A rare and deadly neurological disease was caused by a pigeon virus in a young leukemia patient, according to a case report published in the journal Clinical Infectious Diseases. The report highlights the importance of metagenomic testing, a technique that can identify unknown pathogens in complex samples.
The patient was a 20-month-old boy who had been diagnosed with acute lymphoblastic leukemia (ALL) and was undergoing chemotherapy. He developed progressive neurological symptoms, such as seizures, weakness, and altered mental status, and was admitted to the hospital. Despite intensive treatment, he died after 11 days.
The cause of his neurological disease was initially unknown, as conventional tests for common viruses, bacteria, and fungi were negative. However, using metagenomic testing, which analyzes the genetic material of all organisms in a sample, the researchers were able to identify a novel virus in the patient’s cerebrospinal fluid (CSF).
The virus was identified as pigeon avian paramyxovirus type 1 (PAPMV-1), a strain of avian paramyxovirus that infects pigeons and other birds. PAPMV-1 can cause respiratory and neurological disease in pigeons, but has never been reported to infect humans before.
How did the virus infect the patient?
The researchers speculated that the patient was exposed to the virus through contact with pigeons or their droppings, as he lived in an urban area with a high density of pigeons. They also suggested that his weakened immune system due to leukemia and chemotherapy made him more susceptible to the virus, which was able to cross the blood-brain barrier and cause inflammation and damage in the brain.
The researchers noted that PAPMV-1 is closely related to other avian paramyxoviruses that have been known to infect humans, such as Newcastle disease virus and avian influenza virus. They also pointed out that other viruses that normally infect animals, such as rabies virus and West Nile virus, can cause fatal neurological disease in humans.
The need for metagenomic testing
The case report demonstrates the value of metagenomic testing in diagnosing rare and emerging infectious diseases, especially in immunocompromised patients who may be vulnerable to unusual pathogens. Metagenomic testing can provide rapid and comprehensive results, which can help guide appropriate treatment and prevent further transmission.
The researchers also emphasized the need for more surveillance and research on the potential zoonotic transmission of avian paramyxoviruses, as they may pose a public health threat in the future. They urged clinicians to consider these viruses as possible causes of neurological disease in patients with exposure to birds or bird products.