Development and laboratory evaluation of a polymerase chain reaction for monitoring Schistosoma mansoni infestation of water.

Hamburger, Joseph; Xu, Yuxin; Ramzy, Reda M. R.; Jourdane, J.; Ruppel, Andreas

doi:10.4269/ajtmh.1998.59.468

Cited by 56 publications

(52 citation statements)

References 18 publications

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“…Since the number of amplification ladder bands seems to be related to the schistosomal DNA concentration, 16 the results suggests that different amount of schistosomal DNA were successfully extracted by the extraction procedure.…”

Section: Resultsmentioning

confidence: 86%

“…16 The high detection sensitivity of this assay was demonstrated by the detection of 10 fg of S. mansoni DNA, and of a single cercaria. This assay was also shown to be specific for detecting schistosomes rather than other trematodes, 16 but further specificity analyses are required by cross-amplification assays with DNA from a variety of animal schistosomes. In the present study, the PCR assay identified infected snails at one day (Figure 2 and Table 1), three days, and one week after they were exposed to a single miracidium, with an actual sensitivity of 100% (Table 1).…”

Section: Discussionmentioning

confidence: 99%

“…The NaOH procedure used in the present study was previously used for extracting DNA from cercariae, 16 snails, 9 and sputum of people infected with the lymphatic filaria Wuchereria bancrofti. 18 The simple DNA extraction procedure should greatly facilitate establishment of the PCR approach for monitoring infected snails during early prepatency.…”

Section: Discussionmentioning

confidence: 99%

“…15 Similar primers were previously used in a sensitive PCR assay at conditions adapted for the sensitive detection of cercariae in water. 16 …”

mentioning

confidence: 99%

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A polymerase chain reaction assay for detecting snails infected with bilharzia parasites (Schistosoma mansoni) from very early prepatency.

Hamburger¹,

He-Na²,

Xin³

et al. 1998

Am J Trop Med Hyg

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Abstract. In the present study, we adapted a polymerase chain reaction (PCR) assay, previously shown by us to be very sensitive for detecting cercariae in water, for the sensitive detection of Schistosoma mansoni DNA in infected snails from early prepatency. Polymerase chain reaction primers were designed based on the 121-basepair highly repeated sequence we previously identified in the genome of S. mansoni. The DNA was prepared from the snails by a simple alkaline extraction procedure, and the PCR assay enabled a clear differentiation between infected and normal snails. Infected snails were detected as early as one day after penetration of a single miracidium. The high sensitivity of the test enabled identification of a single infected snail even when its DNA was pooled with material from up to 99 uninfected snails, thus demonstrating the possibility of mass diagnosis in pools of snails. The assay has the potential for large-scale determination of prepatent infection prevalence in snails, thus offering new possibilities for the evaluation of schistosomiasis transmission and for schistosomiais control, as discussed.Schistosomiasis, is caused in humans by three main species of blood flukes (Schistosoma mansoni, S. haematobium, and S. japonicum) and is transmitted by freshwater snails. It continues to plague many developing countries in the tropics 1 with an estimated 200 million infected people worldwide.Freshwater snails, intermediate hosts of schistosomes, become infected by larvae (miracidia) released from schistosome eggs that reach the water with excreta. After several weeks of asexual multiplication within the snail's tissues, larvae infective to humans by active penetration through the skin (cercariae), are released into the water. Snail infection and contact patterns of humans with water infested with cercariae are important factors in the transmission of schistosomiasis, and risk of infection is normally estimated by detecting infected intermediate hosts in sites where humans come in contact with water. 2 Infection rates in field populations of snails are routinely determined by searching for cercariae shed from snails with patent infection. 3 In contrast, prepatent infections, which can constitute a significant proportion of infected snails populations, 4 are not determined routinely because of a lack of a suitable method. Microscopic examination of crushed snails in search of developing cercariae and intramolluscan-multiplying larvae (the sporocysts) 5 is sometimes used for this purpose but is highly inaccurate at early prepatency, and unsuitable for routine large-scale screening of snail populations. 4 Another approach is to examine nonshedding field snails maintained for several weeks in the laboratory for protracted shedding. However, this method is time-consuming, it cannot be done routinely on a large scale, and it can be highly inaccurate if snails mortality is high. The omission of data on prepatent infections leaves out important information for the evaluation and mathematical modeling of trans...

