|
Clinical Reference Systems: Pediatric Advisor 10.0
Incubation Periods of Infections
DESCRIPTION
Young children are afflicted with infectious diseases 10 to
15 times per year. The attack rate decreases with age
because with each new infection we build up antibodies
against future ones.
The incubation period is defined as the time interval between
exposure to a contagious disease and the onset of symptoms.
This information should help answer the questions, "When will
my child come down with it?" and, "Should we cancel our
weekend plans?"
If the outer time limit of the incubation period passes and
your child is still well, he or she has probably escaped that
infection for now (or has previous antibodies against it).
CONTAGIOUS PERIOD
The contagious period is defined as that time interval during
which a sick child's disease is contagious to others.
Knowing the period of contagion helps answer the question,
"How long does my child have to stay home from school or day
care?"
For major illnesses (such as hepatitis), a child will need to
remain in isolation at home or in the hospital until all chance
of spread has passed. For minor illnesses (like the common
cold) the guidelines are less strict. Most physicians would
agree that a child should stay home at least until he feels
well enough to return to school, and the fever has been gone
for 12 hours.
INFECTIONS THAT ARE NOT CONTAGIOUS
Try not to become preoccupied with infections. Some of the
more serious ones are not even contagious. Some infections
are due to blockage of a passageway followed by an overgrowth
of bacteria. Examples of these are ear infections, sinus
infections, and urinary tract infections. Lymph node and
bloodstream infections are also rarely contagious. Pneumonia
is a complication of a viral respiratory infection in most
cases and is usually not contagious. While exposure to
meningitis requires consultation with your child's physician,
most children exposed to this disease do not become infected.
Venereal (genital) diseases are usually noncontagious unless
there is sexual contact or shared bathing arrangements.
GUIDELINES FOR COMMON CONTAGIOUS DISEASES
Incubation
Disease Period (days) Contagious Period
---------------------------------------------------------------
---------------------------------------------------------------
SKIN INFECTIONS
Chickenpox 14 to 16 2 days before rash
until all sores have
crusts (7 days)
Fifth disease 10 to 14 7 days before rash
(Erythema infectiosum) until rash begins
Hand, foot, and mouth 3 to 6 Onset of mouth ulcers
disease until fever gone
Impetigo (strep or staph) 2 to 5 Onset of sores until
24 hours on antibiotic
Lice 7 Onset of itch until
one treatment
Measles 10 to 12 4 days before rash
until rash gone
(7 days)
Roseola 10 to 15 Onset of fever until
rash gone (2 days)
Rubella (German measles) 14 to 21 7 days before rash
until rash gone
(4 days)
Scabies 30 Onset of rash until
one treatment
Scarlet fever 3 to 6 Onset of fever or rash
until 24 hours on
antibiotic
Shingles (contagious 14 to 16 Onset of rash until
for chickenpox) all sores have crusts
(7 days) (Note: No
need to isolate if
sores can be kept
covered.)
Warts 30 to 180 See footnote A
---------------------------------------------------------------
RESPIRATORY INFECTIONS
Bronchiolitis 4 to 6 Onset of cough until
7 days
Colds 2 to 5 Onset of runny nose
until fever gone
Cold sores (herpes) 2 to 12 See footnote B
Coughs (viral) 2 to 5 Onset of cough until
fever gone
Croup (viral) 2 to 6 Onset of cough until
fever gone
Diphtheria 2 to 5 Onset of sore throat
until 4 days on
antibiotic
Influenza 1 to 2 Onset of cough until
fever gone
Sore throat, strep 2 to 5 Onset of sore throat
until 24 hours on
antibiotic
Sore throat, viral 2 to 5 Onset of sore throat
until fever gone
Tuberculosis 14 to 70 Until 2 weeks on
drugs (Note: Most
childhood TB is not
contagious.)
Whooping cough 7 to 10 Onset of runny nose
until 5 days on
antibiotic
---------------------------------------------------------------
INTESTINAL INFECTIONS
Diarrhea, bacterial 1 to 5 See footnote C
Diarrhea, giardia 7 to 21 See footnote C
Diarrhea, traveler's 1 to 6 See footnote C
Diarrhea, viral (Rotavirus) 1 to 3 See footnote C
Hepatitis A 14 to 50 2 weeks before
jaundice begins until
jaundice resolved
Hepatitis B 50 to 180 Same as Hepatitis A
Pinworms 21 to 28 See footnote A
Vomiting, viral 2 to 5 Until vomiting stops
---------------------------------------------------------------
OTHER INFECTIONS
Infectious mononucleosis 30 to 50 Onset of fever until
fever gone (7 days)
Meningitis, bacterial 2 to 10 7 days before symptoms
until 24 hours on IV
antibiotics in
hospital
Mumps 16 to 18 5 days before swelling
until swelling gone
(7 days)
Pinkeye without pus 1 to 5 See footnote A
(viral)
Pinkeye with pus 2 to 7 Onset of pus until
(bacterial) 1 day on antibiotic
eye drops
---------------------------------------------------------------
TABLE FOOTNOTES
(A) Staying home is unnecessary because the infection is
very mild and/or minimally contagious.
(B) Cold sores
- Under age 6 years: Your child should stay home
until the sores are dry (4 to 5 days). However, if
the sores are on a part of the body that can be
covered, your child does not need to stay home.
- Over age 6 years: Your child does not need to stay
home if he is beyond the touching, picking stage.
(C) Diarrhea
- Not toilet trained: Your child should stay home
until stools are formed.
- Toilet trained: Your child should stay home until
the fever is gone, diarrhea is mild, blood and mucus
are gone, and your child has control over loose
bowel movements.
| 
