Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
96 Cards in this Set
- Front
- Back
|
Helminths - general features
|
Host specificity
Don't multiply in human host Most are asymptomatic |
|
|
Helminths - pathogenesis
|
Fecal-oral transmission
Tissue invasion Mass effect Harmful immune responses Deprivation of nutrients |
|
|
Helminths - treatment
|
Ivernectin - chloride channel blocker that interferes with neurotransmission
Mebendazole - binds to parasite tubulin with high affinity |
|
|
Nematodes
|
Ascaris lumbracoides
Enterobius vermicularis (pinworm) Ancylostoma duodenale (hookworm) Strongyloides stercoralis Trichinosis Filariasis Onchocerciasis |
|
|
Biliary and intestinal obstruction
Parasite |
Ascaris lumbracoides
|
|
|
Ascaris lumbracoides - pathophysiology
|
Ingestion of eggs
Enters bloodstream and pulmonary capillaries Swallowed into intestines Produces eggs that enter stool |
|
|
Ascaris lumbracoides - epidemiology
|
Humans only
Egg can survive in environment Sometimes seen in southeastern US |
|
|
Ascaris lumbracoides - treatment
|
Mebendazole
|
|
|
Perianal itching and allergic reactions
|
Enterobius vermicularis (pinworm)
|
|
|
Enterobius vermicularis - pathophysiology
|
Live in cecum
Crawl out at night to lay eggs |
|
|
Enterobius vermicularis - diagnosis
|
Scotch tape test
|
|
|
Enterobius vermicularis - treatment
|
Mebendazole
|
|
|
Rash or itch at site of invasion
Abdominal pain Iron-deficient anemia |
Ancylostoma duodenale (hookworm)
|
|
|
Ancylostoma duodenale - pathogenesis
|
Filariform larvae live in soil
Proteolytic elements allow entry through skin Goes through bloodstream into lungs Swallowed into intestines Lays eggs into stool |
|
|
Ancylostoma duodenale - treatment
|
Mebendazole
Albendazole |
|
|
Lower abdominal rash
Abdominal bloating Weight loss Diarrhea Hyperinfection with HTLV-1 In immunosuppressed patients |
Strongyloides stercoralis
|
|
|
Strongyloides stercoralis - pathogenesis
|
Larvae penetrate skin
Go into lung and intestines Eggs hatch inside intestines Associated with poor sanitation |
|
|
Strongyloides stercoralis - complications
|
Auto-infection in immunocompromised patients
Hyperinfection and sepsis from worms punching holes in intestine |
|
|
Strongyloides stercoralis - diagnosis
|
Larvae in stool
Serology |
|
|
Strongyloides stercoralis - treatment
|
Ivermectin
|
|
|
Fever
Myalgia Eosinophilia Periorbital edema Heliotrope rash |
Trichinosis
|
|
|
Trichinosis - epidemiology
|
Transmitted by eating larval cysts in pork
Goes between rats, pigs, and humans |
|
|
Trichinosis - pathogenesis
|
Ingestion of larval cysts
Digested into intestine Penetrate small intestine Enter muscle and form cysts |
|
|
Trichinosis - complications
|
Encephalitis in acute infection
|
|
|
Trichinosis - diagnosis
|
Serology
Muscle biopsy |
|
|
Trichinosis - treatment
|
Albendazole
Thorough meat cooking |
|
|
Lymphedema of legs
Hydrocoele Elephantiasis of genitals |
Filariasis
|
|
|
Filariasis - pathogenesis
|
Infection by mosquito bite
Larva migrates to lymph nodes and grows worms Sexual reproduction forms microflares (eggs) that enter bloodstream Taken up by mosquitos |
|
|
Filariasis - diagnosis
|
Antigen test, only at night
|
|
|
Filariasis - treatment
