Unusual adenovirus infection Unusual cystitis Unusual hemorrhagic cystitis Increased susceptibility to haemorrhagic cystitis, as manifested by recurrent or severe bladder infection with frank haematuria caused by viral or other atypical organisms. Its occurrence is inherently unusual and can indicate significant immune deficiency. Haemorrhagic cystitis in the context of inborn errors of immunity is predominantly caused by adenovirus and BK polyomavirus, and is a characteristic complication of severe T-cell deficiency and combined immunodeficiency. Unusual haemorrhagic cystitis