What tissue/organ system is affected by Chaga's disease?
Cardiace tissue
What is the agent of mucocutaneous leishmaniasis?
Leishmania braziliensis
What is the agent of cutaneous leishmaniasis?
Leishmania tropica
What is the agent of the Baghdad Boil?
Cutaneous leishmaniasis
Your patient reports that he has been deployed to Iraq in the recent past, and has an annoying skin lesion that doesn't seem to heal, and in fact, might be getting worse. What disease would you add to your differential diagnosis? Can you local lab do a test for you?
Leishmaniasis. Ask the lab. They may have to send it out. THere is a study being done at WRAIR.
Leishmania present three clinical pictures; cutaneous, visceral, and muco-cutaneous. Each of these are associated with their own genus and species. Name the genus/species associated with each clinical presentation.
What is a common name of cutaneous leishmaniasis found in Iraq?
Baghdad Boil
Which cells are parasitized by leishmania?
Cells of the reticulo-endothelial system, macrophages
True/False. Leishmania infections are easily diagnosed with simple blood smear.
False. Traditional diagnosis has been Giemsa stained tissue smears and skin scrapings
True/False. Cattle and sheep are the resevoir hosts of leishmaniasis.
False. Dogs and rodents are important reservoir hosts of Leishmania
What is the name of the flagellated stage of the leishmania parasite that is injected when the vector takes a blood meal?
The promastigote (from mastix meaning whip - flagella in this case) is injected by the vector.
What is the name of the stage of the leishmania parasite that is taken up by macrophages of the reticuloendothelial system?
Amastigotes are found in the macrophages. (from mastix meaning whip - flagella in this case). This form is without flagella thus the name amastigote - without whip or flagella
If a soldier presents with a skin lesion that is difficult to heal and the soldier has a travel history that includes a recent deployment to Iraq, what parasitic disease might you add to your differential diagnosis?
Cutaneous leishmaniasis
What would be the specimen of choice for diagnosis of cutaneous leishmaniasis?
skin scrapings
Name the three clinical presentations of leishmania and the genus and species associated with each
This species of malaria is lethal and has developed drug resistance, making it more of a problem for man.
Plasmodium falciparum
This species of malaria parasitizes RBCs and makes them "sticky." The RBCs containing mature parasites adhere to the walls of the capillaries and mature parasites are difficult to detect in the peripheral blood smear. Often only ring forms and gametocytes are present.
Plasmodium falciparum
This malarial parasite has a characteristic fever periodicity that produces a fever spike every 3 days (72 hours). This periodicity has led to a common clinical name. Name the genus and species as well as the clinical description of the fever cycle.
Plasmodium malariae, quartan malaria
Name the genus and species of the malaria that is sometimes described as benign tertian malaria.
Plasmodium vivax
Name the genus and species of malaria that is sometimes described as malignant tertian malaria.
Plasmodium falciparum
This species of malaria can infect liver cells and "hide" there, providing opportunities for a "relapse."
Plasmodium vivax
This species of malaria produces a sausage-shaped gametocyte that is diagnostic when seen in a blood smear.
Plasmodium falciparum
This form of malarial parasite is ingested by the mosquito in a blood meal.
Gametocyte
This form of the parasite is injected by the mosquito while taking a blood meal.
Sporozoite
A definitive host is the host in which the sexual stage of reproduction takes place. What is the definitive host of malaria?
Mosquito
The intermediate host of a parasite is the host where the asexual stages of the parasites live. What is the intermediate host of malaria?
Humans
What type of reproduction do malaria parsites use to multiply in the liver?
Asexual reproduction: One cell divides to make two, etc. Process is called schizogony. Progeny are called schizonts - fram schizo - meaning split - these are "splitters."
How are soldiers protected against malaria?
Prophylatic doses of anti-malarial drugs can be given, use of insect repellent, mosquito netting while sleeping. Immunization is not effective.
What is the insect vector of malaria? What is the sex of the appropriate vector?
mosquito, female
Malaria infected cells rupture and release the many progeny of the parasite - what is the name of the stage released fromt he red cell?
Merozoites
There are microgametocytes and macrogametocytes of malarial parasites. What is the difference in these two?
Macrogametocytes are analagous to the female, and microgametocytes are analagous to male. The union of a microgamete and a macrogamete produces an ookinete
Describe a typical patient presentation for a person infected with malaria.
Recent travel history (outside USA). Complain of high fever (maybe with chills/maybe not), headache, myalgia, arthralgia, vomiting, diarrhea. Physical findings of splenomegaly. Add malaria to your differential diagnosis.
True/False: I never have to consider malaria in the USA since malaria is not endemic in the USA.
