PARASITOLOGY
Perhaps the best known aspect of the importance of parasites is the role that they play in causing human disease. For example, hundreds of millions of people suffer from malaria and each year over one million human deaths are caused by this parasitic disease.
Diseases caused by many species of parasitic worms, blood flukes, tapeworms, hookworms, and others are still scourges of mankind. Insect parasites such as fleas and lice are, at best, annoyances to man, and as vectors of diseases like bubonic plague and typhus have been responsible for uncountable human mortality. Mosquitoes not only transmit malaria, but spread yellow fever, encephalitis, and other viral diseases, and are responsible for inoculating into humans several species of filarial worms that cause some of the most horrific diseases in the medical literature. Emerging diseases such as Lyme disease, transmitted by ticks are increasingly recognized as significant to human health.
