ID: Parasitic infections Flashcards
list the 3 types of parasites
- single celled–protozoa
- multi celled–worms
- Ectoparasites–aka arthropods–scabies and lice
roundwords or?
nematodes
flatsworms or?
Platyhelminthes
list the subcategories of flatworms
tapeworms (cestodes)
flukes (trematodes)
diseases caused by Protozoa (5)
Giardia Trich malaria chagas dz african sleeping sickness
dz caused by arthropods (4)
lice
scabies
mites
fleas
trophozoite
protozoa life cycle
- motile feeding reproducing form
- surrounded by flexible cell membrane and a cyst–non-motile
cyst of a trophozoite
nonmotile, nonmetabolizing, nonreproducing form surrounded by a thick wall
*survives well in the environment and is often invovled in tramssion
list flaglated protoza
Leishmania
Trypanosoma
what is commonly associated with helminth infections
eosinophilia
aka elevated eosinophil counts
what caues malaria
transmision
unicelled parasite–>plasmodium
transmission=mosquitoe bite from the Anopheles genus
what is the MC and most lethal species of the Plasmodium genus
Plasmodium falciparum–malaria
Malaria
- etiology
- MC where
- what organ is attacked first and then?
- CM
- what happens if untx
PLASMODIUM genus
***MC is the Falciparum and most dangerous:
**tropical dz
Liver is attacked first—then RBCs–>lysis
CM
- Cyclical fever– cold stage–>hot stage/high fever–>diaphoretic/drenching sweats stage fever is every third day*
* HA
* fatigue
* mylagias
* N/V/GI s/s
* splenomealy MC
* hepatomegaly in 1/3 of PT
* anemia
untx:
* extensive brain and kidney damage
* *cerebral malaria-AMS, delirium, seicures, coma
* *blackwater fever=kidney
what disease can partialy protect against malaria
sickle cell
CM for blackwater fever malaria
KIDNEY DAMAGE
- severe hemolysis
- hemoglobinuria
- renal failure
how does malaria relapse
the P. vivax and P. ovale species can cause the relapsing due to the hypnozoites latent in the liver
***can cause malaria years later
how to diagnose malaria
- clinical– fever + recent travel to tropics
- Giemsa-stained blood smear: thick and thin
* THICK=detects precense of organisms
* THIN=used for species ID
* **species ID is imp bc of tx - LABS: CBC will show
* leukopenia
* hemolytic anemia
* thrombocytopenia
first line tx for uncomplicated P. falciparum malaria
- alternative?
- add on agent to kill latent species to prevent recurrence
Chloroquine
Hydroxychloroquine is alternative
Add on: Primaquine
TX for chloroquine-resistant P. Falciparum
1st and 2nd line
first line: Atovaquone/Proguanil or Artemisinin combination therapy
second: doxycycline, tetracycine, or clindamycin PLUS quinine sulfate
life threatening malaria infection tx
IV quinidine gluconate
prophylaxis for malaria if traveling
-sensitive and non resistant areas
Chloroquine for the chloroquine sensitive areas
chloroquine resistant areas: doxycycline, mefloquine or atovaquone-proguanil
what day of malaria infection does PT develop splenomegaly
4th day
what causes Chagas Dz
Trypanosoma cruzi
vector for chagas dz
reduviid bug— kissing bug
bc it most commonly bites humans around the mouth or eyes
what cells are MC affected by Trypanosoma cruzi
myocardial
glial
reticuloendothelial cells
complications from Trypanosoma cruzi or chagas DZ
dilated cardiomyopathy
GI ddz
what is the leadig cause of CHF in latin america
Trypanosoma cruzi or chagas DZ
CM for Chagas DZ
Acute phase:
*facial edema and a nodule near bite
*bite around the eye–>unilateral palpebral swelling–>ROMANAS SIGN
+fever +lymphadenopathy +hepatosplenomegaly
Chronic: not everyone develops this form
- CARDIAC–>dilated cardiomyopathy, CHF, arrythmias (MCC of death)
- GI=
1. megacolon—constipation, colicky abd pain, bloating
2. megaesophagus–dysphagia and regurg of food - CNS=destruction of glial cells
Diagnosis for Chagas DZ– each phase
Acute phase–>peripheral blood smear will show trypomastigotes– flagellated
chronic phase
- ELISA
- EKG
- ECHO
TX for chagas dz
acute phase or PT without significant cardiac or GI disease:
*****benznidazole or Nifurtimox for 90-120 days
No treatment for chronic form with signiicant cardiac or GI dz
what causes african sleeping disese
Trypanosoma brucei gambiense
and
Trypanosoma brucei rhodesiense
vector for african sleeping dz
Tsetse fly
Trypanosoma brucei hambiense causes?
