Hawaii Island’s dengue fever outbreak appears to be the largest in the United States since World War II, according to various reports from the Centers for Disease Control and Prevention and other health sites. ADVERTISING Hawaii Island’s dengue fever outbreak
Hawaii Island’s dengue fever outbreak appears to be the largest in the United States since World War II, according to various reports from the Centers for Disease Control and Prevention and other health sites.
Hundreds and even thousands of cases have been reported in South and Central America, including areas in Mexico near the U.S. border with Texas, as well as within U.S. territories. But since at least 1946, no outbreak within the continental U.S., Alaska or Hawaii has matched the Big Island’s, which, as of Friday, stood at 146 confirmed cases of locally acquired dengue fever.
The distinction is difficult to make, however, largely because the disease is hard to identify and so many cases go unreported or unconfirmed, health experts say.
Meanwhile, some cases are often reported by people after being acquired in a foreign country. Such is the case with a single dengue fever case on Oahu which health officials identified shortly after the outbreak on the Big Island began. That case later was identified as having been acquired elsewhere.
State Epidemiologist Dr. Sarah Park said last week that American Samoa and Puerto Rico had seen “multiple dengue outbreaks with hundreds more (cases) on a regular basis. They’re technically a part of us … so I would not say we are the largest.”
She added that, when fighting an outbreak, focusing on numbers is not nearly as important as focusing on patterns of the disease’s spread.
“Each (outbreak) is different. And Hawaii presents a very different situation from its sister states,” she said. “Looking at numbers (in different areas), it’s like comparing apples and oranges.”
However, despite her insistence that the public shouldn’t focus on numbers, three different agencies, including the state Department of Health, the County of Hawaii and the county office of Civil Defense, continue to release on their websites, over radio broadcasts and via email blasts regular, daily updates on the growing number of confirmed cases as the DOH’s state laboratory works to identify the dengue virus in blood samples from suspected patients.
In a Friday email response to questions, CDC spokeswoman Candice Hoffmann said that her agency does not maintain a comprehensive list of U.S. dengue outbreaks, but she agreed that Hawaii’s outbreak is shaping up to be one for the record books.
“Yes, this is becoming the largest outbreak of reported dengue in a non-endemic area of the U.S. since 1946. Larger outbreaks have occurred in the past, in Hawaii and other states, when dengue was endemic in parts of the United States,” she wrote.
She added that there is not a threshhold number of confirmed infections at which point the federal government might take a more active role in Hawaii Island’s mosquito abatement efforts.
“Throughout the United States, vector control is typically staffed and funded at a local and state, not federal level. In most communities where mosquito-borne outbreaks are uncommon, like the Big Island, investments in vector control staffing, equipment and pesticides are limited,” Hoffmann wrote.
“No known mosquito control measure will stop dengue outbreaks, and it is unclear whether any of the currently employed measures will reduce significantly the number of new cases. CDC and DOH entomologists have done a great deal of mosquito trapping, and their findings can be used to provide vector control recommendations.”
The history of dengue fever in and around the U.S. goes back a long way, to the first suspected dengue outbreaks in 1635 in Martinique and Guadeloupe in the Caribbean and in 1699 in Panama, although clinical procedures for the time make it difficult to positively identify the illnesses as dengue. However, a description of a Philadelphia outbreak in 1780 is “clearly the (dengue fever) syndrome caused by dengue viruses,” reads a 2012 report on the National Library of Medicine website.
“Between 1845 and 1849 there is some evidence of dengue-like outbreaks in New Orleans, Cuba and Brazil,” the report reads. “An epidemic of dengue-like disease was reported after 1850 in New Orleans, Mobile, Ala., Charleston, S.C., and Augusta and Savannah, Ga. … In the following years, sporadic outbreaks were mentioned in the Gulf and Atlantic seaports in the United States, being the largest in 1873 in New Orleans, with 40,000 people affected, and followed by another large epidemic in several southern United States port cities between 1879 and 1880.”
The ensuing years saw more outbreaks in Texas, Louisiana, Florida and Georgia, including a 1922 outbreak of an estimated 30,000 cases of dengue-like disease. But in 1943, the modern era of dengue research began, when dengue viruses were first isolated and diagnostic lab tests became available.
That coincided with a large, Pan-American effort to eradicate the Aedes aegypti mosquito, the primary carrier of the dengue virus. Spraying with insecticides such as DDT began at an “unprecedented” level, the report said. Those efforts made huge dents in the population of the mosquito, but eventually the effort petered out.
Even so, between 1946 and 1980, there was not a single reported case of dengue fever being acquired within the continental U.S., according to a 2010 report on the CDC website.
But now, dengue infections are on the rise worldwide, and in recent years a number of outbreaks have struck areas in Florida, Texas and Hawaii. Most of those outbreaks were relatively small, however, with 29 cases confirmed in south Texas between 1995 and 1996, and 11 cases confirmed in Laredo, Texas, in 1999.
A small outbreak in Brownsville, Texas, in 2005 yielded three cases of locally acquired dengue, with 22 more people being infected after having traveled to Mexico.
Between 2009 and 2010, a dengue outbreak in Key West, Fla., affected 28 people, marking the first outbreak there in decades.
In 2001, an outbreak of locally acquired dengue was the first identified in Hawaii since 1944. A total of 1,644 people with dengue-like illnesses were evaluated by health officials and 122 cases were confirmed. They included four cases on Kauai, 26 cases on Oahu and 92 cases on Maui.
A second Hawaii outbreak in 2011 was confirmed on Oahu, when four people came down with dengue fever.
