Infections Flashcards
(27 cards)
Meningitis is defined as inflammation of the membranes of the brain or spinal cord, specifically the _____________ _____, and is characterized by cellular infiltrates within its confines.
Subarachnoid space
2 most common bacteria in meningitis in infants (less than 1 month)
1 - Group B Strep (S. agalactiae)
2 - Gram-Negative bacilli
2 most common bacteria in meningitis - 1 month - 29 years
1 - Neisseria meningitides
2 - S. pneumoniae
2 most common bacteria in meningitis - > 30 y/o
1 - S. pneumoniae
2 - N. meningitides
Which bacteria are most frequently associated with head trauma, Neurosurgery, or nosocomial meningitis? (5)
-Gram Negatives
-S. aureus
-S. epidermidis
-Streptococcus
-N. meningitides (“meningococcus”)
Which organisms is most frequently associated with fulminant onset disease, epidemics, purpural/petechial rashes, Asplenia, or Complement Deficiency States?
N. meningitides (“meningococcus”)
Which organism is most commonly associated with pneumonia, otitis, or sinusitis?
Strep pneumoniae (“pneumococcus”)
Which organism is most commonly associated with alcoholism, cirrhosis, Sickle-Cell disease/Thalassemia, Multiple-Myeloma, Humoral
S. pneumoniae
Listeria monocytogenes meningitis:
-At risk groups (4)
-Transmission
-Infants (<1 mo)
-Pregnant women
->60 y/o
-Immunocompromised (all ages)
-Food (coleslaw, milk, cheese, undercooked hot dogs)
Most common causes viral meningitis (4)
-Enteroviruses
-Arboviruses
-HSV-2
-West Nile Virus
What are the top 3 most common fungi causing meningitis in Healthy population (immunocompetent)?
1 - Blastomyces dermatitidis
2 - Histoplasma capsulatum
3 - Coccidioides immitis
*Candida spp. meningitis occurs almost exclusively in immunocompromised patients
Parasitic CNS infections - Nematodes (roundworms):
-Most frequent organisms (3)
-Toxocara canis
-Angiostrongylus cantonensis (rat lung worm)
-Strongyloides
What parasite causes visceral larval migrans and ocular/retinal infections
Toxocara canis
Which parasite classically causes eosinophilic meningoencephalitis?
Angiostrongylus cantonensis
Parasitic CNS infections - Trematodes (Flukes):
-Most frequent organisms (3)
-Schitosomiasis (Africa & Asia)
-Paragonimiasis (Africa & Asia)
-Echinococcus granulosus
Which parasite typically causes solitary, unilocular brains cysts in the cerebral hemispheres?
Echinococcus granulosus (Hydatid disease)
Parasitic CNS infections - Cestodes (tapeworms):
-Most frequent organism
-Which stage infects CNS
-Taenia solium (Cysticercus cellulosae)
- Larval stage
Parasitic CNS infections - Amebiasis protozoal infections:
-Most frequent organisms (4)
-Naegleria fowleri
-Acanthamoeba
-Balamuthia
-Entamoeba histolytica
This free-living waterborne ameba is found in ponds and pools. How does it enter CNS?
N. fowleri
-nasal mucosa and cribriform plate
What organisms cause Granulomatous Amebic Encephalitis (2)?
Acanthamoeba & Balamuthia
*Immunocompromised and Children
Although rare, how does Entamoeba histolytica reach the CNS?
Hematogenous route from liver or lung
Which is the only malarial species that causes CNS infections?
Plasmodium falciparum
T/F: Well-nourished individuals are MORE susceptible to Plasmodium falciparum infections than malnourished one.
True - related to body iron status
Which two situations increase risk of severe Plasmodium falciparum infection?
-Pregnancy (relative immunosuppression)
-Steroid administration (a touch of opportunistic infection)