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Section: Resultsmentioning

confidence: 86%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

“…15 Similar primers were previously used in a sensitive PCR assay at conditions adapted for the sensitive detection of cercariae in water. 16 …”

mentioning

confidence: 99%

See 2 more Smart Citations

A polymerase chain reaction assay for detecting snails infected with bilharzia parasites (Schistosoma mansoni) from very early prepatency.

Hamburger¹,

He-Na²,

Xin³

et al. 1998

Am J Trop Med Hyg

Self Cite

View full text Add to dashboard Cite

show abstract

“…There are 5 species of schistosoma that are known to infect humans by contact with its larval stage, the cercariae : Schistosoma mekongi, S. intercalatum, S. mansoni, S. japonicum and S. haematobium, the latter 3 being the main schistosome species that affect humans (Hamburger et al 1998). Adult worm pairs reside in host veins and produce eggs which penetrate the tissue.…”

Section: Introductionmentioning

confidence: 99%

Schistosoma mansoniTOR is a tetraspanning orphan receptor on the parasite surface

2009

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A trispanning orphan receptor (TOR) has been described in Schistosoma haematobium and S. mansoni. Here we report the complete molecular organization of the S. mansoni TOR gene, also known as SmCRIT (complement C2 receptor inhibitor trispanning). The SmTOR gene consists of 4 exons and 3 introns as shown by cloning the single exons from S. mansoni genomic DNA and the corresponding cDNA from the larval stage (cercaria) and the adult worm. The SmTOR ORF consists of 1260 bp and is longer than previously reported, with a fourth trans-membrane domain (proposed new name : Tetraspanning Orphan Receptor) and with, however, an unchanged C2-binding domain on the extracellular domain 1 (ed1). This domain differs in S. japonicum. A protein at the approximate expected molecular weight (55 kDa) was detected in adult worm extracts with polyclonal and monoclonal antibodies, and was found to be expressed on the tegumental surface of cercariae.

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Monitoring schistosomiasis and sanitation interventions—The potential of environmental DNA

et al. 2020

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Transmission of schistosomiasis, a human parasitic disease, is intrinsically linked to inadequate water, sanitation, and hygiene (WASH) facilities and/or their use. The mainstay of control is population-based chemotherapy. Globally, each year, 240 million people are estimated to require this preventative treatment. However, for longterm, sustainable control of this disease, supplementary WASH improvements are required to prevent (re)infection of humans (provision of safe water) and transmission from humans to the environment (improved sanitation). While there is established methodology for monitoring transmission in human populations, presently methods for monitoring the impact of WASH interventions, in particular sanitation, on environmental transmission are lacking. Development of such becomes paramount as integrated control programs combine drug treatments with enhanced WASH facilities and behavior change interventions, with uptake likely correlated to a reduction in fecal matter, and schistosome eggs, in the environment but any impact on infection levels in humans taking longer to become apparent. This article reports and critiques the methods currently used to monitor schistosomiasis in freshwater and soil environments and explores how environmental DNA could be used to better understand and monitor environmental contamination in relation to sanitation. Stronger evidence is required to understand how different sanitation interventions serve to limit the environmental transmission of the parasite and their relative effectiveness in preventing disease.

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Development and laboratory evaluation of a polymerase chain reaction for monitoring Schistosoma mansoni infestation of water.

Cited by 56 publications

References 18 publications

A polymerase chain reaction assay for detecting snails infected with bilharzia parasites (Schistosoma mansoni) from very early prepatency.

A polymerase chain reaction assay for detecting snails infected with bilharzia parasites (Schistosoma mansoni) from very early prepatency.

Schistosoma mansoniTOR is a tetraspanning orphan receptor on the parasite surface

Monitoring schistosomiasis and sanitation interventions—The potential of environmental DNA

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