The WHO said the estimate represents an average figure and reported prevalence varies substantially across studies.
It noted that some well-controlled studies have, however, reported substantially higher figures and the prevalence of autism in many low- and middle-income countries is unknown.
ASDs are characterised by some degree of difficulty with social interaction and communication. Other characteristics are atypical patterns of activities and behaviours, such as difficulty with the transition from one activity to another, a focus on details, and unusual reactions to sensations.
The abilities and needs of autistic people vary and can evolve over time.
“While some people with autism can live independently, others have severe disabilities and require life-long care and support. Autism often impacts education and employment opportunities.
“In addition, the demands on families providing care and support can be significant. Societal attitudes and the level of support provided by local and national authorities are important factors determining the quality of life of people with autism.
“Characteristics of autism may be detected in early childhood, but autism is often not diagnosed until much later. People with autism often have co-occurring conditions, including epilepsy, depression, anxiety, and attention deficit hyperactivity disorder as well as challenging behaviours such as difficulty sleeping and self-injury. The level of intellectual functioning among autistic people varies widely, extending from profound impairment to superior levels,” WHO said.
It said available scientific evidence suggests that there maybe many factors that make a child more likely to have autism, including environmental and genetic factors.
“Available epidemiological data conclude that there is no evidence of a causal association between measles, mumps, and rubella vaccine, and autism. Previous studies suggesting a causal link were found to be filled with methodological flaws.
“There is also no evidence to suggest that any other childhood vaccine may increase the risk of autism. Evidence reviews of the potential association between the preservative thiomersal and aluminium adjuvants contained in inactivated vaccines and the risk of autism strongly concluded that vaccines do not increase the risk of autism,” the global health body said.
The organisation said a broad range of interventions, from early childhood, and across the life span, can optimise the development, health, well-being, and quality of life of autistic people.
It noted that people with autism have the right to the enjoyment of the highest attainable standard of physical and mental health, but they are often subject to stigma and discrimination, including unjust deprivation of health care, education, and opportunities to engage and participate in their communities.
