At the time nobody knew how the virus was spreading.

Thus, the virus cannot grow or spread to other cells.

But experts believe that the virus may eventually spread to all parts of the world.

The virus can spread from one part of the body to another or to other people.

The results will give the state an idea how extensively the virus has spread.

The virus can spread easily even when people try very hard to keep places clean.

Over decades, the virus slowly spread across Africa and later into other parts of the world.

The specialists don't know exactly how far the virus has spread.

The virus may also spread among young children in day care settings.

But scientists say the virus has spread far more widely into the population.