Duck hepatitis A virus prevalence in mainland China between 2009 and 2021: A systematic review and meta-analysis

Duck hepatitis A virus (DHAV) is a single-strand positive-sense small RNA virus that causes high mortality in ducklings. In recent years, the incidence of DHAV-3 subtype has been increasing in China, leading to great economic losses to the duck-breeding industry. We investigated the incidence and mortality rates of DHAV in ducks and analysed the seroprevalence of DHAV in mainland China, by meta-analysis. Twenty-six studies published between 2009 and 2021 were retrieved, with a total of 689,549 cases from 14 provinces. Using the DerSimonian-Laird model, DHAV prevalence was estimated with the variance-stabilizing double arcsine transformation. The incidence of DHAV in mainland China was 12 % (95 % confidence interval [CI]: 3-20 %), and the mortality rate was 11 % (95 % CI: 2-19 %), suggesting that the virus was highly virulent and mortality was high. Time analysis showed that DHAV incidence decreased over time. The typing survey showed that strains of DHAV-1 serotype accounted for 38 % (95 % CI: 21-56 %) and strains of DHAV-3 serotype accounted for 49 % (95 % CI: 31-68%) of the tested samples. The decline in the detection rate of DHAV-1 may be due to the widespread use of the DHAV-1 vaccine, which has effectively controlled the DHAV-1 serotype virus. The DHAV-3 vaccine has been on the market for a short time and has no cross protection with DHAV-1, so DHAV-3 accounted for a high proportion of the tested samples. Subgroup analysis of the detection methods showed little difference between PCR and other detection methods.