Going Viral
What is the most common form of meningitis (1) and what are its most common causes (2)?
(1) Aseptic/viral meningitis
(2) Echoviruses & Coxsackie A + B viruses
(1) What are the most common causes of bacterial meningitis in neonates? (2) In older adults?
(1) Group B Streptococcus, Listeria monocytogenes, E. coli
(2) Neisseria meningitidis, Streptococcus pneumoniae, Listeria monocytogenes
(1) What viruses does the Aedes mosquito carry and where are they found? (2) What viruses does the Culez mosquito carry and where are they found?
(1) Dengue fever, yellow fever, EEEV, WEEV, VEEV; urban areas
(2) St. Louis encephalitis, West Nile encephalitis, EEEV, WEEV, VEEV; forest and urban areas
(1) _____ is the most common cause of neonatal conjunctivitis. (2) What presentation would you expect?
(1) Chlamydia trachomatis (acquired during birth)
(2) Copious mucopurulent discharge, sticking of lids
What is the classic triad of early symptoms of bacterial meningitis?
Fever, headache, stiff neck (nuchal rigidity)
______ is the most common cause of sporadic encephalitis (1) and is usually limited to the ______ lobes (2).
*Bonus: what ages are more likely to be infected what which HSV strain*
HSV; temporal
*HSV-1 is usually the cause in kids 3 months or older, but in neonates, brain involvement is likely due to HSV-2*
What is the DOC for herpatic meningitis and what is its MOA?
Acyclovir; guanine analog that incorporates into DNA and inhibits viral DNA polymerase
Arenaviridae; hamsters/mice
(1) What is the most common cause of infectious corneal blindness?
(2) What is "Hutchinson's sign"?
(1) HSV-1, almost always unilateral
(2) Vesicles at tip of nose in VZV (indicates 75% of ocular squelae)
(1) What is the most common human prion disease? (2) What test is most diagnostic for prion diseases & what result would you expect to see?
(1) Creutzfeldt-Jakob disease
(2) MRI; cortical ribboning
(1) Describe the 2 phases of Rabies infection.
(2) What is the histopathology of the Rabies virus?
(1) -Incubation phase: virus replicates in the cytoplasm of the muscle at site of bite (length of incubation phase is determine by infectious dose & proximity of bite to CNS)
-Prodrome phase: virus infects peripheral nerves & travels to CNS (weeks-months)
(2) Bullet shaped virus, Negri bodies in neural tissue
How do CSF leukocyte, protein, & glucose levels differentiate between bacterial and viral meningitis?
*Bonus: what about for mycobacterial meningitis?*
Bacterial: high leukocytes, slightly elevated/high proteins, low glucose
Viral: slightly elevated/high leukocytes, normal/slightly elevated proteins, normal glucose
*Mycobacterial: high leukocytes, high proteins, low glucose*
EEEV: begins abruptly; very severe abdominal pain; kids can develop edema; high mortality & permanent brain damage in many survivors
WEEV: milder febrile illness; pts who recover can have fatigue, headaches, & tremors for 2 years
VEEV: mild systemic illness; can affect fetus -> placental damage, abortion, stillbirth, neurologic damage
What are the 4 common causes of chorioretinitis?
CMV, toxoplasma gondii, toxocara canis, onchocerca volvulus
(1) Where is Naegleria fowleri found?
(2) What is the most infectious stage of Naegleria fowleri?
(3) What are the amoebas attracted to in the body?
(1) Freshwater lakes, soils, under chlorinate pools & waterparks
(2) Flagellated stage
(3) Neurotransmitters
What are the 4 clinical outcomes of poliovirus infection?
Asymptomatic illness (90%)
Abortive poliomyelitis (5%)
Nonparalytic/aseptic poliomyelitis (1-2%)
Paralytic polio (0.1-0.2%)
What is the DOC for each of the latent, primary, secondary, and tertiary phases of syphilitic meningitis?
Latent, primary, secondary: single, low dose of Benzathine Penicillin G
Tertiary: multiple, higher doses of Benzathine Penicillin G
(1) California encephalitis, Rift Valley fever, and Sandfly fever are all part of Family ______.
(2) This family can exhibit ______ transmission. What is that?
(1) Bunyaviridae
(2) Transovarial; virus survives in mosquito eggs over winter
(1) Why is AOM common in children?
(2) What is the most common cause of AOM?
(1) Eustachian tube is shorter, more flexible, & more horizontal; parental practices (bottle feeding, etc.); environmental issues (daycare, allergies, etc.)
(2) Streptococcus pneumoniae
(1) What is the most common cause of fungal meningitis and where is it found?
(2) What patient presentation would you expect?
(3) What therapy can exacerbate the meningitis?
(1) Cryptococcus neoformans; soil with pigeon guano
(2) Pneumonia, severe lymphopenia, meningitis symptoms
(3) HAART (improving CD4 numbers -> increased inflammatory response)
List and describe the 3 possible outcomes of paralytic polio
1) Paralytic poliomyelitis: asymmetric flaccid paralysis with no sensory loss
2) Bulbar poliomyelitis: involves the muscles of the pharynx, vocal cords, and respiration
3) Postpolio syndrome: sequela of poliomyelitis that occurs later in life (30 – 40 years post-infection) in 20% - 80% of original patients
(1) Acanthamoeba disease has been successfully treated with _____? (multiple answers)
(2) Primary amoebic meningoencephalitis (PAM) treatment includes ______ and the non-pharmacological treatment of _______.
(1) Pentamidine, chlorhexidine, -azole antifungals
(2) Amphotericin B/Miltefosine; therapeutic hypothermia
(1) West Nile Virus, Dengue fever, and Zika virus are part of the Family ______.
(2) Differentiate between Dengue and Zika viruses
(1) Flaviviridae
(2) -Dengue fever: Dengue rash + breakbone fever; "original antigenic sin" phenomenon; Dengvaxia vaccination is available
-Zika: can be transmitted lots of ways; generally febrile illness with rash; treatment is supportive/symptomatic
(1) What is the most common cause of otitis externa?
(2) Describe malignant otitis externa
(1) Pseudomonas
(2) More severe infection that can spread to the skull, meninges, and brain; discharge of foul-smelling, yellow green pus; immunocompromised/diabetic patients
Differentiate between Clostridium tetani and Clostridium botulinum
Clostridium tetani: tennis racket appearance; 3 virulence factors (spore formation, tetanolysin, tetanospasmin); can be generalized or localized; treat with vaccine, Metronidazole, & debridement
Clostridium botulinum: 7 non-heat resistant toxins; foodborne, infant, or wound forms; treat with Metronidazole/Penicillin, antitoxin, & ventilatory support (don't give honey to your baby)