Strep throat may be highly contagious, but a specific diagnosis isn’t as easy to catch. When kids present with a sore throat, the most common cause is viral — but too often pediatricians prescribe antibiotics just in case the infection might be bacterial or to help reassure anxious parents that action is being taken.

Unfortunately, the overuse of antibiotics is a significant contributor to the challenge of antibiotic resistance. Accurately differentiating bacterial cases of pharyngitis helps to ensure that antibiotics are used appropriately and responsibly. Group A Streptococcus is the most common bacterial cause of strep throat, so it warrants a dedicated testing approach.

But testing for group A Streptococcus has been a logistical challenge in the clinic. For optimal outcomes, patients should be informed of their status while still at the doctor’s office or the urgent care center. Most rapid testing options, though, are antigen-based with limited sensitivity; follow-up testing is often recommended for negative results. Historically, the gold standard for establishing a strep throat diagnosis is throat culture. This process can take at least 24 to 48 hours — too long to get an appropriate treatment started right away, and also longer than ideal if a patient originally prescribed antibiotics is found not to actually need them.

Recent advances in molecular diagnostic testing have led to a new option: point-of-care testing with molecular sensitivity and specificity. Depending on what’s most appropriate for their patient populations, clinical laboratory teams working with outpatient practices can now adjust their algorithms to integrate point-of-care testing options for group A streptococcal infections — and ease the burden on central laboratories.

Snapshot: Group A Streptococcus

Commonly known as group A Streptococcus, this pathogen is the gram-positive bacteria Streptococcus pyogenes. According to the Centers for Disease Control and Prevention, group A Streptococcus is the cause of strep throat for 20% to 30% of pediatric cases of pharyngitis and in 5% to 15% of cases in adults.¹ Symptoms, such as fever and sore throat, tend to overlap considerably with other infectious diseases, making for a challenging diagnosis using only clinical observations. The incubation period is generally two to five days.

Strep throat caused by group A Streptococcus is common in children between the ages of five and 15 but rare in those younger than three. It is passed through close contact and is commonly transmitted at daycare centers and schools. Other high-risk settings include homeless shelters and detention facilities.

Concerns about antibiotic-resistant strains of group A Streptococcus have been growing in recent years. Clinical teams have reported finding S. pyogenes strains with limited susceptibility to some of the most commonly used antibiotics used for strep throat, including amoxicillin, ampicillin, and cefotaxime.² In a study of more than 7,000 genomes sequenced from strains isolated from patients, researchers found 137 strains with genetic mutations that could contribute to antibiotic resistance.² The authors reported that “many of our strains had decreased susceptibility in vitro to multiple beta-lactam antibiotics,” noting that these strains were geographically widespread.

Conventional testing protocols

Traditional group A Streptococcus testing workflows typically rely on two types of tests: rapid antigen and throat culture. The CDC recommends the use of rapid antigen tests for point-of-care testing so long as negative results are followed up with the more reliable throat culture for children who are at least three years old.¹ Rapid tests tend to have good specificity, so positive results usually do not need to be questioned. When in doubt, results from a culture are considered the most reliable.

In 2025, the Infectious Diseases Society of America (IDSA) updated its clinical practice guideline for group A Streptococcus testing.³ The revised guideline includes a recommendation for using a clinical scoring system to identify patients for whom group A Streptococcus testing is appropriate; however, this does not apply to cases of children younger than three. According to the recommendation, a clinical scoring system is most useful for determining which patients with pharyngitis are least likely to have infections caused by group A Streptococcus. The IDSA advises that high-risk patients, such as those who have had close exposure to another with a group A streptococcal infection, may warrant testing even if their clinical scores don’t meet set thresholds.

Molecular point-of-care tests

Molecular tests often have a reputation for strong sensitivity and specificity, but they are primarily conducted in clinical laboratories where highly skilled technical experts can oversee their operation. There are several molecular tests for group A Streptococcus, including some rapid lab-based assays that can generate results in an hour or less. While these tests solve certain clinical needs, and allow for much faster results than throat cultures, they do not address the goal of providing testing — and getting answers — at the point of care.

In order to translate the levels of accuracy and reliability seen with molecular tests for use at doctor’s offices, pharmacies, or urgent care clinics, a molecular-based point-of-care testing platform is needed. Fortunately, recent advances in the speed and complexity of molecular testing have enabled the development of these kinds of platforms. Currently, CLIA-waived molecular platforms exist that can be operated at or near the point of care. They deliver highly sensitive, highly specific results in less than 30 minutes — fast enough to deliver results during the patient’s initial visit, enabling timely, informed clinical decision-making while supporting antibiotic stewardship by reducing unnecessary or inappropriate prescribing.

For optimal accuracy, clinical lab teams may want to select a testing platform that had its clinical performance evaluated against an FDA-cleared molecular comparator test rather than against a culture-based test, preferably in a prospective study with a minimum of hundreds of clinical samples collected from individuals of all age groups. This will ensure that the point-of-care platform is well-suited to a broad range of patients and that its results are reliable.

Operational impact 

Beyond generating accurate results quickly, molecular point-of-care tests for group A Streptococcus should offer additional advantages to laboratory medicine teams. For example, their high sensitivity and specificity mean that results do not need confirmation with throat culture, and during peak strep throat season, this could greatly reduce the volume of follow-up testing sent to busy clinical labs.

Ideally, point-of-care tests should connect seamlessly to an institution’s laboratory information system and electronic medical records. Something like a wifi-connected device facilitates an easy flow of data that not only allows for reporting patient results but also makes it possible for the central lab to monitor satellite units for local health trends or consumable needs.

These devices are designed for ease of use, so a good platform will require minimal hands-on time and very little training. For optimal utility, the instrument should work with either operator-collected or self-collected samples, and also function with room-temperature reagents to avoid the need for nearby refrigerated storage. Devices should be quite compact and easily portable.

With molecular point-of-care platforms finally becoming a viable option for group A Streptococcus testing, clinical lab teams have the opportunity to deploy testing instruments more strategically across their health systems to balance their workload and to deliver actionable results to patients in a clinically relevant time frame.

References

1. Clinical guidance for group A streptococcal pharyngitis. U.S. Centers for Disease Control and Prevention. November 18, 2025. Accessed May 28, 2026. https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html.

2. Musser JM, Beres SB, Zhu L, et al. Reduced in vitro susceptibility of streptococcus pyogenes to β-lactam antibiotics associated with mutations in the pbp2x gene is geographically widespread. J Clin Microbiol. 2020;58(4):e01993-19. doi:10.1128/JCM.01993-19. 

3. Barshak, MB, Linder JA, Watson ME, et al. IDSA clinical practice guideline update on group A streptococcal (GAS) pharyngitis. October 14, 2025. Accessed May 28, 2026. https://www.idsociety.org/practice-guideline/streptococcal-pharyngitis2/.