If Zika virus is responsible for microcephaly, which seems likely, this is a serious neurological consequence of the infection in pregnant women.
The Zika virus is starting to cause a great deal of substantiated fear among travelers and pregnant women. A mosquito borne illness, the virus causes mild to moderate symptoms in individuals who have active infection, including a self-limited fever, rash, conjunctivitis, and arthralgias. A blood serum sample can be used to identify the virus, and, according to the CDC website, “There are no commercially available diagnostic tests for Zika virus disease. Zika virus testing is performed at the CDC Arbovirus Diagnostic Laboratory and a few state health departments.”
The current crisis is based on the observation that there has recently been a statistical association between an increase in cases of identified Zika virus infection with a significant increase in babies born with microcephaly, particularly in Brazil. If Zika virus is responsible for the development of microcephaly, which at this point appears highly likely, this is a serious neurological consequence of Zika virus infection in pregnant women. There is no cure for fetal and infantile microcephaly, making Zika virus a major public health concern.
The role of the neurologist in managing Zika virus
Besides limited reports of possible Guillain-Barre syndrome, there had not been a recognized association of Zika virus with neurologic sequelae until 2015. The role of the neurologist in the disease cycle of Zika virus lies in management of the pediatric complications. The neurologist must direct the clinical care of a patient who has a recognized condition (microcephaly) of a new etiology (Zika virus). The prognosis of microcephaly is not good. Furthermore, the neurologic course of babies who were infected with Zika virus in utero may differ from other babies with microcephaly if there are specific areas of the central nervous system further targeted by the virus.
Besides neurologic testing and management of physical and cognitive deficits, there are not any current antimicrobial or anti-inflammatory approaches to the care of fetuses of mothers infected with the virus, for babies born with microcephaly, or for adults who test positive for the virus. The treatment for active Zika virus infection consists of symptomatic treatment and supportive care.
At the current time, the exact mechanism of how the virus affects the brain development of the fetus is not understood, as the conclusion that the virus plays a role in the development of microcephaly is based on observations of the dramatic increase in babies born with microcephaly in areas of Brazil that have suddenly reached a high incidence of Zika virus infection. After this association was noted, several babies with microcephaly have tested positive for the virus.
Since the situation has been identified, the geographic region in which Zika virus has been recognized has widened, and babies outside of Brazil have been found to have the combination of microcephaly and a positive serum or amniotic fluid test for Zika virus. Thus, neurologists should be more aware of the possibility of Zika virus infection in babies who might fall outside of the noted geographic regions.
What criteria do you think is appropriate for testing pregnant women for Zika virus?
Oliveira Melo AS, et al. Zika virus intrauterine infection causes fetal brain abnormality and microcephaly: tip of the iceberg? Ultrasound Obstet Gynecol. 2016 Jan;47(1):6-7.
Interim Guidelines for Pregnant Women During a Zika Virus Outbreak - United States, 2016. Centers for Disease Control and Prevention. January 2016. http://www.cdc.gov/mmwr/volumes/65/wr/mm6502e1.htm