Parasitology

What are the primary habitats for Trichomonas vaginalis?

Vagina, urethra, and prostate.

What is the mode of transmission for Trichomonas vaginalis?

Sexual contact.

Who are the primary reservoirs for Trichomonas vaginalis?

Females.

What is the infective stage of Trichomonas vaginalis?

Trophozoite.

What is the diagnostic stage of Trichomonas vaginalis?

Trophozoite.

Trichomonas vaginalis is notable for the absence of a _ stage in its life cycle.

cyst

What type of motility is characteristic of Trichomonas vaginalis?

Twitching motility / Jerky.

What is the name of the clinical sign in females characterized by punctate hemorrhages on the cervix, seen in Trichomonas vaginalis infection?

Strawberry cervix.

A characteristic sign of Trichomonas vaginalis infection in females is a _ colored discharge.

greenish

What conditions can Trichomonas vaginalis cause in males?

Urethritis, bladder involvement (cystitis), and prostate involvement (prostatitis).

What is the typical shape of a Trichomonas vaginalis trophozoite?

A pear shape.

Describe the nuclear and flagellar structure of a Trichomonas vaginalis trophozoite.

It has only one nucleus, four anterior flagella, and one posterior flagellum with an undulating membrane.

What sample is typically collected for the diagnosis of Trichomonas vaginalis?

Discharge sample.

Besides a discharge sample, what other common cytological test can be used to diagnose Trichomonas vaginalis?

Pap smear.

What is the only stage of Trichomonas vaginalis seen in a microscopic examination or Pap smear?

Trophozoite.

Name one of the specialized culture media used for growing Trichomonas vaginalis.

Lash cysteine hydrolysate serum or Diamond medium.

What is the drug of choice for treating Trichomonas vaginalis?

Metronidazole.

What is a crucial aspect of treatment management for Trichomonas vaginalis to prevent reinfection?

The partner needs to be treated as well.

What is an alternative drug to Metronidazole for treating Trichomonas vaginalis, which can also be given as a single 2g dose?

Tinidazole.

What are the two main genera of hemoflagellates mentioned?

Leishmania and Trypanosoma.

In the mnemonic APET for hemoflagellate forms, what does 'A' stand for?

Amastigote, which has an absent flagella.

In the mnemonic APET for hemoflagellate forms, what does 'P' stand for?

Promastigote, which has a pre-nuclear (anterior) kinetoplast.

In the mnemonic APET for hemoflagellate forms, what does 'E' stand for?

Epimastigote, which has a pre-nuclear (anterior) kinetoplast.

In the mnemonic APET for hemoflagellate forms, what does 'T' stand for?

Trypomastigote, which has a post-nuclear kinetoplast.

According to the mnemonic BET, which two forms are seen in Trypanosoma Brucei?

Epimastigote and Trypomastigote.

According to the mnemonic CATE, which forms are seen in Trypanosoma Cruzi?

Amastigote and Trypomastigote (and Epimastigote, but only seen in insects).

According to the mnemonic LAP, which two forms are seen in Leishmania?

Amastigote and Promastigote.

What disease is caused by Trypanosoma cruzi?

Chagas disease (also known as South American sleeping sickness).

What is the vector for Trypanosoma cruzi?

Reduviid bug (also called triatomine bug).

What is the term for the localized edema at the entry site of T. cruzi infection?

Chagoma.

What is the name for the unilateral periorbital edema seen in acute Chagas disease?

Romana Sign.

Which organ system is primarily affected by chronic Chagas disease, leading to myocarditis?

The heart.

What are the 'mega' syndromes associated with chronic Chagas disease in the GIT?

Megaesophagus and megacolon.

What neurological complication can occur in chronic Chagas disease?

Meningoencephalopathy.

What sample is collected for the culture of Trypanosoma cruzi?

Blood sample or buffy coat.

What specialized culture medium is used for both T. cruzi and Leishmania?

NNN media (Novy-MacNeal-Nicolle medium).

What is the drug of choice for treating Chagas disease?

Benznidazole.

In the life cycle of T. cruzi, what form is found in the feces of the triatomine bug and is infective to humans?

Metacyclic trypomastigotes.

Once inside human cells, T. cruzi trypomastigotes transform into which multiplying form?

Amastigotes.

What is the diagnostic stage of T. cruzi found circulating in the human bloodstream?

Trypomastigotes.

In the T. cruzi life cycle, which form multiplies in the midgut of the triatomine bug?

Epimastigotes.

In T. cruzi's life cycle, epimastigotes differentiate into metacyclic trypomastigotes in the _ of the vector.

hindgut

What disease is caused by Trypanosoma brucei?

Sleeping sickness (African Trypanosomiasis).

Which subspecies of Trypanosoma brucei causes West African sleeping sickness?

T.b. gambiense.

Which subspecies of Trypanosoma brucei causes East African sleeping sickness?

T.b. rhodesiense.

What is the vector for Trypanosoma brucei?

Tsetse fly.

What is the primary reservoir for T.b. gambiense?

Humans.

What is the primary reservoir for T.b. rhodesiense?

Animals (e.g., cattle, wild ungulates).

The _ sign, characterized by posterior cervical lymphadenopathy, is a clinical indicator of West African sleeping sickness.

Winterbottom

Which subspecies of Trypanosoma brucei is associated with higher parasitemia and virulence?

T.b. rhodesiense.

What is the treatment for early-stage West African sleeping sickness (T.b. gambiense)?

