Zika virus was first discovered in 1947 and is named after the Ugandan forest where it was first isolated. More than 50 years later, major outbreaks of the mosquito-borne virus occurred outside of Africa and Asia for the first time, including the Zika outbreak that began in 2015 and is expected to spread across most of the Americas.

Zika virus “has evolved from a little-known virus to a global health security threat,” according to the Journal of Global Infectious Diseases. In February, the World Health Organization (WHO) declared Zika virus a “public health emergency of international concern.” This formal designation has only applied to three other illnesses in the past — most recently to the 2014-2015 Ebola outbreak in West Africa.

The great deal of attention on Zika virus is due to its rapid expansion and link to newborn microcephaly cases, in which infants are born with smaller than normal brains. Microcephaly is a lifelong condition with no known cure; it can be life-threatening. Babies can face severe symptoms such as seizures, hearing and vision loss, feeding problems and intellectual disabilities.

Zika Virus Outbreaks

Zika virus was originally confined to Africa and Asia. Until the early 21st century, the virus had only 14 documented cases and no outbreaks.

Zika virus began its spread in the Pacific with a major outbreak in 2007 in the Yap Islands, an island chain in Micronesia. The outbreak had 49 confirmed and 59 probable cases of Zika virus disease, according to The New England Journal of Medicine. No patients required hospitalization.

The next major Zika virus outbreak occurred in 2013 in French Polynesia. Suspected cases totaled 8,723, and more than 30,000 medical consultations were due to the spread of Zika virus throughout French Polynesia, Eurosurveillance says. Some cases involved neurological complications, including 42 cases of Guillain-Barré syndrome, which can cause paralysis and lead to death. The French Polynesia outbreak led to outbreaks in New Caledonia (1,400 confirmed cases), Cook Islands (more than 900 cases) and Easter Island.

The most alarming Zika virus outbreak began in Brazil in early 2015. By May, the Pan American Health Organization issued an alert regarding the first confirmed case in Brazil, according to the Centers for Disease Control and Prevention (CDC). Brazil reported associations between Zika virus and microcephaly and Guillain-Barré syndrome, the WHO says. By the end of 2015, Zika virus spread to 21 countries and territories in the Americas. As of May 2016, more than 50 countries and territories in the Americas, Oceania/Pacific Islands and Africa have active Zika virus transmission, according to the CDC.

Zika Virus: Symptoms, Treatment, and Transmission

Symptoms

It is common for individuals infected by Zika virus to have no symptoms. For those who develop symptoms, signs of Zika virus infection usually occur within three to 12 days after transmission and last for two to seven days, according to the Journal of Global Infectious Diseases. Only 20 percent of people infected with Zika virus show symptoms including fever, rash, joint pain and conjunctivitis (red eyes).

“People usually don’t get sick enough to go to the hospital, and they very rarely die of Zika,” the CDC says. “For this reason, many people might not realize they have been infected. However, Zika virus infection during pregnancy can cause a serious birth defect called microcephaly, as well as other severe fetal brain defects.” Zika virus is also linked to Guillain-Barré syndrome, an uncommon nervous system sickness. Research on the link between Zika virus and complications is limited.

Treatment

There are currently no antiviral medications or vaccines available for Zika virus; treatment is based on symptoms. Individuals with Zika virus should get plenty of rest, drink plenty of fluids and treat pain and fever with common medications, according to the WHO. Medical care should be sought if symptoms worsen.

Transmission

Zika virus is primarily transmitted through the bite of an infected Aedes mosquito. This type of mosquito is more common in tropical regions, and they usually bite during the day. It is the same mosquito that transmits viruses such as dengue, chikungunya and yellow fever.

Sexual transmission of Zika virus is also possible. Additionally, blood transfusion and other methods of transmission are under investigation.

Initiatives to Combat Zika Virus

CDC

The CDC activated its Emergency Operations Center (EOC) for Zika virus on Jan. 22, 2016, and moved to a level 1 activation — the highest level — on Feb. 8, 2016. The EOC monitors and coordinates the emergency response for Zika virus, bringing together CDC scientists with expertise in subjects like mosquito-borne viruses, developmental disabilities, birth defects, reproductive health and travel health. The EOC is actively:

Conducting studies to evaluate Zika virus and its link to microcephaly and Guillain-Barré syndrome, as well as its transmission;

Developing tests to diagnose Zika virus;

Providing surveillance for the virus in the United States and its territories;

Providing support on the ground for Puerto Rico, Brazil, Colombia, American Samoa, the U.S. Virgin Islands and Panama;

Providing guidance for travelers and Americans living in areas with current outbreaks.

The EOC is able to quickly transport diagnostic kits, samples, specimens and personnel to areas with Zika virus. Nearly 300 CDC members have been deployed across the world, as of June 2016.

WHO

The WHO released the Strategic Response and Joint Operations Plan to investigate and respond to Zika virus. It focuses on increasing preventive measures, communicating risks and providing care to individuals affected by Zika virus. The response consists of three parts.

Surveillance: Providing up-to-date and accurate epidemiological information on Zika virus and its complications. Response: Communicating Zika virus risks to communities and promoting protective behaviors, reducing anxiety, addressing stigma and dispelling rumors and cultural misperceptions; increasing efforts to control the spread of the Aedes mosquito and other species, as well as providing access to protective equipment and supplies; providing guidance and mitigating the impact on women of childbearing age and those who are pregnant, as well as families with children affected by Zika virus. Research: Investigating the increase of microcephaly and neurological syndromes and their association with Zika virus.

Funding for the Strategic Response and Joint Operations Plan is at $56 million, according to the WHO. Twenty-three partners are participating in the response.

Responding to Domestic and International Public Health Threats

Public health professionals are integral in raising awareness and providing solutions to emergencies like Zika virus. Rivier University’s online B.S. Public Health and online Master of Public Health provide students with the knowledge and skills to address public health issues and promote healthy choices. These degree programs take place in a convenient, flexible online format to accommodate students’ work and personal schedules.