Delta hepatitis in Lebanon. Prevalence studies and a report on six siblings with chronic delta-positive active hepatitis.

The prevalence of delta infection in Lebanon is reported for the first time. Delta antigen and antibody were screened for in serum of 43 patients consecutively seen in hospital, 22 with acute hepatitis B (anti-HBc IgM-positive), and 21 with histological evidence of chronic active hepatitis, 6 of whom were brothers in a sibship of eleven. Twenty asymptomatic HBsAg carriers without clinical or biochemical evidence of liver disease were similarly studied. None of the asymptomatic carriers or acute hepatitis B patients had markers of delta infection. In contrast, delta antibody in high titre (greater than 1:5000) was found in 12 (57%) of the patients with chronic active hepatitis, including all six brothers. Five sisters in the sibship were anti-HBs-positive without evidence of liver disease, suggesting a horizontal mode of transmission of the delta virus, as a superinfection on a hepatitis B carrier state. Excluding the sibship, delta infection was present in 6 of 15 (40%) chronic active hepatitis patients. This prevalence is similar to other Middle Eastern countries. Delta infection was associated with severe liver disease.