Clinical Manifestations, Diagnosis, Treatment, and Control
Symptoms of ascariasis vary widely. As is often true for helminthic infections, low worm loads may cause few or no symptoms. Large numbers of larvae in the lungs may produce ascaris pneumonitis, with symptoms resembling pneumonia.
Allergic reactions can cause asthma attacks. Larvae can reach atypical (ectopic) sites such as the brain, eye, or kidney, where they may produce grave, life-threatening conditions, but such events are fortunately rare. Adult worms in the intestine can cause fever, abdominal discomfort, diarrhea, and allergic reactions to their proteins. Fever may induce worms to wander to the larynx, where they can cause suffocation, or to exit the mouth or nostrils. Heavy infections rob the host of nutrients, and tangled masses of worms can result in fatal intestinal obstruction if not treated promptly. Intestinal ascariasis is especially serious in young children. A study in Kenya showed that ascariasis produced signs of protein-energy malnutrition in many children and often retarded their growth; similar results have been reported from other Third World countries. Even if severe effects occur in only a small percentage of cases, the ubiquity of the worm makes it an important cause of morbidity in many countries.Diagnosis is made by detecting eggs in microscopic examination of the feces. Drug treatment is usually safe and effective, but care must be taken to keep the adult worms from wandering about in response to therapy. Intestinal obstruction is treated by inducing vomiting or by surgery. Preventive measures include sanitary latrines, composting feces to be used as fertilizer, and careful washing of fruits and vegetables that are eaten raw. Mass treatment may also reduce the danger of continued reinfection.
K. David Patterson