Evaluating the diagnostic test accuracy of molecular xenomonitoring methods for characterising community burden of lymphatic filariasis

分子异种监测（MX），即检测蚊子体内的病原体DNA，是支持消除淋巴丝虫病（LF）工作的一种推荐方法。MX的潜在作用包括检测社区中LF的存在和量化消除该疾病的进展。然而，MX结果与人类患病率之间的关系尚不清楚。方法对以往报道的野生蚊子中丝虫DNA的流行率（MX率）和相应的人类微丝虫（mf）的流行率进行系统回顾和荟萃分析。我们计算了在mf流行值和蚊子样本量范围内检测阳性社区的MX敏感性的汇总估计。我们进行了线性回归来评估mf患病率与MX率之间的关系。结果我们确定了24项研究，包括144个研究群体。MX的总灵敏度为98.3% (95% CI 41.5, 99.9%)，在mf调查中鉴定出28个阳性社区。一些研究的低敏感性归因于蚊子样本量小（< 1000）和mf患病率非常低（<0.25%）。人类mf患病率和大量给药状况约占MX率变化的一半（R2 = 0.49, p<0.001）。纵向研究的数据显示，在给定的研究区域内，MX率与mf患病率之间存在很强的线性关系（R2 = 0.78, p < 0.001）。结论mx作为检测LF存在的社区和预测人类mf患病率的工具具有明显的潜力。

BackgroundMolecular xenomonitoring (MX), the detection of pathogen DNA in mosquitoes, is a recommended approach to support lymphatic filariasis (LF) elimination efforts. Potential roles of MX include detecting presence of LF in communities and quantifying progress towards elimination of the disease. However, the relationship between MX results and human prevalence is poorly understood.MethodsWe conducted a systematic review and meta-analysis from all previously conducted studies that reported the prevalence of filarial DNA in wild-caught mosquitoes (MX rate) and the corresponding prevalence of microfilaria (mf) in humans. We calculated a pooled estimate of MX sensitivity for detecting positive communities at a range of mf prevalence values and mosquito sample sizes. We conducted a linear regression to evaluate the relationship between mf prevalence and MX rate.ResultsWe identified 24 studies comprising 144 study communities. MX had an overall sensitivity of 98.3% (95% CI 41.5, 99.9%) and identified 28 positive communities that were negative in the mf survey. Low sensitivity in some studies was attributed to small mosquito sample sizes (<1,000) and very low mf prevalence (<0.25%). Human mf prevalence and mass drug administration status accounted for approximately half of the variation in MX rate (R2 = 0.49, p<0.001). Data from longitudinal studies showed that, within a given study area, there is a strong linear relationship between MX rate and mf prevalence (R2 = 0.78, p < 0.001).ConclusionMX shows clear potential as a tool for detecting communities where LF is present and as a predictor of human mf prevalence.