Skip to main content

Search
Should Your Child See a Doctor?

Infection Exposure Questions – Contagiousness

|

Definition

  • This topic includes information about the transmission of common infections, including how long to stay out of school or daycare
     
  • Incubation Period: Time interval between exposure to the infection and onset of symptoms.
  • Contagious Period: Time interval during which a sick child's disease is contagious to others. With precautions, children sometimes can return to day care and school before this period is over.
  • Infections that are not Contagious: Many common bacterial infections are not contagious (e.g., ear infections, sinus infections, bladder infections, kidney infections, and pneumonia). Sexually transmitted diseases are not contagious to children unless there is sexual contact or shared bathing.

Infection Exposure Table

DISEASE INCUBATION PERIOD
(DAYS)
 
CONTAGIOUS PERIOD
(DAYS)
 
Skin Infections/Rashes: 
Chickenpox10-212 days before rash until all sores have crusts (6 - 7days)
Fifth disease (Erythema infectiosum)4-147 days before rash until rash begins
Hand, foot, and mouth disease3-6Onset of mouth ulcers until fever gone
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
Roseola9-10Onset of fever until rash gone (2 days)
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 24 hours on antibiotic
Shingles (contagious for chicken pox)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
Diphtheria2-5Onset of sore throat until 4 days on antibiotic
Influenza1-2Onset of symptoms until fever gone
Sore throat, strep2-5Onset of sore throat until 24 hours on antibiotic
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
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 BMs. Shigella and E-coli 0157 require extra precautions. Consult your day care provider regarding attendance restrictions.

Disclaimer: This information is not intended be a substitute for professional medical advice. It is provided for educational purposes only. You assume full responsibility for how you choose to use this information.

Author and Senior Reviewer: Barton D. Schmitt, M.D.

Last Reviewed: 1/19/2009

Last Revised: 11/18/2006

Copyright 1994-2009 Barton D. Schmitt, M.D.


Should your child see a doctor?

Find out by selecting your child’s symptom or health condition in the list below:

Summer 2014: Good Growing Newsletter

In This Issue

  • Understanding the Power and Influence of Role Models
  • Legal Marijuana Means Greater Poisoning Risks for Children
  • Why Choose Pediatric Emergency Care?

Download Summer 2014 (PDF)