CNS Infections- Enteroviruses/Non-polio Enteroviruses Flashcards
Non-polio enteroviruses have little cross neutralization between serogroups
-There are many (>70) serotypes:
(list
- ECHO virus (enteric cytopathic human orphan virus – many [31] serotypes).
- Coxsackie viruses (A and B - many [30] serotypes).
- Enteroviruses 68→71.
- Human Parechoviruses: HpeV-1→3
- Picornavirus too
Non Polio Enterovirus is one of the most common and important viral pathogens in humans (5-10M symptomatic cases/y in US) and causes a __________
nonspecific febrile illness with or without rash
Responsible for ½ of all febrile illness in _______ during the _________. It’s a major reason why blood culture and&/or spinal taps are done on _________.
infants and young children
summer and early fall months
infants and young children in the US
Among infections of the CNS, they are common and important known causes of morbidity in both children and adults. Most common known cause of ____________.
aseptic meningitis (80 → 90% of all cases) in countries which immunize against mumps.
Transmission of Non Polio Enterovirus
- fecal-oral route (water is most common vehicle)- mainly among small children and adults changing the diapers of an infected infant.
- inhalation of aerosols via the RT
- direct contact with respiratory secretions (e.g., saliva, sputum, or nasal mucus).
- hand→eye, rarely,
- in utero; true for some strains of ECHOvirus and Coxsackie viruses
Reservoir
- Humans are sole host
2. Environment and humans can be reservoir
Both incidence and severity vary inversely with _______
patient age
- Highest attack rate is in children under 1 year old
- Severe disease is more common in adults
- Males and females are equally infected, but males more commonly manifest with disease
Seasonality
In the temperate climates, peak incidence is during the summer and fall months, but sporadic cases occur year round, with the prevalent serotype(s) varying annually
Patients at greatest risk for enteroviral encephalitis and/or sequelae from CNS enteroviral disease include:
- neonates
2. the immunocompromised (humoral or CMI)
Neonatal sepsis is usually caused by an infection with ________.
May be acquired by any route but usually by _________. POE to CNS is via a _______. Predisposing factors to getting this are being _____, _______, and having maternal infection 2 weeks before delivery.
ECHOvirus
vertical transmission
viremia
male, premature
The incubation period is 3 → 7 days, S/S include:
In children and adults, the abrupt onset of a nonspecific illness:
- fever
- headache
- malaise/fatigue
- vomiting, diarrhea.
- maculopapular rash
This febrile, nonspecific disease (described by s/s) sometimes develops into the classic common syndromes:
- fever + rash (mostly maculopapular, can be petechial, vesicular),
- Hand Food & Mouth Disease
- herpangina (often from coxsackie)
- pleurodynia (pain w/ breathing)
- pharyngitis
- conjunctivitis
Febrile, nonspecific disease may also sometimes develop into other SEVERE diseases:
Severe diseases:
- aseptic meningitis
- neonatal viremia + meningitis or encephalitis
- encephalitis
- myocarditis
- hepatitis
Aseptic meningitis is an undifferentiated febrile illness sometimes progresses to acute onset aseptic meningitis in:
- young child (fever, irritability)
- older child (fever, headache, nuchal rigidity)
- adult (fever, nuchal rigidity; and a headache so severe that narcotics are required to manage the pain)
Undifferentiated febrile illness sometimes progress to encephalitis, which is generally a ______________
diffuse, but increasing recognition of focal encephalitis due to these agents
Encephalitis is much _______ than aseptic meningitis, but with a much higher ________.
less common
mortality rate
_________ causes regional & world-wide epidemics of undifferentiated febrile illness that sometimes progress to encephalitis.
Enterovirus 71
Enterovirus 71 produces 3 different encephalitis syndromes based on geographic location:
- a transient or persistent acute flaccid paralysis (AFP) + encephalitis which mimics polio (US, Europe, South America)
- HFMD cases, leading to meningoencephalitis but few case fatalities (China, Japan).
- HFMD cases, leading to encephalitis with brain-stem involvement + pulmonary edema, hemorrhage. Deaths due to pulmonary edema and cardiac dysfunction caused by brain-stem infection, NOT heart-lung infection (Taiwan-1998; Malaysia-1999).
Neonatal sepsis is a ____, not a _____, which may lead to encephalitis/disseminated disease
viremia
bacteremia
Predisposing factors for neonatal sepsis
male, prematurity, maternal infection in 2 weeks before delivery
Neonatal sepsis may lead to encephalomyocarditis, which is caused by
group B coxsackieviruses
Neonatal sepsis may lead to hemorrhage-hepatitis syndrome, which is caused by
echovirus 11
During neonatal sepsis, infection is systemic with corresponding signs and symptoms which occur within the first 2 weeks of life:
- fever/chills/temp instability
- rash
- anorexia/poor feeding
- jaundice (liver)
- GIT distress (vomiting)
- RT distress
- Cardiac distress (tachycardia)
- neurologic findings
- bulging anterior fontanelle (indicates pressure on the brain)
Death is due to hepatic failure from ________, myocarditis from __________, or hemorrhagic infarcts of major organs
ECHOvirus
Coxsackie virus
With CSF specimen, use PCR for ________, Tissue culture is _________, and make sure ______ predominate early, then a shift to lymphocytosis.
enteroviral agents
gold standard, rarely done
PMNs
Treatment is
- symptomatic, supportive
OR with - Pleconaril (which binds to capsid→blocking viral uncoating) on compassionate use/release basis.
