Pathology and life cycle

Pathology and life cycle

The fertilised eggs can survive in a hostile environment for a long time. The hot and humid conditions in the tropics are ideally suited for the eggs to turn into embryos. The fertilised eggs are present in soil contaminated with infected faeces, becoming infective in about 3 weeks. Faecal–oral contamina tion causes human infection. The eggs are ingested and the larvae are released in the jejunum, from where they travel to the liver via the portal sys tem and the lymphatics. The larvae reach the lungs via the sys temic circulation, where they undergo maturation for 2 weeks. The developed larvae reach the alveoli, are coughed up, swallowed and continue their maturation in the small intestine. Sometimes, the young worms migrate from the tracheobron c hial tree into the oesophagus, thus finding their way into the gastrointestinal tract, from where they can migrate to the mon bile duct or pancreatic duct. The mature female, once in the small bowel, produces innumerable eggs that are fertilised and thereafter excreted in the stool to perpetuate the life cycle. Eg gs in the biliary tract can form a nidus for a stone. Pathology and life cycle

The fertilised eggs can survive in a hostile environment for a long time. The hot and humid conditions in the tropics are ideally suited for the eggs to turn into embryos. The fertilised eggs are present in soil contaminated with infected faeces, becoming infective in about 3 weeks. Faecal–oral contamina tion causes human infection. The eggs are ingested and the larvae are released in the jejunum, from where they travel to the liver via the portal sys tem and the lymphatics. The larvae reach the lungs via the sys temic circulation, where they undergo maturation for 2 weeks. The developed larvae reach the alveoli, are coughed up, swallowed and continue their maturation in the small intestine. Sometimes, the young worms migrate from the tracheobron c hial tree into the oesophagus, thus finding their way into the gastrointestinal tract, from where they can migrate to the mon bile duct or pancreatic duct. The mature female, once in the small bowel, produces innumerable eggs that are fertilised and thereafter excreted in the stool to perpetuate the life cycle. Eg gs in the biliary tract can form a nidus for a stone. Pathology and life cycle

The fertilised eggs can survive in a hostile environment for a long time. The hot and humid conditions in the tropics are ideally suited for the eggs to turn into embryos. The fertilised eggs are present in soil contaminated with infected faeces, becoming infective in about 3 weeks. Faecal–oral contamina tion causes human infection. The eggs are ingested and the larvae are released in the jejunum, from where they travel to the liver via the portal sys tem and the lymphatics. The larvae reach the lungs via the sys temic circulation, where they undergo maturation for 2 weeks. The developed larvae reach the alveoli, are coughed up, swallowed and continue their maturation in the small intestine. Sometimes, the young worms migrate from the tracheobron c hial tree into the oesophagus, thus finding their way into the gastrointestinal tract, from where they can migrate to the mon bile duct or pancreatic duct. The mature female, once in the small bowel, produces innumerable eggs that are fertilised and thereafter excreted in the stool to perpetuate the life cycle. Eg gs in the biliary tract can form a nidus for a stone.