Cyclosporiasis: An Emerging Potential Threat for Water Contamination

Abstract

According to the World Health Organization (WHO), 3.4 million people die every year from water-related diseases. Almost half the world's population have no acceptable means of sanitation and availability of potable drinking water. Lack of improved domestic water supply leads to various waterborne diseases, such as cholera, diarrhea, viral hepatitis A, dysentery and typhoid, which are transmitted by contaminated drinking water. Hence, improved water quality, sanitation and personal hygiene can significantly reduce the spread of water-related diseases. Diarrhea is the major illness caused due to the consumption of unhygienic water. It can be of bacterial, viral or parasitic origin. Most of the bacterial and viral agents like coliforms, Salmonella, Shigella, caliciviruses that contaminating water are killed by routine chlorination, but the parasitic forms (dormant/resistant cysts and oocysts) are difficult to remove and need special treatment. According to the World Health Organization (WHO), Cryptosporidium parvum oocysts and Giardia lamblia cysts are introduced to waters all over the world by fecal pollution. Although chlorine is the primary disinfectant of choice in water treatment practice, parasites like Cryptosporidium and Cyclospora are resistant to chlorine treatment and hence pose a formidable threat to water health. Cyclospora cayetanensis is an emerging protozoan parasite and causes small intestine gastroenteritis. The disease has been implicated in many foodborne outbreaks worldwide, especially contaminated products (raspberries, basil and lettuce) imported from developing nations. After washing these products, Cyclospora oocysts were found in water. This intrigued researchers to define the epidemiological link of Cyclospora to water. In the USA, Cyclospora has been detected in several sporadic cases associated with exposure to drinking or recreational sewage and water sources. There is apparently a worldwide distribution, including regions of endemicity, for example, Nepal, Haiti and Peru. Thus, there is an increased risk to travelers visiting these endemic areas. Moreover, because of the recent developments in the detection of protozoal parasites using acid-fast staining, the detection of Cyclospora cases has been raised worldwide. Due to the lack of a quantification technique, there is limited information on the prevalence of Cyclospora in water environments, necessitating the need for further research on pathways and transmission dynamics of cyclosporiasis and encouraging innovative research in water treatment for improving sanitation and public health.