Background\ud\udIndoor residual spraying (IRS) of DDT is used to control visceral leishmaniasis (VL) in India. However, the quality of spraying is severely compromised by a lack of affordable field assays to monitor target doses of insecticide. Our aim was to develop a simple DDT insecticide quantification kit (IQK) for monitoring DDT levels in an operational setting.\ud\udMethodology/ principle findings\ud\udDDT quantification was based on the stoichiometric release of chloride from DDT by alkaline hydrolysis and detection of the released ion using Quantab chloride detection strips. The assay was specific for insecticidal p,p`-DDT (LoQ = 0.082 g/m2). Bostik discs were effective in post spray wall sampling, extracting 25–70% of active ingredient depending on surface. Residual DDT was sampled from walls in Bihar state in India using Bostik adhesive discs and DDT concentrations (g p,p`-DDT/m2) were determined using IQK and HPLC (n = 1964 field samples). Analysis of 161 Bostik samples (pooled sample pairs) by IQK and HPLC produced excellent correlation (R2 = 0.96; Bland-Altman bias = −0.0038). IQK analysis of the remaining field samples matched HPLC data in identifying households that had been under sprayed, in range or over sprayed.\ud\udInterpretation\ud\udA simple dipstick assay has been developed for monitoring DDT spraying that gives comparable results to HPLC. By making laboratory-based analysis of DDT dosing accessible to field operatives, routine monitoring of DDT levels can be promoted in low- and middle- income countries to maximise the effectiveness of IRS.
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机译:背景\滴滴涕的室内残留喷洒(IRS)用于控制印度的内脏利什曼病(VL)。然而,由于缺乏可负担的田间试验来监测杀虫剂的目标剂量,严重影响了喷雾质量。我们的目标是开发一个简单的DDT杀虫剂定量试剂盒(IQK),以在操作环境中监测DDT的水平。\ ud \ ud方法/原理发现\ ud \ udDDT定量基于通过碱水解和检测从DDT中氯化物的化学计量释放使用Quantab氯化物检测条检测释放的离子。该测定法对杀虫性p,p`-DDT(LoQ = 0.082 g / m2)具有特异性。 Bostik圆盘可有效地用于喷雾后壁采样,可根据表面提取25-70%的活性成分。使用Bostik粘性圆盘从印度比哈尔邦的墙壁上采样残留的DDT,并使用IQK和HPLC测定NDT的浓度(g p,p`-DDT / m2)(n = 1964现场样品)。通过IQK和HPLC对161个Bostik样品(合并样品对)进行分析得出了极好的相关性(R2 = 0.96; Bland-Altman偏差= -0.0038)。剩余田间样品的IQK分析与HPLC数据相匹配,以识别出未进行过喷洒,范围内或过度喷洒的住户。通过使现场操作人员可以进行基于实验室的滴滴涕剂量分析,可以在中低收入国家促进对滴滴涕水平的常规监测,以最大限度地发挥IRS的有效性。
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