CDC is studying the link between Zika and Guillain-Barré Syndrome, a rare autoimmune disorder that can lead to life-threatening paralysis. It is known to be a side effect associated with other viral illnesses such as influenza.
Fever, rash, joint pain and conjunctivitis (red eyes) are the most common symptoms of Zika virus. Some patients may also experience muscle pain or headaches.
Zika and Pregnancy
According to CDC, there is no evidence that previous infection will affect future pregnancies.
1948 – The virus is isolated from Aedes africanus mosquito samples in the Zika forest.
1964 – First active case of Zika virus found in humans. While researchers had found antibodies in the blood of people in both Uganda and in Tanzania as far back as 1952, this is the first known case of the active virus in humans. The infected man developed a pinkish rash over most of his body but reported the illness as “mild,” with none of the pain associated with dengue and chikungunya.
1960s-1980s – A small number of countries in West Africa and Asia find Zika in mosquitoes, and isolated, rare cases are reported in humans.
April-July 2007 – The first major outbreak in humans occurs on Yap Island, Federated States of Micronesia. Of the suspected 185 cases reported, 49 are confirmed, and 59 are considered probable. There are an additional 77 suspected cases. No deaths are reported.
2013-2014 – A large outbreak of Zika occurs in French Polynesia, with about 32,000 suspected cases. There are also outbreaks in the Pacific Islands, including Easter Island, the Cook Islands, and New Caledonia during that time. An uptick in cases of Guillain-Barré Syndrome during the same period suggests a possible link between the Zika virus and the rare neurological syndrome. However, it was not proven because the islands were also experiencing an outbreak of dengue fever at the time.
March 2015 – Brazil alerts WHO to an illness with skin rash that is present in the northeastern region of the country. From February 2015 to April 29, 2015, nearly 7,000 cases of illness with a skin rash are reported in that area of Brazil. Zika is not the suspected illness at the time. Later in the month, Brazil provides additional information to WHO on the illnesses.
April 29, 2015 – A state laboratory in Brazil informs WHO that preliminary samples have tested positive for the Zika virus.
May 7, 2015 – The outbreak of the Zika virus in Brazil prompts WHO and the Pan American Health Organization (PAHO) to issue an epidemiological alert.
October 30, 2015 – Brazil reports an increase in the cases of microcephaly, babies born with abnormally small heads: 54 cases between August and October 30.
November 11, 2015 – Brazil declares a national public health emergency as the number of newborns with microcephaly continues to rise.
November 27, 2015 – Brazil reports it is examining 739 cases of microcephaly.
November 28, 2015 – Brazil reports three deaths from Zika infection: two adults and one newborn.
February 8, 2016 – CDC elevates its Emergency Operations Center (EOC) for Zika to Level 1, the highest level of response at CDC.
March 4, 2016 – The US Olympic Committee announces the formation of an infectious disease advisory group to help the USOC establish “best practices regarding the mitigation, assessment and management of infectious disease, paying particular attention to how issues may affect athletes and staff participating in the upcoming Olympic and Paralympic Games.”
September 19, 2016 – CDC announces that it has successfully reduced the population of Zika-carrying mosquitoes in Wynwood and lifts its advisory against travel to the community by pregnant women.