Fighting the Bite during Pandemics: Florida Mosquito Control District Capabilities during the COVID-19 crisis

Background The national wide lockdown order imposed in early April 2020 due to the COVID-19 outbreak has complicated mosquito control activities across the United States (US), and Florida is no exception. Mosquito control districts and public health programs are the rst line of defense against mosquitoes-borne pathogens in the state of Florida. The purpose of study is to understand how the COVID-19 outbreak has impact the capabilities of mosquito programs to implement key mosquito measures to mitigate emergence and/or re-emergence of arthropod-borne arboviral diseases. Methods In a self-administered online survey, we examined capabilities of all Florida mosquito control programs during the COVID-19 outbreak (both state-approved mosquito districts (N = 63) and public health programs (N = 27). Descriptive statistics were used to summarize information about characteristics of responding mosquito control districts and programs, implemented mosquito control and surveillance activities. We used Bivariate analysis to compare the characteristics of responding mosquito control districts and programs and the self-reported mosquito measures. on arboviral surveillance (serology and pool testing) due to the redirected state laboratory in This study highlights the importance of ongoing mosquito control activities and suggests that Florida mosquito control programs are vigilant and have signicant capability to handle potential mosquito-borne disease threats as evidenced by their continued surveillance and control efforts during the COVID-19 outbreak, and mitigation of the 2016 Zika disease outbreak. Findings have implications for local and state mosquito programs including national associations as they work towards mitigating the impacts that COVID-19 has had particularly on health department programs.


Abstract Background
The national wide lockdown order imposed in early April 2020 due to the COVID-19 outbreak has complicated mosquito control activities across the United States (US), and Florida is no exception.
Mosquito control districts and public health programs are the rst line of defense against mosquitoesborne pathogens in the state of Florida. The purpose of study is to understand how the COVID-19 outbreak has impact the capabilities of mosquito programs to implement key mosquito measures to mitigate emergence and/or re-emergence of arthropod-borne arboviral diseases.

Methods
In a self-administered online survey, we examined capabilities of all Florida mosquito control programs during the COVID-19 outbreak (both state-approved mosquito districts (N = 63) and public health programs (N = 27). Descriptive statistics were used to summarize information about characteristics of responding mosquito control districts and programs, implemented mosquito control and surveillance activities. We used Bivariate analysis to compare the characteristics of responding mosquito control districts and programs and the self-reported mosquito measures.

Conclusions
Findings underscore the importance of ongoing mosquito control activities and suggests that Florida mosquito control programs are vigilant and have signi cant capability to handle potential mosquitoborne disease threats, but arbovirus surveillance systems --laboratory testing of mosquito pools and testing of human and nonhuman specimens for arboviruses are needed during pandemics as well.

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There is no questions that mosquito-borne diseases pose a special challenge to public health practitioners and mosquito control districts [1][2][3], owing to their complex nature (biological transmission complexity) [4], and potential to transmit infectious agents that can lead to mosquito-borne diseases, such as malaria, dengue fever, chikungunya, Zika fever, and West Nile fever [5]. In Florida, Aedes and Culex continue to be major vector genera [6][7][8], with the State of Florida having been ground-zero for local transmission of Zika and Dengue viruses [9], and is in close proximity to Latin American where viruses such as Zika and dengue viruses are endemic [2,10]. Surveillance is a key aspect of effective mosquito control and prevention [2,11,12], and is particularly important in economically depressed subtropical areas of the United States (US) that institutionally struggle to sustain mosquito-control efforts [13]. Now the national wide lockdown order imposed in early April 2020 due to the COVID-19 outbreak has complicated mosquito control activities [14], and questioned how we should manage mosquito control programs in the wake of pandemics. The Centers for Disease Control and Prevention (CDC) underscore the importance of initiating or continuing the delivery of mosquito control and public health organization services during public health emergencies and responses to natural disasters" [15] to reduce the risk of mosquito-borne disease. Yet, the National Association of County and City Health O cials (NACCHO) reported COVID-19 impacts on mosquito programs that operate under the auspices of local health departments [21], despite the importance of mosquito control as a basic public health function. This, coupled with major funding and capacity gaps, may put pressure on some already struggling programs, and may exacerbate timely and effective response to (re)emergent arboviral diseases in the future [16]. Therefore, to understand the challenges inherent in implementing mosquito activities during a pandemic, we assessed the capabilities of Florida state-approved mosquito control districts and open programs to carry out mosquito control activities at a time when Florida was still under heightened awareness of and lockdown over the COVID-19 crisis. Our ndings will shed light on Florida mosquito control districts and program, the rst line of defense against mosquitoes-borne pathogens in the state's capabilities as well as challenges in carrying out mosquito control activities during a pandemic.

