Lecture 4: Protozoan Infections Flashcards
worms (hemlinths) vs protozoa
- which is unicellular?
- which is large?
- which causes infections in blood, tissue and intestines
worms (hemlinths) vs protozoa
- unicellular = protozoa
- large = worms
- infections in blood, tissue and intestines = protozoa
What are the 2 types of blood protozoa infections
Blood protozoa infections
- malaria
- Babesiosis
Blood Protozoa infections: Malaria
- what genus causes malaria
- name 4 types occuring in humans
- which causes most deaths
Blood Protozoa infections: Malaria
- genus = plasmodium
- 4 types = P. vivax, ovale, malariae, + falciparum (most deaths)
Blood Protozoa infections: Malaria epidemiology
- where (country) do most deaths occur and in what age group?
- what other group is at incr risk for severe dz/death
Blood Protozoa infections: Malaria Epi
- Deaths MC in Africa and in < 5
- pregnant women = incr risk of severe dz + death
Blood Protozoa infections: Malaria Transmission
- what is the vector + definitive host for malaria
- humans = intermediate host, meaning what type of reproduction occurs
note: rare forms = blood transfusion, vertical
Blood Protozoa infections: Malaria Transmission
- vector = FEMALE mosquitos (anopheles)
- humans = intermed host –> asexual reproduction
How does the malarian parasite cause the cyclical fever seen w/malaria
parasite rel into blood –> rupture of RBCs –> cyclical fever
Uncomplicated Malaria (all species)
1. What is the pattern of fever paroxysms
3 steps
2. what is the fever accompanied by (3) ?
Uncomplicated Malaria (all species)
- Chills –> Fever –> sweats (cyclical w/high spikes)
- Fever a/w HA, N/V
Complicated Malaria
- what the MC species that causes this?
- what is this d/t
- why is considered a medical emergency
Complicated Malaria
- MC species = plasmodium falciparum
- d/t cytoadherence
- medical emergency b/c may cause death in 24 hrs
Pt presents w/ cyclical pattern of fevers with spikes as high as 40C. Pt also presents w/ seizures and opisthotonic posturing. w/ further testing black spots are seen in retinal vessels/brain.
What type of malaria is this?
What species is the cause
Cerebral Malaria
cause = P. falciparum
Pt presents w/ cyclical pattern of fevers. w/ further testing you note severe hemolysis, hemoglobinuria and renal failure
name of this d/o?
a/w with what species
dx = blackwater fever
(hemolysis, hemoglobinuria and renal failure)
cause = P. falciparum
Pt presents w/ cyclical pattern of fevers. On exam you note HSM, signs of shock, and resp distress. Labs show: pancytopenia, Hypoglycemia, acidosis, and incr AST, ALT + Cr
What type of malaria is this?
Dx = complicated malaria
Malaria and Resistance
- in malaria endemic areas does resistance develop quickly or slowly?
- what does incomplete resistance w/malaria mean?
- how does “semi immunity” occur?
Malaria and Resistance
- malaria endemic areas –> resis develops slowly
- incomplete resis = ppl have immunity to clinical manif but not to malaria infxn
- semi-immunity occurs w/constant exposure
Malaria and Genetic factors
- what is required on RBCs for P. vivax to bind/invade?
- what two traits are protective vs malaria
- which protective vs P. falciparum
Malaria and Genetic factors
- Duffy antigen needed for P vivax to bind/invade RBCs
- Sickle cell trait + Beta thalassemia = protective vs malaria
- sickle cell trait = vs P. falciparum specifically
Malaria and Pregnancy/other
- when is a pregnant women more at risk for death from malaria
- What is malaria a/w in pregnancy (3 things)
- what group other than preg women are at risk for developing severe death from malaria d/t lack of immunity
Malaria and Pregnancy
- preg women more at risk for death in 1st preg (lose resis)
- malaria a/w: anemia, LBW and infant mortality in preg
- non-immune adult travelers = risk for developing severe death from malaria d/t lack of immunity
2 main tests used to Dx malaria?
- what is seen w/each
Dx Malaria
- thick + thin blood smears –> parasite in RBCs
- Rapid diagnostic tests (RDT) –> test for parasite antigen in blood
Tx of malaria
- what drug is 1st line if no resistance to it?
