In October 2010, a Minneapolis-Somali mother asked the federal Interagency Autism Coordinating Committee to investigate reports of high numbers of Somali preschoolers with autism. Her concerns were backed by preliminary information from the Minnesota Department of Public Health. In response, Autism Speaks, the National Institutes of Health and the Centers for Disease Control and Prevention (CDC) partnered to further investigate.
Today, researchers from University of Minnesota released their long-awaited findings in a community report.
The report – based on records of autism services provided in 2010 – confirms that the overall prevalence of autism spectrum disorder (ASD) was higher in the Minneapolis Somali community than among the city’s other minority groups. (See Figure 1, below.) It was on par with that of white children. However, the percentage of Somali children with autism complicated by intellectual disability was considerably higher than in other groups. (Figure 2, below left.)
“This study validates the concerns of the Somali community in Minneapolis,” comments epidemiologist Michael Rosanoff, Autism Speaks associate director for public health research. “There may be factors that put Somali-American children at higher risk of autism and autism with intellectual disability,” he says. “Or these findings may reflect better autism awareness and detection within this tight-knit community. We need to explore these possibilities, and that takes further research.”
The study identified roughly 1 in 48 Minneapolis children, ages 7 to 9, as having ASD in 2010. This is considerably higher than the CDC’s nationwide 2008 estimate of 1 in 88. But it’s in line with rates for some CDC reporting sites, which vary widely.
“It shouldn’t be overlooked that we may be underestimating autism prevalence in the U.S.,” Rosanoff adds.
Experts are also concerned by the relatively high age (4.9 years) of first evaluation for Minneapolis children. Autism can generally be diagnosed by age 2, and early intervention is crucial for maximizing a child’s progress.
Autism Speaks Early Access to Care initiative is dedicated to reducing the average age of diagnosis and increasing access to quality early interventions. It places particular emphasis on underserved minority communities, which tend to lag in age of diagnosis and in access to intervention services.
Among Somali immigrant communities, high rates of autism have likewise been reported in Scandinavia and Canada. This has led to speculation about possible risk factors such as vitamin D deficiency due to reduced sun exposure at northern latitudes combined with dark skin and skin-covering clothing. To date, no scientific study has confirmed this or other possible risk factors.
“In addition to follow-up research,” Mr. Rosanoff says, “we must ensure that the needs of this and other communities affected by autism are being adequately met. We thank the Minneapolis Somali community for their support and participation in this study, which has helped improve our understanding of autism and the needs of families.”
The University of Minnesota researchers hope to publish their complete findings in a scientific journal early next year. Autism Speaks was not involved in their research, except as a funder.
Editor's note: The New York Times tapped Mr. Rosanoff's expertise and perspective in their coverage of the study's findings, here.