Pathogenic E. coli strains use a multi-step scheme of pathogenesis that is similar to that used by other mucosal pathogens, which consists of colonization of a mucosal site, evasion of host defences, multiplication and host damage.
Research suggests that autism can be reliably diagnosed by age 2, but this study found that fewer than half of children with autism are diagnosed by age 5. Autism is a complex neurodevelopmental disorder that affects as many as 1 in 88 U.S. children, according to the U.S. Centers for Disease Control and Prevention.
Signs of autism may appear during infancy and the disorder is usually diagnosed by the age of 3. Sometimes the child's development appears normal until about 2 years old and then regresses rapidly. Symptoms of autism occur in various combinations, from mild to severe.