Week 9 Flashcards

Question

Toxoplasma gondii Risks for infection

Answer 1

common infection in US Change litter box daily (don’t do it if you’re pregnant) Uncooked meat (high incidence in France)

Answer 2

1) Asymptomatic 2) Mononucleosis-like illness (sore throat, fever, swollen lymph nodes) 3) TOXOPLASMOSIS 4) Congenital toxoplasmosis

Answer 3

Immunocompromised → cysts rupture and release tachyzoites = TOXOPLASMOSIS **TRIAD = Chorioretinitis, encephalitis, pneumonitis Most common cause of encephalitis in HIV patients

Answer 4

Pregnant woman infected WITHOUT previous exposure → can cross placenta causing congenital toxoplasmosis **chorioretinitis, HYDROCEPHALUS, intracranial calcifications (MULTIPLE ring-enhancing lesions in cortex and basal ganglia on head CT) Blueberry muffin rash, hepato- splenomegaly, hyperbilirubinemia, lymphadenopathy

Answer 5

pyrimethamine, Sulfadiazine, Leucovorin | Prophylaxis: TMP/SMX

Answer 6

hematologic infection - parasites in blood cells (Infects RBCs) > 0.5 million deaths/year, ½ children under age of 5 in Africa

Answer 7

Anopheles mosquito Mosquito bite release sporozoites into bloodstream → LIVER, infects hepatocytes → sporocytes divide into merozoites and released from hepatocytes → infect RBCs → merozoites develop into trophozoites → infected RBCs less flexible → destroyed in spleen (splenomegaly) or RBCs burst and release parasite

Answer 8

Malaria | Anemia, fever, chills

Answer 9

cyclical symptoms (every 3 days), only infect mature RBCs

Answer 10

“relapsing infection” (every 2 days) and infects only reticulocytes (immature RBCs) Schuffner dots unique to P. vivax/ovale - brick red dots in host erythrocytes

Answer 11

most severe, infects ALL RBCs Make RBCs stick to capillary and venule walls → occlusion, hemorrhage - Brain (cerebral malaria) - Kidneys (renal failure) - Lung (pulmonary edema) Sickle cell trait, thalassemia, and glucose-6-phosphate dehydrogenase deficiency confers protection

Answer 12

Trophozoite → band or rectangular | Gametocyte shapes → round

Answer 13

Trophozoite → large, irregular rings | Gametocyte shapes → round

Answer 14

Trophozoites → small rings | Gametocytes → banana-like

Answer 15

whip-like flagella motility 1) Giardia Lamblia 2) Trichomonas vaginalis 3) Leishmania spp 4) Trypanosoma cruzi 5) Trypanosoma brucei

Answer 16

fecal-oral 10-25 cysts required for infection Cysts ingested → become trophozoites in duodenum that attach to duodenal villi

Answer 17

travelers, daycares, homosexual men, hikers, campers - chlorination NOT effective, only boiling/iodine

Answer 18

Diarrhea - foul smelling, fatty stools Malabsorption AND hypersecretion Most common cause of nonbacterial diarrhea in USA NONINVASIVE destruction of villi Can cause lactase deficiency

Answer 19

tear shaped cysts in stool, owl eye nuclei (two nuclei) and four flagella or antigen testing

Answer 20

metronidazole

Answer 21

*Sexually transmitted Lacks cyst form, rarely leaves host

Answer 22

1) Asymptomatic carrier 2) Acute vaginitis 3) Urethritis (men)

Answer 23

- burning, itching, dysuria, frequency) - STRAWBERRY CERVIX - GREEN, foul-smelling vaginal discharge - Vaginal pH > 4.5

Answer 24

vaginal wet mount shows motile pear-shaped flagellated trophozoites (corkscrew motility)

Answer 25

Metronidazole

Answer 26

blood sucking bite of female sandfly Intracellular parasites in macrophages

Answer 27

1) Visceral leishmaniasis = Black Fever 2) Cutaneous leishmaniasis 3) Mucocutaneous leishmaniasis

Answer 28

Intermittent/spiking fever Splenomegaly Pancytopenia Skin hyperpigmentation (“black fever”)

Answer 29

Erythematous papule at sandfly bite which expands and ulcerates

Answer 30

Lesions confined to skin, mucous membranes, and cartilage

Answer 31

tissue biopsy with macrophages containing amastigotes (non motile, non flagellated form) Outside of macrophages, Leishmania spp. Flagellated

Answer 32

sodium stibogluconate, liposomal amphotericin B

Answer 33

painless bite and defecation of Reduviid bug (“kissing bug”)

