What is the risk of Group A Streptococcal (GAS) infection in an infant living in a household with a person diagnosed with streptococcal pharyngitis (strep throat)?

From the Guidelines

Infants living in a household with someone who has strep throat are at increased risk of contracting the infection and should be monitored closely. According to the clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Diseases Society of America 1, diagnostic testing or empiric treatment of asymptomatic household contacts of patients with acute streptococcal pharyngitis is not routinely recommended. However, selected children <3 years old who have other risk factors, such as an older sibling with GAS infection, may be considered for testing 1.

Some key considerations for managing the risk of strep transmission to infants in a household include:

• Good hand hygiene to prevent the spread of the infection
• Avoiding sharing utensils or drinks
• Ensuring the infected person completes their full course of antibiotics (typically penicillin or amoxicillin for 10 days)
• Monitoring the infant for symptoms such as irritability, fever, reduced feeding, or a red, sore throat
• Seeking immediate medical attention for infants under 3 months with fever or for older infants showing symptoms of strep throat, as prompt medical evaluation is important to prevent complications like rheumatic fever if untreated 1.

It's also important to note that breastfeeding mothers with strep throat can continue to nurse while taking antibiotics, as this may provide some protective antibodies to the infant. The risk of transmission is highest during the first 24-48 hours of infection before antibiotics take effect, so limiting close contact during this period is particularly important.

From the Research

Infant Risk of Strep in Household

• The risk of strep in infants is a concern when there is a household member with group A streptococcal pharyngitis, as it can be contagious 2, 3.
• Studies have shown that group A beta-hemolytic streptococcal (GABHS) infection causes 15% to 30% of sore throats in children and 5% to 15% in adults 2.
• The strongest independent predictors of GABHS pharyngitis are patient age of five to 15 years, absence of cough, tender anterior cervical adenopathy, tonsillar exudates, and fever 2.
• Infants and young children are more susceptible to GABHS infections, and household members with strep throat can increase the risk of transmission to infants 4, 5.

Prevention and Treatment

• To diagnose GABHS pharyngitis, a rapid antigen detection test should be ordered in patients with a modified Centor or FeverPAIN score of 2 or 3 2.
• First-line treatment for GABHS pharyngitis includes a 10-day course of penicillin or amoxicillin 2, 4.
• Antibiotics provide only modest benefit in treating sore throat, although their effectiveness increases in people with positive throat swabs for GABHS 5.
• It is essential to follow clinical guidelines and use antibiotics judiciously to minimize the risk of antibiotic resistance and other complications 6, 3.

Household Precautions

• Household members with strep throat should take precautions to prevent transmission, such as frequent handwashing, covering the mouth and nose when coughing or sneezing, and avoiding close contact with infants and young children 2, 4.
• Infants and young children should be kept away from household members with strep throat until they have completed a full course of antibiotic treatment and are no longer contagious 4, 5.