If mosquitoes had read the Center for Disease Control's (CDC) May report, they would have been proud of the dramatic increase in the reporting of vector-borne diseases from 2004 to 2016. Unfortunately for us humans, new mosquito viruses that may threaten the continental US appear to be in the news quite frequently. The most recent CDC report, by Director Robert R. Redfield, M.D. provided this upsetting remark, "Zika, West Nile, Lyme, and Chikungunya - a growing list of diseases caused by the bite of an infected mosquito, tick, or flea - have confronted the US in recent years, making a lot of people sick. And we don't know what will threaten Americans next." Not comforting news.

University of Florida researchers concerned about a new virus

The latest mosquito virus to concern University of Florida (UF) researchers, according to a Pest Control Technology article, is responsible for an outbreak in Venezuela and is "spreading to other parts of the Americas." Closely monitoring the Mayaro virus, Barry Alto, Associate Professor of Entomology at the University of Florida Institute of Food and Agricultural Sciences (IFAS), in Gainesville, is heading up a study which will hopefully figure out whether or not mosquitoes, common in Florida, could transmit the Mayaro virus to humans. Alto noted, that in 2016, a child in Haiti had contracted the disease.

Study finds mosquitoes in South Florida could carry new virus

Alto and his research team found in a new study, published in the journal, Medical and Veterinary Entomology, that yellow fever mosquitoes and Asian tiger mosquitoes, both abundant in South Florida, are capable of carrying the Mayaro virus. Alto elaborated, saying because the Mayaro virus is spreading in the Western Hemisphere, there is reason for concern, as in the past decade, "Florida has experienced outbreaks of other mosquito-borne viruses, including Zika, chikungunya, and dengue."

Mosquito virus outbreaks in other parts of the world are locally transmitted to Florida

The CDC's report also went on to say that historically, before these mosquito viruses are locally transmitted in Florida, they have caused outbreaks in other parts of the world, particularly in the southern part of North America and South America. Notably, the Zika virus struck Brazil during the 2016 Summer Olympics and currently, an outbreak of yellow fever in Brazil is showing up in urban centers, for the first time. A faculty member of the UF/IFAS Florida Medical Entomology Laboratory in Vero Beach, Alto said that increases in mosquito-borne viruses in the Americas, especially those transmitted by mosquitoes that live in Florida, increases the risk of imported and local mosquito-borne viral transmission in the US. "We should probably be moderately concerned that this virus could show up in Florida," Alto said, "Florida's wet, warm climate and presence of yellow fever and Asian tiger mosquitoes, coupled with a lot of human travel, makes the state susceptible to transmission of mosquito-borne viruses."

Globalization is part of the reason for the rise in mosquito viruses in the US

A CBS News article reported that in the Center for Disease Control's report in Vital Signs, "The number of illnesses caused by mosquito, tick, and flea bites have tripled in the United States over the last 13 years," with over 640,000 cases reported and the actual number of illnesses, "likely much higher." While the reason for increasing vector-borne illnesses is "complex and varied," according to the CDC, one of the report's authors, Lyle Peterson, "especially when it comes to mosquitoes, increasing globalization plays an important role in spreading mosquito viruses." He also noted, "expanding global travel and trade, all of these diseases are basically a plane flight away." Peterson went on to point out that during the 2016 Zika outbreak that began in Brazil, spread to South America and then to North America, travelers bit by infected mosquitoes unknowingly brought the virus home. Also, a 2017 report, entitled, The Lancet Countdown: Tracking Progress on Health and Climate Change, warned that in addition to continued globalization, "seasonal patterns and warming [temps] may also speed up mosquito biting rates, accelerate the mosquito life cycle, and decrease the time needed for an infected mosquito to transmit West Nile Virus."

Researchers tested mosquitoes' saliva to determine infectiousness

In the recent UF study, Alto and his colleagues, Indian River College students, Keenan Wiggins and Bradley Eastmond, tested the saliva of yellow fever and Asian tiger mosquitoes to determine infectiousness for Mayaro virus. Infectiousness refers to the state in which mosquitoes can transmit the Mayaro virus, as a result of biting animals and humans. The research team revealed that both species proved "highly susceptible to infection and that the virus readily spread throughout the mosquitoes' bodies." However, Alto said, "far fewer mosquitoes became infected," when they were exposed to the virus. Like Chikungunya virus, Mayaro virus is an alphavirus, belonging to the Togaviridae family of enveloped RNA viruses. Initially discovered by Charles Anderson in the 1950s, Mayaro virus was isolated from humans with febrile illnesses in Trinidad and later characterized as an alphavirus by Jordi Casals and L. Whitman. Outbreaks were later also reported in Bolivia and Brazil. According to a Baylor University study, Mayaro causes symptoms similar to chikungunya. Mayaro symptoms include fever lasting three to five days, chills, headache, rash and severe joint pain, which may persist for months. In light of the CDC's report, Hulett advises South Florida residents to take precaution when working or playing outdoors. You can help deter emerging mosquito viruses from affecting your summer fun by:

  • Repairing or replacing all torn window and door screens.
  • Eliminating standing water on your property and correct places where water can collect.
  • Making sure gutters are clean and downspouts face away from your foundation.
  • Keep your lawn cut short and your property free of clutter.
  • Wear mosquito repellent when spending time outdoors.

If mosquitoes are making you rethink your outdoor plans for this summer, contact Hulett for a free mosquito inspection. Take back your summer from the mosquitoes and protect your family from mosquito-borne illnesses. Just call Hulett!!