Seasonal Dynamics of Mosquito-Borne Viruses in the Southwestern Florida Everglades, 2016, 2017

Mosquitoes were collected for 12 consecutive months beginning June 2016, from 11 locations in the Florida Everglades, Collier County, and tested for viruses by isolation in Vero cells and subsequent identification. One species complex and 31 species of mosquitoes were identified from 668,809 specimens. Ochlerotatus taeniorhynchus comprised 72.2% of the collection. Other notable species were Anopheles crucians complex, Culex nigripalpus, Cx. erraticus, and Cx. cedecei. Seven species of virus were identified from 110 isolations: Everglades, Gumbo Limbo, Mahogany Hammock, Pahayokee, Shark River, Tensaw, and West Nile viruses. Everglades, West Nile, Tensaw, and Mahogany Hammock viruses were most frequently isolated. Largest numbers of viruses were identified from Cx. cedecei, Cx. nigripalpus, and An. crucians complex. Five species of virus were isolated from Cx. cedecei. Viruses were isolated from mangrove, cypress swamp, hardwood hammock, and sawgrass habitats. West Nile virus was isolated August through October when Cx. nigripalpus was most abundant. Everglades virus was the most frequently isolated virus from nine species of mosquitoes collected from June through August. Tensaw virus was isolated primarily from Anopheles species. Isolations were made in July, August, January, February, and April, suggesting that this virus may be present in host-seeking mosquitoes throughout the year. Mahogany Hammock, Shark River, Gumbo Limbo, and Pahayokee viruses were isolated primarily from Cx. cedecei from June through December. Shotgun metagenomic sequencing was used to document that seven pools of Cx. cedecei were infected with two arboviruses. As communities expand into the Everglades, more humans will become exposed to arboviruses.

Reducing Vehicle Submersions and Consequent Fatalities on Highway I-75 in Florida (Alligator Alley): Effectiveness of a Cable Safety Barrier System

Objective: We evaluated the effectiveness of a Cable Safety Barrier (CSB) system in preventing Run-Off-Road (ROR) Vehicle Immersions (VIs) and fatalities in canals along the I-75 freeway (Alligator Alley) in Collier County, Florida. The CSB system, which runs along both sides of the 80-km stretch of freeway and was installed between 2003 and 2004. Methods: Data from the Fatal Analysis Reporting System (FARS) were used to compare annual VIs and VI fatalities between pre-installation of the CSB system (1995-2002) to post-installation (2005-2012). As well, post-installation data from the Florida Department of Transport (FDOT) (2007-2011) and police reports were reviewed to determine the number of, and manner in which, vehicles were either contained by, or crossed, the CSB by either penetrating or overriding the barriers. Results: Pre- to post-installation, total accidents increased from 81.4/y to 106.2/y, accidents resulting in VIs decreased from 13.8% to 2.4%, and accidents resulting in VI fatalities decreased from 3.4% to 0.4% (FDOT). Fatal vehicle immersions decreased from 2.4/y to 0.9/y (P<0.01) and vehicle immersion fatalities decreased from 3.3/y to 1.4/y (P<0.05) (FARS). Post-installation, 531 accidents occurred with 110 ROR vehicles travelling towards the canals; 91 vehicles contacted the CSB with only 14 vehicles (15.4%) penetrating the barrier, and 7 (7.7%) overriding the barrier (FDOT). Conclusion: The CSB system along I-75 in Collier County dramatically decreased ROR vehicles from reaching the parallel canals, and consequent vehicle immersion fatalities. Results support the installation of lateral CSB systems on other high-risk roadways to reduce ROR crashes into water, or with other secondary hazards.

COVID-19 Pandemic Response in a Migrant Farmworker Community: Excess Mortality, Testing Access and Contact Tracing in Immokalee, Florida

Introduction: We aim to estimate the impact of COVID-19 in Immokalee, FL and assess community experiences with workplace conditions, access to testing, sources of information, and contact tracing to inform and strengthen local public health sector efforts in reaching and providing high-quality care to the community. Methods: We conducted a descriptive analysis of data on COVID-19 deaths for Collier County from May-August 2020. We surveyed a cross-sectional, randomized representative sample of 318 adults living in Immokalee from March-November 2020 to assess socio-demographics, sources of information, ability to follow guidelines, and experiences with local programs. Results were compared across language groups. Results: Average excess mortality in Collier County was 108%. The majority surveyed in Immokalee had socio-demographic factors associated with higher COVID risk. Non-English speakers had higher workplace risk due to less ability to work from home. Haitian Creole speakers were less likely to be tested, though all participants were willing to get symptomatic testing and quarantine. Those participants who tested positive or had COVID-19 exposures had low engagement with the contact tracing program, and Spanish-speakers reported lower quality of contact tracing than English speakers. Conclusions: The community of Immokalee, FL is a vulnerable population that suffered disproportionate deaths from COVID-19. This study reveals language inequities in COVID testing and contact tracing should be targeted in future pandemic response in Immokalee and other migrant farmworker communities

