A case report published in Pediatrics recently detailed the illness of a girl aged 12 years with leukemia who developed hyperammonemic encephalopathy resulting from Ureaplasma parvum. Researchers suggested that although the invasive infection is rare, providers should consider it in immunocompromised children with unexplained hyperammonemia.
Jonathan Crews, MD, MS, an assistant professor of pediatrics at Baylor College of Medicine, told Infectious Diseases in Children that this is the first published report of a child with idiopathic hyperammonemia resulting from disseminated Ureaplasma infection.
“Idiopathic hyperammonemia is an entity described in pediatric oncology patients that has a high mortality rate,” he said.
The patient underwent maintenance chemotherapy for T-cell acute lymphoblastic leukemia that was in remission. She was later diagnosed with treatment-associated acute myeloid leukemia and was hospitalized so she could receive induction chemotherapy.
After failure to achieve remission by hospital day 64, the patient developed several episodes of fever for which she was prescribed short courses of empirical broad-spectrum antibiotics.
Crews and colleagues wrote that the patient began cefepime after a new fever developed on hospital day 62. By hospital day 68, she appeared confused and had difficulty answering questions and progressed to excessive sleepiness and became difficult to wake.
At this time, her ammonia level exceeded the lab’s upper level of detection (>1,609 µmol/L; reference range = 18-72 µmol/L).
Blood and urine samples were sent the next day for PCR testing for Ureaplasma and Mycoplasma species, and doxycycline was added to her treatment. U. parvum was identified in both blood and urine samples. After adding azithromycin and levofloxacin to her treatment, her blood ammonia levels decreased to 265 µmol/L. The child was extubated by day 76 and was speaking appropriately.
“This case is an important reminder to obtain an ammonia level when a patient has a sudden decline in their mental status,” Crews said. “The case also supports testing for Ureaplasma infection in children with unexplained hyperammonemia, particularly in immunocompromised patients. Since the organism cannot grow using routine cultures, clinicians should order PCR studies from blood, urine and respiratory specimens when considering hyperammonemia from Ureaplasma.” – by Katherine Bortz
Disclosures: The authors report no relevant financial disclosures.