Bromeliad Malaria 



By Lyman B. Smith 



Department of Botany, U. S. National Museum 



[With 2 plates] 



Malaria is an extremely complex disease, controlled by a series of 

 variables. The first variable is the protozoan Plasmodium, which is 

 the cause of malaria. This organism has a life cycle alternating be- 

 tween some species of vetebrate animal and a mosquito. It consists 

 of several species, four of which occur in man. These four differ in 

 their relation to climate as well as in the symptoms that they produce 

 and in their response to treatment. Since they hardly ever produce 

 immunity beyond one of their numerous regional strains, the strictly 

 clinical problem is excessively complex in itself. 



The anopheline mosquitoes, which carry human malaria, are a 

 greater variable, with numerous species differing widely in their habits 

 and relation to environment. The usual method of controlling malaria 

 is by elimination of the mosquito carrier, but first the species involved 

 must be identified, since they vary greatly in habitat, and it is im- 

 practical, if not impossible, to kill all the mosquitoes. For instance 

 some mosquitoes enter houses freely and can be dealt with by DDT 

 (dichlor diphenyl trichlorethane) in the adult stage, while others bite 

 only out of doors and must be killed as larvae. The investigator must 

 also consider three other factors in looking for a mosquito that is a 

 carrier : anthropophily or its taste for man, its numbers, and its sus- 

 ceptibility to malaria (Rachou and Ferreira, 1947), the final proof 

 being the discovery of the malaria organism in mosquitoes of the 

 suspected species. 



All mosquitoes are alike in spending their larval stage in the water, 

 and in many instances they have been controlled by draining swampy 

 areas and by oiling small bodies of water or adding fish to them. How- 

 ever, the mosquitoes of the subgenus Kerteszia breed in bodies of wa- 

 ter too numerous and inaccessible for the usual control technique. 

 They have adapted themselves to development in the tanks of differ- 

 ent species of Bromeliaceae. 



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