Collecting Anopheles in Loudoun County,

Transcription

1 Collecting Anopheles in Loudoun County, VA using Resting Boxes ( )

2 Study purpose Surveillance of Anopheles mosquitoes Test bloodfed mosquitoes for Plasmodium spp. Bloodmeal analysis to identify local hosts Illustrate recent Anopheles population trends Historical data (2008 thru 2010)

3 Study purpose (cont d) Illustrate proper technique for resting box collection Why useful? Examine relationship between Plasmodium spp. and their vectors Human malaria Bird malaria Host studies

4 Features of Resting Boxes Useful ONLY for Cs. melanura and An. quadrimaculatus in eastern U.S. Cheap and easy to build/set up Efficient collections Only requires 1 daytime visit per week Passive All feeding stages collected Useful for virus/bloodmeal studies, vector dynamics

5 Why Loudoun County? Plasmodium vivax malaria in (2) Loudoun Co. teens in 2002 Diagnosed 8/23/02 and 8/25/02 Patients t lived about ½ mile apart Subsequent surveillance Multiple pools of An. quadrimaculatus and An. punctipennis positive for P. vivax 210 Evidence of local transmission Historical Data Collections from Locations standardized from 2008 to present

6 Background on Domestic Malaria Majority acquired abroad Travel between U.S. and malaria-endemic countries Local transmission is uncommon Presence of capable Presence of capable hosts, vectors, and ideal weather

7 Common Features of VA Malaria Outbreaks (1998 and 2002) Initial case with no known risk factors for malaria Proximity to persons with malaria parasitemia Presence of known vectors Environmental conditions that allow for maturation of malaria parasites

8 Site Selection Proximity to Potomac River Near site of suspected 2002 transmission Dense canopy (>75%) Minimal understory Look for closely planted trees or sewer lines Pine barrens in northeast Little or no direct sunlight Boxes face WEST

9 Site selection, cont d Collection sites Potomac Drive Youngs Cliff Algonkian Regional Park All trap locations are within a 6-mile transect

10 Collection Sites and Proximity to Local Transmission in miles

11 Methods 3 Collection Sites All less than 1 km from Potomac River 8/6/10 10/6/10 Epiweeks 31 thru Resting Box Collections 10 boxes per site Visit all 3 sites 1 day/week 3 trap nights per week during 10 weeks surveillance 30 trap nights per season

12 Methods (Cont d) RB collxns made in early afternoon 12 to 4 pm Specimens transported t to lab on dry ice Cold chain maintained thru testing Feeding status noted as: Unfed Bloodfed Gravid

13 Feeding Status UNFED No swelling of abdomen BLOODFED Visible red or black blood inside id abdomen GRAVID E i ibl ith NO Eggs visible with NO blood present

14 Species Commonly Collected from Resting Boxes in northern VA (2008 thru 2010) An. quadrimaculatus Primary vector of Plasmodium vivax and falciparum in eastern U.S. mammals, humans Flight distance 3-5 miles? An. punctipennis Secondary vector Plasmodium spp. mammals, birds

15 Other species collected from resting boxes in Loudoun County, VA (2008 thru 2010) Cx. erraticus birds, humans, reptile/amphibian? Cx. territans reptiles, amphibians Species collected in very low abundance: Cx. pipiens (13) Cx. restuans (5) Cs. melanura (3) Cq. perturbans (2) Ae. vexans (1) Ur. Sapphirina (1)

16 Abundance of major species collected in resting boxes, 2008 thru 2010 An. punctipennis 330, 3% Cx. erraticus 451, 4% Cx. territans 71, 1% An. quadrimaculatus 9542, 92%

17 Gravid % Feeding status of Anopheles collected from 2008 thru 2010 Unfed % Bloodfed %

18 Since 2008 (84 trap nights) 9,556 Anopheles collected 3,360 Bloodfed Avg. 3,300 Anopheles per season Avg. 330 per epiweek Avg per RB

19 General trends Larger RBs (38 x 38 x 38) attracted t more quads than smaller RBs (30 x 30 x 30). Supported in literature (Burkett-Cadena 2008) Boxes in the back corners of arrangement were darker and held more resting quads Algonkian Regional Park most productive Large amount of earlyseason larval habitat

