HANOI, Vietnam- Vietnam has asked international health experts to help investigate a mystery illness that has killed 19 people and sicked 171 others.

The infection has mostly affected children and young people.

It begins with a high fever, loss of appetite, and a rash that covers the hands and feet.

Patients who are not treated early can develop liver problems and eventually face multi-organ failure.

Nearly 100 people remain hospitalized, including 10 in critical condition.

The illness responds well to treatment if detected early, but 29 patients have been reinfected.