For a virus that - until very recently - was considered too innocuous to merit serious study, the Zika virus is developing some serious street creds. How much of its reputation is truly deserved remains a matter of some debate, but for now Zika's resumé continues to expand.
- Our first clue came two years ago, when an outbreak in the South Pacific appeared to have sparked an unusual number of neurological disorders (see Zika, Dengue & Unusual Rates Of Guillain Barre Syndrome In French Polynesia).
- In October of 2015, Brazil - roughly six months into their first Zika outbreak - noticed a sudden spike in Microcephalic births, leading the WHO to declare a public health emergency 5 weeks ago (see WHO: Zika Virus & Microcephaly Constitute A PHEIC (Public Health Emergency).
- We continue to see increases in Guillain Barre Syndrome (GBS) in the Americas (see WHO Risk Assessment On Guillain-Barré Syndrome & The Zika Virus), and in the past week two additional neurological disorders have been linked to Zika virus infection.
A week ago, The Lancet carried a short report on a 15 year old girl from Pointe-à-Pitre, Guadeloupe, with left hemiparesis (see Acute myelitis due to Zika virus infection), lower back pain, and other neurological deficits. On her second day in the hospital they discovered she had high levels of Zika virus in her serum, urine, and cerebrospinal fluid.
After ruling out other infectious causes, her doctors determined her Myelitis (spinal cord inflammation) was likely due to her Zika virus infection.
Yesterday the NEJM carried a correspondence, this time concerning an 81 y.o. male who after a cruise in the South Pacific, was hospitalized in a comatose state (GCS 6), with hemiparesis, and in need of mechanical ventilation.
The patient spent the first 2 of his 17 days in ICU on a ventilator, and was found to have both Zika virus infection, and his MRI was suggestive of meningoencephalitis, leading the authors to warn: Clinicians should be aware that ZIKV may be associated with meningoencephalitis.
You can read the full report at the link below:
Zika Virus Associated with Meningoencephalitis
March 9, 2016DOI: 10.1056/NEJMc1602964
While both studies are suggestive of a link between Zika virus infection and neurological disorders, neither conclusively prove causality. They do fit in with the GBS/Microcephaly pattern we've been watching, and raise additional concerns.
The NEJM also published a perspective on Zika's suspected neurotropic affinity in:
PerspectiveMarch 9, 2016DOI: 10.1056/NEJMp1602708
Even with limited evidence linking Zika virus to neurologic disorders, the severe potential risks demand decisive, immediate action to protect public health. The WHO recommends applying key interventions such as intensive mosquito control; personal protection against mosquito bites; provision of appropriate clinical care for all patients with Guillain–Barré syndrome and for women before, during, and after pregnancy; and prevention of Zika virus transmission through sexual contact or blood transfusion.4 Most of these are not new interventions, but they do need strengthening. Populations must be informed of the potential current and future risks of neurologic disorders, wherever the virus is being or could be locally transmitted and in other regions inhabited by the mosquito vectors. As the putative link between Zika virus and neurologic disorders is reinforced, refined, or even refuted, public health measures will be adjusted accordingly.