BROMELIAD MALARIA — SMITH 387 



a conqueror of yellow fever in Brazil, was sent to investigate cases of 

 malaria that were developing among construction crews on the new 

 Sao Paulo-to-Santos railroad line (Lutz, 1950). Now malaria has 

 generally been associated with marshy regions, but this epidemic was 

 in the construction camps cut out of the virgin forest on the precipitous 

 seaward slopes of the Serra de Cubatao where the water ran off as 

 fast as it fell. 



Lutz had the suspicion that some blood-sucking insect was respon- 

 sible, and one evening in camp he noticed a small mosquito (Anopheles 

 cruzii) that lost no time in hovering around but attacked with great 

 speed and voracity. Later he was pleased to find that anopheline 

 mosquitoes are carriers of malaria and that he had been correct in sus- 

 pecting this species. 



The next question was where could a mosquito breed in such a com- 

 pletely drained area. In his travels Lutz had observed various groups 

 of plants that held water in their leaves, and he was familiar with 

 the work of Fritz Mueller, the Santa Catarina naturalist who had 

 studied the different forms of life found in bromeliad tanks. After 

 considerable fruitless search, Lutz found bromeliads containing larvae 

 of the mosquito in question, and in 1903 he published his findings in 

 a paper entitled "Waldmosquitos und Waldmalaria." 



The first reaction to Lutz's story of bromeliad malaria was one of 

 almost complete incredulity. Other scientists pointed out how diffi- 

 cult it would be for such a type of malaria to attack humans, and the 

 complex set of conditions that would be necessary for an epidemic to 

 start. For one thing, any mosquito, to carry malaria, must first bite 

 an infected man, then survive against all its natural enemies for sev- 

 eral days while the malaria cycle followed its course, and after that 

 bite an uninfected man. It seemed highly improbable that a forest 

 mosquito would have the opportunity for the repeated biting necessary 

 to carry malaria (Knab, 1913). Nevertheless, over the years opinion 

 swung more and more to Lutz's views as evidence in his favor accumu- 

 lated. Then it was suddenly discovered that the supposedly impossible 

 chain of circumstances had produced a persistent (endemic, in medical 

 language) plague of bromeliad malaria in two widely separated 

 regions, the Island of Trinidad in the British West Indies, and the 

 state of Santa Catarina in southern Brazil. 



BROMELIAD MALARIA IN TRINIDAD 



The malaria problem in Trinidad made a strong contrast to the 

 situation originally studied by Lutz, for being on relatively level 

 ground the possibility of swamp-breeding mosquitoes could not be 

 ruled out at the start (Downs and Pittendrigh, 1946) . When, in 1942, 

 the principal carrier was definitely identified as Anopheles bellator, 



