Haemophilus influenzae infection of a prosthetic knee joint in a patient with CLL: a vaccine preventable disease.

A 71-year-old man was admitted with a 2-day history of the hot and swollen right knee in December 2012. He had undergone a primary cemented right total knee replacement (TKR) in 2002. He also had a history of chronic lymphatic leukaemia (CLL), haemolytic anaemia and splenomegaly, and was in partial remission following chemotherapy in 2008. He underwent arthroscopic washout of right TKR on admission. Blood cultures on admission and joint fluid specimen grew Haemophilus influenzae (Hi). The isolate was identified as a non-encapsulated Hi strain by the reference laboratory. Non-encapsulated Hi strains rarely cause invasive disease. CLL with splenomegaly may have predisposed our patient to severe invasive disease. A recently licensed 10-valent pneumococcal vaccine conjugated to the immunogenic outer membrane protein D of Hi could potentially prevent invasive Hi disease. Routine vaccination should be considered in all patients with prosthetic joints and predisposing comorbidities.