Without the current availability of a vaccine and/or drugs to specifically treat Zika virus infections, the disease has the capability to spread with increased frequency in many parts of the world. The risk of infection with serious consequences tends to increase in pregnant women and the offspring of symptomatic and asymptomatic mothers. Currently, the greatest risk of serious fetal sequelae appears to be with the first-trimester infection. However, infections occurring in the second-trimester of pregnancy may, in some cases, produce serious fetal sequelae.
Since it is known that the Zika virus can cause microcephaly and other severe fetal brain defects, a woman who is infected with Zika during pregnancy has an increased risk of having a baby with these health problems. On the other hand, not all women with Zika virus infection during pregnancy will have fetuses with severe problems. In fact, it has been observed that during the last major Zika outbreak, some infected women have delivered babies that appear to be healthy.
With the increased spread of the Zika virus, case reports have described several complications of the infection, such as sepsis-like presentations, thrombocytopenia, acute respiratory distress syndrome, and Guillain-Barré syndrome (GBS). GBS is a rare autoimmune disorder that affects the central nervous system causing weakness in the extremities and can spread quickly, eventually causing paralysis throughout the body. The condition can present as a medical emergency and require hospitalization. The exact cause of GBS is unknown, but an infectious illness often precedes it. The risk of Zika virus-associated GBS was first recognized during an outbreak in French Polynesia and was estimated at approximately one case per 1,000 infections.
Since the Zika virus can be transmitted by the Aedes mosquito from mother to child during pregnancy, by sexual contact and exposure, and by blood transfusions, the CDC has guidance on pregnancy, sexual practice, travel, and exposure protection plans relative to the Zika virus. In fact, the FDA in 2018 had issued a revised guidance recommending universal testing of donated whole blood and blood components for the Zika virus in the United States and its territories. However, as of 2021, the FDA withdrew the 2018 guidance for Zika testing on donated blood because the virus is no longer considered a threat to potential blood donations.
