Children's Hospital Colorado

Infection Exposure Questions

Barton Schmitt MD, FAAP

  • This topic includes information about transmission of common infections. How long to stay out of school or child care is covered.
  • Incubation Period. Time it takes to start having symptoms after contact with infection.
  • Contagious Period. Time during which a sick child's disease can spread to others. Sometimes, children can return to school before this period is over.
  • Infections that cannot be spread to others, but there are a few exceptions. Your child's doctor will tell you for sure. Many common bacterial infections are not spread to others. Examples are ear, sinus, bladder, or kidney infections. Most pneumonia in children also can't be passed to others, but there are a few exceptions. Your child's doctor will tell you for sure. Sexually transmitted diseases are usually not spread to children. But, they can be spread if there is sexual contact or shared bathing.

Infection Exposure Table

DISEASEINCUBATION PERIOD
(DAYS)
CONTAGIOUS PERIOD
(DAYS)
Skin Infections/Rashes:
Chickenpox10-212 days before rash until all sores have crusts (6 - 7days)
COVID-192-10Onset of symptoms until fever gone and at least 10 days after symptoms started
Fifth disease (Erythema infectiosum)4-147 days before rash until rash begins
Hand, foot, and mouth disease3-6Onset of rash until fever gone. If widespread blisters, return after blisters are dry (6-7 days).
Impetigo (strep or staph)2-5Onset of sores until 24 hours on antibiotic
Lice7Onset of itch until 1 treatment
Measles8-124 days before rash until 4 days after rash appears
Monkeypox5-21Onset of symptoms until all crusts on sores have fallen off (2-4 weeks)
Roseola9-10Onset of fever until fever gone for 24 hours
Rubella (German measles)14-217 days before rash until 5 days after rash appears
Scabies30-45Onset of rash until 1 treatment
Scarlet fever3-6Onset of fever or rash until at least 12 hours on antibiotic and fever is gone
Shingles virus (causes chickenpox in others, not shingles)14-16Onset of rash until all sores have crusts (7 days) (Note: No need to isolate if sores can be kept covered.)
Warts30-180Minimally contagious
Respiratory Infections:
Bronchiolitis4-6Onset of cough until 7 days
Colds2-5Onset of runny nose until fever gone
Cold sores (herpes)2-12Footnote 1
Coughs (viral) or croup (viral)2-5Onset of cough until fever gone
COVID-192-14Onset of symptoms until fever gone and at least 10 days have passed
Influenza1-2Onset of symptoms until fever gone
Sore throat, strep2-5Onset of sore throat until at least 12 hours on antibiotic and fever is gone
Sore throat, viral2-5Onset of sore throat until fever gone
Tuberculosis6-24 monthsUntil 2 weeks on drugs (Note: Most childhood TB is not contagious.)
Whooping cough7-10Onset of runny nose until 5 days on antibiotic
Intestinal Infections:
Diarrhea, bacterial1-5Footnote 2 for Diarrhea Precautions
Diarrhea, giardia7-28Footnote 2 for Diarrhea Precautions
Diarrhea, traveler's1-6Footnote 2 for Diarrhea Precautions
Diarrhea, viral (Rotavirus)1-3Footnote 2 for Diarrhea Precautions
Hepatitis A14-502 weeks before jaundice begins until jaundice resolved (7 days)
Pinworms21-28Minimally contagious, staying home is unnecessary
Vomiting, viral2-5Until vomiting stops
Other Infections:
Infectious mononucleosis30-50Onset of fever until fever gone (7 days)
Meningitis, bacterial2-107 days before symptoms until 24 hours on IV antibiotics in hospital
Meningitis, viral3-6Onset of symptoms and for 1-2 weeks
Mumps12-255 days before swelling until swelling gone (7 days)
Pinkeye without pus (viral)1-5Mild infection, staying home is unnecessary
Pinkeye with pus (bacterial)2-7Onset of pus until 1 day on antibiotic eyedrops

Notes

  1. Cold sores: less than 6 years old, contagious until cold sores are dry (4-5 days). No isolation if sores are on part of body that can be covered. More than 6 years old, no isolation necessary if beyond touching, picking stage.

  2. Diarrhea Precautions: contagious until stools are formed. Stay home until fever is gone, diarrhea is mild, blood and mucus are gone, and toilet-trained child has control over loose stools. Shigella and E-coli 0157 require extra precautions. Consult your child care provider regarding attendance restrictions.

  3. Respiratory Infections: many can also be contagious during the 2 days before symptoms start. For that reason, spread is difficult to control.

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