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Potentially Deadly Dengue and Zika Viruses on U.S. Soil


VirusMosquito-born viruses are wreaking havoc in other parts of the world, but two are of concern now in North America. Dengue and Zika, two potentially deadly viruses spread by mosquitos, are drawing attention and concern on U.S. soil at opposite ends of the country.

The big island in Hawaii is in the midst of its worst dengue fever outbreak since becoming a state in 1959. The total number of confirmed cases of the virus since September is 195. That includes 37 children and 19 visitors to the island. No other Hawaiian island has reported local cases during this infestation.

In December, the first locally transmitted case of the Zika virus was confirmed in Puerto Rico. Local transmission means the sick person did not travel anywhere where and was infected on Puerto Rico, which indicates that some mosquitoes on the island are now carrying Zika and possibly spreading it to other humans.

Both the Dengue and Zika viruses are spread by two types of mosquitoes: Aedes aegypti and Aedes albopictus. Those species are also responsible for spreading chikungunya and yellow fever. The four viruses reportedly account for more than 400 million of the mosquito-born diseases worldwide each year, with dengue being the most prevalent.

Dengue emerged as a worldwide problem in the 1950s. It has since become a leading cause of illness and death throughout the tropics and subtropics. The virus is common in Puerto Rico and popular tourist destinations on Pacific islands, in Latin America and in Southeast Asia. Symptoms can include a sudden high fever, severe headaches, a rash, unusual bleeding (nose, gums or easy bruising) and eye, joint or muscle pain. A more sever form is dengue hemorrhagic fever, which starts like the regular kind but is followed by persistent vomiting, bleeding, and severe abdominal pain.

There are no vaccines or specific medications for either version of dengue. Treating symptoms with pain relievers, acetaminophen (avoid aspirin which can increase bleeding), rest and fluids is appropriate, but if symptoms persist or get worse, patients should see a physician.

Zika was first identified in 1947 in monkeys in the Zika forest of Uganda. It was extremely rare until 2007, when it spread through three-fourths of the residents of the Yap Island in the Pacific. It resurfaced five years later on Tahiti and has spread around other Pacific islands since then. However, this past May, is suddenly surfaced with a vengeance in Central and South America, particularly Brazil, where is has become an epidemic and is believed to have caused birth defects in almost 2,800 babies.

Like dengue, the symptoms can be mistaken for the flu. They include a fever, headaches, a rash, vomiting and joint pain and lasts up to a week. There is no vaccine or medicine to prevent Zika virus infection. Because of the overlapping incidence of Zika infections to pregnant women and babies born with brain defects (specifically microcephaly), the government of Brazil has cautioned women there against getting pregnant now.

Even though only one case of Zika has been identified on Puerto Rico, the U.S. Centers for Disease Control and Prevention (CDC) is taking no chances and issued a travel notice warning people going to Puerto Rico that they need to be vigilant in preventing mosquito bites.

Written and edited by Dyanne Weiss

U.S. Centers for Disease Control and Prevention: Travel & Dengue Outbreaks
U.S. Centers for Disease Control and Prevention: First case of Zika virus reported in Puerto Rico
Hawaii News Now: New cases of dengue fever on Hawaii Island bring total to 195
CBS: Mosquito-borne Zika virus found in Puerto Rico
UPI: Puerto Rico reports first locally-acquired case of Zika virus

Photo courtesy of Pan American Health Organization