Figure 1.
Map showing the location of the study site.
A) Khanh Hoa province, central Vietnam. B) Nha Trang city, Khanh Hoa province. Hon Mieu island is marked with an arrow. C) Hon Mieu island, and the 611 houses that make up Tri Nguyen village.
Figure 2.
Temporal abundance of Aedes aegypti in Tri Nguyen village during different seasons.
A) Mean monthly minimum and maximum temperatures (°C), and total monthly rainfall (mm), recorded during the survey period from Nha Trang weather station. B–D). Box plots of the number of Ae. aegypti III/IV instars and pupae per house, and female Ae. aegypti per BG-trap, for each of the surveys in Tri Nguyen village. Central line = median, dotted line = mean, box = 25th/75th percentiles, whiskers = 10th/90th percentiles, dots = 5th/95th percentiles. Boxed text shows the different seasons in central Vietnam based on 5 year historical weather data.
Figure 3.
The percent contribution of the top 10, 5, 3, and highest households (HH) for each survey to the production of Ae. aegypti.
A) III/IV instars, B) pupae and C) adult females.
Table 1.
Number (expected number) of times households were positive for Aedes aegypti immatures and adult females.
Table 2.
Number (expected number) of times households were ≥90th percentile in terms of Ae. aegypti immature and adult female abundance.
Figure 4.
Spatial clusters of Ae. aegypti III/IV instar and pupae positive and negative houses in Tri Nguyen village.
Horizontally hashed circles or shaded circles represent clusters of III/IV instar positive houses or pupae positive houses (P<0.01), respectively, after taking into consideration the structure of the houses sampled (black dots) (P<0.01). Clear circles represent statistically significant clusters of houses negative for III/IV instars. There was no significant spatial structure amongst houses negative for pupae, or amongst houses positive or negative for Ae. aegypti females (collected with BG-traps).
Figure 5.
Spatial abundance of Ae. aegypti pupae and adult females in Tri Nguyen village.
Shaded circles or diagonally-hashed circles represent statistically significant clusters of houses with high numbers of pupae (P<0.01), or adult females per BG-trap (P<0.01), respectively, after taking into consideration the structure of the houses sampled (black dots) (P<0.01). Letters refer to clusters whose statistics are outlined in Table 3. There was no significant spatial structure in the abundance of Ae. aegypti III/IV instars.
Table 3.
Mean number of pupae or adult female Ae. aegypti collected in houses that were members of the significant clusters or in houses that were not members of the significant clusters.
Figure 6.
Ninety-five percent confidence limits for estimated numbers of adult female Ae. aegypti in Tri Nguyen village (Nov 2006 – Dec 2007).
Confidence limits based on extrapolating pupal survey data from 100 households to 611 households 999 times, and assuming a pupal daily development rate (PDD) of 0.30 or 0.49, a pupal survival rate of 0.83, a female∶male sex ratio of 1∶1, and a probability of daily survival (PDS) for adults of 0.8 or 0.9.