The World Health Organization (WHO) reported Monday on a case of Guillain-Barre syndrome (GBS) with confirmed Zika virus infection in the United States.

Aedes aegypti/CDC
Aedes aegypti/CDC

According to the UN agency, the case is an elderly male resident of the United States with recent travel to Central America. He developed an acute febrile illness shortly after returning to the U.S. and was subsequently hospitalized in January with progressive ascending weakness of the extremities and diminished reflexes.

The patient tested positive for Zika virus infection by polymerase chain reaction (PCR). He improved following treatment and was ready to be discharged. However, he experienced a sudden subarachnoid haemorrhage due to a ruptured aneurysm and died.

In addition, a second case in an adult male resident of Haiti who experienced an acute onset of facial weakness, difficulty swallowing, and numbness of fingers in early January. No antecedent illness was reported. A few days later, he traveled to the United States for additional medical care. Cerebrospinal fluid had elevated protein and normal white blood cells. Physical examination showed mild weakness and diminished reflexes. The patient tested positive for Zika virus infection by serology. He improved with intravenous immunoglobulin therapy and was discharged.

According to WHO, to date, a total of 9 countries or territories have reported an increased incidence of GBS and/or laboratory confirmation of Zika virus infection among GBS cases. This is the first time that a country with no vector borne transmission of Zika virus detects patients with concomitant GBS and Zika virus infection.