The disease most often begins between ages 20 and 40, but may begin before age 10.
The disease has begun to take an economic toll in Canada.
The disease normally starts from age 20 to 30, though may begin in childhood.
But research now under way may start answering major questions about when the disease begins and how best to fight it.
The four people worked together from 1976 to 1980, when it is possible that the disease began in all of them.
The disease may well begin with increased fluid in the eye.
The disease often begins in the fingertips before it works up the arms and throughout the rest of the body.
From 1941, disease and hunger also began to reduce the population.
If disease begins to spread, as many people fear, medical care will become urgent.
But Cuban doctors say that the disease is beginning to affect women and children.