Delta virus infection in Egypt.

The present study was carried out on 124 serum samples of acute hepatitis B, 51 with chronic HBV infection, and 41 chronic HBsAg carriers. Sera were tested by ELISA for HBV markers and anti-delta (anti-HDV). Delta infection (anti-HDV) in acute HB was found to be 16.9% (21 out of 124), 23.5% in chronic HB cases (12 out of 51), and 21.9% among chronic HBsAg carriers (9 out of 41). Out of the twelve delta positive in chronic HB patients, ten (83%) were suffering from CAH (chronic active hepatitis) denoting a possible role of delta infection in deteriorating the course of the disease. A competitive inhibition of HBV replication by coexistent delta infection was demonstrated in the present study. This was reflected on anti-HBc IgM in the acute cases and on HBeAg in chronic HB cases. Anti-HBc IgM was 71.42% (15 out of 21) in delta positive acute HB patients versus 92.23% (95 out of 103) in delta negative acute HB patients. On the other hand, HBeAg percentage was 8.33% (1 out of 12) and 46.15% (18 out of 39) in delta and non-delta chronic HB patients respectively. The difference in both anti-HBc IgM and HBeAg as regards delta positive and negative patients was found to be statistically significant. Out of the twelve chronic HB cases with delta infection, four cases were negative for HBsAg (33.33%). This observation might be attributed to the clearance effect of hepatitis D virus (HDV) on HBsAg (Ischimura et al., 1988) or due to suppressing effect resulting in low undetectable HBsAg level in serum, (Sherlock, 1989). From the present study it may be concluded that delta infection is endemic in Egypt (its incidence ranged from 16.94% in acute HB to 23.53% in chronic HB infection), delta infection possibly also worsens the outcome of chronic HB patients. Delta infection may exert a competitive inhibitory effect on HBV replication.