Drug resistant strains of the tropical disease malaria have emerged in several parts of the world and are resisting massive international efforts at control.

The strains are potentially fatal and many travellers -- especially pregnant women -- cannot be treated by existing drugs.

Although there have been some cases of the dangerous malaria strain -- called salciparum -- reported from South America and Africa, the center of the problem is in Southeast Asia.

Much of the coordination of the fight against the drug-resistant malaria and most of the reserch efforts to find a vaccine and adequate curative drugs have been carried out in two institutions in Australia, the country nearest to the center of the disease.

Gustav Nossal is supervising the vaccine research at his Walter and Eliza Hall Institute of Medical Research in Melbourne and Robert Black is searching for a cure at the Sydney University School of Public Health and Tropical Medicine.

Black said there were 470 cases reported here in 1979, a jump of nearly 60 percent over the previous year and many more than the fewer than 200 a year which was the average in Australia in the early 1970s.

Worse, most of the 470 cases were resistant to the wonder drug, chloroquin, which had kept malaria under control throughout the world since the mid-60s.

Despite research efforts in Australia and the United States there has been no breakthrough in the fight to control or cure the salciparum strain of malaria. It was the only one of the four malaria strains affecting humans that had become resistant to chloroquin.