Answer 34

Chagoma = inflammation at bite site Romana’s sign = swelling/inflammation around eyelids when organisms enter conjunctiva

Answer 35

``` Dilated cardiomyopathy with apical atrophy Cardiac arrhythmias Megacolon Megaesophagus Achalasia ```

Answer 36

flagellated trypomastigotes on blood smear (acute) or non flagellated amastigotes within cells on biopsy Chronic infection → parasitemia below detectable levels

Answer 37

benznidazole and nifurtimox Chronic = supportive care

Answer 38

painful bite of infected tsetse fly | Found in Sub-Saharan Africa

Answer 39

causes African sleeping sickness Early: intermittent fever, malaise, and headache Late: CNS involvement, daytime somnolence, nighttime insomnia, persistent headaches

Answer 40

mobile trypanosomes on blood smear

Answer 41

suramin (early), melarsoprol (late, CNS)

Answer 42

host in which parasite reaches maturity and sexually reproduces within

Answer 43

host that harbors parasite only for a short transition period

Answer 44

host in which parasite can live indefinitely with no harmful effects

Answer 45

intermediate host that does not allow transmission to definitive host → prevent parasite from completing its development

Answer 46

parasitic worms 1) Platyhelminthes (flatworms) 2) Nematodes (roundworms)

Answer 47

1) Cestodes (tapeworms) | 2) Trematodes (flukes)

Answer 48

Platyhelminthes (flatworms) 1) Taenia solium (pork tapeworm) 2) Taenia saginata (beef tapeworm) 3) Echinococcus (dog tapeworm) 4) Diphyllobothrium (fish tapeworm)

Answer 49

Platyhelminthes (flatworms) 1) Schistosoma (blood flukes) = Schistosomiasis 2) Clonorchis sinensis (Asian liver fluke) 3) Paragonimus westermani (lung fluke)

Answer 50

Intestinal roundworms: 1) Enterobius vermicularis (pinworm) 2) Ascaris lumbricoides: giant roundworm 3) Trichinella spiralis 4) Trichuris trichiura: whipworm 5) Strongyloides stercoralis 6) Necator americanus (hookworm) Tissue roundworms: 1) Onchocerca volvulus = River blindness 2) Wuchereria bancrofti

Answer 51

Intestinal infection: ingestion from undercooked pork → mature into adults in small intestine, consume food ingested by host Tissue infection: ingested as eggs from feces → eggs hatch in SI, penetrate intestinal wall → travel to other tissues (brain, skeletal muscle, eye)

Answer 52

4 suckers + circle of hooklets

Answer 53

1) Intestinal infection | 2) Tissue infection: cysts grow slowly and can cause seizures, neurological deficits and blindness

Answer 54

proglottids and eggs in stool or calcified cysticerci in muscle or brain on imaging

Answer 55

praziquantel, albendazole + corticosteroids

Answer 56

ingestion via undercooked beef → intestinal infection, attachment to small intestine wall → eggs passed in feces

Answer 57

Typically asymptomatic** Malnutrition Abdominal discomfort

Answer 58

4 suckers + NO hooklets

Answer 59

identification of proglottids and eggs in stool

Answer 60

praziquantel

Answer 61

ingestion of eggs found in dog feces Eggs → hatch into larvae → small intestine → penetrate and travel to other tissues

Answer 62

tissue infection HYDATID CYSTS in liver, lung, brain - Cysts grow and cause organ displacement/ dysfunction - “EGGSHELL” calcification (typically liver) - Release of cyst contents can cause severe ANAPHYLAXIS and spread of infection Common in sheepherders

Answer 63

albendazole Inject larvicidal solution into cysts during surgery

Answer 64

ingestion of undercooked freshwater fish → larvae mature into adults in SI → consume food/B12

Answer 65

Usually asymptomatic Malnutrition Megaloblastic anemia (B12 deficiency)

Answer 66

proglottids and eggs in stool

Answer 67

praziquantel

Answer 68

Trematodes (flukes) humans and snails Snails excrete cercariae into fresh water that then PENETRATE human SKIN and enter blood → LIVER → mature into adults Adults migrate against portal flow to venous plexuses - release eggs EGGS CAUSE PATHOLOGY → cause acute inflammatory response, passed into feces or urine, etc. Evade immune system via molecular mimicry

Answer 69

1) Cercarial dermatitis (swimmer’s itch) 2) Acute schistosomiasis 3) Chronic schistosomiasis (months to years after infection) 4) Intestinal schistosomiasis 5) Hepatosplenic schistosomiasis 6) GU Schistosomiasis

Answer 70