False. Remember that Plasmodium vivax can infect liver cells and the patient might "relapse" upon return to the USA from an endemic area. Be watchful of anyone with a travel history to a malarious area, especially if they did NOT take prophylactic drugs.
Plasmodium falciparum is more dangerous than the other species of malaria. Can you explain why?
Plasmodium falciparum will infect all red cells, regardless of age, where other species are more selective. P. falciparum is sometimes drug resistant and the infection can progress to death if not treated.
This small nematode lays sticky eggs at night. Eggs are flattened on one side
Enterobius vermicularis
Gravid female worms migrate to the perianal region of the patient at night and lay eggs
Enterobius vermicularis
This adult nematode is characterized as having alae (wings) at the side of the head.
Enterobius vermicularis
This very large nematode is acquired by direct hand-to-mouth infection (patient eats it).
Ascaris lubricoides
The correct method of diagnosis of this nematode is the scotch tape preparation
Enterobius vermicularis
True or false; Ascaris lumbricoides eggs are swallowed, the eggs hatch and the worms mature and live by eating intestinal contents
False. Ascaris lumbricoides eggs hatch, the larvae penetrate the intestinal lining, migrate through the lungs while maturing, ascend the bronchial tree and are swallowed. The adults now live inthe lumen of the intestine
This nematode "sews" its anterior end into the intestinal wall.
Trichuris trichuria
This nematode attaches itself to the intestinal villi by biting with semi-lunar cutting plates
Necator americanus (hookworm)
This nematode attaches itself to the intestinal villi by biting with fang-like teeth.
Ancylostoma duodenale (hookworm)
This nematode has a complicated life cycle that features a free living option and an autoinfective option in addition to its parasitic life cycle.
Strongyloides stercoralis
This nematode infection is often diagnosed by detecting rhabditiform larvae in the stool
Strongyloides stercoralis
This femal nematode is pathenogenic and burrows into the intestinal wall to lay eggs
Strongyloides stercoralis
This larval nematode is the cause of visceral larval migrans. Name the genus and species.
Toxocara canis or Toxocara cati
This larval form of this nematode is the cause of cutaneous larval migrans or creeping nematodes. Name the genus and species.
Ancylostoma caninum (dog hookworm), or any non-human hookworm. The larvae are "lost" and wander under the skin.
This nematode infection is acquired by eating the raw or poorly cooked flesh of mammals. The larvae encyst in the muscle tissue of the human host. Name possible mammalian sources of this infection and name the genus and species of the parasite.
Trichinella spiralis and it can be acquired by eating poorly cooked pork or bear, maybe others
This filarial nematode is acquired by being bitten by mosquitoes
Wucheria bancrofti and Brugia malayi
This filarial nematode is acquired by being bitten by a fly. Adults migrate across the eyeball.
Loa loa
Name the causative agent of elephantiasis.
Wucheria bancrofti and Brugia malayi
Name the genus and species of the filarial nematode that causes "River Blindness."
Onchocerca volvulus
Scotch tape "touch preps" are used to diagnose infections with this parasite.
Enterobius vermicularis
Eggs of this nematode are characteristically flattened on one side.
Enterobius vermicularis
Females of this species of nematode migrate to the perianal region, the uterus prolapses expelling all her eggs. The adult usually dies.
Enterobius vermicularis
This nematode infection can be spread to other in elementary school or day care centers.
Enterobius vermicularis
This nematode burrows into the intestinal lining. It can lay fertilized eggs which hatch and rhabditiform larvae are found in the stool
Strongyloides stercoralis
This nematode can have a free-living life cycle where adults live in the soil.
Strongyloides stercoralis
This nematode has a complex life cycle that features free living adults in soil, direct penetration of human skin and pathenogenic females.
Strongyloides stercoralis
What is the infective stage of Ascaris lumbricoides?
egg
Which nematode can cause physical obstruction of the intestine?
Acaris lumbricoides
Which nematodes migrate through the lungs?
Ascaris lubricoides, hookworm, Strongyloides
What is the infective stage of Enterobius vermicularis?
egg
What is the genus and species of the causitive agent for pinworm?
Enterobius vermicularis
What is the specimen of choice for pinworm detection?
Scotch-tap prep. Clear tape only, not frosted.
Which nematode infection is characterized by intense itching in the perianal area?
Enterobius vermicularis
What is the infective stage of Ancylostoma duodenale?
Filariform larvae
What is the infective stage of Necator americanus?
Filariform larvae
What species of mamal(s) are associated with cutaneous larval migrans (common name)?
Dog and cat
What is the causative agent of cutaneous larval migrans?
Filariform larvae of non-human hookworms
Which nematode actively sucks blood from intestinal villi?
Hookworm (Necator americanus, Ancylostoma duodenale)
Anemia would be expected in which nematode infection?
hookworm
What is the infective stage of Trichuris trichiura?
