Strep is a bacterial infection caused by various species of the Streptococcus genus, and babies can contract it. This infection requires specialized attention in infants because the risks and presentations differ significantly from those in older children or adults. Unlike the common sore throat associated with Strep in school-aged children, the signs in a baby are often subtle and non-specific. Understanding the specific type of Streptococcus bacteria involved is necessary, as the risk profile changes drastically depending on the baby’s age. This infection can progress quickly, making prompt recognition and medical intervention necessary.
Group A and B Strep: Understanding Age-Related Risk
The risk of a Strep infection in infants is determined by two distinct bacterial groups: Group B Streptococcus (GBS) and Group A Streptococcus (GAS). GBS poses the most immediate and serious threat to newborns, typically affecting them in the first three months of life. Newborns acquire GBS through transmission from the mother’s genital tract during labor and delivery.
Infection with GBS can lead to severe conditions like sepsis, pneumonia, or meningitis in a fragile newborn. About 75% of GBS cases in infants occur within the first week of life, known as early-onset disease. Once a baby passes the three-month mark, the risk of GBS infection decreases significantly.
The concern shifts to Group A Streptococcus (GAS), the cause of Strep throat, as the infant grows older. GAS infections are rare in infants under six months old, largely due to the protection afforded by maternal antibodies. As babies age into the toddler range (12 to 36 months), the risk increases, often coinciding with exposure in daycare or from older siblings.
When GAS occurs in this older infant and toddler group, it frequently presents without the textbook complaint of a sore throat. The infection is more likely to manifest as a cold-like illness, requiring parents and providers to look for less obvious indicators.
Identifying Infection: Symptoms Specific to Infants
Because infants cannot communicate a sore throat, the symptoms of Strep infection are often behavioral and gastrointestinal, making diagnosis challenging. One of the most telling signs is a sudden and unexplained refusal to feed, commonly accompanied by increased irritability or fussiness.
A baby with a Strep infection may exhibit a low-grade fever, though any fever above 100.4°F in a newborn requires immediate medical attention. Parents should also observe for thickened or bloody nasal discharge. Unlike older children, who may have pus on their tonsils, infants often present with non-specific signs.
Gastrointestinal symptoms are common in younger children with Strep, including vomiting and abdominal pain. In some cases, a baby may develop a fine, red, sandpaper-like rash, which can signal the development of scarlet fever, a complication of a GAS infection. The rapid progression of symptoms in any infant warrants an urgent consultation with a healthcare provider.
GBS-Specific Symptoms
For GBS specifically, symptoms can be more severe. These may include breathing difficulties, grunting, or periods of not breathing. Newborns may also appear very lethargic, be difficult to wake up, or have a tense or bulging soft spot (fontanelle) on their head, which can indicate meningitis. These signs signal a medical emergency and require immediate care.
Diagnosis and Treatment Protocols
When a Strep infection is suspected in an infant, the medical response begins with confirming the presence of the bacteria. For suspected GAS (Strep throat) in older babies, a rapid antigen detection test (RADT) is attempted using a throat swab. Since false negatives are possible, a throat culture is frequently performed to ensure accuracy, though results may take up to 48 hours.
For newborns suspected of having GBS, diagnosis requires culturing sterile body fluids, such as blood or cerebrospinal fluid obtained through a spinal tap. This is necessary because GBS often causes systemic infection (sepsis) or meningitis. Treatment is often initiated before lab results are finalized due to the urgency of the situation.
Treatment for both GAS and GBS infections involves the use of antibiotics, typically penicillin or amoxicillin. These medications eliminate the bacteria and prevent potentially severe complications like rheumatic fever, kidney inflammation, or sepsis. The baby must complete the full course of antibiotics as prescribed, even if symptoms resolve quickly.
Newborns diagnosed with GBS or those with high risk factors may require immediate hospitalization for intravenous antibiotic therapy and close monitoring. This intensive treatment ensures the infection is addressed systemically to protect against damage to organs and the central nervous system. Early and complete treatment significantly improves the outcome for babies with a Strep infection.