|
Albendazole with diethylcarbamazine or ivermectin
|
|
|
Sclerosing keratitis
Dermatitis Blindness from host immune response |
Onchocerciasis
|
|
|
Onchocerciasis - pathogenesis
|
Transmitted by black flies
Adult worms live in subcutaneous nodules Microfilariae formed in skin from sexual reproduction |
|
|
Onchocerciasis - complications
|
Wolbachia bacterial infection
Treat with doxycycline |
|
|
Onchocerciasis - treatment
|
Ivermectin every 6-12 months
|
|
|
Trematodes (flat worms)
|
Schistosoma mansoni, hematobium
Tapeworm Echinococcus granulosus Diphyllobothrium latum |
|
|
Schistosoma - pathogenesis
|
Swims in water
Attracted by fatty acids in skin Enters skin and circulation Lays eggs inside blood vessel walls Enter stool Attach to snails and undergo development |
|
|
Schistosoma - complications
|
Severe inflammatory response to eggs
|
|
|
Chronic inflammatory response in liver
Vessel sclerosis Portal HTN Esophageal varices Hypereosinophilia |
Schistosoma mansoni
|
|
|
Schistosoma mansoni - pathogenetic factors
|
Surface coat
Antigen complexicty Enzymes that cleave complement |
|
|
Schistosoma mansoni - treatment
|
Kill snails
Good sanitation Chemotherapy Praziquantel |
|
|
Ureteral strictures and fibrosis
Bladder cancer Pulmonary HTN Paralysis from vertebral artery involvement |
Schistosoma hematobium
|
|
|
Schistosoma hematobium - epidemiology
|
Nile Valley
Sub-Saharan Africa |
|
|
Schistosoma hematobium - pathophysiology
|
Invades blood vessels around urinary tract
|
|
|
Schistosoma hematobium - treatment
|
Praziquantel
|
|
|
Cerebral cystercercosis
|
Tapeworm
|
|
|
Tapeworm - pathogenesis
|
Infection from eating cysts of muscle in infected pigs
Attach to intestine and develop a worm Proglottids come out in stools and are ingested Can go to brain and cause seizures |
|
|
Tapeworm - treatment
|
Praziquantel
Albendazole if in brain |
|
|
Mass in liver, lung, or brain
Allergy or dissemination |
Echinococcus granulosus
|
|
|
Echinococcus granulosus - epidemiology
|
Zoonosis of dogs and domestic animals
|
|
|
Echinococcus granulosus - treatment
|
Albendazole
Surgery |
|
|
Fish tapeworm
Vitamin B12 deficiency Megaloblastic anemia |
Diphyllobothrium lactum
|
|
|
Diphyllobothrium lactum - treatment
|
Niclosamide
|
|
|
Protozoans - characteristics
|
One-celled organisms
Multiply in human hosts No eosinophilia |
|
|
Protozoans - host factors
|
Inoculum
Age Nutritional status Coinfection Immune status |
|
|
Fever
Weakness Decreased response Anemia |
Plasmodium falciparum
|
|
|
Plasmodium falciparum - epidemiology
|
Tropics
Sub-Saharan Africa Anopheles mosquito |
|
|
Plasmodium falciparum - pathogenesis
|
Mosquito ingests gametes from infected blood
Sexual reproduction in mosquito Travel to salivary glands Infects liver cells of host Asexual reproduction Move into RBCs |
|
|
Plasmodium falciparum - diagnosis
|
Ring forms on blood smear
|
|
|
Flu-like illness
Malaise Fever Splenomegaly |
Plasmodium vivax
|
|
|
Plasmodium vivax - pathogenesis
|
Duffy antigen on young RBCs
|
|
|
Plasmodium malariae - complications
|
Nephrotic syndrome
|
|
|
Periodic chills, fever, and sweats
Anemia Headache, nausea, and vomiting Acute renal failure Coma and seizures if cerebral |
