [10] and colorectal cancer patients [11]. The cohort group never exceed sample of 300 except two studies which examined 500 stool samples form the aborigine community. There are increasing reports implicating that the parasite causes diarrhoea and stomach bloating [12–14]. The prevalence of Blastocystis sp. varies with different types of population however it can be seen that a large scale survey has never been carried out (Table 1). Furthermore, extensive studies on this parasite showed that Blatocystis sp. infection is not restricted to or just affecting developing countries such as Bangladesh [15], China [16], Nepal [17], Pakistan [15], Thailand [18], Turkey [19] but also developed countries such as Denmark [20], France [21], Germany [15], Japan [15], Singapore [22] and United States [4]. There has not been a pervasive prevalence study on IPI throughout the nation. As the nation is progressing towards a developed status, one of the indicators of achievement is health. Table 1. Prevalence studies on Intestinal parasitic infection in Malaysia from 1999 to 2013. No Type of parasite Type of population Location Total sample size Year Reference 1 Intestinal parasite aborigine children Kelantan 111 2013 [23] 2 Blastocystis sp. Orang Asli Negeri Sembilan, Perak and Pahang 500 2014 [24] 3 Giardia sp. Orang Asli Selangor, Perak and Pahang 500 2012 [25] 4 Blastocystis sp. rural primary schoolchildren Pahang 300 2012 [26] 5 Intestinal parasite rural community West Malaysia 550 2012 [27] 6 Intestinal parasite HIV-infected individuals Malaysia 346 2011 [28] 7 Cryptosporidium sp Orang Asli Selangor 276 2011 [29] 8 Giardia sp. Orang Asli Pahang 321 2008 [30] 9 soil-transmitted helminths Orang Asli Selangor 281 2007 [31] 10 Intestinal parasite Orang Asli Cameron highland 262 2007 [32] [6] 11 intestinal protozoa Orang Asli Pahang 130 2007 12 Cryptosporidium sp.sp HIV-infected Kajang Hospital, Selangor 66 2005 [33] 13 Intestinal parasite public Kuala Lumpur 246 2005 [9] 14 Intestinal parasite interior communities Rejang River, Sarawak 355 2002 [34] 15 Intestinal parasite aborigine children Kelantan 162 1997 [35] 16 Giardia duodenalis rural community Malaysia 917 1998 [36] 17 Blastocystis sp. animal handlers local research institutions and zoo 105 1999 [37] doi:10.1371/journal.pone.0136709.t001 PLOS ONE | DOI:10.1371/journal.pone.0136709 February 25, 2016 2 / (...truncated)