Hookworm is just one type of parasitic roundworm infection that affects humans, according to MedlinePlus. It occurs mainly in the tropics and subtropics---often in places where sanitation is poor. Although hookworm was once common in the southeastern U.S., thanks to improved sanitation the disease is now largely under control, according to the National Institute of Allergy and Infectious Diseases or NIAID.
Hookworm Disease Symptoms
Hookworm is caused by the roundworms Necator americanus and Ancylostoma duodenale, which affect only humans, and Ancylostoma ceylanicum and Ancylostoma braziliense, which affect both people and animals, according to MedlinePlus. Hookworm larvae enter the body through the skin, causing an itchy rash, and then travel to the lungs, where they cause a cough. Eventually they enter the intestines, where they grow to adulthood and are excreted. Other symptoms include abdominal pain, blood in the stool and sputum, diarrhea, tiredness, fever, gas, nausea and vomiting. But sometimes there are no symptoms at all.
Anemia
If a hookworm infection goes untreated for a long time, it can cause anemia, according to NIAID. Large numbers of worms attach themselves to the walls of the intestines and suck the host's blood, which leads to a reduced red blood cell count. If a person already has poor nutrition, is pregnant, or has malaria, this anemia can be severe and dangerous.
Protein and Other Nutritional Deficiencies
The blood loss caused by untreated, chronic hookworm disease can cause the body to lose both protein and iron and lead to a serious deficiency, according to the Centers for Disease Control and Prevention. When these deficiencies occur in children, they can slow growth and mental development, sometimes permanently. This can also lead to fatigue and breathing problems and in severe cases even cause congestive heart failure.
Pregnancy Complications
The anemia caused by hookworm disease can lead to a number of complications for mother and baby if it occurs during pregnancy, according to the Centers for Disease Control and Prevention. These include low birth weight for the baby, reduced production of milk, and a higher risk of death for both mother and child.