within days of infection due to cercariae penetrating skin - **can be seen in USA

Answer 71

1-2 months after infection - serum sickness-like disease | Cough, fever, chills, abdominal pain, dysentery, lymphadenopathy

Answer 72

chronic/intermittent abdominal pain, poor appetite, diarrhea, intestinal bleeding and iron deficiency

Answer 73

hepatomegaly, splenomegaly, periportal fibrosis, portal HTN

Answer 74

hematuria, eggs excreted in urine, dysuria, urinary frequency Can lead to squamous cell carcinoma of bladder

Answer 75

eggs or stool in urine, clinical presentation

Answer 76

(pinworm) Intestinal round worm -Most common helminth in the US Symptoms: perianal itching

Answer 77

fecal-oral Ingest eggs → hatch in duodenum/jejunum → mature in ileum and large intestine Adults mate in colon, at night, females migrate out of rectum to perianal skin and lay eggs

Answer 78

“Scotch tape” test for eggs | Eggs NOT found in stool

Answer 79

benzimidazoles, pyrantel pamoate

Answer 80

giant roundworm intestinal roundworm One of most common helminthic infections worldwide, highest prevalence in tropical countries

Answer 81

Fecal-oral transmission Ingestion of ova → hatch in SI → release larvae that penetrate intestinal wall and migrate hematogenously or via lymphatics to lungs Larvae mature in alveoli and ascend bronchial tree and are swallowed → back in SI → mature into adult worms

Answer 82

1) Asymptomatic (most) 2) Respiratory symptoms 3) Nutritional deficiencies 4) Obstruction of bowel lumen 5) If in biliary tree → biliary colic, cholecystitis, ascending cholangitis, obstructive jaundice

Answer 83

Loeffler’s syndrome (hypersensitive eosinophilic pneumonitis) Dry cough, burning/substernal discomfort, dyspnea, fever, wheezing

Answer 84

stool microscopy with identification of eggs

Answer 85

benzimidazoles, ivermectin

Answer 86

Caused by ingestion of undercooked meat containing larvae of T. spiralis from animal Gastric acid/pepsin in stomach causes larvae to be released from cysts → small bowel mucosa Adults in SI migrate to striated muscles

Answer 87

Domestic cycle: involves pigs, rodents Sylvatic cycle: involves many animals (bears, moose, wild boars)

Answer 88

1) Trichinosis 2) Intestinal phase 3) Invasive phase

Answer 89

associated with consumption of raw or undercooked meat (especially PIGS)

Answer 90

diarrhea, abdominal pain, nausea (occurs within 1 week of inoculation)

Answer 91

myalgia, periorbital edema, eosinophilia, splinter hemorrhages, fever (occurs within 4 weeks)

Answer 92

clinical symptoms + serology or larvae on muscle biopsy

Answer 93

benzimidazoles

Answer 94

whipworm | Intestinal parasite associated with poor hygiene in tropical climates

Answer 95

fecal-oral Unembryoated eggs passed in stool → become infective → ingest via food or hands contaminated with soil → eggs hatch and release mature larvae → mature into adult worms → establish in COLON

Answer 96

Asymptomatic (most) Stools may contain mucus and blood Nocturnal bowel movements Rectal prolapse

Answer 97

stool examination for eggs (FOOTBALL/barrel shape)

Answer 98

Benzimidazoles

Answer 99

fecal-cutaneous Penetrate skin of feet → local itching → enter bloodstream and lungs (pneumonia) Swallowed → mature into adults in SI → invade mucosa and lay eggs Larvae hatch from eggs embed within intestinal wall → inflammation and pain (diarrhea) Can have autoinfection by penetrating intestinal wall to re-enter bloodstream

Answer 100

pneumonia + gastroenteritis

Answer 101

LARVAE seen in stool (not eggs) + eosinophilia

Answer 102

benzimidazoles, ivermectin

Answer 103

Pneumonia Gastroenteritis Anemia (secretion of anticoagulant + consumption of blood by worm)

Answer 104

fecal-cutaneous Infective larvae penetrate skin of FEET → local itching, eventually enter bloodstream → transported to LUNGS → enter alveoli Cause respiratory tract inflammation (pneumonia) → SWALLOW larvae → mature into adults in SMALL INTESTINE and attach to mucosa via cutting plates of teeth Adults mate in lumen of intestine → eggs shed in feces

Answer 105

detection of EGGS (not larvae) in stool + eosinophilia

Answer 106

Human = only definitive host Female black fly bite release onchocerca volvulus larvae → mature into adult form in subcutaneous tissue Adults mate and release microfilariae

