Florida Mosquito Control Association

 

Arbovirus Surveillance Reports - 2007

May, June, July

Arbovirus activity continues at lower than average levels.  In May there were seven seroconversions due to alphaviruses, five to Eastern Equine Encephalitis virus (EEE), resulting in seroconversion rate of 0.3% and two to Highlands J (HJ), rate of 0.1%.  During June there were 12 alphavirus seroconversions (8 to EEE, 0.5% rate and 4 to HJ, 0.3% rate) and 17 in July, 14 to EEE (0.9%) and three to HJ (0.2%).  This level of activity is similar to the historical median levels for those months.

Sentinels seroconverted to flavivirus positive (St Louis Encephalitis virus (SLE) antigen used in the HAI assay): three to WN in May and 7 to WN in June; these levels of activity are similar to historic levels.  During July there were three seroconversions to WN and one to SLE.  WN activity is similar to that of 2006, but lower than seen during 2002 - 2005.

Sera from live wild birds were screened by HAI.  Table 1 lists submissions and results by county by month for Alphavirus antibody.  Table 2 lists submissions and results by county by month for flavivirus antibody.

Dead animal submissions for arbovirus testing (birds, mammals, reptiles) are listed by county in table 3.  Numbers of such submissions have been very low compared to past years.  EEE virus was detected in a horse from Washington County, submitted at the end of June, as well as from another horse submitted from Alachua County however, that horse had been infected in Georgia.  Species submitted are listed in Table 4. 

Mosquito pools were assayed for arboviruses by real-time RT-PCR and cell culture inoculation.  Submissions by county are presented in table 5.  No viruses were detected.

Table 1: Alphavirus antibody positive live wild birds


Alphavirus

# birds

total EEE+

black-bird

blue jay

cardinal

cow-bird

dove

finch

grackle

grosbeak

mocking-bird

sparrow

thrasher

titmouse

June

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

45

7

0+/6

6+/18

1+/9

 

0+/1

0+/4

0+/2

 

 

 

0+/4

0+/1

Santa Rosa

41

6

2+/4

3+/6

1+/17

0+/3

 

0+/5

0+/4

0+/1

0+/1

 

 

 

Walton (North)

49

5

0+/1

0+/4

3+/29

 

 

 

 

 

 

2+/11

 

 

Washington

56

5

0+/4

0+/2

4+/4

 

 

 

 

 

 

1+/16

 

 

totals

191

23

2+/15

9+/30

9+/93

0+/3

0+/1

0+/9

0+/6

0+/1

0+/1

3+/27

0+/4

0+/1

July

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

40

8

0+/2

6+/14

1+/19

 

 

 

1+/1

 

 

 

 

0+/4

Santa Rosa

31

4

 

1+/2

1+/14

1+/1

 

0+/2

0+/1

0+/1

0+/4

 

1+/6

 

Walton (North)

34

3

 

1+/1

0+/24

 

 

 

 

 

 

2+/9

 

 

Washington

36

1

0+/4

0+/1

1+/23

 

 

 

 

 

 

0+/8

 

 

totals

141

16

0+/6

8+/18

3+/80

1+/1

 

0+/2

1+/2

0+/1

0+/4

2+/17

1+/6

0+/4

Table 2: Flavivirus antibody positive live wild birds


Flavivirus

# birds

total EEE+

black-bird

blue jay

cardinal

cow-bird

dove

finch

grackle

grosbeak

mocking-bird

sparrow

thrasher

titmouse

June

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

45

0

0+/6

0+/18

0+/9

 

0+/1

0+/4

0+/2

 

 

 

0+/4

0+/1

Santa Rosa

41

0

0+/4

0+/6

0+/17

0+/3

 

0+/5

0+/4

0+/1

0+/1

 

 

 

Walton (North)

49

2

0+/1

2+/4

0+/29

 

 

 

 

 

 

0+/11

 

 

Washington

56

0

0+/4

0+/2

0+/4

 

 

 

 

 

 

0+/16

 

 

totals

191

2

0+/15

2+/30

0+/93

0+/3

0+/1

0+/9

0+/6

0+/1

0+/1

0+/27

0+/4

0+/1

July

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

40

0

0+/2

0+/14

0+/19

 

 

 

0+/1

 

 

 

 

0+/4

Santa Rosa

31

0

 

0+/2

0+/14

0+/1

 

0+/2

0+/1

0+/1

0+/4

 

0+/6

 

Walton (North)

34

0

 

0+/1

0+/24

 

 

 

 

 

 

0+/9

 

 

Washington

36

0

0+/4

0+/1

0+/23

 

 

 

 

 

 

0+/8

 

 

totals

141

0

0+/6

0+/18

0+/80

0+/1

 

0+/2

0+/2

0+/1

0+/4

0+/17

0+/6

0+/4

Table 3: Animal submissions by county for arbovirus detection/isolation

 

