A 57‐year‐old man with HIV (CD4 count of 7), not currently on antiretroviral treatment, presented with 2 days of fever and cough. On physical exam, he was found to have fever, tachycardia, and tachypnea with diffuse right lung rhonchii on auscultation. Chest imaging showed dense consolidation of the right upper, middle, and lower lobes. Laboratory studies revealed leukocytosis, acute renal failure, and hyperglycemia. He was empirically started on vancomycin and piperacillin/tazobactam at admission with concern for health care–associated pneumonia. This regimen was changed to levofloxacin once sputum cultures were found to grow Serratia marcescens resistant to piperacillin/tazobactam. Sputum acid‐fast bacilli stains were negative. Because he continued to have fevers over subsequent days, meropenem was added; followed later by the addition of voriconazole for empiric fungal coverage. Slow clinical deterioration continued with worsening hypoxia and renal failure. On day twenty‐one of admission, he developed massive hemoptysis followed by PEA arrest. Attempts at resuscitation were unsuccessful. Postmortem examination identified angioinvasive pulmonary mucormycosis, fungal pulmonary embolism with wedge infarct, and fungal pyelonephritis with microabscesses consistent with a summative diagnosis of disseminated mucormycosis.
Hospitalists frequently encounter patients with fever and pulmonary infiltrates. While clinical presentations of pneumonia are more commonly caused by bacterial or viral etiologies, fungal causes must be considered in some cases in order to initiate effective antimicrobial treatment. Mucormycosis is an invasive fungal infection typically caused by Mucor, Rhizopus, or Absidia, which are all organisms found in the soil. Mucormycosis infection most frequently involves the sinuses, brain, or lungs, although it can also involve the gastrointestinal tract or skin. Severe cases present with disseminated infection. Predisposing factors include: AIDS, diabetes, chronic immunosuppressive therapy, and hematologic malignancy. Diagnosis requires biopsy of the affected tissue because culture swabs are not reliable. Treatment requires amphotericin B along with surgical removal of any “fungus ball.” Signs and symptoms of disseminated mucormycosis include: persistent fever, cough, hemoptysis, nausea, vomiting, and abdominal pain. The associated mortality rate is 90% and unfortunately most definitive diagnoses are made during postmortem examination.
Disseminated mucormycosis is a rare but highly fatal infection that can present as a typical pneumonia. Early clinical suspicion and recognition is needed, especially in immunocompromised patients, so that amphotericin B, the only effective treatment, can be initiated.
To cite this abstract:Larson J. The Antibiotics Are Just Not Helping: An Unusual Organism Masquerading As a Usual Pneumonia. Abstract published at Hospital Medicine 2013, May 16-19, National Harbor, Md. Abstract 369. Journal of Hospital Medicine. 2013; 8 (suppl 2). https://www.shmabstracts.com/abstract/the-antibiotics-are-just-not-helping-an-unusual-organism-masquerading-as-a-usual-pneumonia/. Accessed September 16, 2019.