Intestinal Nematodes Infaction ASCARIS LUMBRICOIDES

Ascaris lumbricoides is a species of Ascaris that lives in the human intestine and adults may grow to 12 in. long. Eggs are passed with the feces and require at least 2 weeks’ incubation in the soil before they become infective Ascaris lumbricoides, an intestinal roundworm, is one of the most common helminthic human infections worldwide.

Intestinal Nematodes Infaction ASCARISLUMBRICOIDES

• It is estimated that more than 1.4 billion people are infected with A. lumbricoides, representing 25 percent of the world population.
• The highest prevalence of ascariasis occurs in tropical countries where warm, wet climates provide environmental conditions that favor year-round transmission of infection.
• This contrasts to the situation in dry areas where transmission is seasonal, occurring predominantly during the rainy months

ASCARIS LUMBRICOIDES is found worldwide.

• Transmission is enhanced by the fact that individuals can be asymptomatically infected and can continue to shed eggs for years, yet prior infection does not confer protective immunity
• Infective stage is egg.
• Route of infection is oral.
• The gastrointestinal location of worms is small intes­tine.
• In a 1- to 2-year life span, the female is capable of producing 200,000 eggs per day.
• The eggs are passed with the feces, and a new cycle is started.
• Children up to the ages of 12 to 14 are likely to be infected.
• Adult worm size is 20 – 40 cm.
• The worm passes through the lungs also.
• Intestinal obstruction may be a complication in children under 6 years of age.

Nematodes ASCARIS LUMBRICOIDES

Incubation period of Nematodes ASCARIS

• Transmission occurs mainly via ingestion of water or food (raw vegetables or fruit in particular) contaminated with A. lumbricoides eggs and occasionally via inhalation of contaminated dust.
• When infections with only female worms occurs, infertile eggs that do not develop into the infectious stage are produced.
• With male-only worm infections, no eggs are formed.
• · 65 – 70 days and may survive for one year.
• Larvae usually reach the lungs by four days after ingestion of eggs.
• Within the alveoli of the lungs, the larvae mature over a period of approximately 10 days,
• · Principal symptoms are gastrointestinal and biliaryobstruction.

Nematodes ASCARIS LUMBRICOIDES Life Cycle

CLINICAL FEATURES —

• Direct tissue damage The immunologic response of the host to infection with larvae, eggs or adult worms ,
• Pulmonary and hypersensitivity
• manifestations Intestinal symptoms Intestinal obstruction
• Hepatobiliary and pancreatic symptoms
• Obstruction of an orifice or the lumen of the gastrointestinal tract by an aggregation of worms

Diagnosis of Nematodes ASCARIS

• • By examination of eggs in the stool.

Treatment of Nematodes ASCARIS

• The mainstays of treatment are the benzimidazoles mebendazole and albendazole.
• Mebendazole (100 mg BID for 3 days or 500 mg as a single dose) is an alternative
• A single dose of albendazole (400 mg) is effective in almost 100 percent of cases, although reinfection commonly occurs,
• a single does of either 400 mg albendazole or 200 mcg/kg ivermectin showed similar cure rates (70 percent versus 78 percent) and egg reduction rates (93 percent versus 94 percent) for both therapies,
• However, they should not be given during pregnancy because of possible teratogenic effects; pyrantel pamoate should be used in pregnancy.
• Mebendazole,
• Albendazole,
• Pyrantel pamoate.