John (not real name), a 50-year-old man, started to feel weak gradually for a couple of days. On examination, he was found to have moderate anaemia, that is, a deficiency of haemoglobin. It is unusual for a middle-aged man to be anaemic, hence, further tests were done and when his stool examination results were revealed, he had a hookworm infestation.
Hookworm infestation continues to be a major cause of chronic anaemia and deaths in developing tropical countries. It is a parasite affecting the health of some animals like cats and dogs, and also humans. The eggs stay and hatch in warm sandy soils.
In a person walking barefoot, larvae can penetrate the bare skin through hooks present on the mouth—hence, its name. They grow into adult worms inside the human body and pass through blood vessels to the lungs and windpipe from where they are swallowed.
On reaching the intestines, they suck blood vigorously through the inner lining where they can remain for months to years. This results in chronic blood loss leading to weakness in the affected individual. Eggs are passed in the faeces of the infected person, where they hatch, and another individual can be affected.
Chronic blood loss reduces the resistance of the body, making it more susceptible to infections. Women suffer more because they are more prone to anaemia for other reasons. Co-infection with malaria and hookworm in individuals in tropical developing countries adds to sickness and death among individuals.
It is an occupational hazard for persons working in fields. Infection is maintained in the environment due to ignorance and lack of protective measures among people.
Hookworm infestation causes itching and allergic reactions at the site of infestation. As the larvae reach the lungs, one may have a dry cough. After reaching the intestines and getting embedded in the intestinal mucosa, they cause abdominal discomfort, pain and nausea.
Due to the sucking of the blood by the parasites, one gradually becomes anaemic and malnourished.
During pregnancy, hookworm infestation can cause miscarriage and intrauterine growth retardation. Studies have shown hookworm infection to be passed on in breast milk from affected mother to child due to hormonal changes occurring during delivery.
This is the reason for babies as young as a month old to be infected by hookworm and die. Children with hookworm infestation are known to suffer from intellectual impairment and growth retardation. Thus, it is a problem for the entire community, affecting the present as well as future generations.
A person is not even aware of the infested state unless they become very sick due to the resultant anaemia. Blood tests done may reveal a high percentage of the type of white blood cells indicating allergy, which gives a clue to the parasitic infection. Diagnosis is confirmed by seeing the typical eggs in the stool of the affected person. Treatment is by anthelmintic drugs.
Mass awareness about hookworm infestation and preventive measures can bring down the burden of sickness caused due to hookworm. People working in fields should be advised to wear thick shoes. Defecation in open fields should be discouraged. Night soil should not be used for manure for crops and vegetables. Regular deworming of pet animals also helps to prevent some types of hookworm infestation which can spread from dogs to human beings.
In Rwanda, deworming of school children is very useful in preventing parasitic infestations, including hookworm.
The soil of any area suspected to be contaminated with eggs and larvae of hookworm can be treated with borax powder or brine solution (1.5 pounds of salt/gallon of water) to eradicate hookworms.
Dr Rachna Pande is a specialist in internal medicine.