Mosquito district and program characteristics
Of the recruited mosquito programs, 77 of 90 mosquito programs completed the survey (85.6% response rate). 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 final sample was 73 programs (58 state-approved mosquito control districts and 15 open programs (Figure 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).
Table 1
Characteristics of responding mosquito control districts during the COVID-19 pandemic, Florida, USA, June 2020
Organizational Structure
|
n
|
%
|
95% CI
|
Board of County Commissioners (BOCC)
|
42
|
57.5
|
(46.6 – 69.9)
|
Municipal
|
10
|
13.7
|
(6.8 – 21.9)
|
Independent Tax District
|
16
|
21.9
|
(12.3 – 31.5)
|
Health Department or other department
|
5
|
6.8
|
(1.4 – 13.7)
|
Program Type
|
|
|
|
State-approved program
|
58
|
79.5
|
(69.9 – 89.0)
|
Open programs
|
15
|
20.5
|
(11.0 – 30.1)
|
Did you operate during the pandemic?
|
|
|
|
Yes, fully open and operating
|
44
|
60.3
|
(49.3 -72.6)
|
Partially operating with limited activities
|
27
|
37.0
|
(24.7 – 47.9)
|
No, closed operation until further notice
|
2
|
2.7
|
(0.0 – 6.8)
|
To what extent has COVID-19 affected your mosquito activities?
|
|
|
|
High
|
4
|
7.5
|
(1.9 – 15.1)
|
Medium
|
12
|
22.6
|
(11.3 – 34.0)
|
Low
|
37
|
69.8
|
(56.6 – 81.1)
|
Did you carry out non-chemical control activities?
|
|
|
|
Yes
|
37
|
54.4
|
(42.6 – 67.6)
|
No
|
29
|
42.6
|
(30.9 – 55.9)
|
Not sure
|
2
|
2.9
|
(0.0 – 7.4)
|
Did you conduct pesticide resistance testing?
|
|
|
|
Yes, full capacity
|
11
|
16.2
|
(7.4 – 25.0)
|
No, we did not
|
51
|
75.0
|
(64.7 – 85.3)
|
Yes, limited capacity
|
4
|
5.9
|
(1.5 – 11.8)
|
Do not have a program or not applicable
|
2
|
2.9
|
(0.0 – 7.4)
|
Will the pandemic affect your FY2020-2021 budget?
|
|
|
|
Yes
|
12
|
17.1
|
(10.0 – 25.7)
|
No
|
22
|
31.4
|
(20.0 – 42.9)
|
Not sure
|
36
|
51.4
|
(38.6 – 62.9)
|
Can you hire interns/seasonal workers?
|
|
|
|
Yes
|
16
|
25.4
|
(15.9 – 36.5)
|
No
|
47
|
74.6
|
(63.5 – 84.1)
|
Are staffing levels inadequate due to furloughs or lockdown?
|
|
|
|
Yes
|
8
|
12.3
|
(4.6 – 21.5)
|
No
|
57
|
87.7
|
(78.5 – 95.4)
|
Did you communicate with state/local public health departments?
|
|
|
|
Yes
|
50
|
71.4
|
(60.0 – 81.4)
|
No
|
20
|
28.6
|
(18.6 – 40.0)
|
Note: Excluded are four programs with missing data and those that do not have mosquito programs (e.g., Barker and Lafferty County). Health department includes emergency management programs.
Nearly all responding programs (97.3%, n=71) indicated performing mosquito control activities either fully or partially during the COVID-19 pandemic, 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 pandemic will affect mosquito control programs’ fiscal year (FY) 2020/2021 budgets, 82.9% (n=58) indicated no or that they were not sure (results not shown). There is also large variation in the levels of main vector surveillance and control activities performed (Table 2). For example, while most mosquito control programs (both state approved and open programs) did not perform arbovirus surveillance using flocks of sentinel chickens (84.1%, n=58) or mosquito pooling (83.8%, n=68), the majority maintained larval and adult surveillance during the COVID-19 pandemic (61.8%, n=68 vs 78.9%, n=71). More than three-quarters of mosquito control programs (70.8%, n=65) did not conduct arbovirus surveillance using tidal surveillance, while 35 (49.3%) of programs monitored temperature, wind and daylight. Of the responding mosquito programs, 36 (53.7%) used rain gauges for surveillance, p<0.022. Climatic factors such as temperature, humidity, and rain have been linked to mosquito abundance and transmission (13, 22, 23).
