To B or not to B: how the hepatitis B surveillance case definition can misdirect public health actions.

Abstract: Surveillance case definitions are utilised to understand the epidemiology of communicable diseases and to inform public health actions. We report a case of hepatitis B infection that meets the case definition for newly acquired infection. However, further investigation revealed that this was most likely past resolved hepatitis B infection with subsequent reactivation secondary to immunosuppression, rather than a newly acquired infection. This case highlights the importance of thorough case and clinician interviews, in combination with detailed assessment of pathology results in collaboration with treating clinicians, to determine the most appropriate public health actions.