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.
Symptoms of autism are usually noticed first by parents and other caregivers sometime during the child's first 3 years. Although autism is present at birth (congenital), signs of the disorder can be difficult to identify or diagnose during infancy.