How soon after exposure do symptoms appear?
The incubation period of Group A Strep pharyngitis is 2-5 days. Skin infections
may develop 7-10 days after exposure.
For how long can an infected person carry Group A Strep?
In general, patients treated with penicillin will not be able to transmit Group
A Strep 24-48 hours after beginning treatment. Patients with uncomplicated Group
A Strep pharyngitis, who are not treated with antibiotics, can transmit the bacteria
for weeks or months.
Where are the bacteria that cause Group A Strep infection found?
On the skin and in secretions from the nose, throat, vagina, or perianal area. Bacteria
can contaminate improperly prepared or refrigerated food. Milk and eggs are most
frequently associated with foodborne outbreaks.
Should an infected person be excluded from work or school?
Children with Group A Strep pharyngitis or skin lesions should not return to school
or child care until at least 24 hours after beginning antibiotic treatment or until
they no longer have a fever. In general, adults need not be excluded from work unless
severely ill, or are in a food handling occupation. Persons with skin lesions should
be excluded from food handling duties until a physician determines those lesions
are no longer infectious. Good personal hygiene should be emphasized; properly dispose
of dressings from skin lesions and wash hands after handling.
Why does invasive Group A Strep disease occur?
Invasive Group A Strep infections occur when the bacteria get past the defenses
of the person who is infected. This may occur when a person has sores or other breaks
in the skin that allow the bacteria to get into the tissue, or when the person�s
ability to fight off the infection is decreased because of chronic illness or an
illness that affects the immune system. Also, some strains of Group A Strep are
more likely to cause severe disease than others.
Who is most at risk of getting invasive Group A Strep disease?
Few people who come in contact with Group A Strep will develop invasive Group A
Strep disease. Most people will have a throat or skin infection, and some may have
no symptoms at all. Although healthy people can get invasive Group A Strep disease,
people with chronic illnesses like cancer, diabetes, and chronic heart or lung disease,
and those who use medications such as steroids have a higher risk. Persons with
skin lesions (such as cuts, chicken pox, surgical wounds), the elderly, and adults
with a history of alcohol abuse or injection drug use also have a higher risk for
The CDC lists the groups most at risk for invasive Group A Strep as the elderly,
immunosuppressed, persons with chronic cardiac or respiratory disease, diabetes,
skin lesions (i.e. children with varicella [chicken pox], persons with penetrating
trauma or surgical wounds, intravenous drug users), African-Americans, American
Indians. The groups most at risk for noninvasive disease are children (especially
elementary school age).
What can be done to help prevent Group A Strep infections?
The spread of all types of Group A Strep infection can be reduced by good hand washing,
especially after coughing and sneezing and before preparing foods or eating. Persons
with sore throats should be seen by a doctor who can perform tests to find out whether
the illness is strep throat. If the test result shows strep throat, the person should
stay home from work, school, or day care until 24 hours after taking an antibiotic.
All wounds should be kept clean and watched for possible signs of infection such
as redness, swelling, drainage, and pain at the wound site. A person with signs
of an infected wound, especially if fever occurs, should immediately seek medical
care. It is not necessary for all persons exposed to someone with an invasive group
A strep infection (i.e. necrotizing fasciitis or strep toxic shock syndrome) to
receive antibiotic therapy to prevent infection. However, in certain circumstances,
antibiotic therapy may be appropriate. That decision should be made after consulting
with your doctor.