Some of the lenses had been heat treated and others had been chemically disinfected. The failure of the chemical disinfection resulted from insufficient treatment or rinsing the lenses in contaminated saline after disinfection. PAM is diagnosed by the presence of amoebae in the spinal fluid. GAE is diagnosed by biopsy of the lesion. Clinical diagnosis by experienced practitioners is based on the characteristic stromal infiltrate.
Transmission is through water based fluids or the air.
Eye infections may lead to blindness. Immunodeficients, especially those infected with HIV, may be at risk for atypical infections. PAM, GAE, and eye infections have occurred in otherwise healthy individuals. Since infection is not known to be by way of the digestive tract, the FDA has no regulations concerning these organisms. FDA has published a paper documenting the presence of amoebae in eye wash stations, and warning about the potential danger of such contamination.