Schistosomiasis in areas of low endemicity: a new era in diagnosis

Cavalcanti, Marta Guimarães; Silva, Leonardo F.; Peralta, Regina Helena Saramago; Barreto, Magali Gonçalves Muniz; Peralta, José Mauro

doi:10.1016/j.pt.2012.11.003

Cited by 95 publications

(102 citation statements)

References 76 publications

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“…In these low-endemicity areas, diagnostic strategies must often be combined to obtain a better estimate of the infection rate of Schistosoma spp. in at-risk populations and to evaluate the effectiveness of interventions such as chemotherapy (32) . Assays for the detection of antibodies and antigens offer promising complementary strategies to traditional parasitological examination.…”

Section: Resultsmentioning

confidence: 99%

Performance of POC-CCA® in diagnosis of schistosomiasis mansoni in individuals with low parasite burden

Siqueira

Couto

Taboada

et al. 2016

Rev. Soc. Bras. Med. Trop.

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Introduction: Schistosomiasis, caused by Schistosoma mansoni, is a public health concern in Brazil. However, the most popular diagnostic method, the Kato-Katz technique, exhibits low sensitivity in low-endemicity areas. We aimed to compare the performance of an immunological assay, the point-of-care circulating cathodic antigen (POC-CCA®) test, with that of two parasitological techniques in a low-endemicity population. Methods: Our study included 141 individuals living in Estreito de Miralta, Minas Gerais, Brazil. Fecal samples were obtained from all participants and analyzed for schistosomiasis using two parasitological techniques: the Kato-Katz technique and the saline gradient technique. Additionally, POC-CCA® strips were utilized for testing urine samples. The results obtained by the different techniques were compared. Results: Analysis of two or 24 slides using the Kato-Katz technique resulted in a positivity rate of 10.6% (15/141) or 19.1% (27/141), respectively. The saline gradient technique yielded a positivity rate of 17.0% (24/141). The prevalence according to both parasitological techniques was 24.1% (34/141). The POC-CCA® test yielded a positivity rate of 22.7% (32/141); however, the positivity rate was merely 2.1% if trace results were considered negative. The agreements observed between POC-CCA® and the parasitological techniques were good (Kappa indexes > 0.64). The POC-CCA® test was more sensitive than the two-slide Kato-Katz technique (p < 0.05) in detecting cases of S. mansoni infection when trace results were considered positive. Conclusions: These findings reinforce the importance of using multiple diagnostic techniques in low-endemicity areas for effective control of disease.

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Section: Resultsmentioning

confidence: 99%

Performance of POC-CCA® in diagnosis of schistosomiasis mansoni in individuals with low parasite burden

Siqueira

Couto

Taboada

et al. 2016

Rev. Soc. Bras. Med. Trop.

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“…For this purpose there is a clear need for more standardized and highly sensitive high-throughput diagnostic procedures. 14,15 In recent years, several nucleic acid-based diagnostic tests have been established for specific and sensitive detection and quantification of a broad range of parasite DNA in clinical *Address correspondence to Pavitra Pillay, Department of Biomedical and Clinical Technology, Durban University of Technology, KwaZulu Natal, South Africa. E-mail: pillayp@dut.ac.za samples, including an internal transcribed spacer (ITS)-based Schistosoma-specific multiplex real-time polymerase chain reaction (PCR).…”

Section: Introductionmentioning

confidence: 99%

Real-Time Polymerase Chain Reaction for Detection of Schistosoma DNA in Small-Volume Urine Samples Reflects Focal Distribution of Urogenital Schistosomiasis in Primary School Girls in KwaZulu Natal, South Africa

Pillay¹,

Taylor²,

Zulu³

et al. 2014

The American Society of Tropical Medicine and Hygiene

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Abstract. Schistosoma haematobium eggs and Schistosoma DNA levels were measured in urine samples from 708 girls recruited from 18 randomly sampled primary schools in South Africa. Microscopic analysis of two 10-mL urine subsamples collected on three consecutive days confirmed high day-to-day variation; 103 (14.5%) girls had positive results at all six examinations, and at least one positive sample was seen in 225 (31.8%) girls. Schistosoma-specific DNA, which was measured in a 200-μL urine subsample by using real-time polymerase chain reaction, was detected in 180 (25.4%) cases, and levels of DNA corresponded significantly with average urine egg excretion. In concordance with microscopic results, polymerase chain reaction results were significantly associated with history of gynecologic symptoms and confirmed highly focal distribution of urogenital schistosomiasis. Parasite-specific DNA detection has a sensitivity comparable to single urine microscopy and could be used as a standardized high-throughput procedure to assess distribution of urogenital schistosomiasis in relatively large study populations by using small sample volumes.

