PARASITE CONTROL IN WATERS and ITS IMPORTANCE
Water, which is indispensable for our lives, is also the source of various organic-inorganic materials and microorganisms it can carry. To be able to prevent the water-born diseases, the recovery of the water sources which can be a disease source should be taken care of.
Due to the reasons such as being resistant to the disinfectants, having the high penetration rate, presence of the small cysts in the environment, causing infections in even low doses, the amoebas Entamoeba histolytica, Giardia intestinalis and coccidia, and the parasites Cryptosporidium parvum are the ones which are emphasized in last years. The Ministry of Health obliged the screening of the parasites in both the spring waters and drinking waters in The Regulation Concerning Water Intended for Human Consumption. In this regulation, it is underlined that parasites dangerous for the human health should not be present in 100 ml of drinking and spring waters prepared in the factories.
Bilim Laboratories continue its PCR optimization studies for the detection of pathogen parasites that can be found in waters besides ELISA and IFA methods, particularly by using the conventional microscopic method.
Giardia intestinalis (Giardia lamblia)
Drinking waters have the fundamental transporter role for the Giardia cysts. Individuals infected with the parasite excrete the cysts via stool. Thus, the surface waters such as stream, lake and ponds can be contaminated by the sewage or by the animal stools with Giardia cysts. Groundwater is protected since the soil acts as a filter and holds the cysts. Humans and other mammals can carry Giardia. In case of contamination, Giardia cysts can stay in the water more than 60 days. Giardiasis, which is highly common in our country, is the most commonly seen parasite infection in the world according to the World Health Organization (WHO) reports and each year 500.000 new cases are reported each year, especially with the most patient groups in Asia, Africa, and Latin America.
The Giardia infection show up includes the 1-4 weeks after taking the parasite. For the infection to occur less than 10 cysts are enough. Drug treatment is applied in the presence of infection. It is quite difficult to detect Giardia in water sources. The test methods used for the Giardia contamination is for the confirmation suspicious Giardia contamination. This includes the 5-10 times filtration of water at least, and visualization of the cysts as a result of the analysis. Demonstration of the Giardia lamblia through the PCR is the preferred method to show the presence of Giardia lamblia.
Cryptosporidium is a protozoan which can be spread through the water and which is the Cryptosporidiosis factor. The people swimming in the waters such as lake, river and swimming pools infected with Cryptosporidium, people always near the water, people who can encounter with the contaminated water such as walking or camping around can be infected with this parasite. If the person is washed with or drink the parasite contaminated water, the parasite goes to the intestine and cause disease by reproducing there. Cysts continue their life cycle by being excreted by stools.
Incidence of Cryptosporidiosis which is mostly seen in Asia, Africa, Australia and Latin America, changes between 0,6-20%. The biggest Cryptosporidiosis epidemic was reported in Wisconsin as a result of consumption of the drinking water contaminated with the oocyst by 400.000 people. In the studies, Cryptosporidium parvum oocysts were found to be resistant to the chlorination, they can stay alive in drinking water for 176 days and at the end of this period 89-99% is degraded. Besides the Cryptosporidium epidemics reported from abroad, it is thought that there might be similar epidemics in our country and more notification is required about this issue.
Entamoeba histolytica is a parasite which can spread from human to human and by the water and foods, and which is the intestinal amebiasis (Amebiasis). Amebiasis is common in tropical and subtropical climate regions. In the infection, trophozoite structure is not important when it is unstable. Cysts cause diseases by contaminating the waters and uncooked food materials. The role of house flies is important as a vector in the spreading of the disease.
The cysts taken from the mouth penetrates into the tissue and cause ulcer in the intestine. Amoebas sometimes reaches to liver by getting into the portal vein and at the end they cause abscess. It can also cause abscess in organs where it reaches through the bloodstream. Acute Amebiasis is generally seen 8-10 days after taking the cysts.