Studies highlight Zika-linked neurologic damage – CIDRAP

Two new studies show fatal spinal damage and cognitive impairment associated with Zika infection, while Chinese and American researchers report unsurprising results about the vector competence of the virus in different mosquito species.

Two Brazilian babies who died shortly after birth were found to have severe spinal cord injuries linked to prenatal Zika expose, according to a study published in Clinical Infectious Diseases. In both cases, the mothers reported Zika infection symptoms during the first trimester of pregnancy.

In the first case, a baby boy was born at 36.7 weeks' gestation and died shortly after childbirth. Postmortem autopsy revealed severe deformity of the spinal cord, with a marked loss of boundaries between gray and white matter. Zika RNA was found in the spinal cord but was not detected in the heart, kidney, or sexual organs.

The second case involved another baby boy, born at 37 weeks' gestation, whose mother had confirmed Zka infection after developing a rash and fever in the second month of pregnancy. Autopsy showed extensive brain damage, including damage to the optic nerves and frontal lobes and brainstem atrophy. Zika RNA was found in brain and spinal samples but not in other organs.

The authors say the report is the first to describe the spinal cord damage done by the mosquito-borne virus. While brain damage has been extensively described in literature from Latin America's 2015 Zika outbreak, spinal damage has been less understood by researchers and clinicians. The authors said understanding how the virus attacks the spine could help doctors treat Zika-affected children.

"This diagnosis must be considered in cases where brain damage is insufficient to justify the motor deficit presented by the infant," the authors conclude. "Future studies addressing larger groups of affected children will clarify the importance of spinal cord involvement in the spectrum of neurological lesions of congenital ZIKV syndrome."

In the other study, authors writing in Emerging Infectious Diseases describe a teen who suffered cognitive impairment after traveling to a Zika-endemic region and testing positive.

A teen with a history of mild depression traveled to a Caribbean country in the summer of 2016 and reported several bug bites. Upon returning home to the United States, the teen developed a fever, rash, and headache and tested positive for Zika virus.

Eight days after the first symptoms appeared, the patient began experiencing new and troubling psychiatric symptoms, including increased energy, anxiety, racing thoughts, impulsivity, and rapid speech. The psychiatric symptoms got better but did not resolve during the next 15 weeks, and the patient was treated with antipsychotic medication. During this time, the patient also tested positive for dengue virus.

"Although we cannot prove that the patient's symptoms were related to Zika virus, clinicians should be aware of this potential association and the value of closely monitoring patients with Zika virus infection," the author wrote.

Two other studies published in Emerging Infectious Disease show that the Zika virus could be transmitted via the Aedes albopictus mosquito but not Culex quinquefasciatus mosquitoes. Neither Ae albopictus nor Cx quinquefasciatus were as competent at transmitting Zika as the Ae aegypti, the primary insect vector.

Researchers from both China and the United States were interested in the question of vector competence. In the United States, Ae albopictus could transmit the disease to a farther geographic region than Ae aegypti, a finding that was also true in China.

Studies highlight Zika-linked neurologic damage – CIDRAP

Categories

Archives