Childhood viral illnesses

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Childhood viral illnesses

• Dr. Kevin Forward
• Departments of Pathology, Microbiology and
  Immunology and Medicine
• 473-4109
• kevin.forward_at_cdha.nshealth.ca

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Common Childhood Viral Infections

• Measles (rubeola, red measles)
• Rubella (German measles)
• Erythema infectiosum (Fifth disease)
• Mumps
• Varicella-Zoster (Chickenpox)
• Coxsackievirus and Echovirus associated
  infections (hand-foot-and-mouth disease)

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Measles

• Related to mumps and, RSV, an enveloped ssRNA
  virus
• Worldwide occurrence, epidemics were common in
  North America pre-vaccination but are now rare
• However in the third world 1 million kids die
  yearly
• One of the most infectious of all viruses
• Vaccination instituted in 1963
• Slight increase in incidence in 1980s with need
  to institute 2nd dose vaccine

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Measles

• Transmission direct droplet contact incidence
  greater in winter months
• Incubation 2 weeks
• Rash evolves from face to trunk to extremities
  (including palms and soles)
• Fever and the three Cs cough, coryza and
  conjunctivitis
• Koplik spots (little sugary spots on the mucosa
  next to the molar teeth)
• Diagnosis
• antibody detection (IgM)

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Measles (continued)

• Complications are common in the very young and
  older kids and young adults
• Malnutrition esp vitamin A deficiency is a major
  cause of mortality
• Complications include
• Otitis media
• Pneumonia
• Encephalitis
• Death

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Rubella

• Also known as German measles
• Transmission respiratory droplets
• Incubation period is 2-3 weeks
• Infections may be sub-clinical esp in young kids
• Mild to no prodromal phase
• Rash (face to body notoriously difficult to make
  a clinical diagnosis)
• Adenopathy (swollen lymph nodes)
• Adults may also get mild arthritis

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Rubella

• Congenital rubella is the most severe
  complication
• Most infections and complications occur in the
  first 16 weeks of pregnancy (90 transmission
  rate to fetus)
• Infants are born with numerous defects
• Cardiac abnormalities
• Cataracts
• Deafness
• Brain, liver and organ damage

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Rubella
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Erythema infectiosum

• Also known as Fifth disease
• Caused by Parvovirus B19 infection
• Small single-stranded icosahedral DNA virus
• Worldwide infection
• Seroprevalence increases with age (15-60 by age
  5-9)
• Transmission
• Respiratory droplets
• Vertical (mom to fetus)

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Erythema infectiosum

• Distinct facial rash slapped cheek sparing the
  area around the mouth
• Lacy pink rash of the extremities
• Resolves within one week but can return with
  exposure to heat
• May cause fetal abnormalities if pregnant women
  are infected
• Diagnosis Antibody detection (IgM)

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Fifth Disease
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Fifth disease
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Mumps

• Occurs worldwide
• Uncommon because of vaccine use and esp after the
  introduction of a second dose of MMR
• Transmission Droplet spread
• Incubation 2-3 weeks

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Mumps

• No rash parotid gland swelling associated with
  ear ache is seen in 95
• Other salivary glands and lymph nodes in head and
  neck 10
• Menningitis in 15, encephalitis is rare
• Occasionally orchitis (common in young men but
  rarely leads to sterility), oopheritis
• Diagnosis Antibody testing or finding the virus
  in saliva or urine (culture or PCR).

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• Mumps Outbreak United States 2006

Provisional Number of Cases by State as of June
20, 2006
16
Onset information missing for 55 cases 3
asymptomatic
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ChickenpoxVaricella-zoster virus

• Infection is primarily by the airborne route
• Very infectious (90 of non-immune household
  contacts will become infected).
• Almost all children will be infected by the age
  of 15
• Unlike other human herpes viruses almost all
  infections are symptomatic.
• Infections in immune compromised and neonates can
  produce encephalitis, pneumonia or disseminated
  infection.

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Chickenpox (varicella)

• Chicken pox is usually characterized by fever and
  a generalized vesicular eruption.
• The virus replicates in the throat and
  subsequently spreads during secondary viremia to
  the skin, reticuloendothelial tissue and rarely
  to lungs and brain.
• The incubation time is usually 11-13 days.
• Typical progression is Maculegtpapulegtvesicl
  egtpustulegtulcergtcrust
• Dew drop on a rose petal

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Complications of chickenpox

• Pneumonia (Approximately 15 of adults with
  chickenpox)
• Varicella in the immuno-compromised host
• Varicella causes severe infections in newborns
  whose mothers are non-immune, and in patients
  with abnormal CMI
• Central nervous system involvement (This is quite
  rare1 in 200)
• Bacterial super-infection (usually due to S.
  aureus and to S. pyogenes).

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Shingles (varicella zoster)

• The incidence increases with age, 10-20 of
  adults will eventually get shingles
• Patients altered cell mediated immunity are most
  susceptible. (ie altered cell mediated immunity)
• The virus becomes latent in dorsal root and
  cranial nerve ganglia, reactivating later in life
• Shingles are characterized by inflammation of
  sensory nerve and their ganglia and a localized
  vesicular rash along the distribution of that
  nerve.
• Intense post-herpetic neuralgia is the principal
  complication

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Diagnosis of varicella zoster infections

• Clinical syndrome recognition.
• Electron microscopy (all Herpesviridae look
  alike).
• Virus isolation (the varicella zoster virus grows
  slowly and cultures are frequently negative).
• Viral serology usually not necessary however,
  this may be useful to determine the immune status
  of an exposed individual.

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Prevention of varicella-zoster infections

• Vaccine
• Now universal in Nova Scotia (Jan 2003)
• A live vaccine that may produce mild chickenpox
• Shingles may follow
• VZ immune globulin (VZIG)Post exposure
  prophylaxis
• Congenital or acquired immunodeficiency
  (congenital, malignancy or drug-induced).
• Newborn of a mother developing chickenpox from
  five days to two days after delivery.

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Treatment of varicella-zoster infections

• Usually only local measures are necessary.
• Patients with pneumonia may need oxygen therapy
  and other forms of respiratory support.
• Acyclovir or a cousin may be used in the
  immune-compromised host and in patients with
  varicella pneumonia or with central nervous
  system infections.
• These drugs may also be useful in the treatment
  of patients with zoster.

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Coxsackieviruses and Echoviruses

• Enteroviruses, members of the Picornavirus family
• Infections occur June-October
• Transmission fecal-oral
• 50-80 of infections are asymptomatic
• Can cause skin rash and can look mimic other
  virus infections
• Common cause of meningitis, myocarditis
• Hand-foot-and-month disease (vesicular type)
• Usually secondary to Coxsackie A16
• Children lt10
• Sore throat, vesicles, fever, cutaneous lesions
  including hand and feet

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Coxsackieviruses and Echoviruses

• Diagnosis
• virus isolation
• Antibody detection not useful (there are too
  many serotypes for this to be useful or available
  widely)