Few cases have been reported in people over 20 years of age.
Less than one case per year has been reported since 2000.
So far no cases have been reported in the area.
About 2,600 cases have been reported among children under the age of 13.
In 1998, 19 cases were reported and 12 people died.
In the first four months of the year alone, 33 countries reported more than 6,500 cases.
So far 3,279 cases been reported and 27 people have died, the health department said.
The number of cases reported in the state was always small.
Since 1972, only 32 human cases have been reported in this country.
About 7,400 cases were reported in this country last year.
