Area-wide control of Aedes aegypti

Aedes aegypti surveillance and
control in an epicenter of dengue
virus transmission
Roberto Barrera, Manuel Amador, Veronica Acevedo, Gilberto Felix, Ryan Hemme
Entomology and Ecology Activity
Dengue Branch, CDC
Puerto Rico
• Use of the CDC Autocidal Gravid Ovitrap (AGO
trap) for the surveillance and area-wide
control of Ae. aegypti in Puerto Rico for the
last three years
Autocidal, sticky gravid ovitrap
(AGO; CDC patent EIR I- 018-11)
• Features:
– 5-Gal plastic trap
– Highly attractive / sensitive to Ae. aegypti
gravid females
– Can be deployed in the field for 2 months
without maintenance or servicing
– Does not use insecticides
– Relatively inexpensive
– Small sample size for reliable observations (30
- 100 traps)
– Has higher sensitivity than ovitraps
– Correlated with BG trap captures without lure
Mackay AJ, Barrera R, Amador M. 2013. An autocidal gravid ovitrap for the control and surveillance of
Aedes aegypti. Parasites and Vectors 6:225
Setting the AGO trap
Inspecting the AGO trap
AGO traps as surveillance tools
AGO traps as surveillance tools:
Positive relationship between AGO and Ovitraps
AGO traps as
surveillance tools:
Positive, significant
relationship between
AGO and BG trap
captures (Oct. 2011 –
Oct. 2012)
AGO traps as control tools
Aedes aegypti control
• We tested the effectiveness of the AGO traps (3 traps/home; 81% of
homes) to control Ae. aegypti in one isolated urban area (intervention
area) and compared it with another urban area (reference area) in
southern Puerto Rico for one year (Phase I; Oct. 2011 – Oct. 2012)
• We used BG-Sentinel and AGO traps (2.5 traps/Ha) to monitor the
density of female Ae. aegypti every week
La Margarita (Intervention area;
327 bldgs.)
Villodas (Reference area;
241 bldgs.)
Barrera et al. 2014a. Use of the CDC Autocidal Gravid Ovitrap to control and prevent outbreaks of Aedes
aegypti (Diptera: Culicidae). J. Med. Entomol. 51(1): 145-154; DOI:
Results from the
first year (Oct 2011 – Oct
Female Ae. aegypti in AGO
(top) or BG-traps (bottom)
Lines = mosquitoes per trap per
Bars = Rainfall
There was 50 - 70%
reduction in female Ae.
aegypti in the
intervention area; most
notably during the rainy
Years two - three
Intended to further demonstrate the effectiveness of the
traps by placing AGO control traps in the community that
formerly served as non-intervention or reference,
expecting that Ae. aegypti density would converge to the
low values observed in the intervention community
We also added two new, nearby reference communities
without control traps for comparison purposes
Barrera R, Amador M, Acevedo V, Hemme, RR, Félix G. 2014b. Sustained, area-wide control of Aedes aegypti using CDC
Autocidal Gravid Ovitraps. Am. J. Trop. Med. Hyg., 00(0), 2014, pp. 000–000. doi:10.4269/ajtmh.14-0426
Study areas (Southern Puerto Rico, 4 communities)
New reference community
January 2013 – to date
La Margarita
Initial intervention community
December 2011 – to date
New reference community
January 2013 – to date
Second intervention community
February 2013 – to date
Former reference community
December 2011 –January 2013
La Margarita (Intervention I; 327 bldgs.)
Playa (Reference I)
Villodas (Intervention II; 241 bldgs.)
Arboleda (Reference II)
Results – control traps added to former reference area
Shows convergence
to low, steady
Results – Ae. aegypti density in urban sites without and with
AGO control traps
Ae. aegypti density is 7-13 times
higher in untreated sites
No AGO control traps
traps /
• 3 AGO traps in 85% of the households controlled
Ae. aegypti populations in 60-80%
• What traps do is eliminate gravid females and
reduce # eggs per container (sink effect)
• Mosquito outbreaks followed rainfall in nonintervention areas – no mosquito outbreaks were
observed in intervention areas
• Are these observed reductions enough to prevent
dengue virus / chickungunya transmission? Under
• Need to understand better the dynamics of Ae.
aegypti at low population densities

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