Intestinal Helminthic Infections Flashcards
Intestinal Taeniasis lab diagnosis
1) Stool examination - wet mount saline or iodine.
Eggs are T. Saginata and T. Solium are round containing embryo with six hooklets surrounded by embryophore. Bile stained & not float in saturated salt solution.
Proglottids can be differentiated by lateral branches in uterus , accessory lobe in ovary and vaginal sphincter.
2) antigen detection in stool by ELISA to detect taenia specific coproantigen
3) molecular method by using PCR targeting mitochondrial DNA.
Hymenolepiasis lab diagnosis
Stool microscopy detecting the characteristic egg confirm’s diagnosis.
1) Egg round to oval in shape
2) Non bile stained and colourless on saline mount.
3) Has two members surrounding embryo with six hooklets
4) Presence of polar filaments at both polar ends of embryophore
Dipylidium caninum lab diagnosis
Eggs in feces are present in groups like egg packets. Proglottids are barrel shaped and contains 2 genital pores.
Diphyllobothriasis lab diagnosis diphyllobothrium latum
School examination shows operculated eggs with a knob at the other end. Eggs are bile stained and do not float in saturated salt solution and blood examination shows eosinophilia and megaloblastic anaemia.
Schistosomiasis lab diagnosis
Stool microscopy - eggs are oval elongated and has lateral spine. Egg shell is acid fast. Hatching test can be done when stool Specimen is diluted in water and beam of light is passed in water.
ELISA or dipstick test are used to detect circulating cathodic and anodic antigens in serum and urine.
Antibody detection which can also be useful but it still remains positive after successful treatment.
Fasciolopsiasis lab diagnosis
Stool microscopy shows large operculated eggs.
Trichuriasis lab diagnosis caused by trichuris trichura.
Stool microscopic examination by saline or iodine mount or by concentration of stool sample. Eggs are barrel shaped with mucus plugs at ends which are bile stained and float in saturated solution.
Enterobiasis lab diagnosis caused by enterobius vernicularis
Microscopy of the peri anal skin sample in which specimen is collected by cellophain tape or by NIH swab.
Eggs are planoconvex with tadpole shaped larvae inside it
NUMBER OF SPECIMEN COLLECTED ARE IN SERIES OF 4 TO 6 CONSECUTIVE DATES AND TIMING OF SAMPLE IS LATE EVENING OR EARLY MORNING.
Ascariasis lab diagnosis caused by ascaris lumbricoides
School examination by detecting fertilized and unfertilized eggs by iodine wet Mount or saline mount.
Eggs have presence of albuminous coat with unsegmented ovum with cresentric space present (Fertilized) or absent at both poles.
Concentration techniques by formal ether sedimentation method to improve detection.
Other methods include detecting in stool or sputum sample of the patient by naked eyes or barium meal x-ray of the GIT.
Larvae can be found in sputum or gastric aspirates during the early pulmonary migratory phase.
Molecular techniques include detecting ascaris specific genes by using PCR assay. You see no failure is prominent during early lungs stage.
Presence of charcot Leyden crystals in sputum and stool.
Hookworm lab diagnosis caused by ancyclostoma duodenale or nector Americanus.
Stool microscopy shows eggs of hookworm. Ovum is segmented made of 4 blastomeres and presence of clear space between egg shell and embryo.
Stool culture in agar plate technique or harada Mori filter paper tube method.
Molecular diagnosis by targeting mitochondrial cytochrome oxidase genes.
Other findings include hypochromic microcytic anemia, eosinophilia and hypoalbuminemia.
Strongyloidiasis lab diagnosis caused by strongyloides stercoralis.
Stool microscopy shows presence of rhatditiform larvae which has shorter buccal cavity and large genital primordium.
Entero test which is done by using duodenal aspirate can be examined for presence of larvae.
Stool culture by using harada Mori filter paper tube method and agar plate technique.
Serology by using ELISA.
Coproantigen detection in stool by using ELISA.
Molecular techniques like RTPCR targeting various genes of S. stercoralis.