June

July

 

# birds

# mammals

# birds

# mammals

Dade

7

 

1

 

Hillsborough

1

 

1

 

Holmes

 

1

 

 

Marion

 

 

 

1

Osceola

 

 

 

1

Walton

 

1

 

 

Washington

 

1

 

1

 

8

3

2

3

Table 4:  Animal submissions by species by month

 

June

July

Bunting

1

 

Chicken

1

 

Crow

 

1

Dove

3

 

Duck

3

 

Hawk

 

1

Equine

3

4

total

11

6

Table 5:  Mosquito submissions by county by month

 

June

July

Flagler

23

15

Pinellas

 

2

Sarasota

46

60

 

69

77

February, March, April

Arbovirus activity has been very light, as expected due to the extraordinarily dry weather.  In February there were six seroconversions due to alphaviruses, five to Eastern Equine Encephalitis virus (EEE), resulting in seroconversion rate of 0.6% and one to Highlands J (HJ), rate of 0.1%.  During March there were two seroconversions to EEE (0.2%) and in April, three to EEE (0.2%) and one to HJ (0.1%).  This level of activity is similar to the historical means for those months.

There were no HAI flavivirus positive sentinels (St Louis Encephalitis virus (SLE) antigen used in the HAI assay) during these months, similar to historic levels.

Sera from live wild birds were screened by HAI.  Table 1 lists submissions and results by county by month for Alphavirus antibody.  Table 2 lists submissions and results by county by month for flavivirus antibody.

Dead animal submissions for arbovirus testing (birds, mammals, reptiles) are listed by county in table 3, as are Cloacal swabs were submitted from birds being treated by Wildlife rehabilitators.  Virus was not detected in any of these specimens.  Species submitted are listed in Table 4. 

Mosquito pools were assayed for arboviruses by real-time RT-PCR and cell culture inoculation.  Submissions by county are presented in table 5.  A California group virus was detected in a pool of 50 Anopheles crucians collected on March 2 in Sarasota County.  Highlands J virus was cultured from a pool of 50 Culiseta melanura collected on May 2 in Flagler County.

Table 1: Alphavirus antibody positive live wild birds

Alphavirus

# birds

total +

black-bird

blue jay

card-inal

cow-bird

dove

finch

grackle

Gros-beak

mockin-gbird

sparrow

thras-her

Tit-mouse

Towhee

Warbler

February

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

45

6

0+/1

4+/5

2+/8

 

 

0+/6

 

 

 

0+/20

0+/1

 

 

0+/2

Santa Rosa

44

4

 

 

1+/43

 

 

 

 

 

 

3+/34

0+/1

 

 

0+/5

Walton (North)

60

0

 

0+/5

3+/37

 

 

 

 

 

 

0+/18

 

 

 

 

Washington

60

2

1+/2

0+/7

1+/30

 

 

 

0+/4

 

 

0+/17

 

 

 

 

totals

209

12

1+/3

4+/17

7+/79

 

 

0+/6

0+/4

 

 

3+/89

0+/2

 

 

0+/7

March

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

75

6

0+/5

5+/11

0+/6

 

 

 

0+/4

 

 

0+/41

1+/2

0+/2

0+/1

0+/2

Santa Rosa

82

0

0+/2

 

0+/9

 

0+/2

0+/1

0+/1

 

0+/4

0+/59

 

 

 

0+/4

Walton (North)

69

3

 

0+/2

3+/44

 

 

 

 

 

 

0+/23

 

 

 

 

Washington

49

1

0+/5

0+/3

1+/31

 

 

 

 

 

 

0+/10

 

 

 

 

totals

275

10

0+/12

5+/16

4+/90

 

0+/2

0+/1

0+/5

 

0+/4

0+/133

1+/2

0+/2

0+/1

0+/6

April

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

49

5

0+/2

4+/10

0+/11

 

 

 

1+/3

 

 

0+/21

0+/2

 

 

 

Santa Rosa

35

3

0+/3

2+/3

1+/4

 

0+/1

0+/1

0+/3

 

0+/2

0+/18

 

 

 

 

Walton (North)

34

1

 

0+/1

1+/19

 

 

 

 

 

 

0+/14

 

 

 

 

Washington

38

1

0+/4

0+/4

1+/19

 

 

0+/1

0+/2

 

 

0+/8

 

 

 

 

totals

156

10

0+/9

6+/18

3+/53

 

0+/1

0+/2

1+/8

 

0+/2

0+/61

0+/2

 

 

 

May

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

36

4

0+/1

4+/11

0+/17

0+/2

 

 

0+/1

 

 

 

0+/3

0+/1

 

 

Santa Rosa

37

4

0+/5

3+/8

1+/12

0+/3

0+/3

0+/1

0+/2

0+/1

0+/1

 

0+/1

 

 

 

Walton (North)

