Nocardia beijingensis pericarditis presenting with cardiac tamponade: A case report.

We report the first case of Nocardia beijingensis pericarditis in a 32-year-old HIV-infected patient. He presented with cardiac tamponade after failing to respond to treatment for smear-negative pulmonary and pericardial tuberculosis (TB). The pericardial fluid was examined several times before it eventually revealed filamentous branching organisms in Gram and modified acid-fast bacilli stain. The culture grew Nocardia spp. and was identified by 16s rRNA sequencing as N. beijingensis. Eight previously reported cases of Nocardia pericarditis in HIV-infected patients were caused by Nocardia asteroides. All patients had low CD4 cell count (range: 17-239 cells/mm3) and 50% of patients were treated for tuberculous pericarditis prior to making the correct diagnosis of Nocardia pericarditis. This report revisits the issue of nocardiosis as a great TB mimicker. It should always be considered in the differential diagnosis among HIV-infected patients suspected of having pericardial TB that is failing treatment.