23 Sep Zika Virus and Its Impact on Brain Defects
Whether it regards Miami, Puerto Rico or the Olympics in Brazil, the publicity and understandable anxiety caused by the outbreak of the Zika virus cannot be denied. In particular, the fear of Zika-related brain birth defects has been the topic of regularly breaking news, creating an atmosphere of caution and concern.
In April 2016, CDC scientists announced that based on an accumulation of evidence, they have concluded that contracting the Zika virus during pregnancy is the cause of severe birth defects, such as microcephaly. This has led to a concerted effort to research these birth defects in order to determine solutions to prevent them.
The World Health Organization (WHO) declared in August 2016 that the Zika virus could infect up to four million people this year. They also chronicle that since 2015, 65 countries and territories have reported evidence of Zika virus transmission. The expansion of outbreaks in Brazil has fanned the Zika controversy over the summer Olympics. WHO reports that since the outbreak in that country in May 2015, Brazil has recorded approximately 4,000 cases of microcephaly (compared to statistics prior to that date, in which Brazil had fewer than 200 annual cases). This led to the notification on the eve of the Olympics, in which the CDC issued an Alert Level 2—Practice Enhanced Precautions—for those attending the Games.
Microcephaly is a birth defect, which results in a baby’s head being smaller than those of the same age and sex. Microcephaly also indicates compromised development, resulting in smaller brains.
The precise cause and effect between Zika and microcephaly is unclear. However, speculation by experts regarding more widely studied viruses closely related to Zika and their impact on birth defects suggests that the virus damages the stem cells during early-stage brain development.
While currently in the spotlight, microcephaly is not the only brain defect linked to Zika. It can also cause hydrocephalus (water on the brain).
Both microcephaly and hydrocephaly are in the family of cephalic disorders. Cephalic means “head” or “head end of the body.” These are congenital (present at birth) disorders that result in abnormal development or damage to the developing nervous system.
According to the Centers for Disease and Prevention (CDC), microcephaly is still relatively rare. The CDC estimates that in the U.S., its occurrence ranges from two to 10 babies per 10,000 live births. In contrast, the Hydrocephalus Foundation estimates that three of every 1,000 babies are born with hydrocephalus. Some estimates even claim one out of every 500 births.
Because hydrocephalus is so common, at Advanced Neurosurgery Associates (ANA), we feel it is important to call awareness to this neurological condition and mark September as Hydrocephalus Awareness Month. Hydrocephalus, which we often treat in our practice, touches 1 million Americans, according to the Hydrocephalus Association (HA).
Whereas extreme microcephaly has a poor prognosis for general brain function, a reduced life expectancy and relatively non-existent treatments (there are only supportive therapies), hydrocephalus is very treatable. With the procedures and care of neurosurgeons, patients can live normal lives and function normally. One of our many patient stories illustrates a typical example of treatment and this very outcome.
As for Zika, perhaps there will be some answers from a study supported by the National Institutes of Health (NIH). Researchers monitored potential exposure to Zika virus by some of the athletes, coaches and U.S. Olympic Committee (USOC) staff who were among those at both the Summer Games and Paralympics in Brazil.