Evidence of possible vertical transmission of duck circovirus

- DuCV-1 and DuCV-2 DNAs were detected from newly hatched ducklings, dead duck embryos and non-embryonated duck eggs.
- Mixed infection of DuCV-1 and DuCV-2 was detected from newly hatched ducklings, dead duck embryos and non-embryonated duck eggs.
- The infection of DuCV-2 was more common than that of DuCV-1 in newly hatched ducklings, duck embryos and eggs.
- This report presents the first evidence of DuCV infection by vertical transmission.

To test the hypothesis that duck circovirus (DuCV) may be vertically transmitted from infected breeder ducks to their ducklings, we investigated 120 newly hatched ducklings, 30 dead duck embryos and 80 non-embryonated duck eggs with the duplex polymerase chain reaction (PCR). DuCV DNA was present in 15 newly hatched ducklings, 4 duck embryos and 3 non-embryonated eggs. Four ducklings from two flocks were co-infected by DuCV-1 and DuCV-2, three ducklings from three flocks were DuCV-1 single infection, and eight ducklings from six flocks were DuCV-2 single infection. One duck embryo and one non-embryonated egg were positive for both DuCV-1 and DuCV-2 DNAs, one embryo for DuCV-1 DNA, and two embryos and two non-embryonated eggs for DuCV-2 DNA. The findings provide evidence of possible vertical transmission of DuCV and simultaneous transmission of DuCV-1 and DuCV-2 from breeder ducks to ducklings.