- what is name of PO drugs given in combo
- what are the 2 drug options for sever malaria
- what is the tx regimen for P. ovale or vivax (2 drugs)
Tx of malaria
- Chloroquine = 1st line in sensitive areas
- ACT = artemisinin combo therapy
- severe malaria –> IV quinidine or IV artesunate (artemisinin)
- P. ovale or vivax –> chloroquine (for active phase) –> primaquine (tx hypnozoite phase)
what are the main 2 ways to prevent malaria in travelers
Prevention of malaria in travelers
- decr exposure to mosquitos (ITNs, insect repellent, cover skin)
- ppx (depends on area)
Control Strategies of Malaria for Endemic areas: ITNs
- why are they used
- what are some cons a/w w/them?
Control Strategies of Malaria for Endemic areas: ITNs
- used to decr mortality (in kids + preg)
- cons: uptake, cost, resistance, LLINs, re-tx needed Q6-12 mos
Control Strategies of Malaria for Endemic areas: IPTp (Intermittent Preventative Tx in preg)
- how many times ppx given while preg?
- what does it protect against? (2 things)
Note: also IPTi (for infants)
Control Strategies of Malaria for Endemic areas: IPTp (Intermittent Preventative Tx in preg)
- given > 2x while preg
- protects vs anemia + LBW
Control Strategies of Malaria for Endemic areas
- what is the name for vector control?
- main chemical used?
Control Strategies of Malaria for Endemic areas
- vector control = IRS (indoor residual spraying)
- MC chemical = DDT
(others organophosphates, Pyrethroids, carbamates)
Babesiosis
- what is the MC type of species that infects humans in US?
- how is this dz mainly transmitted? (gen + spp)
- what animal is the reservoir for this dz
Babesiosis
- MC species infecting humans in US = B. microti
- transmission = tick (lyodes scapularis)
- resevoir = white-footed mouse
Pt w/ functional asplenia due to sickle cell dz travels to Cape Cod and develops a fever, chills, fatigue, and HA.
On blood smear you see maltese cross pattern.
Dx?
note: other endemic area = midwest
note: other groups at high risk = elderly, HIV +
Dx = Babesiosis
what dz other than Babesiosis involves tick lyodes scapularis
- conseq of this?
Lyme Dz –> can get co-infected w/both
What are the complications of Babesiosis
complications of Babesiosis
- ARDs
- hemolysis
- CHF
- Renal failure
- death
Tx of Babesiosis: severe or symptomatic dz
- what are 2 combo options (2 drugs each)
- what if pt is HIV +
- how do you r/o co-infection w/lyme dz
Tx of Babesiosis
- tx options - Atovaquone + azithromycin or…
clinda + quinine - HIV + –> long term suppressive Tx
- r/o co inf w/lyme dz by serology for borrelia burgdorferi
what protozoa has an owl eyed faced, pear shaped, flagellated trophozite
Giardiasis (Giardia intestinalis or lamblia)
What is the reservoir for Giardia
beavers –> “beaver fever
Pt coming back from camping trip and is now c/o of abd cramping + bloating, nausea, wt loss, malaise and anorexia. He says recently his stool has been loose, foul smelling. on fecal examination you notice trophozites and cysts in the stool
Dx?
Giardiasis (Giardia intestinalis or lamblia)
what are the 3 main ways to test for/dx Giardia
Dx Giardia
- fecal examination
- fecal antigen test
- PCR
2 major abxs used to tx Giardia
tx Giardia
- Metronidazole
- Tinidazole - one dose
What is the pathogenic bug that causes amoebiasis?
- can you differentiate it from the non-pathogenic bug on microscopy?
Amoebiasis
- pathogenic bug = entamoeba histologica
- CANNOT be differentiated from non-pathogenic bug on microscopy
Amoebiasis
- where is it MC?
- What 2 groups is it MC seen in for the US?
- what is the route of transmission?
Amoebiasis
- MC in tropically areas w/crowded living conditions + poor sanitation
- US = MC in hispanic males + immigrants (asia, pacific islands)
- transmission = fecal oral
30 y/o male Hispanic pt presents w/ gradual onset of diarrhea, abd pain, wt loss, fever, and dysentery. On rectal exam you obtain and + heme stool sample
Dx?
Dx = Amoebic colitis
immigrant for pacific islands presents w/diarrhea, abd pain, wt loss, fever, jaundice and cough for past 4 wks. on exam you note Hepatomegaly and aspiration reveals “anchovy paste”
dx?
cause?
