Infection Exposure Questions
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- 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
| DISEASE | INCUBATION PERIOD
(DAYS) | CONTAGIOUS PERIOD
(DAYS) |
| Skin Infections/Rashes: |
| Chickenpox | 10-21 | 2 days before rash until all sores have crusts (6-7 days) |
| Fifth disease (Erythema infectiosum) | 4-14 | 7 days before rash until rash begins |
| Hand, foot, and mouth disease | 3-6 | Onset of rash until fever gone. If widespread blisters, return after blisters are dry (6-7 days). |
| Impetigo (strep or staph) | 2-5 | Onset of sores until 24 hours on antibiotic |
| Lice | 7 | Onset of itch until 1 treatment |
| Measles | 8-12 | 4 days before rash until 4 days after rash appears |
| Mpox (monkeypox) | 5-21 | Onset of symptoms until all crusts on sores have fallen off (2-4 weeks) |
| Roseola | 9-10 | Onset of fever until fever gone for 24 hours |
| Rubella (German measles) | 14-21 | 7 days before rash until 5 days after rash appears |
| Scabies | 30-45 | Onset of rash until 1 treatment |
| Scarlet fever | 3-6 | Onset of fever or rash until at least 12 hours on antibiotic and fever is gone |
| Shingles virus (causes chickenpox in others, not shingles) | 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 |
| COVID-19 | 2-14 | Onset of symptoms until fever gone and at least 10 days have passed |
| Influenza | 1-2 | Onset of symptoms until fever gone |
| Sore throat, strep | 2-5 | Onset of sore throat until at least 12 hours on antibiotic and fever is gone |
| Sore throat, viral | 2-5 | Onset of sore throat until fever gone |
| Tuberculosis | 6-24 months | 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 | 7-28 | 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) |
| 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 |
| Meningitis, viral | 3-6 | Onset of symptoms and for 1-2 weeks |
| Mumps | 12-25 | 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 |
Notes
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 stools. Shigella and E-coli 0157 require extra precautions. Consult your child care provider regarding attendance restrictions.
Respiratory Infections: many can also be contagious during the 2 days before symptoms start. For that reason, spread is difficult to control.
Copyright 2000-2025 Schmitt Pediatric Guidelines LLC.
Barton Schmitt MD, FAAP