Louisiana Office of Public Health Infectious Disease Epidemiology Section Phone: 1-800-256-2748 www.infectiousdisease.dhh.louisiana.gov Zika Virus What is Zika disease? Zika virus disease is an infectious disease caused by a virus in the same family as West Nile and Dengue (the Flavivirus genus), which is transmitted to people through the bite of an infected insect vector and less commonly through sexual contact. The immediate symptoms of Zika virus infection are typically mild. However, there is a potential for severe birth defects following infections during pregnancy. How do people get Zika disease? Mosquitoes: The main way Zika disease is transmitted is from the bite of infected mosquitoes. Once a mosquito bites a person who is infected with the virus, after about 10 days, the mosquito is able to transmit the virus to the other people it bites. The mosquitoes that can transmit the virus include Aedes aegypti (the Yellow Fever mosquito, which primarily bites humans) and Aedes albopictus (the Asian Tiger mosquito, which primarily bites animals). These mosquitoes are abundant across Louisiana and prefer to live near people and households. They breed in small containers (even bottle caps) and prefer to lay eggs in or near standing water. These mosquitoes are aggressive day-time biters (especially at dusk and dawn), but may also bite at night. These species also spread Dengue and Chikungunya, which can cause symptoms similar to Zika. Mother to Infant: Since the virus is present in the blood, there is a risk for congenital transmission from a pregnant woman to her baby during pregnancy. It is rare for a mother infected with Zika around the time of delivery to pass the virus on to the infant. Currently there are no reports of infants getting Zika through breastfeeding. Sexual Contact: It is also possible for Zika to be spread through unprotected sexual contact, including sharing sex toys. This is possible even if the infected person is asymptomatic. Blood Transfusion: There have been cases of the virus spreading through blood transfusion in other countries, resulting in blood screening tests in the United States. There have been no confirmed cases of Zika transmission through blood transfusion in the United States. Where can Zika disease be found? The virus was first isolated in 1947 from a rhesus monkey in the Zika Forest of Uganda. It has occurred since the 1950s within a narrow equatorial belt from Africa to Asia, causing about 15 documented cases until 2007. In 2007, there was an outbreak reported in Micronesia, which spread to some other Pacific Islands in 2013-2014. In May 2015, the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed Zika virus infections in Brazil. In December 2015, Puerto Rico reported its first locally transmitted confirmed Zika virus case. In August 2016, the CDC reported locally transmitted cases in Miami-Dade County, Florida. In November 2016, Texas reported locally transmitted cases in Brownsville, Texas. However, Miami and Brownsville no longer report local transmission of the virus. Most cases of Zika disease in the U.S. are imported cases reported in returning travelers. Is there Zika in Louisiana? Aedes mosquitoes are common in Louisiana, but there has been no documentation of local mosquitoes being infected. While there have been cases of imported infections in Louisiana (people who became infected outside of the state), to date there have been no documented cases of local transmission. Local transmission occurs when a person has not traveled recently and gets bitten by an infected mosquito where they live, work, or play. Travelers from Louisiana to areas of the world where Zika virus is found (including parts of Africa, Southeast Asia, the Pacific Islands, Caribbean, Central, and South America) should protect themselves from mosquito bites while traveling and once they return to Louisiana for three weeks, even if they do not feel sick. For country-specific travel information and recommendations visit www.cdc.gov/travel. What are the symptoms of Zika? Symptoms usually begin 2-7 days after being bitten by an infected mosquito. Not all persons bitten by an infected mosquito will develop symptoms. 80% of people will remain asymptomatic and never know they were infected. Only about 1 in 5 people infected with Zika will become ill. See a doctor if you develop any of the following symptoms after a potential exposure to Zika virus: Fever Muscle or joint pain Headache, especially behind the eyes Rash Conjunctivitis (red eyes) Vomiting There have been reports of increased cases of Guillain-Barré Syndrome in Zika-infected persons. This extremely rare nervous system disorder may cause muscle weakness or even paralysis. Researchers are still working to understand the connection between Zika virus and Guillain-Barré Syndrome.