Study design
In June 2020, a cross-sectional survey was conducted using an anonymous electronic self-administered survey distributed to all Florida state-approved mosquito districts (n=63) and open programs (n=27) for a total of 90 programs. A team from the University of Miami conducted the survey, at a time when the state was in a COVID-19 "full phase 1 re-opening plan" [17], and on a 2-3 month postponement of the arbovirus surveillance program as the state virus laboratory in Tampa was redirected for COVID-19 response.

Survey Instrument
The survey instrument was re ned from previous similar studies to address the study objectives [16,[18][19][20] (Supplemental File 1). The survey was pilot tested with four mosquito districts and distributed using the online survey software Qualtrics. We obtained a list of agency contact information from the Florida Department of Agriculture and Consumer Services (FDACS).
The questionnaire consisted of 45 questions divided into six sections: mosquito district characteristics (8 questions); sta ng levels (4 questions); mosquito program capabilities and challenges (19 questions); program budgets (4 questions); COVID-19 communication (1 question); participant demographics and partnership needs (9 questions). Almost all but 10 questions consisted of closed-ended questions, which allowed respondents the opportunity to provide further detail if the 'other, please specify' option was selected from the multiple choices. The closed-ended questions were multiple choice, categorical, dichotomous and Likert-type questions with ve-point rating scales.

Study population
We recruited all Florida mosquito control districts (n=63) and mosquito programs (n=27) via email.
Representatives of mosquito control districts and programs were contacted directly and were asked to complete the survey by July 6. We sent follow-up reminders weekly during the rst two weeks in June, and every three days during the third and fourth week. Follow-ups constituted of both email and telephone calls. The survey closed on July 6, 2020. Program respondent anonymity was maintained and the researchers blinded by using the web-based survey tool (Qualtrics) for collection and collation of data.

Data analysis
Survey responses were analyzed using IBM SPSS Statistics, version 26.0 [21]. We used descriptive statistics to summarize information about characteristics of responding mosquito control districts and programs, implemented mosquito control and surveillance activities. Bivariate analysis was used to compare the characteristics of responding mosquito control districts and programs and the self-reported mosquito measures performed. Characteristics including respondents' mosquito program capabilities such as arbovirus, population, environmental surveillance and routine control of domestic mosquitoes including challenges were analyzed using the χ 2 test. Ordinal data collapsed into groups and analyzed as dichotomous groups, a conservative approach when using non-parametric tests. CC, the nature of self-reported changes to practice and characteristics of the respondents.

Mosquito district/program characteristics
Of the recruited programs, 77 completed the survey (85.6% response rate; 77/90). Five state-approved programs did not respond to the survey: one was due to a death of the mosquito director; one had the person responsible for mosquito activities reassigned to COVID-19 response, one did not have a person responsible for mosquito activities at the time of the survey and two did not respond. The excluded totaled four programs, including two that indicated not having a mosquito program (Baker and Lafayette Counties), and two with missing information on relevant measures. The nal sample was 73 programs (58 state-approved mosquito control districts and 15 open programs (Fig. 1).
Of the responding programs, 57.5% (n = 42) were Board of County Commissioners (BOCC) programs, 21.9% (n = 16) were independent tax districts, 13.7% (n = 10) were municipal programs, and only 6.8% (n = 5) were either health or emergency departments (Table 1). Nearly all responding programs (97.3%, n = 71) indicated performing mosquito control activities either fully or partially during the COVID-19 outbreak, and only 7.5% (n = 4) reported being highly impacted by COVID-19. Three quarters of respondents (75.0%, n = 51) did not perform arboviral surveillance (send mosquito pools for testing). It seems possible that these results are due to the redirection of the state health laboratory in Tampa to COVID-19 response, and similarities of testing supplies needed for COVID-19 and mosquito pool testing.

