Toxoplasmosis, MAC, Fungal Diseases Flashcards
What causes toxoplasmosis
protoxoa: toxoplasma gondii
animal that T. gondii completes its reproductive cycle
cat
where does toxoplasma live, when is it not dormant
nucleated cells, when immunosuppressed
4 ways of infection by toxoplasmosis
contaminated meat, produce, water; ingestion cat feces/soil, vertically (mother-fetus), organ transplant
How many in US are seropositive for T. gondii
11% age 6-49
most common mode of transmission in us of toxoplasmosis
consumption undercooked meat
climate preferred by toxoplasmsois
hot humid (SW USA)
what is third most common cause of lethal foodborne disease in US
toxoplasmosis
S/S toxoplamsosi (4)
fevers/chills/sweats, cervical lymphadenopathy, myalgia/arthralgia/HA/sore throat/rash, chorioetinitis (inflam eye)
diagnosis of toxoplasmosis
serologic testing with toxoplasmosis IgM antibody levels
treatment of toxoplasmosis
3 drug regimen: pyrimethamine, sulfasalazine, leucovorin calcium
competent pts = 2-4wks, immunocompromised = longer
Congenital toxoplasmosis risk vs severity
1st trimester 15% low risk, disease most severe
3rd trimester 60% high risk, disease sublcinial/symp not at birth
Do congenital toxoplasmosis children present at birth
2/3 DON’T
classic traid of congenital toxoplasmosis
retinochorionitis, intracranial calcifications, hydrocephalus (tirad rarely seen)
50% of immunocompromisd pts get what with toxoplasmosis
CNS involvement: sz, blance changes, cranial nerve deficits, focal deficits, AMS, HA
T/F immunocompromised pts will get flulike symp and lymphadenopathy like comp pts
true
MRI with contrast might show wat in immunocmprised pts with toxopalsmosis
encephalitis, mass lesions or meningoencephalitis
how does histoplasmosis infect
inhalation of fungal spores (bird droppings, contaminated soil aersolizes during construction)
pathophys of hisoplasmosis
pulmonary macrophages ingest it but can’t kill it, fungus grows and divides inside, macrophage takes it through blood to lungs, spleen, liver, fungus trapped in fibrotic, calcified caseating granuoloma
What type of hypersensitivity reaction occurs with histoplasmosis
delayed-type hypersensitity rxn (t-lymph develops immunity for macrophages and lymphocytes to sterilize granulomas)
how common is asymptomatic histoplasmosis
90% of competent w/ low exposure are asymp; others flu-like for 1-4 wks
If pt has calcifications on incidental CXR what might they have
might have had asymptomatic histoplasmosis years ago
acute/subsactute pum histopalsmosis S/S, who gets it, recovery prognosis
fever, myalgia, abd pain, rales, heavy exposure competent or less in immunocompromised; ill wks-months; almost never fatal
chronic pulmonary histoplasmosis; S/S; who gets it
older pts with COPD, progressive apical cavitary lesions, weight loss, productive cogh, fever, lasts 3+ months, (possible TB b/c apical)
Progressive disseminated histoplasmosis
immunocomprimsed (like pts on TNF inhibitors), develop fever, cough, dyspnea, 20% AMS, pericardial effusions, ulcerative lesions of mucous memb and viscera; fatal w/in weeks
3 main and 3 other S/S that indicate histoplasmosis
pneumonia with lymphadenopathy, cavitary lung disease, pulm manifestations w/ arthritis or arthragai plus erythema nodosum
minor: mediastinal or hilar masses, pericarditis w/ mediastinal lymphadenopathy, suspected sacroidosis
systemic manifestations with pts with disseminated histoplasmossi
pancytopenia, LFT abn, erythema nodosum
how to diagnose histoplasmosis
blood cutlures, complement fixation antibody titer, serum or urine antigen detection assay (none close to 100% sensitive)
CT or MRI to see extenet of disease
2 invasive procedures and 2 meds for histoplasmosis
bronchoscopy, pericardial window
itraconazole for wks up to a year; if severe: amphotericin B used briefly