Malaria
|
|
|
Malaria - pathogenesis
|
Hemolysis and decreased RBC production
Proteins adhere to RBCs and cause clumping, obstruction, and infarction Released cytokines cause fever and hypotension |
|
|
Malaria - diagnosis
|
Blood smears
Antigen detection |
|
|
Malaria - treatment
|
Prevention - mosquito nets and insect repellant
Prophylaxis - chloroquine, primaquine, doxycycline, malarone, mefloquine |
|
|
Malaria - risk factors
|
Pregnant women
Children |
|
|
Unilateral orbital edema
Inflammation around inoculation site Cardiomyopathy CHF Megacolon |
Trypanosoma cruzi (Chagas disease)
|
|
|
Trypanosoma cruzi - epidemiology
|
Latin America
Transmitted by insects Zoonosis of small animals Some risk of vertical transmission |
|
|
Trypanosoma cruzi - pathogenesis
|
Transmitted by insect bites and feces
Infect macrophages and muscle Enter bloodstream and become infectious |
|
|
Trypanosoma cruzi - complications
|
Reactivation with immunosuppression
Risks with blood transfusion |
|
|
Trypanosoma cruzi - diagnosis
|
Detection in blood or inoculation site
Xenodiagnosis |
|
|
Trypanosoma cruzi - treatment
|
Nifurtimox or benznidazole for acute cases
|
|
|
Cutaneous scarring ulcers
Satellite lesions along lymphatics |
Cutaneous leishmaniasis
|
|
|
Ulcers on lips, soft palate, and nose
|
Mucocutaneous leishmaniasis
|
|
|
Subacute onset fever and weight loss
Hepatosplenomegaly Anemia Leukoplakia Thrombocytopenia Death from secondary infection, anemia, and hemorrhage |
Visceral leishmaniasis
|
|
|
Leishmania - pathogenesis
|
Transmitted in sand fly
Infects macrophages |
|
|
Leishmania - epidemiology
|
Zoonosis in rats and dogs
Mostly in Middle East, South America, and southeast Asia |
|
|
Leishmania - diagnosis
|
Amastigotes in macrophages
Culture and PCR Serology |
|
|
Leishmania - treatment
|
Antimony
Amphotericin Ambisome |
|
|
Multiple ring-enhancing lesions
Acute encephalitis in AIDS patients Mono-like symptoms in healthy patients |
Toxoplasma gondii
|
|
|
Toxoplasma gondii - pathophysiology
|
Transmitted in oocysts in cat feces or in muscle of intermediate hosts
|
|
|
Toxoplasma gondii - complications
|
Congenital toxoplasmosis can cause blindness, brain damage, and death
|
|
|
Toxoplasma gondii - treatment
|
Pyramethamine
Sulfadiazine |
|
|
Bloody diarrhea
Liver abscess Fever RUQ pain |
Entamoeba histolytica
|
|
|
Entamoeba histolytica - pathogenesis
|
Trophozooites come out in stool and are ingested
|
|
|
Entamoeba histolytica - complications
|
Perforation into peritoneum and death
|
|
|
Entamoeba histolytica - diagnosis
|
Stool exam
Liver abscess |
|
|
Entamoeba histolytica - treatment
|
Metranidazole
Nitazoxamide |
|
|
Wasting non-bloody diarrhea
|
Giardia lambia
|
|
|
Giardia lambia - pathophysiology
|
Water-borne
Infection after ingestion of cysts Adheres to intestinal walls |
|
|
Giardia lambia - diagnosis
|
Stool analysis
Antigen detection |
|
|
Giardia lambia - treatment
|
Metranidazole
|
|
|
Watery diarrhea
Fever Malaise Anorexia |
Cryptosporidium parvum
|
|
|
Cryptosporidium parvum - complications
|
Chronic diarrhea in children or immunocompromised
|
|
|
Yellow vaginal discharge
Strawberry cervix Dysuria |
Trichomonas
|
|
|
Trichomonas - treatment
|
Metranidazole
|
