Growing catalogue of fraud.

The recent invasion of the Amazon area by nonimmune people is creating serious health problems. Ten years ago the situation regarding malaria was much more satisfactory. I travelled extensively in the Amazon around that time, and the ministry campaign against malaria (SUCAM) had it fairly well controlled. Brazil was fortunate in that the major anophelene vector, Anopheles darlingi, had not developed genetic resistance to dichlorodiphenyltrichlorophane (DDT). The fleet of small boats in Manaus would go up the multitude of rivers spraying the houses: people live mainly on the banks of a river as it is the only route of cheap transport. Naturally eradication was not possible but the level of control was high. At that time P falciparum resistant to chloroquine had been reported but was still uncommon; now it is the rule. Also A darlingi has developed so called behavioural resistance; it is no longer resting on the sprayed walls but bites its hosts around dwellings. Therefore the malaria problem grows. Also a large part of this population influx is speculators mining mainly for gold or diamonds or cattle rearing. The miners are the worst because they are virtually impossible to control, flying into remote areas, often secretly, because of the lure of what is beneath the ground. Nobody knows how many mining concerns there are in this region but it must be hundreds. The ministry struggles with the problem of controlling malaria among them as well as the transmission ofAIDS. It is a herculean task. Development of antimalarial drugs has been related to wars and the availability ofquinine. After the second world war six groups of antimalarials were available but P falciparum has a remarkable capacity to develop resistance. The Vietnam war highlighted the problem for the American army, which set up an admirable drug screening programme at the Walter Reed Army Institute of Medical Research in Washington. To date this programme has screened 300 000 compounds for antimalarial activity. Mefloquine is the result of this programme, but because it is another quinoline (like quinine) resistance has already been reported, though it is still unknown in Brazil. Such powerful, effective schizonticides must be rigorously controlled otherwise indiscriminate use will result in resistance as occurred with chloroquine. Today the situation for treating severe falciparum malaria in Brazil is better than it has been for some years, as apart from mefloquine there are other new schizonticides to which resistance is still unknown.