42

2

 

0+/4

2+/29

 

0+/1

 

 

 

 

0+/8

 

 

 

 

Washington

48

4

0+/3

0+/5

3+/26

 

 

 

 

 

 

1+/14

 

 

 

 

totals

163

14

0+/9

7+/28

6+/84

0+/5

0+/4

0+/1

0+/3

0+/1

0+/1

1+/22

0+/4

0+/1

 

 

Table 2: Flavivirus antibody positive live wild birds

Flavivirus

# birds

total +

black-bird

blue jay

card-inal

cow-bird

dove

finch

grackle

Gros-beak

mockin-gbird

sparrow

thras-her

Tit-mouse

Towhee

Warbler

February

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

45

6

0+/1

0+/5

0+/8

 

 

0+/6

 

 

 

1+/20

0+/1

 

 

0+/2

Santa Rosa

44

4

 

 

0+/43

 

 

 

 

 

 

1+/34

0+/1

 

 

0+/5

Walton (North)

60

0

 

0+/5

0+/37

 

 

 

 

 

 

0+/18

 

 

 

 

Washington

60

2

0+/2

0+/7

0+/30

 

 

 

0+/4

 

 

0+/17

 

 

 

 

totals

209

12

0+/3

0+/17

0+/79

 

 

0+/6

0+/4

 

 

2+/89

0+/2

 

 

0+/7

March

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

75

3

0+/5

1+/11

0+/6

 

 

 

0+/4

 

 

2+/41

1+/2

0+/2

0+/1

0+/2

Santa Rosa

82

0

0+/2

 

0+/9

 

0+/2

0+/1

0+/1

 

0+/4

0+/59

 

 

 

0+/4

Walton (North)

69

0

 

0+/2

0+/44

 

 

 

 

 

 

0+/23

 

 

 

 

Washington

49

0

0+/5

0+/3

0+/31

 

 

 

 

 

 

0+/10

 

 

 

 

totals

275

3

0+/12

1+/16

0+/90

 

0+/2

0+/1

0+/5

 

0+/4

2+/133

1+/2

0+/2

0+/1

0+/6

April

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

49

0

0+/2

0+/10

0+/11

 

 

 

0+/3

 

 

0+/21

0+/2

 

 

 

Santa Rosa

35

0

0+/3

0+/3

0+/4

 

0+/1

0+/1

0+/3

 

0+/2

0+/18

 

 

 

 

Walton (North)

34

0

 

0+/1

0+/19

 

 

 

 

 

 

0+/14

 

 

 

 

Washington

38

0

0+/4

0+/4

0+/19

 

 

0+/1

0+/2

 

 

0+/8

 

 

 

 

totals

156

0

0+/9

0+/18

0+/53

 

0+/1

0+/2

0+/8

 

0+/2

0+/61

0+/2

 

 

 

May

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Okaloosa

36

0

0+/1

0+/11

0+/17

0+/2

 

 

0+/1

 

 

 

0+/3

0+/1

 

 

Santa Rosa

37

3

0+/5

3+/8

0+/12

0+/3

0+/3

0+/1

0+/2

0+/1

0+/1

 

0+/1

 

 

 

Walton (North)

42

0

 

0+/4

0+/29

 

0+/1

 

 

 

 

0+/8

 

 

 

 

Washington

48

0

0+/3

0+/5

0+/26

 

 

 

 

 

 

0+/14

 

 

 

 

totals

163

3

0+/9

3+/28

0+/84

0+/5

0+/4

0+/1

0+/3

0+/1

0+/1

0+/22

0+/4

0+/1

 

 

Table 3: Animal submissions by county for arbovirus detection/isolation

 

February

March

April

May

 

# birds

# swabs

# mammals

# birds

# swabs

# mammals

# birds

# swabs

# mammals

# birds

# swabs

# mammals

# reptiles

Alachua

 

 

 

 

 

 

 

 

1

 

 

 

1

Brevard

 

 

 

 

 

 

 

1

 

 

 

 

 

Citrus

 

 

 

 

 

 

 

1

 

 

 

 

 

Collier

 

 

 

 

 

 

 

2

 

 

 

 

 

Dade

3

 

 

1

 

 

2

1

 

14

 

 

 

Gilchrist

 

 

 

 

 

 

 

 

 

1

 

 

 

Hernando

1

 

 

2

 

 

 

 

1

 

 

 

 

Hillsborough

8

 

 

2

 

 

5

 

1

 

 

1

 

Indian River

 

 

 

 

 

 

 

1

 

 

 

1

 

Jefferson

1

 

 

 

 

 

 

 

 

 

 

 

 

Lee

 

 

 

 

 

 

 

4

1

 

 

 

 

Madison

 

 

 

1

 

 

 

 

 

 

 

 

 

Manatee

 

 

 

 

 

 

 

6

 

 

 

 

 

Marion