ABSTRACT
To demonstrate the effect of indoor spraying and window screens on Aedes aegypti mosquito density after space spraying. Methods: A total of 141 households (the study houses) in six communities of Songkhla City, located in Songkhla Province of southern Thailand, were randomly selected and the adult Ae. aegypti populations were assessed pre- and post-insecticide spraying from March to October, 2014. Houses close to (within a 20 m radius) the study houses were analyzed using spatial analysis tools. The Aedes aegypti density in the study houses and house density index were compared with the density in the neighbouring houses, based on three spraying conditions: (i) unsprayed (ii) only outdoor sprayed and (iii) indoor plus outdoor sprayed. Results: Only spraying houses indoors was the most effective (P<0.05). There was insufficient evidence that the source of the increase in the number of mosquitoes in unsprayed houses was due to their migration from neighbouring houses which had been sprayed. However, the study houses without screens on their windows were found to have a likely higher dengue vector population after spraying, but the difference was not significant. Conclusions: In dengue endemic areas, all houses should be fully screened and the number of houses ultra-low volume sprayed indoor plus outdoor should be increased with the cooperation of householders and communities during epidemics.
ABSTRACT
To determine the morphological characteristics of variations in populations of female adult sand fly, Sergentomyia anodontis Quate and Fairchild, 1961 in caves in southern Thailand using morphometric analysis. Methods: A total of 107 female Sergentomyia anodontis were isolated from 651 sand flies captured by CDC light traps overnight in caves in Surat Thani, Nakhon Si Thammarat, Satun and Songkhla provinces from February to December 2017. Measurement of 23 external and internal morphological characteristics was conducted. Data were tested with preliminary statistics (Kolmogorov-Smirnov test, Levene's test and Box's test of equality of covariance matrices) and by one-way ANOVA or Kruskal-Wallis test. Measurements were analyzed using canonical discriminant analysis. Results: There were 11 morphological characteristics with high variability while two characteristics exhibited low variation. The sand fly populations from Nakhon Si Thammarat, Satun and Songkhla provinces were very similar but were separate from that in Surat Thani province based on canonical discriminant analysis data. This indicates that the morphological variation founding is a result of the diversity of habitats in each population and the geographic features of caves in each area, such as their altitude above sea level. Conclusions: There is a certain variation in the morphology of Sergentomyia anodontis sand flies at the population level which may be used for future classification of sand flies.
ABSTRACT
Objective:To examine the resurgence rate, house density index (HDI) and parous rate of the Aedes aegypti vector after space spraying carried out by the routine spraying team, and compare with the rates after standard indoor ultra low volume (SID-ULV) spraying carried out by the trained research spraying team. Methods:Between March and September 2014, a cluster randomized controlled trial including 12 clusters (6 regular ULV, 6 SID-ULV) with totally 4 341 households was conducted, and around 20–31 houses in each cluster were selected for assessment. The parous rate and HDI of collected mosquitoes 2 days before and 1, 2 and 6 days after spraying were obtained and compared. Results:The HDI dropped significantly from the baseline 1 and 2 days after spraying to a non-zero value in the SID-ULV treated locations but not in the regular ULV group locations. However, by 6 days after spraying, the HDI of both groups had returned to the base value measured 2 days before spraying. There were no statistically significant differences in the parous rate between groups. Conclusions: SID-ULV is more effective in reducing Aedes aegypti populations. However, rapid resurgence of dengue vector after spraying in urban areas was observed in both groups.
ABSTRACT
Genitourinary amoebiasis is a rare form of kidney and urinary tract infection caused by Entamoeba histolytica. Here, we describe the first case of unusual infection caused by E. histolytica in Bueng Kan province, northeast, Thailand. A 63-year-old female patient was diagnosed as acute pyelonephritis. E. histotolytica trophozoites were accidentally found in urine collected from a catheter.
ABSTRACT
Objective: To examine the resurgence rate, house density index (HDI) and parous rate of the Aedes aegypti vector after space spraying carried out by the routine spraying team, and compare with the rates after standard indoor ultra low volume (SID-ULV) spraying carried out by the trained research spraying team. Methods: Between March and September 2014, a cluster randomized controlled trial including 12 clusters (6 regular ULV, 6 SID-ULV) with totally 4. 341 households was conducted, and around 20-31 houses in each cluster were selected for assessment. The parous rate and HDI of collected mosquitoes 2 days before and 1, 2 and 6 days after spraying were obtained and compared. Results: The HDI dropped significantly from the baseline 1 and 2 days after spraying to a non-zero value in the SID-ULV treated locations but not in the regular ULV group locations. However, by 6 days after spraying, the HDI of both groups had returned to the base value measured 2 days before spraying. There were no statistically significant differences in the parous rate between groups. Conclusions: SID-ULV is more effective in reducing Aedes aegypti populations. However, rapid resurgence of dengue vector after spraying in urban areas was observed in both groups.