Officials said they need more information before making a diagnosis.

Usually, your doctor will order more than one test before making a diagnosis.

The doctor may find something wrong and make a diagnosis right away.

Here's how you can help your doctor make the right diagnosis.

They said a diagnosis was never made on the basis of the test alone.

Treatment should only be given after a positive diagnosis has been made by means of a blood test.

It may be weeks or months before a doctor makes a diagnosis.

You may need many medical tests before a final diagnosis is made.

Eight of the victims died less than 24 months after the diagnosis was made.

A diagnosis can only be made by taking a blood sample.