Prevalence of PBC ranges from 19 to 402 cases/million depending on geographic location, with a 9:1 female preponderance and median ages of diagnosis of 68.5 years for females and 54.5 years for males.At diagnosis, 50% of PBC patients are asymptomatic, indicative of an early stage of disease, while another 50% report fatigue and daytime sleepiness. Other symptoms include pruritus and skin lesions, and in prolonged cholestasis, malabsorption and steatorrhea leading to fat-soluble vitamin deficiency. Disease progression is accompanied by intensifying portal hypertension and hepatosplenomegaly. Clinically, diagnosis generally requires a 1:40 or greater titer of anti-mitochondrial antibody (AMA) against PDC-E2 and elevated alkaline phosphatase persisting for 6+ months.Ursodeoxycholic acid (UDCA) is an FDA-approved first-line treatment for PBC. At moderate doses, UDCA has been demonstrated to slow disease progression and improve transplant-free survival. A complete response is achieved in 25-30% patients, and similar survival as the general population is expected in 2/3 of patients on UDCA. For the 1/3 non-responders, obeticholic acid (OCA) is approved by the FDA as a second-line treatment.The precise etiology of PBC remains poorly understood, though a clearer picture is starting to emerge. A loss of immune tolerance is indicated by the presence of AMAs and autoreactive CD4+ and CD8+ T cells targeting cholangiocytes that line the bile ducts. Cholangiocytes are normally responsible for 40% of bile flow, mostly through secretion of bicarbonate into bile via anion exchanger 2 (AE2) on their apical membrane. The resulting bicarbonate "umbrella" that forms over cholangiocytes provides protection from toxic bile salts.
Other effective agents include tribendimidine and nitazoxanide.About 0.8 to 1.2 billion people globally have ascariasis, with the most heavily affected populations being in sub-Saharan Africa, Latin America, and Asia. This makes ascariasis the most common form of soil-transmitted helminthiasis. As of 2010 it caused about 2,700 deaths a year, down from 3,400 in 1990. Another type of Ascaris infects pigs. Ascariasis is classified as a neglected tropical disease. Signs and symptoms
In populations where worm infections are widespread, it is common to find that most people are infected by a small number of worms, while a small number of people are heavily infected. This is characteristic of many types of worm infections. Those people who are infected with only a small number of worms usually have no symptoms. Migrating larvae
As larval stages travel through the body, they may cause visceral damage, peritonitis and inflammation, enlargement of the liver or spleen, and an inflammation of the lungs. Pulmonary manifestations take place during larval migration and may present as Loefflers syndrome, a transient respiratory illness associated with blood eosinophilia and pulmonary infiltrates with radiographic shadowing. Intestinal blockage
The worms can occasionally cause intestinal blockage when large numbers get tangled into a bolus or they may migrate from the small intestine, which may require surgery. More than 796 A. lumbricoides worms weighing up to 550 g (19 oz) were recovered at autopsy from a two-year-old South African girl. The worms had caused torsion and gangrene of the ileum, which was interpreted as the cause of death.The worms lack teeth.