Information gained from the sequencing project also will provide clues to how the grain-of-rice-sized insects pass on infection-causing organisms to people and other animals. “If we have a relatively complete louse genome, we can do experiments necessary to discover how lice can digest human blood and transmit disease,” says Pittendrigh. “The more we learn about the biochemical workings of these tiny creatures, the greater our chance of influencing issues associated with human health.”
Body lice spread epidemic typhus by transmitting an organism called “Rickettsia prowazekii.” The disease usually occurs in areas where people have poor hygiene, especially in developing countries or in crowded places, such as jails. The disease has a 10-percent to 60-percent fatality rate, and experts say that the disease-causing organism could be used as a biological weapon.
“Currently there are no complete genomes of this type of insect, mainly because most disease-carrying species have such large genomes,” Pittendrigh says. “Body lice have the smallest insect genome known to date.”