-severity of dz
african sleeping sickness along water courses in WEST africa
-chronic course over several years
Trypanosoma brucei rhodesiense
causes afican sleeping sickness along arid regions of EAST africa
-acute, rapidly progressive dz
CM for african sleeping sickness
EARLY STAGE–hemolytic stage
- painless chancre at the bite site 2-3 days after bite
- intermittent fever, malaise, HA, joint pain, itching
- generalized or regional lymphadenopathy– usually LARGE– MC cervical LNs–> Winterbottom’s sign
LATE STAGE–CNS stage
- encephalitis: HA, insomnia, mood changes
- muscle tremors
- slurred speech
- day-time somnolence and coma
what causes the sleepiness in african sleeping sickness
tryptophol realsed by the dz
how to diagnose african sleeping sickenss- both stages
EARLY
- blood smears or aspirate from enlarged LN
- ELISA
LATE
*presence of trypanosomes
TX for african sleeping sicness
-both strains
Trypanosoma brucei gambiense
- early=Pentamidine
- late=Eflornithine and Nifurtimox
Trypanosoma brucei rhodesiense
- early= Suramin
- late=Melarsoprol +/- Nifurtimox
toxoplasmosis is caused by
toxoplasma gondii
toxoplasmosis
- cm
- diagnosis
- tx-pregnant and not pregnant
primary infection: usually asympto for immunocompetent adults
-some can resemble mononucleosis
Reactivation
- **encephalitis–MC in AIDS pt with CD4<100
- **Chorioretinitis: posterior uveitis, eye pain and decreased visual acuity
- pneumonitis: fever, dyspnea, nonproductive cough– similar to PCP pneumonia
diagnosis:
1. microscopic examination of Giemsa-stain— crescent shaped trophozoites during acute infections
2. immunofluorescence assay/ELISA–>anti-toxoplasma IgG antibody
3. MRI–>multiple ring enhancing lesions
tx:
1. Sulfadiazine or clindamycin PLUS Pyrimethamine
* *add folic acid/leucovorin to prevent depletion
- if pregnant: spiramycin
Prophylaxis: for PT with CD4 <100
- Trimethoprim-sulfamethoaxazole (Bactrim DS)
- Alternative: Dapson + Pyrimethamine & Leucovorin
when can mother transmit toxoplasmosis to fetus?
if mother is newly infected DURING pregnancy
triad for CM in congential toxoplasmosis
- chorioretinitis–inflammation of choroid in eye
- encephalitis/hydrocephalus
- intracranial calcifications
diagnosis for congenital toxoplasmosis
ELISA for anti-toxoplasma IgM antiboies
which antibodies do we test for:
- non congential toxoplasmosis
- congential toxoplasmosis
non congential–> anti-toxoplasma IgG
congential–> anti-toxoplasma IgM
three main groups of helminths
nematodes
cestodes
trematodes
types of nematodes
roundworms
pinworms
hookworms
whipworms
types of cestodes
beef, pork and fish tapeworms
types of trematodes
flukes— each one is IDed whre in the body it is located
Roundworms
-name ?
Ascariasis–GIANT roundworm infection
Ascariasis
- caused by?
- transmission
- CM
- can lead to?
- diagnosis
- tx: preg and not preg
Ascaris Lumbricoides
soil transmission
CM: depends on worm load
- small load: asympto
- larger load: vague abd s/s: anorexia, nausea, vomiting, abdominal discomfort
- HIGH load: intestinal obstruction–MC, hepatic or biliary manifestations
* can cause Ascaris pneumonia*
diagnosis: stool O/P
+eosinophilia
TX:
- albendazole or Mebendazole
- pregnant: pyrantel (only after 1st trimester)
which is the largest intestinal nematodes as adults?
ascariasis
two species of nematode worms associated with?
- transmission and the cycle
- can cause?
hookworm infection
- Necator americanus–US and australia
- Ancylostoma doudenale–
transmission= eggs deevlop into larvae in soil contaminated with dog or cat feces–penetrate skin–travel through venous circulation—lungs–coughed up—swallowed–enter intestines—dev into mature adults–attach to the blood vessels and can cause anemia
cm of hookworm infection
diagnosis hookworkm
-tx?
phase 1 (skin)–very pruritic erythematous maculopapular dermatitis (feet and ankles MC)— resolves few days
phase 2 (transpulmonary)–>MC asympto
pahse 3 (GI): N/V/D
phase 4 (anemia): blood los at the site of attachment in the small intestine *****major impact of hookworm infection
Diagnosis:
- CBC: hypochromatic microcytic anemia
- Eosinophilia: increased IgE
- stool guaiac: +
- Stool O/P: eggs in stool
TX:
- ***Albendazole or Mebendazole or Pyranetel
- iron supplements and vitamins
what is the major impact of hookworm infection
anemia
Enterobius vermiclaris
- pathogen?
- occurs in?
- MC IN?
- diganosis
- tx
- preg tx
pinworms
only occurs in humans– no animal resvoir or vector***
transmission: fecal-oral with contaminated fomites
MC in: school age kids 5-10YO
CM:
- perianal itching–esp at night (bc eggs are laid at night)
- severe cases: abdominal pain, nausea, vom
Diagnosis:
- cellophane tape test or pinworm paddle test—early in Am to look for eggs under a micrscope
- O/P—- will NOT show eggs but the adult worms
TX:
- Albendazole, Mebendazole or Pyrantel–only kill adult worms in COLON and not the eggs– so re-treatment is needed x2 weeks
- pregnant– Pyrantel