OSHA and the National Institute for Occupational Safety and Health (NIOSH) are monitoring the impact of the Zika virus on U.S. states and territories, Central and South America, Mexico and parts of the Caribbean. For the most up-to date information, check the Centers for Disease Control and Prevention (CDC) Zika website frequently.
Vectors that can transmit Zika virus are or have been previously found in U.S. territories and some U.S. states. Although active Zika virus transmission has been detected in some areas of the U.S., most cases of Zika virus have been travel-associated.
Zika virus is primarily spread through the bites of infected mosquitoes. Mosquitoes can become infected when they bite infected people and can then spread the Zika virus to other people they subsequently bite. Many people infected with Zika virus won't have symptoms or will only have mild symptoms; however, Zika infection during pregnancy can cause serious birth defects.
Zika virus historically has been found in Africa, Southeast Asia and the Pacific Islands. The first case was identified in the Zika Forest in Uganda in 1947. In 2015, cases of Zika virus were reported in the Americas and the Caribbean.
Visit the CDC's "Areas with Zika" website to learn where cases of local mosquito-borne transmission of Zika virus disease have been reported and where there is an active transmission. Zika virus has the potential to spread anywhere that mosquitoes capable of transmitting the virus are found. Aedes species mosquitoes are the principal vectors (i.e., carriers) of Zika virus in the U.S. Aedes aegypti (commonly known as yellow fever mosquitoes) are typically concentrated in the Southern U.S. as well as parts of the Southwest.
Another vector for Zika virus is Aedes albopictus (commonly known as Asian Tiger mosquitoes), which are found in much of the Southern and Eastern parts of the U.S. In addition, meteorological conditions, the number of people travelling from areas with ongoing transmission, and socioeconomic factors play a role in Zika transmission in the contiguous U.S. (the lower 48 states). For example, Aedes aegypti can thrive in many areas during summer months (July-September) but are only active in winter months (December-March) in areas where temperatures do not fall below 50 F. The mosquitoes that spread Zika usually do not live at elevations above 6,600 feet.
Although Zika virus is primarily spread through the bites of infected mosquitos, exposure to an infected person's blood or other bodily fluids may also result in transmission.
Symptoms
Many people infected with Zika virus will not have symptoms or will only have mild symptoms. Exactly how often people have Zika virus infections without symptoms is not known. When people do experience symptoms, they usually begin about 3-14 days after the bite of an infected mosquito, are usually mild and typically last 2-7 days. The most common symptoms of Zika virus infection are fever, rash, joint pain, and red or pink eyes. Other symptoms include myalgia (muscle pain) and headache.
Prevention
CDC recommendations for preventing Zika virus infection include special precautions, such as avoiding or delaying travel to Zika-affected areas for women who are or may become pregnant. In areas affected by Zika virus transmission, protect yourself and others from possible exposure to Zika virus by always taking steps to prevent mosquito bites. There is no approved vaccine to prevent Zika virus, and there is no specific treatment for individuals who become infected.
For more information, visit www.cdc.gov/zika or www.osha.gov.
