SEATTLE — The Zika virus, a predominantly mosquito-borne disease, arrived in Brazil last spring, sparking global health concerns as it traveled quickly throughout the region. Since then, more than 26 countries and territories in the Americas have reported cases of the virus, and as many as four million people could be infected by the end of the year, according to the World Health Organization (WHO).
WHO declared the Zika virus a public health emergency of international concern on Feb. 1, 2016, due to its suspected link to a range of health concerns, specifically birth defects in babies born to mothers who are infected with the virus.
“Possible links with neurological complications and birth malformations have rapidly changed the risk profile for Zika, from a mild threat to one of very serious proportions,” said Margaret Chan, the Director-General of WHO, in a strategy paper issued by the organization.
Zika is not a new virus. It was first reported in 1947, with small outbreaks occurring in South-East Asia, Africa and the Pacific Islands. It was generally not considered a threat, as only one-fifth of people who contract the disease fall ill, and the symptoms that develop are generally mild, lasting up to a week. Individuals rarely get sick enough to seek treatment and fatalities are a rare occurrence.
Once it reached Brazil, however, the virus took the world by surprise. The Pan American Health Organization issued an alert in May 2015, after the first confirmed Zika infection in Brazil. Few people in the Western hemisphere have immune defenses against the virus, leaving the population vulnerable. Transmission levels quickly surged to endemic levels, and it is likely the virus will continue to spread to new areas, according to the United States Centers for Disease Control and Prevention (CDC).
The focus of concern quickly shifted due to a growing number of cases of microcephaly, which has been linked to the contraction of the Zika virus. The rare condition causes infants to be born with abnormally small heads, resulting in lasting brain damage. It has also been linked to the development of neurological disorders, like Guillain-Barre syndrome, in adults.
While scientists have not been able to solidly confirm the link between the Zika virus and the health issues, Brazil, French Polynesia, El Salvador, Venezuela, Colombia and Suriname have all reported more cases of microcephaly and Guillain-Barre syndrome occurring at the same time as the outbreak.
Communities affected by poverty are those that are the most at risk, as the mosquito-borne virus is easily transmitted in crowded areas without access to sheltered, air conditioned areas. A lack of running water and waste management, combined with poor housing situations in urban areas, also leads to the continued spread of the virus.
Across the globe, governments have acted with increased concern, and the quick spread of the virus has brought women’s reproductive health to the public’s attention. The government of El Salvador has advised women to attempt to refrain from becoming pregnant for two years, or until 2018, so the country can get a handle on the situation.
In the U.S., the CDC has issued warnings to pregnant women who may travel where Zika is located, to prevent transmission.
“In these areas, women who are pregnant need to protect themselves from mosquito bites by using repellants, permethrin-coated clothing, long sleeves and pants, and by staying indoors as much as is practical,” said Tom Frieden, the director of the CDC to CNN. “We advise women to postpone travel to areas where Zika is spreading.”
On Feb. 16, WHO said that $56 million would be required to fund a strategy to combat the virus until June. The large area affected by the virus, combined with the the lack of reliable tests in the affected areas, has contributed to the need for the funds, according to the agency. The CDC is currently working with United Nations Agencies, the Global Outbreak Alert and Response Network, public health and research partners, and non-governmental organizations regionally and globally to develop strategic responses to combat the spread of the virus.