Infections

Question 1

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.

Answer 1

Subarachnoid space

Question 2

2 most common bacteria in meningitis in infants (less than 1 month)

Answer 2

1 - Group B Strep (S. agalactiae)
2 - Gram-Negative bacilli

Question 3

2 most common bacteria in meningitis - 1 month - 29 years

Answer 3

1 - Neisseria meningitides
2 - S. pneumoniae

Question 4

2 most common bacteria in meningitis - > 30 y/o

Answer 4

1 - S. pneumoniae
2 - N. meningitides

Question 5

Which bacteria are most frequently associated with head trauma, Neurosurgery, or nosocomial meningitis? (5)

Answer 5

-Gram Negatives
-S. aureus
-S. epidermidis
-Streptococcus
-N. meningitides (“meningococcus”)

Question 6

Which organisms is most frequently associated with fulminant onset disease, epidemics, purpural/petechial rashes, Asplenia, or Complement Deficiency States?

Answer 6

N. meningitides (“meningococcus”)

Question 7

Which organism is most commonly associated with pneumonia, otitis, or sinusitis?

Answer 7

Strep pneumoniae (“pneumococcus”)

Question 8

Which organism is most commonly associated with alcoholism, cirrhosis, Sickle-Cell disease/Thalassemia, Multiple-Myeloma, Humoral

Answer 8

S. pneumoniae

Question 9

Listeria monocytogenes meningitis:
-At risk groups (4)
-Transmission

Answer 9

-Infants (<1 mo)
-Pregnant women
->60 y/o
-Immunocompromised (all ages)

-Food (coleslaw, milk, cheese, undercooked hot dogs)

Question 10

Most common causes viral meningitis (4)

Answer 10

-Enteroviruses
-Arboviruses
-HSV-2
-West Nile Virus

Question 11

What are the top 3 most common fungi causing meningitis in Healthy population (immunocompetent)?

Answer 11

1 - Blastomyces dermatitidis
2 - Histoplasma capsulatum
3 - Coccidioides immitis

*Candida spp. meningitis occurs almost exclusively in immunocompromised patients

Question 12

Parasitic CNS infections - Nematodes (roundworms):
-Most frequent organisms (3)

Answer 12

-Toxocara canis
-Angiostrongylus cantonensis (rat lung worm)
-Strongyloides

Question 13

What parasite causes visceral larval migrans and ocular/retinal infections

Answer 13

Toxocara canis

Question 14

Which parasite classically causes eosinophilic meningoencephalitis?

Answer 14

Angiostrongylus cantonensis

Question 15

Parasitic CNS infections - Trematodes (Flukes):
-Most frequent organisms (3)

Answer 15

-Schitosomiasis (Africa & Asia)
-Paragonimiasis (Africa & Asia)
-Echinococcus granulosus

Question 16

Which parasite typically causes solitary, unilocular brains cysts in the cerebral hemispheres?

Answer 16

Echinococcus granulosus (Hydatid disease)

Question 17

Parasitic CNS infections - Cestodes (tapeworms):
-Most frequent organism
-Which stage infects CNS

Answer 17

-Taenia solium (Cysticercus cellulosae)
- Larval stage

Question 18

Parasitic CNS infections - Amebiasis protozoal infections:
-Most frequent organisms (4)

Answer 18

-Naegleria fowleri
-Acanthamoeba
-Balamuthia
-Entamoeba histolytica

Question 18

This free-living waterborne ameba is found in ponds and pools. How does it enter CNS?

Answer 18

N. fowleri
-nasal mucosa and cribriform plate

Question 19

What organisms cause Granulomatous Amebic Encephalitis (2)?

Answer 19

Acanthamoeba & Balamuthia

*Immunocompromised and Children

Question 20

Although rare, how does Entamoeba histolytica reach the CNS?

Answer 20

Hematogenous route from liver or lung

Question 21

Which is the only malarial species that causes CNS infections?

Answer 21

Plasmodium falciparum

Question 22

T/F: Well-nourished individuals are MORE susceptible to Plasmodium falciparum infections than malnourished one.

Answer 22

True - related to body iron status

Question 23

Which two situations increase risk of severe Plasmodium falciparum infection?

Answer 23

-Pregnancy (relative immunosuppression)
-Steroid administration (a touch of opportunistic infection)

Question 24

What is the transmission of Toxoplasmosis protozoal infections?

Answer 24

Ingestion of oocysts shed in cat feces

Question 25

CNS Toxoplasmosis is primarily seen in which two patient populations?

Answer 25

-AIDS
-Congenital cases