children in economically deprived rural areas. Historically, there have been high rates of infection among children in the American South. Juveniles cannot survive freezing temperatures, so the highest prevalence occurs in areas with warmer temperatures and greater rainfall. The greatest incidence of infections occurs in Asia and sub-Saharan Africa, especially in poverty-stricken areas with poor sanitation. A. duodenale infections occur at a lesser rate and are seen primarily in Europe and the Mediterranean. Genome A draft assembly of the genome of Necator americanus has been sequenced and analyzed. It comprises 244 Mbp with 19,151 predicted protein-coding genes; these include genes whose products mediate the hookworm's invasion of the human host, genes involved in blood feeding and development, genes encoding proteins that represent new potential drug targets against hookworms, and expanded gene families encoding likely immunomodulator proteins, whose products may be beneficial in treating inflammatory diseases and asthma. Diagnostics The most common method for diagnosing N. americanus is through identification of eggs in a fecal sample using a microscope. N. americanus eggs have a thin shell and are oval shaped, measuring roughly 56–74 by 36–40 μm. Treatments The most common treatment for N. americanus infection are benzimidazoles, specifically albendazole and mebendazole. Benzimidazoles kill adult worms by binding to the nematode’s β-tubulin and subsequently inhibiting microtubule polymerization within the parasite. The efficacy of single-dose treatments for hookworm infections were: 72% for albendazole, 15% for mebendazole, and 31% for pyrantel pamoate. A current concern with this parasite is the increase in drug resistance, such as benzimidazoles and mebendazoles. Pregnant women should not be treated within their first trimester. During the 1940s, the treatment of choice was tetrachloroethylene, given as 3 to 4 cc in the fasting state, followed by 30 to 45 g of sodium sulfate. Tetrachloroethylene was reported to have a cure rate of 80 percent for Necator infections, but 25 percent in Ancylostoma infections, and often produced mild intoxication in the patient. Prevention and control Infection and transmission of others can be prevented by not defecating outdoors or using human feces as fertilizer. This parasite is not transmittable directly from person to person. Pigs may be an intermediate host for N. americanus. Economic burden N. americanus causes hookworm diseases, which are associated with blood loss and anemia. Patients who are infected with around 25 to 100 worms experience symptoms such as fatigue, weight loss, and slight headaches. As the infestation number