Acquired after birth. Severe dual sensory disabilities that develop after birth represent only a small portion of deaf-blindness cases. They are most often the result of meningitis, encephalitis, or various accidental injuries. (from the "Lega del Filo d'Oro")
How to communicate with a deaf-blind person
The hand is the deaf-blind person's primary tool for perception and connection. With it, they see, listen, read, and speak, using conventional signs.
The simplest communication method is the "Malossi" system. It uses light finger pressures applied to the palm of the deaf-blind person's hand, where—by convention—the letters of the alphabet and numbers are positioned.