PARENT CARE:  INFECTION EXPOSURE QUESTIONS Definition This guideline includes information about the transmission of common infections. 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. DISEASE INCUBATION PERIOD (DAYS) CONTAGIOUS PERIOD (DAYS) Skin Infections/Rashes: Chickenpox 14-16 2 days before rash until all sores have crusts (6-7 days) Fifth disease (Erythema infectiosum) 10-14 7 days before rash until rash begins Hand, foot, and mouth disease 3-6 Onset of mouth ulcers until fever gone Impetigo (strep or staph) 2-5 Onset of sores until 24 hours on antibiotic Lice 7 Onset of itch until 1 treatment Measles 10-12 4 days before rash until rash gone (7 days) Roseola 10-15 Onset of fever until rash gone (2 days) Rubella (German measles) 14-21 7 days before rash until rash gone (4 days) Scabies 30 Onset of rash until 1 treatment Scarlet fever 3-6 Onset of fever or rash until 24 hours on antibiotic Shingles (contagious for chicken pox) 14-16 Onset of rash until all sores have crusts (7 days) (Note: No need to isolate if sores can be kept covered.) Warts 30-180 Minimally contagious Respiratory Infections: Bronchiolitis 4-6 Onset of cough until 7 days Colds 2-5 Onset of runny nose until fever gone Cold sores (herpes) 2-12 Footnote 1 Coughs (viral) or croup (viral) 2-5 Onset of cough until fever gone Diphtheria 2-5 Onset of sore throat until 4 days on antibiotic Influenza 1-2 Onset of cough until fever gone Sore throat, strep 2-5 Onset of sore throat until 24 hours on antibiotic Sore throat, viral 2-5 Onset of sore throat until fever gone Tuberculosis 14-70 Until 2 weeks on drugs (Note: Most childhood TB is not contagious.) Whooping cough 7-10 Onset of runny nose until 5 days on antibiotic Intestinal Infections: Diarrhea, bacterial 1-5 Footnote 2 for Diarrhea Precautions Diarrhea, giardia 7-21 Footnote 2 for Diarrhea Precautions Diarrhea, traveler's 1-6 Footnote 2 for Diarrhea Precautions Diarrhea, viral (Rotavirus) 1-3 Footnote 2 for Diarrhea Precautions Hepatitis A 14-50 2 weeks before jaundice begins until jaundice resolved (7 days) Hepatitis B 50-180 2 weeks before jaundice begins until jaundice resolved (7 days) Pinworms 21-28 Minimally contagious, staying home is unnecessary Vomiting, viral 2-5 Until vomiting stops Other Infections: Infectious mononucleosis 30-50 Onset of fever until fever gone (7 days) Meningitis, bacterial 2-10 7 days before symptoms until 24 hours on IV antibiotics in hospital Mumps 16-18 5 days before swelling until swelling gone (7 days) Pinkeye without pus (viral) 1-5 Mild infection, staying home is unnecessary Pinkeye with pus (bacterial) 2-7 Onset of pus until 1 day on antibiotic eyedrops Footnotes: 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. 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. Back to Top 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. Pediatric HouseCalls Online. Copyright © 2000-2005 Barton Schmitt, M.D. FAAP Reviewed 8/2005 Revised 7/2005 View Index of Topics