Testing Infants for Strep Throat Should Be Avoided
Infants and children under 3 years old should not be routinely tested for group A streptococcal pharyngitis because the incidence of strep throat is extremely low in this age group, acute rheumatic fever is rare, and the classic presentation of streptococcal pharyngitis is uncommon. 1
Age-Specific Epidemiology
- Group A streptococcal pharyngitis is primarily a disease of children between 5 and 15 years of age 1
- The incidence in children under 3 years is sufficiently low that routine testing is not warranted 1
- Acute rheumatic fever—the primary complication that drives treatment decisions—is exceptionally rare in children under 3 years old 1
When Testing May Be Considered in Young Children
Selected children under 3 years may warrant testing only when specific risk factors are present, such as:
- An older sibling with documented GAS infection 1
- Close contact with a confirmed case in the household 1
Even in these circumstances, the decision should be made cautiously, as most pharyngitis in this age group remains viral in origin.
Clinical Presentation Differences
- Infants and toddlers rarely present with the classic features of streptococcal pharyngitis (sudden onset sore throat, fever, tonsillar exudate, tender anterior cervical lymphadenopathy) 1
- Viral features such as cough, rhinorrhea, and conjunctivitis are much more common in this age group and strongly suggest non-streptococcal etiology 1
Risk of Misidentification
Testing young children increases the likelihood of identifying asymptomatic GAS carriers rather than true infections:
- Up to 15% of school-age children may be asymptomatic GAS carriers during peak season 1
- Neither throat culture nor rapid antigen detection tests can distinguish between acute infection and chronic colonization 1
- A positive test in an infant with viral pharyngitis may lead to unnecessary antibiotic treatment 1
Common Pitfalls to Avoid
- Do not test infants with clear viral symptoms (cough, rhinorrhea, conjunctivitis, hoarseness) as this leads to unnecessary antibiotic use and identifies carriers rather than true infections 1, 2
- Do not assume that tonsillar exudate or fever in an infant indicates strep throat—these findings occur commonly with viral infections in this age group 1
- Avoid testing asymptomatic household contacts of older children with strep throat, even in the infant age group, unless the infant develops symptoms 1
The Bottom Line
The combination of low disease incidence, rare complications, atypical presentations, and high carrier rates makes routine strep testing in infants under 3 years both unnecessary and potentially harmful by promoting antibiotic overuse. 1, 2