Term
| How is leishmania transmitted? |
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Definition
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Term
| What are the human stages of leishmania? |
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Definition
1) Sandfly bites and injects promastigote stage into skin
2) Promastigotes are phagocytized by macrophages
3) Promastigotes transform into amastigotes inside macrophages
4) Amastigotes multiply inside cells of various tissues |
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Term
| What happens in cutaneous leishmaniasis? |
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Definition
| A simple skin lesion occurs where the sandfly bit the skin |
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Term
| What happens in mucocutaneous leishmaniasis? |
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Definition
| Lesions appear in the mucocutaneous tissues of the mouth, nose, and genital areas |
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Term
| What happens in visceral leishmaniasis? |
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Definition
| Internal lesions appear in the spleen, liver, and bone marrow. It causes hepatosplenomegaly, anemia, and hypergaminaglobulinema (polyclonal B cell activation that coats RBCs and causes the anemia) |
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Term
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Definition
| Yes, it can infect many wild animals such as rodents, sloths, and domestic dogs |
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Term
| How is leshmaniasis affected by HIV? |
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Definition
| Visceral Leishmaniasis is more pathogenic in HIV-infected people |
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Term
| What is the infective stage of Toxoplasma? |
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Definition
| oocysts, cyst (with trophozites) and free trophozites |
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Term
| What is the pathology stage of Toxoplasma? |
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Definition
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Term
| How is Toxoplasmosis transmitted? |
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Definition
| Ingestion of oocysts from cat feces, ingestion of cysts with trophozites from meat, or congenital transmission of trophozites |
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Term
| How does Toxoplasma behave in the body? |
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Definition
| It is an intracellular parasite that can disseminate by lymphatics to the lymph nodes. It can be killed unless cysts reach the brain or eyes, where it can cause CNS ataxia or blindness |
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Term
| What are the symptoms of toxoplasmosis in immunocompetent people? |
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Definition
| Most are asymptomatic, but can present with lymphadenopathy with enlarged lymph nodes, mimicry of mononucleosis, and mild disease in some elderly people |
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Term
| What are the symptoms of toxoplasmosis in congenital infections? |
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Definition
| It varies from asymptomatic to severe CNS damage or stillbirth but can include eye damage, learning disabilities, convulsions, or hydrocephalus |
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Term
| What are the symptoms of toxoplasmosis in immunosuppressed people? |
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Definition
| Recrudescent infection in AIDS patients, encephalitis, and dissemination to any organ of the body causing different symptoms depending on the organ infected |
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Term
| How can toxoplasmosis be prevented? |
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Definition
| Avoid cats or keep cats indoors, cook meat properly, freeze meat, garden with gloves, and wash hands and food well |
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Term
| What species cause malaria? |
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Definition
| Plasmodium falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesi |
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Term
| What are the two ways malaria can act in the body? |
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Definition
| The parasites can either travel to the liver and become schizonts, or there can be a latent stage where parasites live as hypnozoites. Either way, once it develops it lives in the blood as pathogenic merozoites. Some parasites become gametocytocides to be picked up by mosquitos |
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Term
| What are the three core symptoms of malaria? |
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Definition
| Fever, anemia, and splenomegaly |
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Term
| What is special about P. vivax? |
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Definition
| It has a latent exoerythrocytic schizont stage that can cause disease months after a bite or cause relapses. The hypnozoite must be killed with Primaquine |
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Term
| What receptors are required on RBCs for invasion by malarial parasites? |
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Definition
| Glycophorin A for P. falciparum or Duffy blood group antigens for P. vivax |
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Term
| What are the complications of P. falciparum? |
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Definition
| Anemia, hepatosplenomegaly, renal failure, hypoglycemia, cerebral malaria, or death |
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Term
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Definition
| A malarial pigment that is a byproduct of hemoglobin metabolism that the body must eliminate. It causes the liver an spleen to overwork, leading to hepatosplenomegaly and renal failure |
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Term
| What is the spleen pathology in malaria? |
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Definition
| An increase in antibody-producing cells and reticulocytes causes splenomegaly. The spleen can rupture, disrupting RBC filtering and making malaria become fatal quickly |
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Term
| Why is it impossible to develop a vaccine for P. falciparum. |
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Definition
| Antigenic variability: it has hundreds of variable genes from the molecule that mediates cytoadhesion to RBCs |
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Term
| How does immunity to malaria work? |
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Definition
| People are immune as long as they have a low grade infection. Once the parasites are lost, the immunity is lost |
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Term
| Who can die from malaria? |
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Definition
| Children under two because they have inadequate immunity and any aged person without immunity |
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Term
| How does malaria affect a pregnancy? |
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Definition
| There is increased risk of severe pathology during the 1st pregnancy in infected mother, and the cerebral malaria risk is increased. Low birth weight is also common--can hinder development and even death |
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Term
| What combination drug can be used for blood stages of malaria? |
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Definition
| ACT = artemisinin combination therapy |
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Term
| Why is Primaquine dangerous? |
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Definition
| Toxicity in G6PD-deficient people can lead to hemolytic anemia |
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Term
| How does malaria affect HIV? |
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Definition
| Immunosuppression caused by malaria leads to elevated HIV viral loads |
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Term
| What is the infectious organism of Amebiasis? |
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Definition
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Term
| What are the stages of amebiasis? |
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Definition
| The infective stage is a cyst, the pathology stage is the trophozite |
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Term
| How is Entamoeba histolytica transmitted? |
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Definition
| Via fecal contamination of food and water and anal sex |
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Term
| Where does amebiasis reside in the body? |
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Definition
| Large intestine, liver, CNS, and skin |
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Term
| What are the main symptoms of amebiasis? |
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Definition
| Bloody diarrhea from the intestinal form due to an ulcer or chest pain from the liver form seen with large hepatic abscesses |
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Term
| What are the complications associated with amebiasis? |
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Definition
| If the parasites infest deep enough, they can cause peritonitis and hemorrhage. Rarely a granulomatous mass that looks like a neoplasm called an amoeboma can form |
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