CDC: Invasive Group A Streptococcus Incidence Among People Experiencing Homelessness in Missoula County, Montana, Was About 100 Times That of the General Population
An investigation published by the U.S. Centers for Disease Control and Prevention (CDC) in Morbidity and Mortality Weekly Report (MMWR) on October 29 found that the incidence of invasive group A Streptococcus (GAS) infections among people experiencing homelessness in Missoula County, Montana, was about 100 times that of the general population.
The investigation covered July 27, 2024 through September 20, 2025. Missoula County identified 69 GAS cases through routine and enhanced surveillance, of which 39 cases (57 percent), including three reinfections, occurred among 36 persons experiencing homelessness.
Of those 39 cases, 18 (46 percent) were identified only through enhanced surveillance, which added housing-status data to case records and allowed health officials to link infections to homelessness.
Among the patients experiencing homelessness, 15 were hospitalized with invasive GAS disease and one died. Lead author Beth Hopkins, MPH, and colleagues wrote that incorporating housing status into routine surveillance data helps health departments detect and respond to outbreaks in high-risk populations that general statistics may miss.
The report appears in MMWR 2026;75(42):626-629 (DOI: 10.15585/mmwr.mm7542a1).
Source: GSM · USA (original Chinese edition)
Photo: A 组链球菌显微图像（资料图）。美国疾病控制与预防中心（CDC）公共卫生图像库，公共领域，经 Wikimedia Commons。 / Streptococcus pyogenes micrograph (file image). CDC Public Health Image Library, public domain, via Wikimedia Commons.