20 0 (39) 10/3/10 0 (40) Mean weekly temperature vs. NORM ( ) 0 (21) 5/30/10 0 (22) 6/6/10 (23) 6/13/10 (24) 6/20/10 0 (25) 6/27/10 (26) 7/4/10 (27) 7/11/10 (28) 7/18/10 (29) 7/25/10 (30) 8/1/10 (31) 8/8/10 (32) 8/15/10 (33) 8/22/10 (34) 8/29/10 (35) 9/5/10 (36) 9/12/10 (37) 9/19/10 (38) 9/26/10 Date (Epiweek) NORM -All years warmer than the 100-year norm, 2010 (+5.5%) 2008 (72.0) 2009 (72.7) 2010 (74.6) NORM (70.5) Weather data from 5/16/10 (20) 5/23/10 Mean Weekly Temperature (F)

21 10/3/10 (40) Total weekly precipitation ( ) /23/10 (21) 5/30/10 (22) 6/6/10 (23) 6/13/10 (24) 6/20/10 (25) 6/27/10 (26) 7/4/10 (27) 7/11/10 (28) 7/18/10 (29) 7/25/10 (30) 8/1/10 (31) 8/8/10 (32) 8/15/10 (33) 8/22/10 (34) 8/29/10 (35) 9/5/10 (36) 9/12/10 (37) 9/19/10 (38) 9/26/10 (39) Date (Epiweek) -23 days with rainfall over.5 inches in Relatively wet July and August 2008 (25.75) 2009 (19.07) 2010 (24.07) NORM (18.46) Weather data from 5/16/10 (20) Prec ipitation (i n.)

22 Number of Anopheles collected from each of (3) resting box sites (2008) Potomac Drive Youngs Cliff Algonkian /2 -- 8/8 (31) 8/9 -- 8/15 (32) 8/ /22 (33) 8/ /29 (34) 8/ /5 (35) 9/6 -- 9/12 (36) 9/ /19 (37) 9/ /26 (38) 9/ /3 (39) 10/ /10 (40) Date (epiweek) Total # Anopheles

23 Weekly abundance of Anopheles vs. precipitation (2008) 2008 Precip 2008 Totals Total # Anopheles /23 5/30 /30/10 (22) 6/6/10 (23) 6/13 /13/10 (24) 6/20 /20/10 (25) 6/27 /27/10 (26) 7/4/10 (27) 7/1 /11/10 (28) 7/18 /18/10 (29) 7/25 /25/10 (30) 8/1/10 (31) 8/8/10 (32) 8/15 /15/10 (33) 8/22 /22/10 (34) 8/29 /29/10 (35) 9/5/10 (36) 9/12 /12/10 (37) 9/19 /19/10 (38) 9/26 /26/10 (39) 10/3 0/3/10 (40) Date (epiweek) /16/10 (20) /23/10 (21) 5/16 Precipitation (in.)

24 Number of Anopheles collected weekly from (3) resting box sites (2009) Potomac Drive Youngs Cliff Algonkian 8/2 -- 8/8 (31) 8/9 -- 8/15 (32) 8/ /22 (33) 8/ /29 (34) 8/ /5 (35) 9/6 -- 9/12 (36) 9/ /19 (37) 9/ /26 (38) 9/ /3 (39) 10/ /10 (40) Date (epiweek) Total # Anopheles

25 Weekly abundance of Anopheles vs. precipitation (2009) 2009 Precip 2009 Totals Total # Anopheles /10 (20) 5/23 23/10 (21) 5/30 30/10 (22) 6/6/10 (23) 6/13 13/10 (24) 6/20 20/10 (25) 6/27 27/10 (26) 7/4/10 (27) 7/11 11/10 (28) 7/18 18/10 (29) 7/25 25/10 (30) 8/1/10 (31) 8/8/10 (32) 8/15 15/10 (33) 8/22 22/10 (34) 8/29 29/10 (35) 9/5/10 (36) 9/12 12/10 (37) 9/19 19/10 (38) 9/26 26/10 (39) 10/3 0/3/10 (40) Date (epiweek) 5/16 Precipitation (in.)

