Enteroviruses Flashcards
ENTEROVIRUSES
◦ members of Picornaviridae
◦ transient inhabitants of the human alimentary tract and may be isolated
from the throat or lower intestine but do not cause disease there
POLIOVIRUS Pathogenesis:
◦ enters
the mouth →
multiplies in
oropharynx or
intestine → circulation
→ PNS → CNS (lower
motor neurons of SC
or brain)
POLIOVIRUS CLINICAL FINDINGS
- Abortive/Mild Disease
◦ most common form
◦ fever, malaise, drowsiness, headache,
nausea, vomiting, constipation, and sore
throat
◦ recovery - Nonparalytic Poliomyelitis (Aseptic
Meningitis)
◦ stiffness and pain in the back and neck
◦ complete recovery
◦ rarely progresses to paralysis - Paralytic Poliomyelitis
◦ flaccid paralysis resulting from lower motor
neuron damage
◦ incoordination 2° to brain stem damage
and painful spasms of nonparalyzed
muscles
◦ residual paralysis - Progressive Postpoliomyelitis Muscle
Atrophy (Postpolio Syndrome)
◦ recrudescence of paralysis and muscle
wasting decades after paralysis
◦ more common in women
POLIOVIRUS
PREVENTION
Salk/IPV (Inactivated Polio
Vaccine)
•killed formalinized virus
•induces production of plasma IgG
and IgM
Sabin/OPV (Oral Polio
Vaccine)
•live attenuated virus
•induces production of IgG, IgM
and intestinal IgA
COXSACKIVIRUS A & B
◦ Aseptic Meningitis
◦ fever, malaise, headache, nausea, and abdominal pain
◦ sometimes progression to mild muscle weakness
◦ Nonspecific Febrile Illness (Summer Grippe)
◦ acute onset of fever, malaise, and headache
◦ occasional upper respiratory symptoms, and N/V
COXSACKIEVIRUS A
◦ Hand-Foot-and-Mouth Disease
◦ oral and pharyngeal ulcerations and a
vesicular rash of the palms and soles that
may spread to the arms and legs
◦ Herpangina
◦ severe febrile pharyngitis
◦ abrupt onset of fever and sore
throat with discrete vesicles on the
posterior half of the palate,
pharynx, tonsils, or tongue
◦ Acute Hemorrhagic Conjunctivitis
◦ severe eye pain, blurred vision, photophobia, watery discharge
◦ edema, chemosis, subconjunctival hemorrhage, punctate keratitis and conjunctival
follicles
◦ preauricular adenopathy
COXSACKIEVIRUS B
◦ most common cause of viral heart disease
◦ Pleurodynia
◦ a.k.a. epidemic myalgia, Bornholm disease
◦ sudden fever and stabbing chest pain, sometimes preceded by malaise,
headache, and anorexia
◦ Myocarditis and Pericarditis
◦ acute inflammation of the heart or its covering membranes (pericarditis)
◦ Generalized Disease of Infants
◦ an extremely serious disease in which the infant is overwhelmed by
simultaneous infection of multiple organs, including the heart, liver, and brain
ECHOVIRUS
◦ enteric
cytopathogenic
human orphan
viruses
◦ cause aseptic
meningitis,
encephalitis, febrile
illnesses with or
without rash,
common colds, and
ocular disease
◦ Enterovirus 70 - chief
cause of acute
hemorrhagic
conjunctivitis
RESPIRATORY
VIRUSES
Rhinoviruses
Coronaviridae
Influenza Virus
Paramyxoviridae
•Parainfluenza Virus
•Respiratory Syncytial Virus (RSV)
•Human Metapneumovirus
RHINOVIRUSES
◦ members of Picornaviridae
◦ most common cause of common colds/URTI
◦ >150 serotypes
◦ 1-2 attacks per year
◦ sneezing, nasal obstruction, nasal discharge, and sore throat; headache,
mild cough, malaise, and a chilly sensation
◦ most common viral culprit in asthma exacerbation
CORONAVIRIDAE
◦ cause common colds, LRTI, and
gastroenteritis
◦ largest genome among RNA viruses
◦ solar corona – club- or petal-shaped
projections that are widely spaced
on the outer surface of the envelope
CORONAVIRIDAE
SARS-CoV (Severe Acute Respiratory Syndrome Corona Virus)
• 2003 in Southern China
• Origin: probably bats
• serious respiratory illness, including pneumonia and progressive respiratory failure
• fever, malaise, chills, headache, dizziness, cough, and sore throat, followed by SOB
• abnormal chest radiographs
• some progress rapidly to acute respiratory distress, requiring ventilatory support
• death in 10%
MERS-CoV (Middle East Respiratory Syndrome Corona Virus)
• 2012 in Saudi Arabia
• Origin: probably bats → camels
• pneumonia and respiratory failure
• death in ~30%
CORONAVIRUS DISEASE 2019 (COVID-19)
◦ caused by SARS-CoV-2
◦ previously called 2019-nCoV (2019 novel coronavirus)
◦ Origin: probably bats
◦ December 2019 in Wuhan, China
◦ declared a pandemic on March 11, 2020
◦ Transmission: droplet, direct contact, indirect contact (fomites),
but there are studies that show airborne transmission
◦Incubation Period: 2-14 days (ave: 5 days)
CORONAVIRUS DISEASE
Prevention:
◦ Wear face mask.
◦ Practice social distancing.
◦ Wash your hands with soap. (Soap destroys envelope of the virus).
◦ Practice self-quarantine for 14 days if exposed.
◦ Preventive measures flatten the
curve. The purpose of preventive
measures is not to stop the increase
in the number of cases, but to slow it
down so that the number of cases
does not exceed healthcare capacity.
CORONAVIRUS Diagnosis
◦ RT-PCR (Reverse Transcription Polymerase Chain Reaction)
◦ Definitive diagnosis (gold standard)
◦ Specimen: nasopharyngeal and oropharyngeal swab
◦ detects presence of viral RNA
◦ nucleic acid amplification test
*Note: A negative RT-PCR result for a patient with history of exposure does not mean
that self-quarantine is unnecessary. The patient may still develop symptoms and
become COVID-19-positive within the incubation period. Thus, self-quarantine must still
be completed for 14 days.
