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TechLab. Parasitology. GIARDIA TEST Cryptosporidium TEST E.histolytica II TEST. Giardia lamblia. Background Morphology and life cycle Incidence Symptoms Available Tests for diagnosis. Background. First described by Leeuwenhoek in 1681
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TechLab Parasitology GIARDIA TEST Cryptosporidium TEST E.histolytica II TEST
Giardia lamblia • Background • Morphology and life cycle • Incidence • Symptoms • Available Tests for diagnosis
Background • First described by Leeuwenhoek in 1681 • First report of Giardiasis credited to Lambl in 1859 • The most commonly diagnosed flagellate in the intestinal tract • Three groups have been described: • Giardia muris - rodents, birds, reptiles. • Giardia agilis - amphibians • Giardia intestinalis (lamblia) - mammals
Incidence • The most commonly isolated intestinal parasite worldwide • Especially prevalent in children - outbreaks in daycare centers and within families • Giardia cysts have been detected in 81% of raw water samples and 17% of filtered • Waterborne transmission is a cause of Giardiasis in travelers and backpackers • Can be sexually transmitted
Symptoms • Incubation period is usually 1-2 weeks • Low grade fever, chills, nausea and anorexia can be early symptoms • Subsequently - explosive, watery, foul smelling diarrhea; marked abdominal gurgling; flatulence; abdominal distension and belching with a foul taste. • The acute stage can resemble travelers diarrhea and is often not recognized as giardiasis
Available Tests • Iodine Wet Mount • Immunofluorescent antibody Test • Enzyme Immunoassays • Rapid assays - gold conjugates
GIARDIA TEST • Monoclonal antibody based • Detects a cyst wall protein (CWP1) • Variable first incubation time (results available in as little as 40mins) • 3 wash steps • Sensitivity: 97 - 100% • Specificity: 100%
Giardia Tests • TechLab GIARDIA TEST • Alexon Trend ProspecT (both micorplate & flow through) • Seradyn Color Vue Giardia (subsidiary of Alexon-Trend) • Remel RIM (subisidiary of Alexon-Trend) • Biosite Triage Parasite Panel • BD ColorPac
TechLab GIARDIA TEST • Monoclonal antibody based • The only test available where the protein detected has been fully characterized • Detects the same protein as the other monoclonal antibody based tests • Using a 10min first incubation, it is the most rapid microtiter EIA available • Can be run in the same format as the Cryptosporidium TEST
Cryptosporidium • Background • Morphology and life cycle • Incidence • Symptoms • Available Tests for diagnosis
Background • First description of an organism resembling Cryptosporidia was by Clark in 1895 • In 1910 Tyzzer proposed the genus name Cryptosporidium for the protozoan parasite • 1976 - first human case of Cryptosporidiosis described • 1980s the onset of AIDs in the US brought attention to the association of Cryptosporidium with diarrheal illness • Only species infectious to humans is C.parvum
Incidence • The prevalence rate in North America and Europe is 1 - 3% • It can reach up to 20% in underdeveloped countries • Children are the most susceptible • Several nosocomial infections have been reported • Patients with late stage AIDs are very susceptible and develop life threatening diarrhea
Incidence continued…. • Waterborne outbreaks continue to be a problem as the organism is resistant to chlorine and passes through filters of both filtration plants and public swimming pools • In 1993, 400,000 people in Milwaukee Wisconsin were exposed & over 100 died. • Swimming pools are a source of infection due to babies in diapers and AFR (accidental fecal release) • Can be foodborne
Symptoms • Incubation period is 5 to 28 days • Diarrhea is profuse and watery with as many as 71 stools per day and up to 17 liters per day • May be accompanied by low grade fever, nausea and vomiting • Symptoms wax and wane and may correlate with oocyst shedding
Available Tests • Microscopy • Immunofluorescent Test • EIA • Lateral Flow Immunochromatographic Tests
Microscopy for Cryptosporidium is insensitive due to the small size of the organism - it is very difficult to see!
Cryptosporidium Tests • TechLab Cryptosporidium TEST • Alexon Trend ProspecT Cryptosporidium (in both microplate and flow through format) • Seradyn Color Vue Cryptosporidium (subsidiary of Alexon Trend) • Alexon Trend Giardia/Cryptosporidium Assay • Biosite Triage Parasite Panel • BD ColorPac Giardia/Cryptosporidium
TechLab Cryptosporidium TEST • Monoclonal Antibody based • 2 wash steps • Sensitivity: 97% • Specificity: 97.7 - 100% • Crypto and Giardia Tests can be run in the same format (Crypto format)
Entamoeba histolytica • Background • Morphology and life cycle • Incidence • Symptoms • Available Tests
Background • Presence of organism was first described in a woodworker in Northern Russia in 1875 • In 1925 Brumpt differentiated a pathogenic invasive form from a non pathogenic form • Recently Clark and Diamond verified the existence of both pathogenic and non pathogenic strains
Incidence • Infections occur worldwide and it has been suggested that 12% of the world’s population may be infected • 10% develop clinical symptoms causing between 40,000 to 120,000 deaths per year • Transmission by water is common in developing countries and does occur in this country • Serious outbreaks have occurred in the USA, however, are not well documented • Can be sexually transmitted and foodborne
Symptoms • Incubation period varies from a few days to months • asymptomatic colonization • acute amebic colitis - abdominal pain, bloody stools, fever • fulminant colitis - abdominal pain, profuse bloody diarrhea, fever • ameboma - asymptomatic lesion or a tender mass accompanied by dysentery
Available Tests • Microscopy • Culture and zymodeme analysis • TechLab E.histolytica Test • Alexon Trend Entamoeba histolytica Test • Biosite Triage Parasite Panel