Dx = liver abscess
cause = amoebiasis
What is the main way of dx Amoebiasis + why?
Main Dx = stool antigen detection
- can differentiate b/t 2 species
Tx for invasive amoebiasis (colitis, liver abscess)
- drug for active phase
- drug for cysts
what is the only drug given for Asx pts?
Note: also give fluids
Tx for invasive amoebiasis (colitis, liver abscess)
- drug for active phase = Metronidazole
- drug for cysts = luminal agent
Asx = luminal agent only
Which intestinal protozoa is transmitted person to person (day care), zoonotic (farm + animal handlers) and waterborne via swimming pools + public drinking water
Crpytosporidium parvum
Intestinal Protozoa: Crpytosporidium parvum
- what 2 groups is it MC in?
Intestinal Protozoa: Crpytosporidium parvum
MC in kids and HIV + pts
5 y/o kid presents with chronic, watery diarrhea, wt loss, abd pain, fever, N/V and FTT. On exam you note signs of dehydration. You perform a modified acid test that comes back (+) for red, round protozoa
Dx?
Crpytosporidium parvum
HIV (+) pt presents w/ chronic watery diarrhea, wt loss, abd pain, fever and N/V. You check is CD4 count and it is 150
Dx?
Crpytosporidium parvum
Crpytosporidium parvum
Other than Modified acid fast test, what other type of microscopy test can be used to Dx Crpytosporidium parvum?
2 antigen tests?
Direct immunofluorescence
2 antigen tests
- EIA
- PCR
Tx of Crpytosporidium parvum
- if the pt has HIV
- Otherwise give?
Tx of Crpytosporidium parvum
- if the pt has HIV–> ARVs
- Otherwise –> Nitazoxanide
What are the 2 types of dzs caused by Trypanosomiasis
Trypanomiasis Diseases
- HAT - Human African Trypanosomiasis
- Chagas Dz (American Trypanosomiasis)
Trypanosomiasis: HAT
- what are the names of the 2 types of HATs caused by Trypanosoma brucei
- what is the vector for HAT (how transmitted to humans)
Trypanosomiasis: HAT
- Gambesian HAT and Rhodesian HAT
- Vector: Tsetse fly
Trypanosomiasis: HAT 2 types (Rhodesian + Gambian)
- which type occurs in West Africa + no animal reservoir
- which type occurs in East Africa w/ cattle reservoir
Trypanosomiasis: HAT 2 types (Rhodesian + Gambian)1.
- occurs in West Africa + no animal reservoir = Gambian HAT
- occurs in East Africa w/ cattle reservoir = Rhodesian
Trypanosomiasis: HAT 2 stages of illness
- where are the tryps found in the early stage + what lesion characterizes this stage/where
- where are tryps found in late stage
- what does the late stage lead to? and therefore HAT is called ______
Trypanosomiasis: HAT 2 stages of illness
- early stage –> tryps in blood + LNs (enlarged)
- painless chancre at site of bite - Late stge –> tryps in CSF
- Late stage –> coma + death –> “ Sleeping Sickness”
Winterbottom’s Sign in HAT
- what is it
- a/w Gambian or Rhodesian HAT
Winterbottom’s Sign
- posterior cervical adenopathy
- a/w Gambian HAT
Pt presents w/ intermittent fever, posterior cervical adenopathy, constant HAs, diurnal somnolence, nocturnal insomnia, behavior changes, and wasting. Sxs present over 6 months
Which type of HAT is this?
