Siliguri, Sept. 29: A team of experts from the regional office of the central government?s health and family welfare department today completed its 28-day study and is returning to Calcutta tomorrow to collate their findings in the Naxalbari area of Darjeeling district.

The region witnessed a large number of malaria cases this year, with over 600 patients being treated for the disease. Over 50 per cent of the cases this time had Plasmodium falciparum, which leads to malignant malaria.

The objective of the five-member team was to find out the extent and level of resistance that the patients had developed for chloroquine, the first line drug for this disease. ?Resistance to chloroquine is on the rise all over the world and the exercise was a study of various endemic zones,? said a senior district health official.

A similar study conducted by another team at Sukna, north of Siliguri, in 2003 found more than 50 per cent of the malaria cases resistant to the first-line drug. ?The reports of such studies are sent to the office of National Vector-borne Disease Control Programme in New Delhi, which determines what second-line drug has to be given and in which area,? the official said.

Second line drugs like sulfadoxine pyrimethamine will have to be prescribed by the government before they are administered in chloroquine resistant cases, as they are costlier. Also, indiscreet prescription of second line drugs could lead to a resistance developing to them as well, experts pointed out.

Meanwhile, all patients with fever in the endemic zones are being given ?fever radical treatment? after collecting blood samples, said T.K. Chattoraj, chief medical officer of health. People living in the endemic regions have been asked to have their blood tested at the earliest and use mosquito nets, he added.