Saturday, March 2, 2013

Ascaris Lumbricoides

The answer to yesterday's Image Challenge was #1 - Ascariasis

Ascaris lumbricoides worms were causing intestinal obstruction in this child from Kenya.  After the intestine blockage was removed, the child recovered.

Ascariasis is a disease caused by roundworms.  The parasite, Ascaris lumbricoides  is one of the most common infections in the world and it affects up to one fourth of the worlds population and up to 95% of Africans are infected with roundworms at any time.   The life-cycle of this parasite is amazing.

Infection starts when food contaminated with Ascaris eggs from feces are swallowed.  the larvae hatch in the intestine, burrow through the gut wall and migrate to the lungs through the blood system.  They then pass through the alveoli, up the trachea and esophagus where they are coughed up and swallowed.  They then pass through to the stomach for a 2nd time into the intestine where they mature into adult worms,  Adult worms have a life-span of 1-2 years.

The adult worm can be from 6-13 inches and the female worm may be as thick as a pencil.  Up to 100 worms could potentially infect the human body.

A person could be infected with Ascaris lumbricoides and have no symptoms.  In heavy infections symptoms may be vague abdominal pain, coughing, wheezing or pneumonia when they are in the lungs, or complete blockage of the small intestine.

Diagnosis can be difficult until the worms are adults, but stool samples showing eggs or live worms will make the diagnosis.  Treatment with mebendazole, albendazole, or pyrantel pamoate are effective to eradicate infection but where there is poor sanitation, re-infection is common. 

When we see these gross pics, it is hard to believe that this infection is so common in the world.  Remember that over 40% of the world's population does not have  good sanitation.  That is 2.5 billion people and women in developing countries walk an average of 6.5 kilometers ( almost 4 miles ) each day just to get water.


Anonymous said...

That is amazingly gross. Hard to believe that the infestation is so widespread too. You come up with such interesting material, Dr. Brayer.

Cary McNeal said...

All that was inside a child's intestine? OY. He must feel a LOT better now. No more spaghetti for you, kid.