Infections in an Immunocompromised Host Flashcards
opportunistic pathogen
organism capable of causing disease only when the host’s resistance is lowered by other diseases or drugs.
OR
Causes atypical or more severe infectious clinical syndrome in a compromised host.
If a patient presents with an unusual pathogen causing infection or a severe infection, consier screening for immunodeficiency
what bacteria could this be?
gram negative bacilli
- pseudomonas, stenotrophomonas, enterobacterieae (ecoli, klebsiella, enterobacter, yersinia, salmonella, shigella)
- bacterides fragilis
this ended up being pseudomonas aeruginosa
outline the enterobacteriae
treatment for pseudomonas (name 6)
pseudomonas is a gram negative bacteriae.
- aztreonams
- gentamycin and tobramycin (aminoglycosides)
- colistin
- carbapenems/piptaz
FQ/cirpofloxacin
- Ceftazidime (3rd generation cephalosporin)
What part of the immune system is defective?
suspecting AID/HIV because of the recurrent infection. This would mean her CD4+ helper T cells would be affected. She is susceptible to intracellular pathogens, viruses, fungi and parasites.
She has a fungal and viral infections– indicates a T cell deficiency (or PMN)
clinical manifestations of PJP on an exam and on x ray findgins?
- progressive dyspnea, cyanosis
- tachycardia, tachypnea
- fever
- non-produtive cought
- chest pain
- pneumothorax
Chest X ray findings: bilateral diffuse infiltrates extending from hilum typically. but it can still bey unilateral, nodules etc.
- lymphadenopathy
You suspect PJP in immunocompromised patient. What do you order and how do you treat?
bronchoscopy fluid sample or lung tissue (histological staining or PCR)
- high dose of TMP-SMX (sulfamethoxazole)– covers gram positive and gram negative, or predinosone
when should you give PJP prophylaxis
in HIV+ and immunocompromised individuals.
- CD4<200 for primary prophylaxis. You should stop it once immune reconstitution occurs.
what do you give for PJP prophylaxis
low dose septra for PJP, until stabilized with HIV treatment. Also give nystatin and fungin for thrush
risk factors for candida esophagitis
high grade colonization due to HIV, diabetes, hematologic malignancies, chemotherapy, broad spectrum antibiotic use, impaired esophageal motility etc.
common yeast seen in subsaharan africa that really affects people with HIV
cryptococcus neoformans.
a person from subsaharan africa who is HIV positive is suspected to have cryptococcus neoformans because of indolent meningitis, fever, mental status changes, and suspected pneomonia. What do you do to diagnose and treat it?
diagnosis:
-lumbar puncture– then a fungal stain and CRAG antigen test
treatment:
amphoterocin PLUS FLUCYTOSINE (induction)– 2 weeks or until CSF is sterilized.
- THEN you give high dose fluconazole (ergosterol synthesis inhibitor)
although neoformans affects immunocomrpomised hosts, which cryptococcus seen in pacific rim affects healthy hosts, causing meningitis and pneumonia?
cryptococcus gattii– it is difficult to treat and there’s poor outcomes.
someone presents with fever, malaise, splenomegaly, cerival lymphadenopathy, sore throat, rash, and atypical lymphocytosis (indicating acute infection). Additionally, they own a cat and don’t practice good hand hygiene. what is a suspected toxin?
toxoplasma gondii.
diagnosing toxoplasma gondii
- serology:
igM within one week, IgG appears within 1-2 weeks and persists for life.
- Histology: significant for isolation of parasite in CSF and retina.
- CT
treatment for an immunocompromised case of toxoplasmosis
pyrimethamine, sulfadizaine, folinic acid
OR
TMP-SMX, clindamycin
what part of the immune system is defective?
he has physical barrier dysruption because of IVs, AND he also has severe prolonged marrow suppressionbecause he’s not taking to the graft. therefore, T cell, B cell, blood borune and physical barrier immunity is being affected.
diagnosing aspergillus infection on radiography– what is a characteristic feature?
diagnosing and treatment for aspergillus
- bronchoscopt or tissue biopsy with fungal stains and culture.
treatment
- voriconzaole
- amphotericin
Prophylaxis: AML, MDS, allo-stem cell transplant and posaconazole.
daignosing CMV
- serology via IgM and igG
- PCR using blood and tissue/body fluids
- histopatholoogy: tissue sample.
sympyoms of a CMV primary infection? wb a systemic/reactivation of the diesase?
reactivation includes fever, fatigue, cytopenias and elevated liver enzymes.
reasons why someone might have reactivation of CMV
- stress
- focal organ disease like colitis, hepatitis, myocarditis, encphalitis.
treatment of CMV
gangcyclovir (IV) or valgancyclovir (po)
prophylaxis:
- daily prophylaxi during high risk periods post-transplant
- weekly CMV viral load monitoring with early preemptive treatment if viral load becomes detectable.
what part of the immune system is defective?
3 most common pathogens that affects someone with hyposplenism
streptococcus pneumo
kaemophilus influenzae
neisseria meningtidits
(people with sickle cell anemia at high risk)
how to prevent infection in hyposplenic/asplenic patients?
