Fig. 1

Map of Sri Lanka showing the climatic zones. Shaded in grey: dry zone where malaria was endemic; yellow: the intermediate zone where in some parts malaria was endemic and also prone to epidemics; blue: wet zone which was not endemic for malaria but very rarely epidemic prone. The district boundaries of Moneragala where the index case was resident; adjacent Ampara where some contacts were traced to; Colombo where the introduced case was resident, are demarcated. The residence of the index case and the site of transmission; the Government Base Hospital where the introduced case was first admitted to are shown by a red dot. The residence of the introduced case was near the hospital and cannot be depicted on the map at this resolution