Changes in Pumping-Induced Groundwater Quality Used to Supply a Large-Capacity Brackish-Water Desalination Facility, Collier County, Florida: A New Aquifer Conceptual Model

Brackish-water reverse osmosis (BWRO) desalination facilities are designed to treat feedwater within a fixed range in salinity. If the salinity and ion concentrations of the feedwater rises above the maximum design concentrations, then the plant may ultimately fail. BWRO plants typically use groundwater as a feedwater source. Prior to the process design, a detailed groundwater assessment is made to characterize the source aquifer system and to develop a solute-transport model that is used to project the changes in water quality over the expected useful life of the facility. Solute transport-modeling performed for the Collier County (Florida) South BWRO facility, which was designed to produce 30,303 m3/d with an expansion to 75,758 m3/d, used an aquifer system conceptual model that assumed upwards migration over time of brackish waters with higher salinities into the production zones. This conceptual model is typical of how most BWRO systems developed in the United States operate. The original solute transport model predicted a range of increases in dissolved chloride concentrations over a 20-year period from a low of 5 mg/L/yr, a mid-range of 35 mg/L/yr, and a high range of 85 mg/L/yr. Actual data collected over a 11- to 13.5-year period showed that the dissolved chloride concentration average of the feed water decreased by 16 mg/L/yr. The original conceptual model was found to be inaccurate in that it suggested an upwards recharging system, whereas downward leakage (or perhaps lateral migration) of fresher water appears to be occurring in the system. This is an example of a long-term solute-transport model audit, which is rarely performed, in which a new conceptual model was found to be applicable to an aquifer system used to feed a BWRO facility.

ORNAMENTAL BROMELIADS OF LOCAL BOTANICAL GARDENS SERVE AS PRODUCTION SITES FOR PYRETHROID-RESISTANT CULEX QUINQUEFASCIATUS (SAY) IN COLLIER COUNTY, FLORIDA

The Naples Botanical Garden, located in Collier County, Florida, attracts over 220,000 visitors each year. The gardens house a collection of plants from around the world, including a featured area for over 100 species of exotic and native bromeliads. Ornamental bromeliads have previously been investigated to define their “tank” structure as a haven for mosquito eggs and larvae. The Naples Botanical Gardens was investigated for the presence of juvenile mosquitoes inhabiting large-tanked bromeliads. A survey of mosquito species inhabiting bromeliads in the gardens indicated that the most abundant species was Culex quinquefasciatus. With the ongoing threat of vector borne diseases such as West Nile virus, the abundance of vector mosquitoes and heavy tourist traffic in the gardens, insecticide resistance testing was performed on Cx. quinquefasciatus originating in the gardens in order to assess the ability of pyrethroid-based insecticides used by the local vector control agency to successfully target this species in the event of a disease outbreak. We identified pyrethroid resistance in Cx. quinquefasciatus collected from Naples Botanical Gardens, and that oxidase activity was the primary mechanism responsible for its pyrethroid resistance status.

The Impact of Hurricane Irma on Our Community and the Collier Mosquito Control District's Mission

ABSTRACT The Collier Mosquito Control District, located in southwest Florida, is uniquely positioned in a subtropical environment between the Gulf of Mexico and Everglades National Park. The District's mission is focused on the control of disease vector and nuisance mosquitoes in Collier County, which is accomplished through integrated mosquito management. Hurricane Irma made landfall in the county on September 10, 2017, leaving in its wake tremendous property and infrastructure damage, and it also disrupted communications and airport operations. These factors greatly affected the District's operations and its ability to meet its mission. In addition, the lengthy loss of electrical power forced most residents outdoors, increasing their exposure to mosquitoes. From challenges in completing poststorm treatments to outdated policies that caught us off-guard, the event prompted a new hurricane policy and plan to ensure improved preparedness for the next natural disaster. The poststorm environment also provided a rich foundation for research into mosquito populations after tropical disturbances of this scale. Here we report the impact on the District's aerial mosquito control operations, changes to internal policies, and mosquito population abundance following Hurricane Irma.