26 Number of Anopheles collected weekly from (3) resting box sites (2010) Potomac Drive Youngs Cliff Algonkian 8/9 -- 8/15 (32) 8/ /22 (33) 8/ /29 (34) 8/ /5 (35) 9/6 -- 9/12 (36) 9/ /19 (37) 9/ /26 (38) 9/ /3 (39) 10/ /10 (40) 8/2 -- 8/8 (31) Date (epiweek) Total # Anopheles

27 Weekly abundance of Anopheles vs. precipitation (2010) 2010 Precip 2010 Totals Total # Anopheles /23 5/30 /30/10 (22) 6/6/10 (23) 6/13 /13/10 (24) 6/20 /20/10 (25) 6/27 /27/10 (26) 7/4/10 (27) 7/1 /11/10 (28) 7/18 /18/10 (29) 7/25 /25/10 (30) 8/1/10 (31) 8/8/10 (32) 8/15 /15/10 (33) 8/22 /22/10 (34) 8/29 /29/10 (35) 9/5/10 (36) 9/12 /12/10 (37) 9/19 /19/10 (38) 9/26 /26/10 (39) 10/3 0/3/10 (40) Date (epiweek) /16/10 (20) /23/10 (21) 5/16 Precipit ation (in.)

28 Total number of Anopheles collected weekly across (3) resting box sites ( ) 2008 totals 2009 Totals 2010 Totals 3-year AVG /1/10 (31) 8/8/10 (32) 8/15/10 (33) 8/22/10 (34) 8/29/10 (35) 9/5/10 (36) 9/12/10 (37) 9/19/10 (38) 9/26/10 (39) 10/3/10 (40) Date (epiweek) -Late August to early September are most active (epiweeks 34 to 36) -In 2010 peak came from 1 st collection (epiweek 31) Number of Anopheles

29 Mean weekly number of Anopheles ( ) 3-year AVG /1/10 (31) 8/8/10 (32) 8/15/10 (33) 8/22/10 (34) 8/29/10 (35) 9/5/10 (36) 9/12/10 (37) 9/19/10 (38) 9/26/10 (39) 10/3/10 (40) Date (epiweek) -Late August thru mid-september generally yield the highest collections -epiweeks 35 thru 38 Mean # Anopheles

30 Feeding status of Anopheles collected by year ( ) Unfed Bloodfed Gravid year AVG had less than average unfed (-17%) and gravid (-35%) Anopheles -Above average numbers of bloodfeds (+13%).

31 Raw historical data Resting box collections Total # Anopheles collected # of bloodfed Anopheles tested # pools submitted was more productive than 2009 in total # Anopheles, but only half as productive as Higher proportion of bloodfed mosquitoes in 2010

32 To Be Continued PCR (DNA) testing at VCU Test bloodfeds from 2008, 2009, and 2010 Host bloodmeal (phase 1) Human/Avian Plasmodium spp. (phase 2)

33 Results thus far The bad news 2008 samples not responding Degraded? The good news 2009 samples responding well to universal primers Mammal/bird/reptileamphibian H i f th b t ith Hoping for the best with 2010 samples!

34 Other recent resting box studies Komar 1995 (SE Kweka 2009 (Tanzania) Massachusetts) Host odor-baited resting Nestable fiber pots boxes (cow sweat/urine) melanura, quads gambiae s.s., arabiensis Alternative to HLC? Odiere 2007 (Kenya) Clay pots gambiae, quinqs Bentley 2009 LED resting boxes Unlit attracted more bloodfeds Red/IR LEDs attracted more quads overall Need for additional studies Integrate baits with control? non-repellent insecticides Entomopathogenic fungi Mark/recapture Flight range analysis

35 Thanks due to... VMCA Officers and Members Clarke Employees Patrick Patterson (el Jefe) Lauren Wright (help with collections) VCU Dept. of Biology (Richmond) Dr. Ghislaine Mayer Priya Krishnan Caty Wallace Property Owners AJ Palotta Tommy Palotta Algonkian Regional Park Loudoun County Health Department Dr. David Goodfriend Loudoun Co. residents

36 QUESTIONS???