Answer 107

- Fibrosis around adult worms - Inflammation due to microfilariae → thick, scaling, hyperpigmented pruritic rash (“lizard skin”) -River blindness: when microfilariae reach eye MAJOR cause of blindness

Answer 108

skin biopsy with microfilariae

Answer 109

ivermectin

Answer 110

1) Lymphatic filariasis | 2) Tropical pulmonary eosinophilia

Answer 111

lymphedema and elephantiasis (scrotum, arms, breast) | ONLY adult worms causes elephantiasis (not microfilariae)

Answer 112

caused by microfilariae in lung → immediate hypersensitivity reaction, increased IgE, eosinophilia, coughing, wheezing at night

Answer 113

female mosquito deposits larvae in skin → enter lymph nodes → after 1 year larvae mature into adult worms and trigger inflammation, fever, lymphadenopathy → obstruction of lymphatics Mosquito transmission

Answer 114

blood with microfilariae

Answer 115

diethylcarbamazine

Answer 116

GET GAP on the Metro Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes (bacteroides, C. diff - BELOW the diaphragm), H. Pylori

Answer 117

pro-drug targets enzyme unique to parasite Generates free radicals → cytotoxic intermediates that inhibit DNA synthesis

Answer 118

disulfiram-like reactions, metallic taste, headache, nausea

Answer 119

Cryptosporidiosis in non-AIDS patients

Answer 120

longer half life, better tolerated than Metronidazole

Answer 121

aminoglycoside abx Mechanism of action: binds A site of 30S ribosome, inhibits protein synthesis (bactericidal) - concentrates in gut

Answer 122

entamoeba histolytica, leishmania donovani, giardia minimal toxicity

Answer 123

used for treatment/prophylaxis of P. jirovecii infection in patients with sulfa allergies Minimal side effects

Answer 124

antifolate that acts synergistically to target enzymes involved in folate synthesis → impair parasite DNA synthesis Use: Malaria

Answer 125

Mebendazole, Albendazole NEMATODES - Ascaris, Necator (hookworm), Enterobius (pinworm), Trichuriasis (whipworm)

Answer 126

poor absorption, concentrates in GI tract, excreted in bile Used to treat nematode infections isolated to GI tract

Answer 127

better absorption, distributed into tissues

Answer 128

inhibit microtubule assemble by binding interface of alpha-beta tubulin dimer Selectively bind to parasite tubulin Widespread resistance exists

Answer 129

NEMATODES - Ascariasis (roundworm), Enterobiasis (pinworm), Hookworm

Answer 130

ACh receptor agonist → spastic paralysis of worm

Answer 131

Cysticercosis (pork tapeworm, Taenia solium) Cystic hydatid disease (echinococcus

Answer 132

Ca2+ ionophore→induce paralysis, detachment, excretion Induces tegmental damage - activates host immune system **DO NOT use if neurocysticercosis - can cause permanent damage

Answer 133

act against erythrocytic stage of infection, block detoxification of heme into hemozoin → heme accumulates and is toxic to plasmodium

Answer 134

used for all except falciparum (widespread resistance) Toxicity: retinopathy, pruritus, hepatotoxicity, cardiac disorders MUST exclude G-6-PD deficiency

Answer 135

used for P. ovale or P. vivax - activity against hypnozoites which can remain dormant in liver for months to years MUST exclude G-6-PD deficiency

Answer 136

treatment or prophylaxis for P. falciparum or P. vivax Used for prophylaxis during pregnancy Rarely used due to psychotic disturbances as side effects

Answer 137

treatment and cure of erythrocytic stages of chloroquine resistant and MDR P. falciparum malaria Mechanism: inhibit parasite feeding mechanism, generate oxidative stress

Answer 138

``` Cinchonism - visual dysfunction, tinnitus, nausea, vomiting Stimulates pancreatic B-cells Hypotension MUST exclude G-6-PD deficiency CONTRAINDICATED in pregnancy ```

Answer 139

Use: drug resistant P. falciparum, PCP pneumonia Mechanism: - Atovaquone → block electron transport chain of P. falciparum - Proguanil → inhibit parasite dihydrofolate reductase and potentiate mitochondrial toxicity of atovaquone

Answer 140

Mechanism: bind iron, break down peroxide bridges → generate free radicals Use: Fastest parasite clearance times of any antimalarial and act rapidly killing blood stages of ALL Plasmodium species -Often combined with other drugs to prevent resistance

Week 9 Flashcards

(164 cards)