Occurrence of Cryptosporidium and Giardia in potable water sources in Chandigarh, Northern India Kjersti Selstad Utaaker, Himanshu Joshi, Anil Kumar, Suman Chaudhary and Lucy J. Robertson ABSTRACT Contamination with Cryptosporidium and Giardia from drinking water sources in a city in Northern India was assessed. A protocol modified from a standard ISO protocol, which includes filtration, concentration, separation and detection steps, was tested and showed comparable recovery efficiencies (Giardia mean ¼ 77.4%, Cryptosporidium mean ¼ 61.8% from the modified protocol, compared with Giardia mean ¼ 61.6%, Cryptosporidium mean ¼ 69% from the ISO protocol) at a substantial cost reduction. This protocol was used for analysing 71 samples of potable water from different areas of Chandigarh, where sampling locations were divided into groups according to the population density, which also partially equates with the level of infrastructure. Samples were collected during (n ¼ 29) and outside the monsoon season (n ¼ 42). Of all samples analysed, 16 (22.5%) were Cryptosporidium- and/or Giardia-positive. Parasites per sample were low (1–10 (oo) cysts per 10 L), although one sample contained large numbers of Giardia cysts (>1,000). Polymerase chain reaction analyses on the small subunit ribosomal ribonucleic acid (SSU rRNA), triose-phosphate isomerase (tpi), glutamate dehydrogenase (gdh) and beta-giardin (bg) gene sequences on Giardia- positive samples and SSU rRNA on Cryptosporidium-positive samples tended to be unsuccessful, although Giardia cysts of Assemblages B and C were identified. No association with the season was detected, but an association with the location of water supply was identified. Samples from areas with the lowest infrastructure were not associated with higher levels of contamination, but samples from the middle level were significantly more likely to be contaminated than those from the highest level of infrastructure. Results indicate that even in a city with a well-developed infrastructure, the contamination of potable water with protozoan parasites remains a public health risk. Kjersti Selstad Utaaker (corresponding author) Lucy J. Robertson Parasitology Laboratory, Department for Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Adamstuen Campus, P.O. Box 8146 Dep. 0033, Oslo, Norway E-mail: kjersti.utaaker@nina.no Himanshu Joshi Anil Kumar Suman Chaudhary Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh 16002, India Suman Chaudhary Nanomedicine Laboratory of Immunology and Molecular Biomedical Research (NLIMBR), School of Medicine (SoM), Centre for Molecular and Medical Research (C-MMR) Strategic Research Centre, Faculty of Health, Deakin University, Waurn Ponds, Victoria 3216, Australia Key words | Cryptosporidium, detection, drinking water, Giardia, public health INTRODUCTION The World Health Organization (WHO) estimates that about 1.1 billion people globally drink unsafe water (Kind- hauser & WHO ), and the vast majority of diarrhoeal diseases in the world (88%) is attributable to unsafe water, poor sanitation, and general lack of hygiene interventions. Waterborne parasitic protozoan diseases result in 842,000 deaths per year and 1.7 billion cases of diarrhoea (WHO ; Checkley et al. ), and the morbidity and mortality caused by the waterborne diarrhoeal disease make them one of the planet’s largest environmental health threats to many populations (Gadgil ). Cryptosporidium and Giardia are two of the most common aetiological agents of childhood diarrhoea in developing countries, causing morbidity as well as mor- tality (Kotloff et al. ; Platts-Mills et al. ), and an expert elicitation found that waterborne transmission 483 © IWA Publishing 2019 Journal of Water Supply: Research and Technology—AQUA | 68.6 | 2019 doi: 10.2166/aqua.2019.157 Downloaded from http://iwaponline.com/aqua/article-pdf/68/6/483/600945/jws0680483.pdf by guest on 14 June 2022