Short and long term evaluation of the efficiency of PermaNet® 2. 0 bed net against environmental factors and washing using bioassay tests

ABSTRACT The aim of the present study was to examine the resistance of PermaNet® 2.0 bed nets against repeated washing and environmental factors by using bioassay tests. After 5, 15 and 21 washings with detergents and by using bioassay tests, the resistance of 40 PermaNet® 2.0 bed nets was compared with that of 40 bed nets conventionally treated with one K-O tablet. To examine the long-term resistance, 31 PermaNet® 2.0 bed nets were also distributed among villagers, and were re-collected to perform bioassay tests after 1, 2 and 5 years. In the first phase of this study, the insecticidal effect of the conventionally-treated nets significantly decreased due to repeated washings (P < 0.001); however, it was not significant regarding PermaNet® 2.0 bed nets (P = 0.92 in continuous exposure and P = 0.12 in mortality tests). In the long-term phase of this study, the time required for knockdown of PermaNet® 2.0 increased over the first 2 years and then decreased. In addition, the mortality rate decreased over the first 2 years and then increased. In conclusion, it seems that the technique used by the manufacturer for impregnation of PermaNet® 2.0 bed nets has an acceptable efficiency in comparison with conventional techniques.

Challenging loop-mediated isothermal amplification (LAMP) technique for molecular detection ofToxoplasma gondii

Objective:To compare analytical sensitivity and specificity of a newly described DNA amplification technique, LAMP and nested PCR assay targeting the RE and B1 genes for the detection ofToxoplasma gondii (T. gondii)DNA.Methods: The analytical sensitivity of LAMP and nested-PCR was obtained against10-fold serial dilutions ofT. gondii DNA ranging from 1 ng to 0.01 fg. DNA samples of other parasites and human chromosomal DNA were used to determine the specificity of molecular assays.Results:After testing LAMP and nested-PCR in duplicate, the detection limit of RE-LAMP, B1-LAMP, RE-nested PCR and B1-nested PCR assays was one fg, 100 fg, 1 pg and 10 pg ofT. gondii DNA respectively. All the LAMP assays and nested PCRs were 100% specific. The RE-LAMP assay revealed the most sensitivity for the detection ofT. gondii DNA.Conclusions:The obtained results demonstrate that the LAMP technique has a greater sensitivity for detection ofT. gondii. Furthermore, these findings indicate that primers based on the RE are more suitable than those based on the B1 gene. However, the B1-LAMP assay has potential as a diagnostic tool for detection ofT. gondii.