Twelve of the cases were reported in Pong district, one of the nine districts in this northern province, according to Dr Kraisuk Phetcharaburanin, chief of the provincial office.

He said five measures to deal with the potentially fatal bacterial disease, often transmitted by animal urine or by water or soil containing animal urine coming into contact with breaks in the skin, had been activated, and called on anyone with high fever, aching calves and muscle pains to seek immediate treatments.

He also called on doctors to immediately test for leptospirosis and administer treatment. Follow-up measures include controls to contain the disease and coordination with concerned government agencies tasked with containment operations.