What's interesting to note in the study, and media coverage of it in this BBC article, is that the scientists and doctors are all looking ahead to what needs to be done. There's no debate about the facts of a rising case load. Though the authors note that reasons for the increase are unclear -- they say it could be better evaluations, a broader "diagnostic criteria" or increased incidence -- they go on to say: "Services in health, education, and social care will need to recognise the needs of children with some form of ASD, who constitute 1% of the child population." In other words, we have to deal with this situation better than we are now.
The scientists who wrote the study note that "recent reports have suggested that the prevalence of autism and related spectrum disorders (ASDs) is substantially higher than previously recognised. We sought to quantify prevalence of ASDs in children in South Thames, UK," that is, the London hospital.
The Lancet is a subscription-only publication, and free registration is required to see an abstract. The key statistic from the abstract: "The prevalence of childhood autism [in this study] was 38.9 per 10,000 and that of other ASDs was 77.2 per 10,000, making the total prevalence of all ASDs 116.1 per 10,000."
"We knew of no one with autism. The pro-football star Doug Flutie had not yet raised national awareness of this disorder. His autistic son had not yet been born. Back then, doctors still cited an incidence of two in 10,000 births, compared with today's one in 166."