Right on the heels of a May 1st CBS News story reporting that the Center for Disease Control’s (CDC) Vital Signs publication revealed that mosquito and tick viruses had tripled from 2004-2016, Pest Control Technology magazine highlighted a study published by University of Florida (UF) researchers that speculates that another mosquito species may carry Zika virus. Led by UF/IFAS Medical Entomology Department’s Associate Professor, Chelsea Smartt, her team detected Zika virus in the saliva of southern house mosquitoes, collected from Gainesville and Vero Beach. The study revealed that further testing is needed to confirm early lab reports to establish a species, known as Culex quinquefasciatus, as a Zika carrier.
Zika first gained wide recognition in Brazil as the country underwent an outbreak of the virus just prior to the 2016 Rio de Janeiro Summer Olympics. A single-stranded RNA mosquito-borne arborvirus, Zika cycles between mosquitos and humans in urban environments. Brazil’s Zika outbreak in 2016 quickly spread to the southern US, “transmitted primarily by Aedes aegypti.” Currently, Aedes aegypti is still the primary Zika carrier. According to Smartt’s study, published in Frontiers in Microbiology, field-collected Culex quinquefasciatu from Brazil “were found infected with genome fragments of ZIKA and field collections from Mexico were found infected with live Zika.” However, lab report results differ concerning the viability of the Culex species to support Zika.
Zika and microcephaly
The major health concern regarding the spread of Zika centers on the cases of microcephaly that this virus can cause. Microcephaly, a rare neurological condition, results in infants born with significantly smaller heads than other newborns. While Zika has been hard to pin down as the definitive cause of microcephaly, many of the mothers whose babies were affected in Brazil reported an illness, according to IFL Science, “that was consistent with Zika virus infection in early pregnancy.” About a year before the critical numbers of microcephaly incidents occurred, a dengue-like illness, featuring fevers and rashes began in northeastern Brazil. Zika was identified as the cause six months later.
Culex quinquefasciatus is common in Florida
Meanwhile, as Smartt indicated, more research and experimentation is required to determine what role, if any, Culex quinquefasciatus, aka southern house mosquitoes, play in the spread of the Zika virus. While southern house mosquitoes are common in the southern states, they thrive in abundance in Florida. Culex quinquefasciatus, found in tropical and sub-tropical areas, like most mosquitoes, is common also in Brazil, Africa, and Southeast Asia.
Much attention and research worldwide, in addition to Smartt’s study, are underway to understand the origins of Zika and gain insights about how to control the virus. “In areas of the world where these mosquitoes feed on humans, there may be populations of Culex quinquefasciatus that can spread Zika,” Smartt said.
Nine new vector-transmitted diseases since 2004
In the CDC’s Vital Signs report, the agency also reported that nine new tick and mosquito germs have been discovered since 2004. CDC director, Robert R. Redfield, M.D. said in a briefing, “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.”
Globalization and rising temps
When asked about the reasons for the increases in occurrences of vector-related diseases, one of the study’s authors and the CDC’s director of vector-borne diseases, Lyle Peterson, M.D., said that, continued globalization has played an important role, especially when it comes to mosquito-borne diseases, noting that with “expanding global travel and trade, all of these diseases are basically a plane flight away.” Lyle went on to say, “This was the case during the 2016 Zika outbreak, which began in Brazil and spread to other parts of South and North America,” after mosquitoes bit infected travelers who unknowingly brought the virus home.” The CDC said also that warmer temps and longer warm seasons are playing an important role in tick populations moving north.
For the first line of defense in controlling mosquito and tick diseases, the CDC suggests
State and local health agencies should develop and sustain programs that test and track diseases spread by mosquitoes and train vector control staff on the five core competencies used in prevention and control protocols including:
- Conducting routine mosquito surveillance through standardized trapping and species identification and make treatment decisions using surveillance data.
- Applying larvicides and adulticides or both.
- Conducting routine vector control activities that include biological, source reduction and environmental management.
- The CDC stresses the importance of state and local health agencies launching initiatives that educate and remind the public to take precautions during outdoor activities, by increasing community and neighborhood awareness.
In addition to education, monitoring and reducing mosquito populations on the state and local level, Hulett would like to remind South Florida homeowners that vigilance in your own backyard will help prevent mosquitoes from ruining your summer. With mosquito-borne disease on the rise, applying insect repellant when gardening, mowing or entertaining is an essential precaution as is:
- Repairing or replacing window and door screens
- Removing all containers from your property that can collect water
- Changing water in bird baths at least once a week
- Correcting all water prone areas where mosquitoes might breed
Many products, such as citronella and DEET only mask the scents that attract mosquitoes to humans. If mosquitoes are putting a damper on your outdoor plans, contact Hulett to learn more about our Mosquito Reduction Program. Our licensed and certified technicians will inspect your property, identifying areas where mosquitoes are likely to breed and hide. Treating those areas with a residual product, we also apply a sticking agent to areas where mosquitoes rest in the daytime. A micro-encapsulated product applied to all entryways will create a protective barrier from mosquitoes and other insects. Enjoy your summer without the worry of mosquitoes ruining your plans. Just call Hulett!