Human Hookworm: Causes, Types, Diagnosis, Symptoms, Treatment

By December 19, 2016 No Comments

Hookworms are actually parasites which live off other living beings. It is also known as Human hookworm disease which is a common helminth infection mostly caused by the nematode parasites Necator americanus and Ancylostoma duodenale. Organisms like Ancylostoma ceylonicum,  Ancylostoma braziliense, and Ancylostoma caninum also play role in occurence of Hookworm to certain extent. In simple words it is a disease which is caused because of infection by a parasitic bloodsucking roundworm. These worms live in the small intestine. They affect  the lungs and small intestine. Humans are contracted with hookworms through roundworm eggs and larvae which are present in dirt contaminated by feces. When the soil is contaminated then it can remain infected so up to 9 days. It is estimated that around 440 million people worldwide are infected with Human hookworm however Centers for Disease Control and Prevention states that 576 to 740 million people worldwide are infected with hookworm. Mostly poor sanitation problems in the tropics and subtropics region face this problem. The problem of hookworm infection is quite rare in the developed countries. It is one of the leading causes of health problems among the mother and children in the tropical and sub tropical developing countries. Once infected, hookworms may persist in the human body for many years. It will then impair the physical and intellectual development of children. This condition eventually leads to affect the economic development of communities and country.

Causes of Human Hookworm infection

Hookworm infections are caused by parasitic roundworms, or hookworms. Necator americanus and Ancylostoma duodenale are the two types of hookworms which cause this problem. It is alarmingly scary to know that, every day, a mature female duodenale worm produces about 10,000-30,000 eggs, and a mature female N americanus worm produces 5000-10,000 eggs inside the intestine. When an infected person passes feces then the eggs of hookworm are left on the ground. Those eggs hatch into larvae which can enter into the human body through the skin. The hookworm larvae will enter through the skin then travel through the bloodstream to finally enter the lungs. Those larvae can also travel to the intestine through the windpipe. A fully grown hookworm can live inside the small intestine for over an year. Then it starts to pass through the feces. If the pet or animals have hookworm then human beings can also get it from the animals.

Signs and Symptoms of Hookworm

There are many signs and symptoms which may indicate the attack of hookworm on the human being. One of the main primary symptoms is that the hookworm enters into the body through some breakage in the skin, and in that part certain allergic reaction or itching sensation may be felt. After that the patient may suffer from diarrhea because the hookworm lives in the intestines. There are other symptoms too which are involved with hookworm. They are as listed below:

  1. The patient may experience abdominal pain.
  2. If a child is infected then that child might cry excessively.
  3. There will be colic, or cramping.
  4. Nausea and fever will be experienced.
  5. Blood will be noticed in the stool
  6. Intestinal cramps and loss of appetite will be experienced.
  7. Itchy rashes may appear on the body.
  8. Severe infection may cause Coughing, chest pain, wheezing or constipation.
  9. The conditions may result in intestinal inflammation, progressive iron-deficiency anemia and protein deficiency.

Types of hookworm disease

Hookworm disease can be divided into three different types. They are as follow.

  1. Classic hookworm disease- In this type there is maximum blood loss which may cause iron-deficiency anemia and protein malnutrition. It is a gastrointestinal (GI) infection which is mostly caused by by N americanus and A duodenale while it is less likely to be caused by zoonotic species A ceylonicum.

2.Cutaneous larva migrans- In this infection the manifestations occur on the skin. It is mostly caused by A braziliense, which has dogs and cats as hosts.

  1. Eosinophilic enteritis- It is also a gastrointestinal (GI) infection which causes abdominal pain but no blood loss. This kind of condition is caused by dog hookworm A caninum.

Generally in terms of severity and occurrence of worms, the hookworm infection can be classified into three other stages.

They are Light, moderate and heavy. Light infection involves less than 40 worms while moderate infection involves 100-500 worms. Heavy infection means infection by over 500 worms.


Microscopic examination of the stool is done to find finding characteristic worm eggs involving hookworm. However, it is difficult to detect it in early stages. The eggs are oval or elliptical in shape. They measure 60 µm by 40 µm and they are colorless and not bile stained. They have a thin transparent hyaline shell membrane. It is difficult to see the adult worms except through endoscopy, surgery or autopsy.

Complications involved in hookworm infection

If the hookworm is left undetected and untreated for a long time that may cause anemia to the patient. In severe cases, it drops down the red blood cell count, which can lead to heart failure. There may be other reasons as well for anemia but hookworms feeding on the blood can be one major factor. A condition known as ascites and nutritional deficiency is caused by hookworm infection.  Ascites is a condition in which there is protein loss and results in fluid buildup in your abdomen. In case of children, the frequent hookworm infection can affect their mental development too because of loss of protein and iron.

Treatment of Hookworm infection

As Hookworm may affect in different areas of human body, so the treatment of hookworm is targeted towards getting rid of the parasites by improving nutrition, and treating complications from anemia. It is necessary to seek medical attention as soon as symptoms related to hookworm are noticed. Medicines like  albendazole (Albenza) and mebendazole (Emverm) may be prescribed by the doctors to get rid of the parasites. It is necessary to take doses of 1-3 days for the medicine to give desired result. If the patient is suffering from anemia because of Hookworm then the doctor may also recommend iron supplement to fulfill the deficiency. If ascites is detected then the doctor will recommend additional amount of protein in diet.

Preventive measures

As it is always said in health sector that “Prevention is better than cure” so it is best that we take care of preventing the illness than rather repenting because of the effects. We can be safe from hookworm if we apply the following measures.

  1. Wearing shoes while walking outdoors, especially in places where there are feces in the soil.
  2. Drink safe and purified water.
  3. The food has to be cleaned and cooked before eating.
  4. Make a habit of properly washing hands.
  5. Sanitation and cleanliness should be adopted in places having chances of hookworm infection
  6. Preventive treatment on high risk groups as children, pregnant women, lactating women and working men at risk can be practiced.
  7. Public health education regarding Hookworm is also important to prevent it.
  8. Deworm pets including cats and dogs at home.
  9.  Defecation in the open should be strictly prohibited. Toilets should be built.
  10. Untreated human excreta or raw sewage should not be used as fertilizer for agriculture purpose.

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