Egg
What is the genus and species of whipworm?
Trichuris trichiura
Which nematode "sews" itself into the intestinal wall?
Trichurius trichiura
Which nematod can cause prolapse of the rectum?
Trichurius trichiura
Name the host of the nematode that encysts in muscle tissue.
Pig (also bear). Trichinella spiralis
What is the causative agent of River Blindness?
Onchocerca volvulus
Name the genus and species of the nematode that can crawl across the eyeball.
Loa loa
Name the genus and species of the nematode that can be acquired by eating poorly cooked pork.
Trichinella spiralis
Name the agent(s) of visceral larval migrans.
Toxocara canis and Toxocara cati
What is the definitive host of the nematode that causes cutaneous larval migrans?
Most often - domestic dog.
What is the normal definitive host for Toxoplasma gondii?
Cats
Toxoplasmosis is usually acquired by...
ingestion of oocysts from feces or poorly cooked flesh.
Congenital Toxoplasmosis infection is most like viral infection with....
Rubella
Name the host of a sporozoan that causes congenital infections.
Cats
Cryptosporidium parvum is transmitted by....
Fecal-oral route
Which protozoan "hides" in R-E cells and macrophages?
Leishmania spp.
Kala-azar ("black fever in Hindu") is associated with which causative agent?
Leishmania donovani
Name a sporozoan that can cause congenital infections.
Toxoplasma gondii
Name the agent for muco-cutaneous leishmaniasis.
Leishmania braziliensis
Another name for visceral leishmaniasis
Kala azar, black death
Name the vector for leishmaniasis
sandfly
Name the definitive host for malaria
Mosquito
What is the vector for malaria?
Mosquito
Name the genus and species for quartan malaria.
Plasmodium malariae
Name the genus and species for benign tertian malaria.
Plasmodium vivax
Name the genus and species for malignant tertian malaria.
Plasmodium falciparum
Toxoplasmosis is especially harmful to what population group?
human fetus
What is the new name for Pneumocystis carnii?
Pneumocystis jiroveci
Name three species of trypanosomes and where they are found in the world.
Trypanosoma brucei rhodesiense: Africa (Eastern part), very virulent.
Trypanosoma brucei gambiense: Africa (Western part).
Trypanosoma cruzi: Central and South America
What is Winterbottom's sign?
Lymphadenopathy of the posterior cervical nodes that occurs in some patients infected with T.b. rhodesiense or T.b. gambiense
Why are African trypanosome infections often called "African Sleeping Sickness?"
These trypanosomes invade the central nervous system and cause a lethargic, debilitating condition and can lead to coma and death. Victims appear to be sleepy or lethargic. T.b. rodesiense tend to invade the CNS much earlier than T.b. gambiense, hence T.b. rhodesinse's reputation for rapid virulence.
What is the reservoir host of African sleeping sickness?
Domestic animals and wild game.
What is the vector of African sleeping sickness?
Flies (genus Glossina, or tsetse flies). Bites from these flies are painful.
What is the vector of American trypanosomiasis?
Kissing bug - reduvid bugs. The bite of these insects is painless - hence the nickname of kissing bug.
What is another name for American trypanosomiasis?
Chaga's disease
T. cruzi is an intracellular parasite. What is its host tissue?
Heart tissue. It has been one of the leading causes of cardiomyopathy
Describe the method of infection associated with kissing bugs.
The bug will bite painlessly often near the eyes or nose or mouth. When it injests blood it also defecates. The saliva from the bite induces itching and the victim rubs the feces into the wound while scratching to relieve the itch.
What is Chagoma or Romana's sign?
Unilateral palpebral edema - (one eyelid swells shut) the eye that received the bite of the kissing bug will become swollen after the bite. This is termed a Chagoma or Romana's sign.
Describe the pathology associated with long term Chaga's disease.
The parasites replicate in many different cell types to include CNS, muscle of heart, and bowel. The destruction of this muscle tissue results in loss of muscle tone and enlargement of the organ (heart, colon, esophagus).
True/False. Chaga's disease is a rare condition in Central and South America.
False. Prevalence rates are around 15 million persons in Central and South America. Simplest control is to use insecticides to eliminate the vectors.
Why don't we see large numbers of cases of Chaga's disease in the United States?
The United States does not have the required vector.
How is Chaga's disease diaganosed?
Simple method is Giemsa stained blood smears or examination of tissue sections for amastigotes. It is simple, but difficult and dependent on having large numbers of parasite present. Blood banks do NOT screen for this infection except by questionnaire. It can be transmitted by transfusion.
Author
whcobb
ID
95212
Card Set
IPAP - Microbiology Exam 5
Description
Microbiology Exam 5 (IPAP - Class 11-2, 25 JULY 2011)
