By Kim Smiley
In 2014, fewer than 150 babies were born with microcephaly in Brazil, but the number dramatically increased in 2015 with more than 2,700 cases. Microcephaly is a neurological disorder where the growth of the head is stunted with reduced brain function in 90 percent of cases. Infants with microcephaly often have reduced life spans and require significant long-term care. The spike in microcephaly is so alarming that some doctors and health officials are encouraging women in the regions with a high concentration of microcephaly cases to avoid becoming pregnant at this time.
Health officials are still working to understand exactly what caused the increase in microcephalic babies, but many believe Zika virus is contributing to the problem. Zika virus is a mosquito-borne virus and the symptoms are similar to many other mosquito-borne viruses such as dengue and chikungunya. Latin America reported their first Zika virus cases in 2014 and the spread of Zika virus matches the timing of the increase in microcephaly cases. Additionally, many mothers of babies with microcephaly report having symptoms associated with Zika virus early in their pregnancies.
A Cause Map, a visual root cause analysis, can be built to illustrate what is known about this issue as this time. As more information becomes available the Cause Map can easily be expanded to incorporate new information. A Cause Map is built by asking “why” questions and laying out all the causes that contribute to an issue to show the cause-and-effect relationships. Understanding all the causes that contribute to an issue can aid in development of effective solutions.
In this example, more evidence is needed to confirm that Zika virus is responsible for the microcephaly increase in babies. (A box with a question mark on a Cause Map indicates areas where more information is required.) The timing of the increase in microcephaly cases and the spread of Zika virus is certainly suspect, but additional data will be needed to ensure that other factors aren’t involved as well. An autopsy on a baby born with microcephaly revealed the presence of Zika virus, which is another data point, but again isn’t enough to conclusively prove the connection between Zika virus and microcephaly.
Tracking cases of Zika virus is difficult for several reasons. Many people infected with Zika virus have no symptoms so it is difficult to determine exactly how many have been infected, including pregnant woman. Zika is spread by mosquitos so everyone in the region is potentially exposed. Only a few labs in Brazil have the capability to test for Zika virus which makes researching the virus more difficult. Scientists are working on solving this mystery as quickly as they can, but reality is it will likely be some time before the connection between Zika virus and microcephaly is definitively proven or disproven.
Health officials are working to reduce the number of mosquitos in Brazil, even going door-to-door to look for potential breeding locations. Reducing the number of mosquitos should hopefully reduce the number of cases of microcephaly if the suspicion about the involvement of Zika virus is correct. Additionally, pregnant women are encouraged to stay indoors and wear plenty of insect repellant to prevent mosquito bites. And of course, woman may want to avoid pregnancy as recommended until the mystery is solved, but this obviously isn’t always possible or practical.
To view an initial Cause Map of this issue, click on “Download PDF” above.