Ascariasis

It is a common intestinal disease caused by Round worm ( Ascaris lumbricoides). The worm lives in the intestine and causes a number of disorders.

Occurrence: It is a common disease found throughout world. However, more frequent in tropical countries. It is more common among children than in adults. It is most common in persons with unhygienic habits.

Causative organism: The causative organism is Ascaris lumbricoides.

Reservoir and source of infection: The reservoir is an infected person who discharges eggs in faecal matter. The soil and water containing the embryonated eggs are also the source of infection.

Mode of transmission: A healthier person is infected by direct or indirect transmission of embryonated eggs from soil or contaminated food/drinks to mouth. The embryonation takes about one month after the release of eggs. The contaminated food, drinks, raw fruits and vegetables, dirty fingers are main cause for infection. The flies also play role to contaminate food and drinks.

·         After ingestion the embryonated eggs pass into intestine where they hatch into larvae. The larva penetrates the wall of intestine and undergoes a course of circulation by blood and lymph. The larva reach the liver then to heart and then to lungs. In lungs, larva penetrates the wall of alveoli and come into alveoli. From alveoli they ascend up into trachea and come into buccal cavity and are swallowed and again come into intestine. Some larva may come out through mouth and nose from buccal cavity. In intestine they grow up to maturity. The mature female lays about 2000000 eggs each day and the eggs are passed out along with faeces. About 500 to 5000 adult worms may be present in the intestine of a host.

Incubation period: It is of about two months.

Symptoms: 

·          Abdominal discomfort and pain.

·         Indigestion, Diarrhoea, Vomiting and slight fever.

·         Bleeding and inflammation in lungs.

·         Weight loss, anaemia and weakness.

·         Appendicitis or blockage of intestine due to large number of worms.

Diagnosis: The diagnosis is done by identification of eggs in faeces; stool test.

Preventive methods:  The preventive methods are:

·         Mass education to use toilet, wash hands with soap water after defecation and before eating.

·         Contaminated food and drinks should be avoided.

·         Proper disposal of faecal matter of infected persons.

·         Raw fruits and vegetables should be sterilized before eating.

·         Protection of water supply from sewage contaminaton.

Treatment: The anti-helminthic drugs like piperazine, mebendazole, alcopar etc. are effective for the treatment of ascariasis.