The World Health Organization declared the fast-spreading Zika virus to be a global health emergency on Monday, a designation that will help free up additional resources for tackling the disease.

The organization has declared three previous global health emergencies, according to the Washington Post.

“The first time was in 2009 during the H1N1 influenza epidemic that is believed to have infected up to 200 million worldwide; the second in May 2014 when a paralyzing form of polio re-emerged in Pakistan and Syria; and the third in August 2014 with Ebola in West Africa,” the Post writes. 

The Centers for Disease Control and Prevention recently warned Hawaii that the state’s Department of Health is understaffed and has “critical deficiencies” that could impact its ability to deal with a Zika outbreak.

“Longer term, introductions of other mosquito-borne diseases such as Zika and chikungunya are likely and will require entomologic expertise at the State Department of Health that currently does not exist,” Lyle R. Petersen, director of the CDC’s Division of Vector-Borne Diseases, wrote last month in an assessment of the state’s response to the current dengue fever outbreak.

The World Health Organization is estimating that there could be as many as 4 million cases of the disease in the next year in the Americas, according to the Associated Press.

The disease is spread by the same mosquitoes that transmit Dengue and yellow fever. There is no vaccine or treatment for the disease.

Zika is an illness with symptoms similar to dengue, including fever and joint pain. In most instances, the symptoms are mild, but there is mounting evidence that the disease may cause a serious birth defect known as microcephaly.

The link between Zika and microcephaly — a condition where a baby is born with an abnormally small head and brain development issues — has not been proven. But the rising number of cases of microcephaly among children born from mothers who had contracted the Zika virus is leading to a crisis-level response from many nations.

Just like dengue, it is transmitted most commonly by the Aedes aegypti mosquito. The mosquito picks up the virus when it bites an infected person, and spreads it by biting another person.

Medical experts have said that the threat of a Zika outbreak in Hawaii is very low, but add that Hawaii should be more proactive addressing the issue.

The Aedes aegypti was eradicated from most of Hawaii by the 1960s, but can still be found in several areas on Hawaii Island — where it has been the carrier in the recent dengue outbreak there. Zika and dengue can also be spread by another mosquito that is much more common on all the islands. However, the Aedes albopictus mosquito is not as aggressive and is deemed to be less effective at spreading the diseases.

Hawaii currently has half as many state-employed vector control workers and entomologists as it had seven years ago. Lawmakers have introduced several bills this session that would restore vector control positions at the Department of Health.

Because of the possible risks to pregnant women, even a small outbreak of Zika could devastate tourism in Hawaii for a year or two, Rep. Richard Creagan told Civil Beat last week.

“That could cost the state a billion dollars,” Creagan said. “Putting $10 million or $30 million in right now is probably a good way to go.”