Ascariasis is prevalent worldwide, especially in tropical and subtropical countries. The ascariasis pathogen in humans, Ascaris lumbricoides is a roundworm of the Nematoda phylum. Adult ascaris (...)
Ascariasis is prevalent worldwide, especially in tropical and subtropical countries. The ascariasis pathogen in humans, Ascaris lumbricoides is a roundworm of the Nematoda phylum. Adult ascaris parasitizes in the small intestine, has a length of 15-40 cm, a diameter of 5 mm, and produces 200,000 eggs per day.
Infections happen when a human swallows water or food contaminated with eggs, which hatch into juveniles in the duodenum and enters the blood stream. From there, it is carried to the liver and heart, and enters pulmonary circulation to break free in the alveoli, where it grows and molts. In three weeks, the larva passes from the respiratory system to be coughed up, swallowed, and thus returned to the small intestine, where it matures to an adult male or female worm.
Often, no symptoms are seen with an A. lumbricoides infection. However, in the case of a particularly severe infection, symptoms may include bloody sputum, cough, fever, abdominal discomfort, intestinal ulcer, and passing worms. Ascariasis is also the most common cause of Löffler’s syndrome worldwide. Accompanying symptoms include pulmonary infiltration, and eosinophilia.
The presence of an infection may be identified by:
microscopy: detection of eggs in feces; serology: detection of antibodies by ELISA.
Most diagnoses are made by identifying the appearance of the worm or eggs in feces. This method is effective when the adult roundworms parasite in the intestine. During the larvae migration the efficiency of ascariasis diagnosis can be increased with ELISA for the detection of antibodies to helminth antigens. The results of the serological analysis coupled with anamnesis and clinical symptoms facilitate diagnosis of the Ascaris invasion at the early stages and enable to begin the therapy before complications of the disease appear.