Localized Pulmonary Nocardia farcinica Infection As the Presenting Symptom of Acquired Immunodeficiency Syndrome

Nocardiosis is an opportunistic infection that most commonly affects immunocompromised patients, with clinical presentations ranging from localized to disseminated disease. In the United States, the reported incidence is approximately 500 to 1,000 cases per year, with an observed male-to-female predominance of 3:1. We present the case of a 37-year-old male with a past medical history of malaria who presented with watery, non-bloody diarrhea for four days associated with a fever for two weeks. The human immunodeficiency virus (HIV) was positive in the emergency room before admission. Computerized tomography (CT) of the chest with contrast revealed an irregular pleural base mass in the right lower lobe with several small air foci. CT of the abdomen and pelvis revealed the right pleural base lung mass to be adherent to the diaphragm, as well as mild splenomegaly. The cluster of differentiation 4 (CD4) count was 9 cells/mm3. An acid-fast bacilli (AFB) sputum culture was positive for Nocardia farcinica. Trimethoprim-sulfamethoxazole was started for a Nocardia farcinica pulmonary infection, in addition to antiretroviral therapy. The patient was strongly encouraged to follow-up at the outpatient department.