What should I do if I think I have Zika disease? You should discuss your concerns with your health care provider, who will examine you and ask you questions (for example, about your health and where you have traveled within 2 weeks before getting sick). Zika disease is diagnosed by testing blood, urine, spinal fluid, or tissue. Since the symptoms of Zika are similar to those of Dengue and Chikungunya, your healthcare provider may order tests for those diseases or other similar viruses. You should protect yourself from mosquito bites in Louisiana for 3 weeks following illness or travel to an area with active Zika transmission. If a mosquito bites you, it can become infected and spread the virus to others nearby. Who should be tested? Zika testing guidelines change regularly. Please reference Zika Testing Guidelines published by CDC or on the LDH website. How is Zika disease treated? There is only supportive care to manage the symptoms and signs of infection. The use of aspirin and other NSAIDS should be avoided until dengue virus infection is ruled out. Zika’s symptoms typically resolve within several days to one week on their own. Severe disease requiring hospitalization is uncommon and death is rare. Pregnant women who test positive for Zika should consult with their physicians and receive serial ultrasounds throughout the pregnancy. How do I prevent getting Zika? No drugs or vaccines for preventing Zika virus infection are currently available. The best prevention strategy is protection from mosquito bites: Wear long-sleeved shirts and long pants or permethrin- treated clothing Use door and window screens in good repair to keep mosquitoes outside Empty standing water and scrub, turn over, cover, or throw out items that can hold water around your home (including tires, buckets, planters, toys, trash, and gutters) Use insect repellant according to instructions (containing DEET, picaridin, IR3535 and some oil of lemon eucalyptus and para-menthane-diol products). More info: https://www.cdc.gov/westnile/faq/repellent.html Individuals travelling to countries with active Zika transmission should use condoms during travel to prevent sexual transmission. In order to prevent sexual transmission, it is advised that men avoid unprotected sex for three months following travel to an area with Zika transmission or following symptom onset. It is advised that women avoid unprotected sex for two months following travel to an area with Zika transmission or following symptom onset. Pregnant women with sex partners who live in or traveled to an area with risk of Zika should use condoms during sex or abstain from sex for the duration of pregnancy. Because there is neither a vaccine nor prophylactic medications available to prevent Zika virus infection, CDC recommends that all pregnant women consider postponing travel to areas where Zika virus transmission is ongoing. Is it safe to use insect repellent if I am pregnant or nursing? Using an insect repellent is safe and effective. Pregnant women and women who are breastfeeding can and should choose an EPA-registered insect repellent and use it according to the product label. What is the risk to pregnant women? Pregnant women can be infected with Zika virus in any trimester. No evidence exists to suggest that pregnant women are more susceptible to Zika virus infection or experience more severe disease during pregnancy. Zika virus infection has been linked to a range of birth defects, including microcephaly (a birth defect where a baby’s head is smaller than normal). A significant increase in the number of infants born with microcephaly has been reported during the Zika outbreak in Brazil. Birth defects are possible to occur for both symptomatic and asymptomatic pregnant mothers. More Info: https://www.cdc.gov/mmwr/volumes/67/wr/mm6731e1.htm?s_ci d=mm6731e1_w If a woman who is not pregnant infected with Zika virus, will her future pregnancies be at risk? There is no evidence that Zika virus infection poses a risk of birth defects for future pregnancies. Zika virus usually remains in the blood of an infected person for only a few days to a week. The virus will not cause infections in a baby that is conceived after the virus is cleared from the mother’s blood. What is being done to prevent the spread of Zika in the United States? The Centers for Disease Control and Prevention (CDC) has been working with State and Local Health Departments to advise people on how to prevent infection. It is expected that there will be some Zika cases in the United States, but it is unlikely to be as widespread as in other countries. Mosquito spraying and monitoring will continue to aid in preventing the spread of the virus in Louisiana. More Information: Louisiana Department of Health: www.ldh.la.gov/zika Centers for Disease Control and Prevention: www.cdc.gov/zika