Zika virus is primarily transmitted by the Aedes species mosquito, which originally was found only in tropical and subtropical zones but now can be found on every continent other than Antarctica. The mosquito bites an infected individual and then transfers the virus to the next person bitten.
The illness caused by the Zika virus is generally mild – in fact, only 20 percent of those infected experience symptoms, which include fever, a rash, aching joints and red eyes (conjunctivitis) for a few days to a week. Treatment consists of rest, fluids, and over-the-counter fever and pain relievers such as acetaminophen (e.g., Tylenol).
During the most recent outbreak in Brazil and Latin America, however, two serious medical problems have emerged as possibly being linked to the virus.
Pregnant women who contract the virus may have a significantly higher chance of having a baby with a serious birth defect known as microcephaly. Microcephalic babies have smaller heads than normal and many associated complications including severe, sometimes deadly, developmental delays. More than 3,500 Brazilian children have been born with this condition since the Zika virus outbreak began.
Also being investigated is a possible link to a rare neurological disorder, Guillain Barre syndrome, which can cause various degrees of muscle weakness and paralysis for weeks or months.
The United States has Aedes species mosquitos, especially in the southern states, but so far, no cases of mosquito-transmitted Zika virus have occurred here. There have been a number of cases of travel-associated Zika virus – infections which occurred during travel to affected areas, or through sexual contact with an individual infected during travel.
It is not known if a significant Zika outbreak will occur in the U.S., but the possibility exists. Prevention initiatives include efforts to develop a vaccine and to eradicate disease-transmitting mosquitos as well as education about avoiding mosquito bites and practicing safe use of condoms.
Until recently, the Zika virus was relatively unheard of. Discovered in 1947 in Uganda, the mosquito-borne illness, which in most cases causes mild symptoms, occurred sporadically, mostly in Africa, Southeast Asia and the Pacific Islands, for 70 years. That changed dramatically in May 2015 when an outbreak detected in Brazil spread rapidly – and was linked to an increase in microcephaly, a birth defect causing small head size. Since then, the virus has swept across Latin America and the World Health Organization has declared an international public health emergency. While few cases have yet been discovered in the U.S., President Obama has sought $1.8 billion in funding from Congress to proactively fight Zika here and help curb it abroad.
Mosquito-borne Zika has moved from Brazil through Latin America and has entered Puerto Rico, America Samoa and the U.S. Virgin Islands. No locally-acquired mosquito-borne cases have been found in the U.S., but travel-associated cases have occurred. For updated information from the Centers for Disease Control (CDC), click here.
Concerns for Pregnant Women & Infants:
For more information on pregnancy and Zika-associated birth defects, click here.
The possibility of a connection between Zika virus and Guillain-Barre Syndrome, a rare neurological disorder that causes various degrees of muscle weakness and paralysis, is being investigated. For more information, click here.