Mass General Brigham AI Flags 10 Million Undiagnosed Long COVID Cases in U.S.
Updated
Updated · WBUR News · Jun 1
Mass General Brigham AI Flags 10 Million Undiagnosed Long COVID Cases in U.S.
2 articles · Updated · WBUR News · Jun 1
Mass General Brigham researchers estimate at least 10 million Americans have long COVID that was never formally diagnosed, based on a study published in JAMA Network Open.
Nearly 460,000 medical records fed into an AI model that tracked patients with prior COVID infections who later sought care for symptoms linked to long COVID, suggesting 16% develop lasting illness.
The study argues many cases are missed because long COVID has no single diagnostic test and often appears as separate problems such as fatigue, breathing trouble, dizziness or depression.
That estimate is more than double some earlier benchmarks, including the WHO's 6% figure, though a 2024 CDC survey found 18% of U.S. adults said they had experienced long COVID.
Outside experts split on the findings: one Washington University specialist said the analysis likely overstates prevalence, while others said it reinforces that long COVID remains a persistent, disabling chronic illness.
AI reveals millions of hidden Long COVID cases. Why does its research funding lag so far behind other major diseases?
With the national Long COVID office closed since 2025, is the US prepared for this 'compounding crisis' of chronic illness?
Over 18 Million Americans Affected: New AI-Driven Study Reveals Hidden Scale and Societal Impact of Long COVID in 2026
Overview
A groundbreaking study from Mass General Brigham, published in May 2026, used advanced artificial intelligence to analyze nearly half a million patient records. This research dramatically reshaped our understanding of long COVID by revealing that over 16% of people who had COVID-19 developed long COVID—more than double previous estimates. The study showed that the true scale of long COVID has been significantly underestimated and that its impact continues to rise across the United States. These findings highlight a vast, hidden epidemic affecting millions of Americans and call for urgent attention to this growing public health crisis.