Chapter 1 : Hunting Microbes

Abstract:

Pasteur devised a method called pasteurization to control the offending microbes. Charles-Louis Alphonse Laveran spent much of his time looking at autopsy material but also examined fresh specimens. Ronald Ross worked mostly with the gray and striped-wing kind of mosquitoes. When these mosquitoes were dissected, the whiplike flagella were found in the mosquito stomach; however, no further development occurred. This result was no more informative than what Laveran had seen in a drop of blood on a microscope slide nearly 20 years earlier. Ross’ discovery of infectious stages in the mosquito salivary glands in a bird malaria appeared to be the critical element in understanding transmission of the disease in humans. Ross claimed that it was only after Giovanni Battista Grassi, had read his work on the transmission of malaria in birds that he recognized that human malaria occurred only in areas where Anopheles existed and that Culex was not involved, since Grassi did not publish this or the development of the parasite in these mosquitoes until late 1898. Ross, shortly after discovering that the mosquito was a vector for Plasmodium, presumed that after entry into the bloodstream, the inoculated sporozoites burrowed into red blood cells immediately. Grassi, however, suggested that the nucleus of the sporozoite was so different from that found in the blood stages that a considerable degree of transformation would be necessary to convert one directly into the other.