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Diseases of the Liver and Biliary System - part 5

Nuốt phải trai nguyên và hàu từ nguồn nước bị ô nhiễm đã gây ra dịch bệnh. Hấp trai không có thể giết chết virus, nhiệt độ đạt được trong trai không đủ cao. Ô nhiễm trong giai đoạn chuẩn bị đã dẫn đến việc truyền tải thông qua các loại thực phẩm khác, bao gồm bánh mì, nước cam | Viral Hepatitis General Features Hepatitis A Hepatitis E and Other Viruses 275 Ingestion of raw clams and oysters from polluted waters has caused epidemics. Steaming the clams may not kill the virus for the temperature achieved inside the clams is not sufficiently high. Contamination during preparation has resulted in transmission via other foods including sandwiches orange juice potato salad and meat. Clinical course The hepatitis is usually mild particularly in children where it is frequently sub-clinical or passed off as gastroenteritis. The disease is more serious and prolonged in adults. Needle liver biopsy in patients with acute type A hepatitis shows a particularly florid portal zone lesion with expansion marked cellular infiltration and erosion of the limiting plate. Cholestasis is marked. It is therefore surprising that hepatitis A infection never leads to ongoing chronic hepatitis or cirrhosis. Fibrin ring granulomas are described 16 . Cholestatic hepatitis A affects adults 7 . The jaundice lasts 42-110 days and itching is severe. Serum IgM anti-HAV is positive. The prognosis is excellent. A case can be made for cutting short the jaundice and relieving the itching by a short course of prednisolone 30 mg reducing to zero over about 3 weeks. The nephrotic syndrome has been reported with immune complex mesangial proliferative glomerulonephritis 25 . Hepatitis A may trigger chronic autoimmune hepatitis type 1 in genetically predisposed individuals 19 . This may be related to defects in T-cell suppressor-inducer cells. Relapsing hepatitis A. Occasionally after 30-90 days the patient relapses. The serum transaminase levels have never returned to normal. The relapse resembles the original attack clinically and biochemically and virus A is found in the stools 18 . The relapse may last several months but recovery eventually ensues 6 . Rarely the relapse can be associated with arthritis vasculitis and cryoglobulinaemia 4 . Prognosis This is excellent and recovery .