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 (eg otitis media, sinusitis, urinary tract infection, pneumonia, and bacteremia). 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

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.