Mosquito program capabilities for arbovirus, population, environmental surveillance
When asked whether the COVID-19 outbreak will affect their scal year (FY) 2020/2021 budgets, 82.9% (n = 58) indicated no or that they were not sure. There is also large variation in the levels of main vector surveillance and control activities performed (   In some areas, Aedes aegypti has not been identi ed hence no control measures for this species were performed (eight BOCC programs, on independent tax district and one health or other department program). Likewise, one independent tax district reported the same for Aedes albopictus and Culex nigripalpus. Except for rain gauge and tidal surveillance, a chi-square test of independence showed no statistically signi cant difference in the proportion of programs who performed mosquito measures by organizational structure (Table 3).

Discussion
Although the risk of arboviral diseases in Florida is high, mosquito control programs in the state are vigilant and have signi cant capability to control potential mosquito-borne disease threats as evidenced by their surveillance and control efforts that were carried out during the COVID-19 outbreak. We observed a relatively impressive rst line of defense against the effects of mosquito-borne disease arboviruses -mosquito control, so much that there is some form of state-approved mosquito control district and/or program within each of Florida's counties whose mandate is to ght pest mosquitoes and species of mosquitoes that have potential to transmit mosquito-borne pathogens [24,25].
While we observed marked differences in the level of performed mosquito control activities, most programs (97.3%, 71 of 73), (including state-approved mosquito control districts and open mosquito programs) performed mosquito control activities either fully or partially particularly larval and adult surveillance during a time when the world is facing great challenges due to the COVID-19 outbreak. The majority of programs also engaged in routine control of domestic mosquitoes such as Aedes species of mosquitoes that can cause Aedes-borne arboviruses like dengue virus (DENV), chikungunya virus (CHIKV), yellow fever virus (YFV), and Zika virus (ZIKV) including Culex species of mosquitoes that can cause Culex-arboviruses like SLEV and WNV. In addition, mosquito surveillance is enhanced by the existence of ongoing meteorological, climatological, and water table monitoring [29]. This demonstrates that although Florida mosquito programs have a long history and experience with the Culex-arbovirus systems, these programs have the capability to provide mosquito control against Culex species as well, and as evidenced by the quick mitigation of the 2016 ZIKV outbreak [26].
Florida's mosquito control capabilities maybe attributed to the very nature of the ongoing mosquito control programs with permanent personnel, including several research projects that have been implemented over the years on mosquitoes and mosquito-borne diseases, which combined may have enhanced mosquito control capabilities as it relates to effective, e cient, and environmentally good mosquito control [27]. However, the lack of arbovirus surveillance for serology and pool testing observed during the COVID-19 crisis limits the generation of evidence about when to anticipate a surge in arbovirus infection and in programs' ability to detect or monitor arbovirus presence. This nding was also reported by Hadler et al. in their "assessment of arbovirus surveillance 13 years after the introduction of WNV in the US [28]. It is critically important to improve arbovirus surveillance, build the captivity of mosquito control districts and programs laboratories capacity to allow programs to investigate the circulating strains of arboviruses and to establish viral genomic databases as a reference for current and future research.

Conclusion
Our ndings suggest that despite the imposed COVID-19 lockdown, the vast majority of responding programs in Florida did not cease mosquito control operations. Those that remained open were mostly BOCC, municipal and independent tax district programs. However, the impact of COVID-19 testing was evident on arboviral surveillance (serology and pool testing) due to the redirected state laboratory in Tampa. This study highlights the importance of ongoing mosquito control activities and suggests that Florida mosquito control programs are vigilant and have signi cant capability to handle potential mosquito-borne disease threats as evidenced by their continued surveillance and control efforts during the COVID-19 outbreak, and mitigation of the 2016 Zika disease outbreak. Findings have implications for local and state mosquito programs including national associations as they work towards mitigating the impacts that COVID-19 has had particularly on health department programs.

Declarations
Ethics approval and consent to participate The Institutional Review Board (IRB) at the University of Miami determined that this study did not require IRB review since it posed the lowest amount of risk to potential subjects, was exempt from IRB approval and informed consent was not obtained from study participants.
(CDC) had no role in the design of the study, the collection, analysis, and interpretation of data, or in writing the manuscript.
Authors' contributions MIK was responsible for study design, developed the research questions and objectives for this study and performed analysis as well as wrote the manuscript. WRL, RX and CM led the data cleaning and data exploratory. OV was responsible for reviewing the manuscript for important intellectual content. All authors read and approved the nal manuscript.

Figure 1
Florida Mosquito Control Districts that responded to the survey conducted in June 2020 by program type

Supplementary Files
This is a list of supplementary les associated with this preprint. Click to download.