Table 2
Arbovirus surveillance activities conducted during the COVID-19 pandemic, Florida, USA, June 2020
Did you conduct arbovirus surveillance during the COVID-19 pandemic using the following:
|
Yes, full or limited capacity
n (%)
|
No, we did not conduct this arbovirus surveillance activity n (%)
|
Fisher’s exact test
|
P-value
|
Using flocks of sentinel chickens
|
|
|
|
Board of County Commissioners (BOCC) Programs
|
9 (21.4)
|
33 (78.6)
|
0.110
|
Other Mosquito Programs
|
2 (7.4)
|
25 (92.6)
|
|
Using mosquito pooling
|
|
|
|
Board of County Commissioners (BOCC) Programs
|
9 (22.0)
|
32 (78.0)
|
0.102
|
Other Mosquito Programs
|
2 (7.4)
|
25 (92.6)
|
|
Larval surveillance
|
|
|
|
Board of County Commissioners (BOCC) Programs
|
26 (61.9)
|
16 (38.1)
|
0.588
|
Other Mosquito Programs
|
16 (61.5)
|
10 (38.5)
|
|
Adult surveillance
|
|
|
|
Board of County Commissioners (BOCC) Programs
|
36 (85.7)
|
6 (14.3)
|
0.081
|
Other Mosquito Programs
|
20 (69.0)
|
9 (31.0)
|
|
With rain gauges
|
|
|
|
Board of County Commissioners (BOCC) Programs
|
17 (42.5)
|
23 (57.5)
|
0.022
|
Other Mosquito Programs
|
19 (70.4)
|
8 (29.6)
|
|
Tidal surveillance
|
|
|
|
Board of County Commissioners (BOCC) Programs
|
9 (23.1)
|
30 (76.9)
|
0.145
|
Other Mosquito Programs
|
10 (38.5)
|
16 (61.5)
|
|
Temperature, wind and daylight was monitored
|
|
|
|
Board of County Commissioners (BOCC) Programs
|
24 (57.1)
|
18 (42.9)
|
0.088
|
Other Mosquito Programs
|
11 (37.9)
|
18 (62.1)
|
|
Note: Other mosquito programs includes independent tax district, municipal and health department or other department mosquito programs
Mosquito program capabilities for routine control of domestic mosquitoes
Despite the wide variation in performed mosquito activities, both state-approved and open programs either fully or with limited capacity performed control activities for Aedes aegypti (85.2%, n=46), Aedes albopictus (87.3%, n=55), Culex quinquefasciatus (92.1%, n=58), and Culex nigripalpus (91.9%, n=57). In some areas, Aedes aegypti has not been identified hence no control measures for this species were performed (eight BOCC mosquito control programs, one independent tax district and one health department program). Likewise, one independent tax district reported the same for Aedes albopictus and Culex nigripalpus. Except for rain gauge, a Fisher’s exact test of independence showed no statistically significant difference in the proportion of programs that performed mosquito measures by organizational structure (Table 3).
Table 3
Arbovirus control activities conducted during COVID-19 pandemic, Florida, USA, June 2020
Did you engage in routine control of these domestic mosquitoes during the COVID-19 pandemic?
|
Yes, full or limited capacity
n (%)
|
No, we did not conduct this arbovirus surveillance activity n (%)
|
Species not identified in the area
n (%)
|
χ2
|
P-value
|
Aedes aegypti
|
|
|
|
|
|
BOCC Programs
|
28 (71.8)
|
3 (7.7)
|
8 (20.5)
|
3.373
|
0.185
|
Other Mosquito Programs
|
18 (72.0)
|
5 (20.0)
|
2 (8.0)
|
|
|
Aedes albopictus
|
|
|
|
|
|
BOCC Programs
|
34 (89.5)
|
4 (10.5)
|
0 (0.0)
|
1.889
|
0.389
|
Other Mosquito Programs
|
21 (80.8)
|
4 (15.4)
|
1 (3.8)
|
|
|
Culex quinquefasciatus*
|
|
|
|
|
|
BOCC Programs
|
35 (92.1)
|
3 (7.9)
|
0 (0.0)
|
|
0.666
|
Other Mosquito Programs
|
23 (92.0)
|
2 (8.0)
|
0 (0.0)
|
|
|
Culex nigripalpus
|
|
|
|
|
|
BOCC Programs
|
35 (92.1)
|
3 (7.9)
|
0 (0.0)
|
1.548
|
0.461
|
Other Mosquito Programs
|
22 (88.0)
|
2 (8.0)
|
1 (4.0)
|
|
|
Note: BOCC, Board of County Commissioners; Other mosquito programs, includes independent tax district, municipal and health department or other department mosquito programs; *, Fisher’s exact test