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Wastewater Protozoa Sampling, Testing, and Analysis
Published in Frank R. Spellman, Fundamentals of Wastewater-Based Epidemiology, 2021
Note: Three prescription drugs are available in the United States to treat giardiasis: quinacrine, metronidazole, and furazolidone. In a recent review of drug trials in which the efficacies of these drugs were compared, quinacrine produced a cure in 93 percent of patients, metronidazole cured 92 percent, and furazolidone cured about 84 percent of patients (Davidson, 1984).
Water Treatment and Purification
Published in P.K. Tewari, Advanced Water Technologies, 2020
Protozoa are unicellular eukaryotic microorganisms that lack cell walls and usually obtain their food by ingesting other organisms or organic particles. Protozoa can infect humans by staying as parasites in the intestines of humans. The most common protozoal diseases are diarrhea and dysentery. Giardia lamblia causes an acute form of gastroenteritis. The cyst form is 8–12 μm long and 7–10 μm wide. It is infectious to people by the fecal-oral route of transmission. Their germination in the gastrointestinal tract brings about the symptoms of giardiasis like diarrhea, nausea, vomiting and fatigue. These cysts can survive several days (up to 77 days in water at less than 10°C) and are highly resistant to chlorine disinfection, however they get inactivated when subjected to temperatures of 54°C and above for 5 minutes.
Design Criteria in Water Treatment Processes
Published in Willy J. Masschelein, Unit Processes in Drinking Water Treatment, 2020
Amoebae. The causal organism of amebic dysentery is a cyst of Endamoeba hystolytica, which can be carried undetected until it causes chronic outbreaks. There have been several outbreaks of the illness since World War II (e.g., United States, 1955). The disease is a potential danger throughout the world, but is encountered more frequently in tropical and subtropical regions. Disinfection requires high doses of chemicals; however, sand filtration is also efficient. Ninety-two percent of cases of the illness transmitted by public distribution systems are the result of deficiencies in treatment but can also be caused by insufficient protection of the distribution mains (back-siphonage). Giardia lamblia is a flagellated protozoan causing giardiasis. Amoebae of the Naegleria type have been involved in amebic encephalitis. Both organisms are transmitted by water in recreational areas.
Giardia spp. cysts and Cryptosporidium spp. oocysts in drinking water treatment residues: comparison of recovery methods for quantity assessment
Published in Environmental Technology, 2021
Kamila Jessie Sammarro Silva, Lyda Patricia Sabogal-Paz
The genera of protozoa Giardia and Cryptosporidium include the most commonly encountered enteric parasites, responsible for gastrointestinal diseases causing nutritional imbalances and severe health problems, especially in children and people with immunological deficiencies [4]. The diseases caused by Giardia and Cryptosporidium are called giardiasis and cryptosporidiosis, respectively.