I hate to pop Ken Burton's bubble and the crocodile tears he sheds for the poor, benighted Plasmodium parasite, but he's made several mistakes in his letter about making "malaria extinct" ("All Creatures," Mailbox, April 7). First of all there are four, not 11, species of human-specific Plasmodium: P. vivax, P. malariae, P. falciparum and P. ovale. Also, Leptospira is the causative organism of Leptospirosis, not Yellow Fever, and it is not spread by mosquitoes but by infected mouse and rat droppings. It is also quite endemic in California Sea Lions. Yellow fever is caused by Flavivirus, which may or may not be species-specific for humans.
As for the Plasmodium parasite: It is one of the most versatile and interesting organisms on the planet. Plasmodia have been around for millions of years longer than humans, so these four species obviously evolved to infect humans. They're smart enough to outwit humans. If we ever do possess the technology and wherewithal to extinguish malaria (infecting approximately 200 million people a year and killing about a million of them) in human populations, the human parasites will almost certainly morph into a form to infect some other animal.
One of the hallmarks of biological life, both plant and animal, is that all species eventually become extinct or evolve into new species. It's only the accelerated pace of human-caused species extinction, which rivals the famous Cretaceous Extinction that wiped out the dinosaurs, that is so worrisome.
Personally, I don't have a whole lot of sympathy for the Plasmodium. True, they are a fascinating life form, but they also cause untold human suffering, not to mention that humans evolved Sickle Cell Anemia (another type of human suffering) to develop a certain resistance.
Plasmodium will do just fine, with or without our intervention.
Stephen Kamelgarn, M.D.,