Pentamidine.

What is the treatment for late-stage West African sleeping sickness (T.b. gambiense)?

Eflornithine/Nifurtimox.

What is the treatment for early-stage East African sleeping sickness (T.b. rhodesiense)?

Suramin.

What is the treatment for late-stage East African sleeping sickness (T.b. rhodesiense)?

Melarsoprol.

In the life cycle of T. brucei, what is the infective stage injected into humans by the tsetse fly?

Metacyclic trypomastigotes.

In the human host, T. brucei trypomastigotes multiply in the blood, lymph, and _.

spinal fluid

What form of T. brucei is ingested by a tsetse fly during a blood meal on an infected human?

Trypomastigotes.

In the tsetse fly, T. brucei trypomastigotes transform into _, which multiply in the salivary glands.

epimastigotes

In the 'Myocarditis' mnemonic for parasites causing myocarditis, 'Y' stands for _.

Trypanosoma cruzi

In the 'Myocarditis' mnemonic for parasites causing myocarditis, 'O' stands for _.

T.B. Rhodesiense

What is the common name for visceral Leishmaniasis?

Kala-azar.

What is the vector for Leishmaniasis?

Sandfly.

What is the infective form of Leishmania for humans?

Promastigote.

What is the diagnostic form of Leishmania found within human cells?

Amastigote.

Amastigotes of Leishmania seen by microbiologists are also known as _ bodies.

L.D. (Leishman-Donovan)

The name Kala-azar is due to the characteristic _ pigmentation of the skin.

blackish

What is the most sensitive sample for diagnosing Kala-azar, although it carries a risk of bleeding?

Spleen aspirate.

Due to safety concerns with spleen aspirates, what is the most preferred sample for diagnosing Kala-azar?

Bone marrow (BM) aspirate.

A key laboratory finding in patients with Kala-azar is _, which can be detected by Napier's aldehyde test.

hypergammaglobulinemia

What rapid card test is used for the diagnosis of Leishmaniasis by detecting a specific antigen?

RK39 antigen test.

What is the drug of choice for treating Leishmaniasis (Kala-azar)?

Liposomal Amphotericin B.

What condition, characterized by hypopigmented nodules, can develop 1-2 years after treatment for Kala-azar?

Post Kala Azar Dermal Leishmaniasis (PKDL).

What is the recommended treatment for Post Kala Azar Dermal Leishmaniasis (PKDL)?

Oral Miltefosine.

Which species of Leishmania causes Oriental Sore (Delhi Boil)?

L. tropica.

Which species of Leishmania causes Mucocutaneous Leishmaniasis (Espundia)?

L. brasiliensis.

What is the term for the atopic, relapsing form of Leishmaniasis that occurs due to inadequate treatment?

Leishmaniasis Recidivans.

In the Leishmania life cycle, what happens to promastigotes after being injected by a sandfly and phagocytized by human macrophages?

They transform into amastigotes.

What form of Leishmania is ingested by a sandfly when it takes a blood meal from an infected human?

Amastigotes (within macrophages).

Inside the sandfly's gut, Leishmania amastigotes transform into _.

promastigotes

What are the five main Coccidian parasites listed that affect humans?

Toxoplasma gondii, Cryptosporidium, Cyclospora, Isospora, and Sarcocystis.

What is the definitive host for Toxoplasma gondii?

The cat.

Who is the intermediate host for Toxoplasma gondii?

Humans.

What are the three different forms of Toxoplasma gondii?

Sporulated oocyst, bradyzoite, and tachyzoite.

How can humans acquire Toxoplasma gondii through ingestion?

By ingesting sporulated oocysts from contaminated soil/food/water or bradyzoites from undercooked meat.

Besides ingestion, what are two other modes of transmission for Toxoplasma gondii?

Blood transfusion and transplacental transmission of tachyzoites.

During which trimester of pregnancy is congenital toxoplasmosis most severe?

The first trimester.

What ocular manifestation is a classic feature of congenital toxoplasmosis?

Chorioretinitis.

What type of calcification is seen in the brain with congenital toxoplasmosis?

Intracerebral calcification.

What neurological symptoms can occur in congenital toxoplasmosis?

Convulsions, microcephaly, and mental retardation.

How does adult toxoplasmosis typically present in immunocompetent individuals?

It is often asymptomatic, but may cause enlarged lymph nodes (LN enlarged).

In HIV-positive patients, what part of the body is most commonly affected by toxoplasmosis?

The brainstem.

While Toxoplasma shows intracerebral calcification, CMV characteristically shows _ calcification.

periventricular

What is the gold standard test for diagnosing toxoplasmosis?

The Sabin Feldman test.

What substance is used in the Sabin Feldman test to check for the presence of antibodies?

Methylene blue.

In serological testing for toxoplasmosis, an interpretation of IgM+ and IgG- indicates what type of infection?

Acute infection.

In serological testing for toxoplasmosis, an interpretation of IgM+ and IgG+ with low avidity indicates what type of infection?

Acute infection.

An interpretation of IgG+ with strong avidity in toxoplasmosis serology suggests a(n) _ infection.

chronic

What is the standard treatment regimen for toxoplasmosis?

Pyrimethamine + Sulfadiazine.

Which three coccidian parasites are major causes of diarrhea in immunocompromised hosts?

Cryptosporidium, Cyclospora, and Isospora.

What is the typical size of Cryptosporidium oocysts?

4-6 micrometers.