It has been established that the EDS virus affects only the shell gland, but with ND and IB every portion of the reproductive tract can be affected. If one disease had to be singled out as being responsible for the majority of the economically significant production losses in egg layers, it would have to be infectious bronchitis. Infectious bronchitis virus, a coronavirus, has a preference for the mucus membranes of the respiratory and reproductive tracts. The kidney is also affected by certain IB virus strains. Not only is eggshell quality affected, but internal quality also declines.
Watery whites are very common and can persist for long periods after egg production returns.
Also, an IB outbreak can result in a pale-colored shell in brown shell eggs.