Opisthorchis viverrini: Southeast Asian liver fluke
Paragonimus westermani: Lung fluke
In cases of malaria, the primary exoerythrocytic cycle occurs in the:
The following organism was found in the fecal sample of a patient with diarrhea and elevated liver enzymes. Some organisms had the presence of ingested red blood cells in their cytoplasm. This organism is most likely:
B) Entamoeba histolytica
The parasite Toxoplasma gondii is acquired via the ingestion of infected oocysts from cat feces. A diagnosis is primarily made through:
E) serologic tests
The flotation method of concentration is used primarily to recover
A) cysts and eggs from stool
Taenia solium, which can grow to be 1.5 to 8 meters long, contains 7 to 13 lateral uterine branches along the proglottid. The intermediate host is:
(T/F) PVA fixative is appropriate for permanent staining including the Trichrome stain.
How are specimens collected for the detection of the organism shown here?
D) Scotch Tape Test
A medical laboratory scientist (MLS) is examining a thin blood film from a patient suspected of having Plasmodium infection. After examining the slide for 5 minutes and viewing approximately 100 oil immersion fields, the MLS does not observe any structures associated with Plasmodium. Which one of the following statements explains this discrepancy?
A) The MLS may have missed the organism; more than 300 fields should be viewed.
A young couple was recently vacationing in Massachusetts where they spent a lot of time hiking. Two weeks after returning from their trip, one of them comes down with fevers that spike every three hours. A thin smear of her blood yields the associated photo. What arthropod vector is responsible for spreading this disease and what parasite is the cause of her symptoms?
Human body louse
Match the following organism with the best diagnostic specimen.
Massive hemolysis, blackwater fever, and central nervous system involvement are most common sequelae of infection by:
B) Plasmodium falciparum
Humans acquire infections with Diphyllobothrium latum adult worms by:
A) Ingestion of raw or undercooked fresh water fish
A young girl from Arkansas presents with a history of abdominal pain. Hematologic tests show that she is anemic. An Ova and Parasite exam is ordered. The organism below is observed in her stool.
What organism is this?
C) Necator americana
The duodenal capsule technique involves the collection of duodenal contents to examine the presence of which of the following parasites?
C) Giardia lamblia
The examination of sputum maybe necessary to diagnose infection with:
D) Paragonimus westermani
Cutaneous larva migrans is associated with which of the following organisms?
D) Toxocara canis
A definitive diagnosis can be made in a Trichinella infection on the basis of which of the following findings?
D) Identification of encysted larvae through muscle biopsy
Which specimen would be the best to collect to discover this organism?
A) Vaginal or urethral swab
The permanent stained smear protocol of the O&P examination:
D) is designed to facilitate the identification of intestinal protozoa.
Which of the following parasitic stages is NOT usually detected after using a concentration technique?
A 28 yr old AIDS patient presented with watery, profuse, non-bloody diarrhea. When antibacterial medications did not alleviate his condition, a specimen was sent for further examination. Routine culture did not produce growth. A wet preparation from concentrated sediment showed the following organism.
What is this organism and to what group of parasites does it belong?
C) Isospora, Coccidia
When amebiasis is strongly indicated but no parasitic forms are detected from any of three submitted fecal samples, the next step might be
B) to collect material obtained from sigmoidoscopy and examine for parasites.
A 17-year-old male with a severe eye infection admits that he does not clean his contact lenses as often as he should. His eye infection is most likely the result of which parasite?
B) Acanthamoeba spp.
The eggs of which intestinal parasite are not commonly found in feces and must be detected by other diagnostic techniques?
D) Enterobius vermicularis
Primary amoebic-encephalitis may appear as bacterial meningitis and is caused by:
B) Naegleria sp.
More cyst forms of a parasite would be seen with which stool consistencies? (Select 2 answers)
Please explain why a symptomatic patient should submit at least 3 different stool specimens from 3 different days to the lab for parasite examination:
Individual examination of each of the three stool samples collected over a 9 day period increases the chances of detecting a parasite or it eggs that are constantly being removed from the body daily by natural flushing of the GI tract.
Molecular methods, including PCR, have been developed to detect specific parasites in a stool specimen. Choose 3 parasitic organisms that the CDC currently tests for using PCR.