As the weather warms up, cities across the country are starting to brace against a new wave of mosquitoes and, with that, the Zika virus. Public health officials worry that the number of Zika infections will continue to climb this spring and summer — a concern supported by new data released Wednesday by the U.S. Centers for Disease Control and Prevention. But why are Zika rates on the rise in the U.S.? A combination of environmental and technological factors have impacted the number of cases reported in the country.
The CDC analyzed data from the 2016 U.S. Zika Pregnancy Registry (USZPR) and discovered that 1 in 10 pregnant women who contracted the Zika virus had children or fetuses with Zika-associated birth abnormalities, according to Fortune. Nearly 1,300 Zika-infected pregnant women across 44 states were reported to the USZPR between Jan. 15, 2016 and Dec. 27, 2016; the CDC found that, of those cases, 51 of the 972 completed pregnancies involved infants with Zika virus-related birth defects. Many were born with microcephaly, a rare neurological condition characterized by an abnormally small head, among other severe fetal brain defects, according to the report.
According to Fortune, the mothers of the 51 infants or fetuses born with Zika-related birth abnormalities had been exposed to the virus while visiting one of the 16 countries or U.S territories gripped by the Zika virus.
Public health officials consider travel one of the main causes of the increase in Zika virus cases in the United States. According to the CDC, people who become infected while visiting an Zika-endemic area can transmit the virus back home through mosquitoes that bite them and then bite and infect others. Zika can also be spread through sex, blood transfusion, and pregnancy. Since pregnant women are most at risk of infection, the CDC warns pregnant to avoid regions with a higher prevalence of Zika, according to NPR.
Climate change has also been loosely connected to a surge in Zika rates. According to KTRE, the mild winter temperatures caused by climate change has helped create the perfect breeding ground for the Aedes albopictus mosquito — the species that carries the Zika virus — to multiply rapidly in the United States.
But the increase in Zika virus cases can’t be tied entirely to environmental factors. Technological advances have also helped doctors identify people who has contracted the virus, which means more cases can be confirmed, KTRE reported.
Whatever the cause, people, especially pregnant women, should remain vigilant to avoid exposure to the virus. Limit travel and invest in a lot of bug spray, everyone.