Prevalence, risk factors, and strain distribution of group A <em>Streptococcus</em> carriage among Indigenous children in the Southwest United States — ASN Events
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  3. Prevalence, risk factors, and strain distribution of group A Streptococcus carriage among Indigenous children in the Southwest United States

Prevalence, risk factors, and strain distribution of group A Streptococcus carriage among Indigenous children in the Southwest United States (#149)

Catherine Sutcliffe 1 , Victoria Sergent 1 , Joyselynn Pitalua 1 , Sopio Chochua 2 , Chris Gregory 2 , Chloe Hurley 1 , Zhongya Li 3 , Saundra Mathis 3 , Lesley McGee 2 , Jennifer Okaro 2 , Theresa Tran 2 , Robert Weatherholtz 1 , Laura L Hammitt 1
  1. Center for Indigenous Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
  2. Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States
  3. ASRT Inc, Contractor to Pneumonia and Streptococcus Laboratory Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States

Background

Indigenous individuals in the Southwest United States are disproportionately affected by group A Streptococcus (GAS) infections. Understanding prevalence and risk factors for carriage, and characteristics of carriage isolates provides critical insight to inform use of existing interventions and vaccine development and evaluation.

Methods

In Navajo Nation and White Mountain Apache Tribal lands, cross-sectional carriage studies were conducted among Indigenous children aged 0–14 years (n=768) in 2019 and 0–4 years (n=498) in 2022–2023. Study activities included a questionnaire, medical chart review, and collection and culture of an oropharyngeal sample. Isolates were sequenced to determine emm type. We evaluated GAS carriage prevalence and risk factors and calculated the percentage of emm types covered by a 30-valent vaccine in development.

Results

Carriage prevalence among children aged <5 and 5–14 years was 4.2% (n=33/792; no difference between studies) and 18.1% (n=86/474), respectively. Prevalence was higher among males, older children, and children with a prior GAS infection. The top three emm types were 12 (26.9%), 91 (13.5%), and 1 (8.4%). Emm clusters varied by age, with more emm types from the D1-5 cluster among children 5-14 years (28% vs. 6%;p=0.015). The percentage of emm types covered by the 30-valent vaccine was 74%.

Conclusions

Similar to the general U.S. population, carriage prevalence was higher among school-aged children, suggesting that interventions in this age group could be impactful in preventing GAS disease. It will be important to monitor GAS carriage and disease in these communities over time, particularly as vaccines become available.

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