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“…No parasite DNA could be detected in limited stored blood samples. While real-time PCR has been successfully used in the diagnosis of other parasite infections in human blood samples, including the systemic coccidian Toxoplasma gondii (Ricciardi and Ndao, 2015;RobertGangneux and Dardé, 2012) and blood flukes Schistosoma spp (Cavalcanti et al, 2013;Wichmann et al, 2013), these methods are generally most effective in the acute phase of infections (Wichmann et al, 2013;Zhou et al, 2011) where increased host immune response to a new insult results in parasite degradation and increased circulating parasite DNA. Given the high prevalence of Neospirorchis spp.…”

Section: Aim 4 -Explore and Develop Potential Methods For The Diagnosmentioning

confidence: 99%

“…(Cavalcanti et al, 2013;Gentile et al, 2011;Lier et al, 2008;Wang et al, 2011;Wichmann et al, 2013). Real-time PCR utilising…”

Section: Development Of Techniques For Sea Turtle Parasite Investigationmentioning

confidence: 99%

“…Molecular techniques such as real-time polymerase chain reaction (PCR offer sensitive and specific options for the detection of parasite infections related to those considered here, including schistosomiasis (Cavalcanti et al, 2013;Gentile et al, 2011;Lier et al, 2008;Wang et al, 2011;Wichmann et al, 2009), cryptosporidiosis and giardiasis (Ricciardi and Ndao, 2015;Verweij et al, 2004;Verweij and Stensvold, 2014) and toxoplasmosis (Liu et al, 2015). At present, molecular tools for identification of Caryospora spp.…”

Section: Introductionmentioning

confidence: 99%

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Diversity, impacts and diagnosis of pathogenic parasites in sea turtles from Queensland, Australia

Chapman¹

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Parasitism is a significant cause of stranding and mortality in endangered sea turtles. Two parasites in particular (or groups thereof) have been noted for their impacts on green sea turtle populations. The first are the spirorchiid blood flukes, which inhabit the circulatory systems of their host. The second is the eimeriid coccidian Caryospora cheloniae, a systemic parasite affecting a number of organs. Diversity among these organisms is poorly explored, and is almost certainly greater than currently recognised. The parasites and their associated diseases fluctuate both temporally and spatially in terms of prevalence and severity, however, the factors driving these fluctuations are poorly understood. A variety of questions remain unanswered in terms of the epidemiology and relative pathogenicity of the different parasite species. Of particular interest are brain lesions, which have been associated with both parasites and in some cases lead to neurological deficiency and subsequent mortality. Difficulties in finding answers to these questions is compounded by a lack of reliable, fast and quantitative ante-and post-mortem diagnostic tools for either parasite, which restricts their investigation.In order to catalogue local species and assess diversity, adult spirorchiid flukes were collected during post-mortem examination of deceased sea turtles and characterised by molecular and morphological means. Eleven distinct species or genotypes were identified, comprising a mix of previously described and novel species or variants. Samples were also collected from green sea turtles that died during a coccidiosis related mass mortality event in south east Queensland and northern New South Wales. While only one species of coccidian (C. cheloniae) had been previously described, molecular characterisation of the organism implicated in the outbreak revealed two distinct coccidian genotypes, which has significant implications for diagnosis and management.Spirorchiid ova have been associated with granulomatous lesions in a wide range of host tissues. However, it has not been possible to identify spirorchiids beyond the genus level based on morphology, which has frustrated any attempts to identify the species or variants responsible for severe lesions. In this thesis, a molecular approach was used and a terminal restriction fragment length polymorphism (T-RFLP) assay was developed to detect and identify individual species within the often mixed assemblages of ova in turtle tissues. This assay proved to be a more specific and sensitive alternative to traditional iii microscopic detection methods. Through correlation with histopathology and gross pathology, the tissue tropisms, relative occurrence and pathogenicity of each species were investigated. The most common species (Neospirorchis Genotype 2) was found in 96% of samples, encompassing tissues from all organs sampled. On average, a greater number of spirorchiid species were detected in tissues where lesions were present, and numbers increased along with the severity o...

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Schistosomiasis in areas of low endemicity: a new era in diagnosis

Cited by 95 publications

References 76 publications

Performance of POC-CCA® in diagnosis of schistosomiasis mansoni in individuals with low parasite burden

Performance of POC-CCA® in diagnosis of schistosomiasis mansoni in individuals with low parasite burden

Real-Time Polymerase Chain Reaction for Detection of Schistosoma DNA in Small-Volume Urine Samples Reflects Focal Distribution of Urogenital Schistosomiasis in Primary School Girls in KwaZulu Natal, South Africa

Diversity, impacts and diagnosis of pathogenic parasites in sea turtles from Queensland, Australia

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