A trichrome stain of preserved stool is another method used to detect Giardia. Microscopic examination of the stool can be performed for diagnosis. This method is not preferred, however, due to inconsistent shedding of trophozoites and cysts in infected hosts. Multiple samples over a period of time, typically one week, must be examined. The Entero-Test uses a gelatin capsule with an attached thread. One end is attached to the inner aspect of the hosts cheek, and the capsule is swallowed. Later, the thread is withdrawn and shaken in saline to release trophozoites which can be detected with a microscope. The sensitivity of this test is low, however, and is not routinely used for diagnosis. Immunologic enzyme-linked immunosorbent assay (ELISA) testing may be used for diagnosis. These tests are capable of a 90% detection rate or more.Although hydrogen breath tests indicate poorer rates of carbohydrate absorption in those asymptomatically infected, such tests are not diagnostic of infection. Serological tests are not helpful in diagnosis. Prevention
The CDC recommends hand-washing and avoiding potentially contaminated food and untreated water.Boiling water contaminated with Giardia effectively kills infectious cysts. Chemical disinfectants or filters may be used. Iodine-based disinfectants are preferred over chlorination as the latter is ineffective at destroying cysts.Although the evidence linking the drinking of water in the North American wilderness and giardiasis has been questioned, a number of studies raise concern. Most if not all CDC verified backcountry giardiasis outbreaks have been attributed to water.
The states of Illinois, Kentucky, Mississippi, North Carolina, Oklahoma, Tennessee, Texas, and Vermont did not notify the Center for Disease Control regarding cases in 2018. The states with the highest number of cases in 2018 were California, New York, Florida, and Wisconsin. There are seasonal trends associated with giardiasis. July, August, and September are the months with the highest incidence of giardiasis in the United States.In the ECDCs (European Centre for Disease Prevention and Control) annual epidemiological report containing 2014 data, 17,278 confirmed giardiasis cases were reported by 23 of the 31 countries that are members of the EU/EEA. Germany reported the highest number at 4,011 cases. Following Germany, the UK reported 3,628 confirmed giardiasis cases. Together, this accounts for 44% of total reported cases. Research
Some intestinal parasitic infections may play a role in irritable bowel syndrome and other long-term sequelae such as chronic fatigue syndrome. The mechanism of transformation from cyst to trophozoites has not been characterized but may be helpful in developing drug targets for treatment-resistant Giardia. The interaction between Giardia and host immunity, internal flora, and other pathogens is not well understood.The main congress about giardiasis is the "International Giardia and Cryptosporidium Conference" (IGCC). A summary of results presented at the most recent edition (2019, in Rouen, France) is available. Other animals
In both dogs and cats, giardiasis usually responds to metronidazole and fenbendazole. Metronidazole in pregnant cats can cause developmental malformations. Many cats dislike the taste of fenbendazole. Giardiasis has been shown to decrease weight in livestock. References
External links
Giardiasis Fact Sheet