Ecological modeling of Aedes aegypti (L.) pupal production in rural Kamphaeng Phet, Thailand.
BACKGROUND
Aedes aegypti (L.) is the primary vector of dengue, the most important arboviral infection globally. Until an effective vaccine is licensed and rigorously administered, Ae. aegypti control remains the principal tool in preventing and curtailing dengue transmission. Accurate predictions of vector populations are required to assess control methods and develop effective population reduction strategies. Ae. aegypti develops primarily in artificial water holding containers. Release recapture studies indicate that most adult Ae. aegypti do not disperse over long distances. We expect, therefore, that containers in an area of high development site density are more likely to be oviposition sites and to be more frequently used as oviposition sites than containers that are relatively isolated from other development sites. After accounting for individual container characteristics, containers more frequently used as oviposition sites are likely to produce adult mosquitoes consistently and at a higher rate. To this point, most studies of Ae. aegypti populations ignore the spatial density of larval development sites.


METHODS
Pupal surveys were carried out from 2004 to 2007 in rural Kamphaeng Phet, Thailand. In total, 84,840 samples of water holding containers were used to estimate model parameters. Regression modeling was used to assess the effect of larval development site density, access to piped water, and seasonal variation on container productivity. A varying-coefficients model was employed to account for the large differences in productivity between container types. A two-part modeling structure, called a hurdle model, accounts for the large number of zeroes and overdispersion present in pupal population counts.


RESULTS
The number of suitable larval development sites and their density in the environment were the primary determinants of the distribution and abundance of Ae. aegypti pupae. The productivity of most container types increased significantly as habitat density increased. An ecological approach, accounting for development site density, is appropriate for predicting Ae. aegypti population levels and developing efficient vector control programs.
Department of Geography, University at Buffalo, Buffalo, New York, United States of America. geojared@buffalo.edu
Jared
J
Aldstadt
Constantianus J M
CJ
Koenraadt
Thanyalak
T
Fansiri
Udom
U
Kijchalao
Jason
J
Richardson
James W
JW
Jones
Thomas W
TW
Scott
D000330:Aedes / Q000254:growth & development*; D000818:Animals; D017753:Ecosystem; D006801:Humans; D007303:Insect Vectors; D015233:Models, Statistical; D011156:Population Density; D011157:Population Dynamics; D011679:Pupa / Q000254:growth & development; D012424:Rural Population; D012621:Seasons; D013785:Thailand; D014867:Water
D014867:Water
J Med Entomol. 1993 Jan;30(1):94-9
8433350
Am J Trop Med Hyg. 2006 Feb;74(2):290-302
16474086
Ann Trop Med Parasitol. 2006 Apr;100 Suppl 1:S53-S59
16630391
Am J Trop Med Hyg. 1995 Dec;53(6):595-601
8561260
PLoS Med. 2008 Nov 4;5(11):e205
18986209
IDrugs. 2008 Jan;11(1):42-5
18175262
J Med Entomol. 2006 May;43(3):484-92
16739405
J Med Entomol. 1998 Jul;35(4):578-83
9701948
Am J Trop Med Hyg. 2006 Apr;74(4):692-700
16607007
J Med Entomol. 2004 Nov;41(6):1123-42
15605653
Bull World Health Organ. 2010 Mar;88(3):173-84
20428384
J Med Entomol. 2007 Nov;44(6):938-44
18047191
Am J Trop Med Hyg. 2005 Feb;72(2):209-20
15741559
Am J Trop Med Hyg. 2000 Jan;62(1):11-8
10761719
Am J Epidemiol. 2002 Jul 1;156(1):40-51
12076887
Lancet. 2005 Feb 12-18;365(9459):613-7
15708107
Am J Epidemiol. 2002 Jul 1;156(1):52-9
12076888
JAMA. 1982 May 14;247(18):2543-6
7069920
Nat Rev Microbiol. 2007 Jul;5(7):518-28
17558424
Curr Top Microbiol Immunol. 2010;338:115-28
19802582
Am J Trop Med Hyg. 2009 Dec;81(6):1013-9
19996430
PLoS Med. 2008 Mar 18;5(3):e68
18351798
Bull World Health Organ. 1972;46(2):211-26
4537483
Am J Trop Med Hyg. 2002 Sep;67(3):247-59
12408663
Bull World Health Organ. 1972;46(3):416-25
4537857
Am J Trop Med Hyg. 1986 Nov;35(6):1263-79
3789275
Am J Trop Med Hyg. 2003 Nov;69(5):494-505
14695086
Am J Trop Med Hyg. 2007 Apr;76(4):659-65
17426166
Am J Trop Med Hyg. 2008 Aug;79(2):230-8
18689629
Am J Trop Med Hyg. 2003 Feb;68(2):209-17
12641413
J Med Entomol. 2007 Jan;44(1):65-71
17294922
Ann Trop Med Parasitol. 2008 Mar;102(2):161-71
18318938