ABSTRACT
With the Global Program for the Elimination of Lymphatic Filariasis continuing to make strides towards disease eradication, many locations endemic for the causative parasites of lymphatic filariasis are realizing a substantial decrease in levels of infection and rates of disease transmission. However, with measures of disease continuing to decline, the need for time-saving and economical molecular diagnostic assays capable of detecting low levels of parasite presence is increasing. This need is greatest in locations co-endemic for both Wuchereria bancrofti and Brugia parasites because testing for both causative agents individually results in significant increases in labor and reagent costs. Here we describe a multiplex, TaqMan-based, real-time PCR assay capable of simultaneously detecting W. bancrofti and Brugia malayi DNA extracted from human bloodspots or vector mosquito pools. With comparable sensitivity to established singleplex assays, this assay provides significant cost and labor savings for disease monitoring efforts in co-endemic locations.
Subject(s)
Brugia malayi/isolation & purification , Elephantiasis, Filarial/diagnosis , Elephantiasis, Filarial/parasitology , Molecular Diagnostic Techniques/methods , Multiplex Polymerase Chain Reaction/methods , Real-Time Polymerase Chain Reaction/methods , Wuchereria bancrofti/isolation & purification , Animals , Blood/parasitology , Brugia malayi/genetics , Culicidae/parasitology , DNA, Helminth/genetics , DNA, Helminth/isolation & purification , Humans , Molecular Diagnostic Techniques/economics , Multiplex Polymerase Chain Reaction/economics , Parasitology/economics , Parasitology/methods , Real-Time Polymerase Chain Reaction/economics , Sensitivity and Specificity , Wuchereria bancrofti/geneticsABSTRACT
Lymphatic filariasis (LF) is targeted for worldwide elimination. In Yemen, all mainland implementation units met the WHO criteria for stopping mass drug administration (MDA) after 5 rounds. However, in Socotra Island these criteria were not met. Our study evaluated the efficacy of applying expanded polystyrene beads (EPBs) on the Culex population and the effect on LF transmission. Human and mosquito surveys were conducted in 40 randomly selected households in Hadibo (capital of Socotra) before and after application of EPBs. The EPBs intervention resulted in a reduction in mosquito density of 80% and a 64.3% reduction in microfilaria prevalence. The majority of interviewed households (98%) thought EPBs considerably reduced the mosquito population. After the intervention all collected pools tested negative. Application of EPBs is an effective supplement to MDA for achieving the goal of LF elimination.
Subject(s)
Elephantiasis, Filarial/prevention & control , Endemic Diseases/prevention & control , Mosquito Control/methods , Polystyrenes , Animals , Culex/parasitology , Elephantiasis, Filarial/epidemiology , Elephantiasis, Filarial/transmission , Humans , Outcome and Process Assessment, Health Care , Statistics, Nonparametric , Surveys and Questionnaires , Wuchereria bancrofti , Yemen/epidemiologyABSTRACT
Lymphatic filariasis [LF] is targeted for worldwide elimination. In Yemen, all mainland implementation units met the WHO criteria for stopping mass drug administration [MDA] after 5 rounds. However, in Socotra Island these criteria were not met. Our study evaluated the efficacy of applying expanded polystyrene beads [EPBs] on the Culex population and the effect on LF transmission. Human and mosquito surveys were conducted in 40 randomly selected households in Hadibo [capital of Socotra] before and after application of EPBs. The EPBs intervention resulted in a reduction in mosquito density of 80% and a 64.3% reduction in microfilaria prevalence. The majority of interviewed households [98%] thought EPBs considerably reduced the mosquito population. After the intervention all collected pools tested negative. Application of EPBs is an effective supplement to MDA for achieving the goal of LF elimination
Subject(s)
Polystyrenes , Mosquito Control , Surveys and Questionnaires , Elephantiasis, FilarialABSTRACT
PCR has recently been studied as a promising tool for monitoring the progress of efforts to eliminate lymphatic filariasis. PCR can be used to test concurrently at least 30 pools, with as many as 40 mosquitoes in each pool, for the presence of filarial larvae. The SspI PCR assay for the detection of Wuchereria bancrofti DNA in pools of mosquitoes has been used since 1994 in a variety of laboratories worldwide. During that time, the original assay has been modified in these different laboratories and no standardized assay currently exists. In an effort to standardize and improve the assay, a meeting was held on 15-16 November 2001, at Emory University in Atlanta, with representatives from most of the laboratories currently using the assay. The first round of testing was designed to test the four most promising methods for DNA extraction from pools of mosquitoes. Two of the four methods stood out as clearly the best and these will be now optimised and evaluated in two further rounds of testing.
