Hepatitis A viral load in relation to severity of the infection

Abstract A correlation between hepatitis A virus (HAV) genomes and the clinical severity of hepatitis A has not been established. The viral load in sera of hepatitis A patients was examined to determine the possible association between hepatitis A severity and HAV replication. One hundred sixty‐four serum samples from 91 Japanese patients with sporadic hepatitis A, comprising 11 patients with fulminant hepatitis, 10 with severe acute hepatitis, and 70 with self‐limited acute hepatitis, were tested for HAV RNA. The sera included 83 serial samples from 20 patients. Viral load was measured by real‐time RT‐PCR. The detection rates of HAV RNA from fulminant, severe acute, and acute hepatitis were 10/11 (91%), 10/10 (100%), and 55/70 (79%), respectively. Mean values of HAV RNA at admission were 3.48 ± 1.30 logcopies/ml in fulminant, 4.19 ± 1.03 in severe acute, and 2.65 ± 1.64 in acute hepatitis. Patients with severe infection such as fulminant hepatitis and severe acute hepatitis had higher initial viral load than patients with less severe infection ( P  < 0.001). Viremia persisted for 14.2 ± 5.8 days in patients with severe infection and 21.4 ± 10.6 days in those with acute hepatitis after clinical onset ( P  = 0.19). HAV RNA was detectable quantitatively in the majority of the sera of hepatitis A cases during the early convalescent phase by real‐time PCR. Higher initial viral replication was found in severely infected patients. An excessive host immune response might follow, reducing the viral load rapidly as a result of the destruction of large numbers of HAV‐infected hepatocytes, and in turn severe disease might be induced. J. Med. Virol. 83:201–207, 2011. © 2010 Wiley‐Liss, Inc.