สำนักราชบัณฑิตยสภา

«“√ “√ √“™∫— ≥±‘µ¬ ∂“π ªï ∑’Ë Ú˜ ©∫— ∫∑’Ë Û °.§.-°.¬. ÚıÙı π‘ ¿“ ®√Ÿ ≠‡« ¡å ¯Ûı Abstract Evolution of Malaria Nibha Jaroonvesama Associate Member, the Academy of Science, the Royal Institute, Thailand Malaria was recorded in the year 1600 B.C. and was diagnosed in the 1st and 2nd centuries A.D. In 1880, Laveran discovered the malaria parasite and in 1897-1948 the life cycle of malaria in mosqui- toes and in humans was identified. In 1961-1962, malaria parasites began to resist chloroquine and now resist many antimalarial drugs. The mechanisms of resistance are due to several factors (a) malaria having had a long time in contact with long half-life antimalarial drugs, gene mutation develops (b) the ability of the parasite to produce enzyme which drugs cannot inhibit and changes in the metabolic pathway and chromo- somes to get rid of the drugs 40-50 times more than usual, and (c) the ability of the parasite to spon- taneously mutate genes without contact with drugs and develop after biting, cross resistance to other antimalarial drugs which have similar chemical structures. The anopheles mosquito, which is the vector of malaria, also has evolved by changing its habit: resting on a house wall which has been sprayed by DDT and their developing resistance to DDT. The evolution of research work included the research on pathophysiology and pathogenesis, which led to useful and correct treatments, and the success in culturing malaria in vitro, as well as discovering certain genes and cloning malaria. In the field of treatment, many antimalarial drugs have been produced and the best is qinghaosu which contains three synthetic derivatives: artemether, artesunate and arteeter. The conjunctive treat- ment for severe cases is exchange blood transfusion. Concerning prevention of malaria, currently there is no preventive drug. Everyone who visits an area where malaria is endemic must avoid mosquito bites. The evolution of prevention in the future is likely to involve a malaria vaccine that is under developement. Key words : malaria, evolution protective effect of the Spf 66 ma- laria synthetic vaccine against Plas- modium falciparum infection in a ran- domized doubled-blind placebo-con- trolled field trial in an endemic area ventional course of primaquine and chloroquine: report of two cases. Southeast Asian J Trop Med Publ Hith. 1973; 4:135-7. of Ecuador. Vaccine 1994; 12: 337- 42. Ù¯. ª√’ ™“ ‡®√‘ ≠≈“¿, µ√–Àπ— °®‘ µ À–√‘ ≥ ÿ µ. Relapses of vivax malaria after a con-