Oxidase, Esterase, and KDR-Associated Pyrethroid Resistance in Culex quinquefasciatus Field Collections of Collier County, Florida

ABSTRACT In several insect species, resistance to pyrethroids and DDT (dichlorodiphenyltrichloroethane) is linked to point mutations in the voltage-gated sodium channel (VGSC) gene. Pyrethroid-based insecticides prolong the opening of sodium channels, causing paralysis known as a “knockdown” effect before mortality occurs. Point mutations in the VGSC gene result in decreased pyrethroid binding and reduced sensitivity to the insecticide—this resistance mechanism is known as knockdown resistance (kdr) as insects do not die but recover from paralysis with time. In Culex mosquito species loss of target site sensitivity to pyrethroids is linked to a number of substitutions, one of which is leucine (L) to phenylalanine (F) at residue 1014 (L1014F) in the VGSC gene. Here we report the identification of kdr-associated pyrethroid resistance and developing resistance in Cx. quinquefasciatus field collections from Collier County, FL. Evaluation of position 1014 of the VGSC in Cx. quinquefasciatus collections from 7 locations in Collier County, FL, revealed a wide range of genotypes from one part of the district to the other. Centers for Disease Control and Prevention bottle bioassay, linear regression analysis, and cage trial evaluations suggest that the L1014F mutation plays a role, at least in part, to the pyrethroid resistance status of Cx. quinquefasciatus collected in Collier County, FL. Furthermore, we identified resistance attributed to both oxidase and esterase activity, indicating that multiple mechanisms are responsible for pyrethroid resistance in Collier County Cx. quinquefasciatus.

High Incidence of Hypopigmented Marks in the Endangered Florida Bonneted Bat

Aberrant patches of white skin or fur known as hypopigmented marks have been observed in many mammal species worldwide, but they are typically limited to only a few individuals in a population. Hypopigmented marks were documented in only two museum specimens of the federally endangered Florida bonneted bat (Eumops floridanus) as early as 1950, but recent observations suggest that these marks may be more common in this species than previously believed. To better understand the occurrence and persistence of hypopigmented marks in Florida bonneted bats, we evaluated the variation in frequency, compared effects on survival, and assessed spatial and temporal differences of specimens at an intensively studied site and across the species range. From 2014 through 2017, we regularly captured Florida bonneted bats for demographic studies at Babcock–Webb Wildlife Management Area in Charlotte County and we observed hypopigmented marks on 172 (80.8%) of 213 individuals, the highest incidence known for bats. The proportion of hypopigmented marks did not differ with sex, age at first capture, or reproductive status, and importantly, we documented the persistence of hypopigmented marks in individuals over multiple months. We also found no difference in survival or capture probability between hypopigmented and solid-colored individuals. Using data from concurrent mist-net studies, we assessed the proportion of Florida bonneted bats with hypopigmented marks across the species range and found a higher proportion of individuals with hypopigmented marks in the two northern counties (80.8% in Charlotte County and 61.5% in Polk County) compared with the two southern counties (21.1% in Miami–Dade County and 16.7% in Collier County). Additionally, we compared the proportion of hypopigmented individuals in Miami–Dade County between recently captured/collected bats (post-2004) and historically (pre-1965) collected museum specimens and found more hypopigmented marks in recently captured bats. The persistence of hypopigmented marks over time, the presence of marks on bats from different locations, and our finding of no effect of age on the presence of marks all strongly suggest that the hypopigmented marks in Florida bonneted bats are the result of genetic rather than environmental factors. Further study is required to understand the mechanism underlying the high incidence of hypopigmented marks and to determine whether the prevalence of hypopigmented marks indicates low genetic diversity that could threaten Florida bonneted bats.

Watermelon Pest Management Strategic Plan (PMSP)

Florida ranks first in the U.S. in the production of watermelon, accounting for nearly 20 percent of national production. In 2001-2002, 759 million pounds of watermelon valued in excess of $62 million were produced on 23,000 acres ($2,700/acre). Concentrated production occurs in the southern region of the state during the winter months. As the spring arrives, plantings start northward and scatter out across the state. For this reason, a Pest Management Strategic Plan (PMSP) meeting for the Florida watermelon industry was conducted October 14, 2004 at the UF/IFAS Southwest Florida Research and Education Center in Collier County, Florida. This document is PI-52, one of a series of the Pesiticide Information Office, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date August 2005.