Scientists from different parts of the world figured out the genetic code of the bloodsucking tsetse fly which spreads fatal African sleeping sickness, hoping to learn more about its biological rareness and finally eradicate the malady.
Public health campaigns effectively decreased the number of sleeping sickness - also known as the human African trypanosomiasis cases and deaths in the past few years but the disease strikes in outbreaks. In 1998, the estimated number of cases was 300,000 while there were 26,574 reported cases in 2000. In 2013, United Nation's World Health Organization (WHO) reported 5,967 cases and said that the predicted number of sleeping sickness cases is less than 10,000, adding that the disease is currently in the process of elimination.
Treatment for sleeping sickness is long and hard and it could lead to death without proper care. Scientists are not very hopeful in developing a preventive vaccine for sleeping sickness because of how the parasite avoids the mammalian immune system so prevention of the disease was focused on reducing the insect population.
Expects are looking for new ways to kill or repel the flies, whose bite causes a parasitic disease which drives its victims crazy before they become comatose and die. These insects are also nagana-carriers, a virus that weakens and/or kills cattle affecting the livestock and economy of Africa.
Tsetse flies are mammalian. Its genome is twice the size of a fruit fly's but only 1/10 the size of the human genome. The insect has around 12,000 genes and 366 million letters of genetic codes. Pregnant females nourish its young with milk inside the womb. It gives birth to an undulating larva close to her size and produces only eight to 10 offspring her entire life. The tsetse gene shows a regulatory protein called ladybird late which orchestrates the milk production of the insect. Scientists aim to target this protein with inhibitory substances to control population. The less milk the fly produces, the less fertile it becomes.
"If you can eliminate one female, it can have a big effect on the population," Yale School of Public Health professor of epidemiology Serap Aksoy said. "Other insects produce many progeny and hope a few survive. With tsetse, the hatch rate is nearly 100 percent." The researchers are optimistic that the genetic blueprint could lead them to new ways to eradicate the tsetse fly through improved traps or chemicals that interfere with its reproduction.
