Part of South Florida is now under a mosquito-borne illness alert, as new cases of dengue fever have been reported in Broward and Miami-Dade counties in recent days.Broward County reported its first case this year of locally transmitted dengue fever last Friday, while Miami-Dade reported its fourth such case.Mosquito control officials say the cases transmitted in our region come from South Florida mosquitoes that most likely have bitten people who have dengue when they come here from South and Central America and the Caribbean.The Pan American Health Organization says more than 2 million people in the tropical region have contracted the disease this year, while 723 have already died from it. Children tend to be most prone to becoming infected with it.Dengue is transmitted by bites from infected Aedes aegypti mosquitoes. Although those are the same types of bites that spread the Zika virus, dengue can be fatal in some cases.The most common symptoms associated with dengue include: high fever, severe headache, pain behind the eyeballs, and joint and muscle aches.Severe cases can include shock, internal bleeding and death.Bindu Mayi, professor of microbiology for the College of Osteopathic Medicine at Nova Southeastern University, says, “There is no cure for dengue and no antiviral agent we can give to shorten duration of illness. About one in 20 people will get a severe case and it has to be addressed. The best thing is prevention.”Officials suggest taking these precautionary measures:-Wear repellent products, and concentrations of up to 30 percent DEET. Other U.S. Environmental Protection Agency-approved repellents contain picaridin, oil of lemon eucalyptus, para-menthane-diol, or IR3535. They may be obtained from most pharmacies.-Wear shoes, socks, and long pants and long sleeves when outside, especially at dusk.-Drain water from garbage cans, house gutters, buckets, pool covers, coolers, toys, flower pots or any other containers where sprinkler or rain water has collected.-Repair broken screening on windows, doors, porches, and patios to keep mosquitoes out of the home.Mosquito control officials in Broward and Miami-Dade say they are in the process of doing additional truck spraying, in addition to house-to-house spraying, to prevent further spreading.Broward Mosquito Control adds that they are also going door-to-door with backpacks to spray, particularly in southern portions of the county.“We know where the areas are with the types of mosquitoes that carry dengue and we will treat those more aggressively,” says Ahn Ton, Broward County’s director of mosquito control.Miami-Dade Mosquito Control Division Director William Petrie says his division had already treated the neighborhood where the newest local case was reported, and will now treat that area again. He adds, “We will treat the area more intensively and target a wider area. We also will trap mosquitoes and send them off for testing.”To request a mosquito inspection or report a breeding ground in Miami-Dade, call 311. Broward County residents may request mosquito spraying by completing the Mosquito Spray Request Form at Broward.org, or by calling (954) 765-4062.