An RNA virus, designated hepatitis G virus (HGV), was identified from the plasma of a patient with chronic hepatitis. Extension from an immunoreactive complementary DNA clone yielded the entire genome (9392 nucleotides) encoding a polyprotein of 2873 amino acids. The virus is closely related to GB virus C (GBV-C) and distantly related to hepatitis C virus, GBV-A, and GBV-B. HGV was associated with acute and chronic hepatitis. Persistent viremia was detected for up to 9 years in patients with hepatitis. The virus is transfusion-transmissible. It has a global distribution and is present within the volunteer blood donor population in the United States.

Thi-hiuW~ been QVPpoe i 1.f It~iI~l sj EPIDEMIOLOGY OF HEPATITIS B L5'_ibvti&~ ~__'i~at.4IN THE GEZIRA REGION OF SUDAN

A bibliographic search was conducted of English-language articles dealing with chronic hepatitis B virus (HBV) infection to evaluate the risk of chronicity following acute infection. Chronic HBV infection was defined as carriage of hepatitis B surface antigen (HBsAg) for at least 6 months. On the basis of incidence studies employing standard serological test methods, the highest risk (80%-90%) of chronic infection was found to be among infected neonates born to hepatitis B e antigen-positive carrier mothers. Of children infected before 6 years of age, chronic infection was reported to develop in approximately 30%. A relatively wide range of risks (< 1%-12%) was found among diverse populations of older children and adults. However, most of the 10 identified incidence studies of generally healthy adults indicated that the risk of chronicity is very low: < or = 5% in eight studies. In addition, the pooled incidence of chronicity was < 5% among two different adult population groups: initially uninfected subjects, who usually experienced asymptomatic infection, and patients presenting with acute hepatitis B. In addition to the primary influence of age, the studies revealed a higher risk of chronic HBV infection among males and among patients with impaired immunity due to various causes.

Until we can better understand what constitutes health and illness in all adult populations, we risk repeated occurrences of unexplained symptoms among veterans after each war.

Gastroenteritis caused by enterotoxigenic E. coli and shigella resistant to a number of drugs was a major problem that frequently interfered with the duties of U.S. troops during Operation Desert Shield.