Gambian HAT
What is the difference b/t Gambian and Rhodesian HAT
Rhodesian HAT develops more rapidly than Gambian (weeks vs mos-yrs)
Dx HAT
- Microscopy w/Giemsa staining
- what 2 things taken as samples
- what do you test in late stage dz - what test can ONLY be used for Gambian HAT
Dx HAT
- Microscopy w/Giemsa staining
- samples from LN aspirate or blood
- late stage dz –> test CSF - Test ONLY be used for Gambian HAT
- CATT agglutination/blood test
Trypanosomiasis: Chagas Dz
- what is the cause
- where is dz burden highest (2 places)
- classic name given to vector of this dz (and real name of MC)
- Vector’s ideal habitat
Trypanosomiasis: Chagas Dz
- cause = Treponema cruzi
- dz burden highest = Subcentral/south Am
- vector = “kissing bug” (Triatoma MC) or Rhonius
- Vector’s ideal habitat = adobe houses/roofs; b/t bricks
Trypanosomiasis: Chagas Dz
- what 2 signs a/w ACUTE dz
- what 3 things a/w CHRONIC dz
Trypanosomiasis: Chagas Dz
- ACUTE = Chagoma, Romana’s sign
- CHRONIC = CHF, dilated cardiomyopathy, Mega colon/esophagus
Trypanosomiasis: Chagas Dz (acute)
- what is a Chagoma
- what is Romana’s sign
Trypanosomiasis: Chagas Dz (acute)
- Chagoma = indurated/inflam nodule at bite site
- Romana’s sign = unilat periorbital swelling
Trypanosomiasis: Chagas Dz Dx
- what test can be used to Dx acute AND chronic
- what test is spp used to Dx acute
- what test is spp used to Dx chronic
Trypanosomiasis: Chagas Dz Dx
- Test to Dx acute AND chronic = PCR
- Test to Dx acute = microscopy
- Test to Dx chronic = serology (IgG for T.cruzei)
Trypanosomiasis: Chagas Dz Tx
- class of drugs used for Tx? general length of Tx needed? effective?
- what other 2 Tx options avail?
Trypanosomiasis: Chagas Dz Tx
- drug class = antiparasitic drugs, not very eff (long duration, mos)
- 2 other Tx options
- pacemaker
- heart transplant
Pt living in South Am in adobe house presents w/ malaise, fever, unilateral R eye swelling and inflamed nodule on her R eye. Further workup reveals myocarditis and ECG changes.
Dx?
Dx = Acute Chagas Dz
Pt living in South Am in adobe house presents w/ CHF. Further workup reveals that dilated cardiomyopathy also present. on XR you see dilated esophagus and colon
Dx?
Dx = chronic Chagas dz
Leishmaniasis
- vector for this dz?
Leishmaniasis
- vector = female sandfly
Leishmaniasis
- what are the 3 major types of it?
Leishmaniasis
- Visceral Leishmaniasis (VL)
- Cutaneous Leishmaniasis (CL)
- Mucocutaneous Leishmaniasis
What is the name of the main type of VL
Kala-azar
Leishmaniasis: VL/Kala-azar
- 2 countries MC in
- what type of infxn is it in HIV/AIDS pts
- what is reservoir
- what types of cells does it invade/where
Leishmaniasis: VL/Kala-azar
- MC in = india + sudan
- opportunistic infxn in HIV/AIDS pts
- reservoir = dogs
- invades phagocytes in liver, LN, bone marrow
Leishmaniasis: VL/Kala-azar
- invades phagocytes in liver, LN, bone marrow –> causing _______
Leishmaniasis: VL/Kala-azar
- invades phagocytes in liver, LN, bone marrow –> causing
skin rxn
3 y/o Pt in India presents w/ fever, wt loss, HSM, and hyperpigmentation. PE reveals HSM. Labs reveal pancytopenia and hypergammaglobulinemia
Dx?
dx = Kala-azar (VL)
Leishmaniasis: VL/Kala-azar
- main way to Dx? (w/what 2 things as samples?)
others: microscopic visualization of amastigotes and serology
Leishmaniasis: VL/Kala-azar
- main way to Dx = PCR of blood or Bx
Leishmaniasis: VL/Kala-azar
- ToC in US
note untreated –> death
Leishmaniasis: VL/Kala-azar
- ToC in US = amphotericin B
Pt who initially had an small erythematous papules w/ an ulcer on his hand that has since healed. He now has a raised, bordered scar. Initially he had no pain but now says he has pain at the site.
Dx?
Dx = CL (Cutaneous Leishmaniasis)
CL (Cutaneous Leishmaniasis)
- main way to Dx it?
Main way to Dx = Bx
Tx for CL
- mild vs mod dx: flip over to see (lot)
Tx for CL
- mild dz
- topical paromoycin
- heat therapy
- intralesional antimony - mod dz
- pentavalent antimony
- Flu/Ketoconazole
- PO miltefosine
What is the dz a/w only the species L. braziliensis, which is only located in central/south america
Mucocutaneous Leishmaniasis
- only species = L. braziliensis
Pt presents w/destructive mucosal lesions in mouth and nose. Years ago the patient had cutaneous lesions that have since resolved.
Dx?
Mucocutaneous Leishmaniasis
