Diagnostic accuracy of a novel enzyme-linked immunoassay for the detection of IgG and IgG4 against Strongyloides stercoralis based on the recombinant antigens NIE/SsIR

Abstract Background The diagnosis of strongyloidiasis is challenging. Serological tests are acknowledged to have high sensitivity, but issues due to cross-reactions with other parasites, native parasite antigen supply and intrinsic test variability do occur. Assays based on recombinant antigens could represent an improvement. The aim of this study was to assess the sensitivity and specificity of two novel immunoglobulin (Ig)G and IgG4 enzyme-linked immunosorbent assays (ELISAs) based on the recombinant antigens NIE/SsIR for the diagnosis of strongyloidiasis. Methods This was a retrospective diagnostic accuracy study. We included serum samples collected from immigrants from strongyloidiasis endemic areas for whom there was a matched result for Strongyloides stercoralis on agar plate culture and/or PCR assay, or a positive microscopy for S. stercoralis larvae. For the included samples, results were also available from an in-house indirect fluorescent antibody test (IFAT) and a commercial (Bordier ELISA; Bordier Affinity Products SA) ELISA. We excluded: (i) samples with insufficient serum volume; (ii) samples from patients treated with ivermectin in the previous 6 months; and (iii) sera from patients for whom only routine coproparasitology was performed after formol–ether concentration, if negative for S. stercoralis larvae. The performance of the novel assays was assessed against: (i) a primary reference standard, with samples classified as negative/positive on the basis of the results of fecal tests; (ii) a composite reference standard (CRS), which also considered patients to be positive who had concordant positive results for the IFAT and Bordier ELISA or with a single “high titer” positive result for the IFAT or Bordier ELISA. Samples with a single positive test, either for the IFAT or Bordier ELISA, at low titer, were considered to be “indeterminate,” and analyses were carried out with and without their inclusion. Results When assessed against the primary reference standard, the sensitivities of the IgG and IgG4 ELISAs were 92% (95% confidence interval [CI]: 88–97%) and 81% (95% CI: 74–87%), respectively, and the specificities were 91% (95% CI: 88–95%) and 94% (95% CI: 91–97%), respectively. When tested against the CRS, the IgG ELISA performed best, with 78% sensitivity (95% CI: 72–83%) and 98% specificity (95% CI: 96–100%), when a cut-off of 0.675 was applied and the indeterminate samples were excluded from the analysis. Conclusion The NIE-SsIR IgG ELISA demonstrated better accuracy than the IgG4 assay and was deemed promising particularly for serosurveys in endemic areas. Graphical abstract

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Multiple-bead assay for the differential serodiagnosis of neglected human cestodiases: Neurocysticercosis and cystic echinococcosis

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0010109 ◽

2022 ◽

Vol 16 (1) ◽

pp. e0010109

Author(s):

Ana Hernández-González ◽

Belén González-Bertolín ◽

Laura Urrea ◽

Agnes Fleury ◽

Elizabeth Ferrer ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Cystic Echinococcosis ◽

Neurological Diseases ◽

Added Value ◽

P Value ◽

Neglected Diseases ◽

Serological Tests ◽

Recombinant Antigens ◽

Set Up ◽

Multiplex Bead

Background Neurocysticercosis (NCC), and cystic echinococcosis (CE) are two neglected diseases caused by cestodes, co-endemic in many areas of the world. Imaging studies and serological tests are used in the diagnosis of both parasitic diseases, but cross-reactions may confound the results of the latter. The novel multiplex bead-based assay with recombinant antigens has been reported to increases the diagnostic accuracy of serological techniques. Methodology We set-up an immunoassay based on the multiplex bead-based platform (MBA), using the rT24H (against Cysticercus cellulosae, causing cysticercosis) and r2B2t (against Echinococcus granulosus sensu lato, causing CE) recombinant antigens, for simultaneous and differential diagnosis of these infections. The antigens were tested on 356 sera from 151 patients with CE, 126 patients with NCC, and 79 individuals negative for both diseases. Specificity was calculated including sera from healthy donors, other neurological diseases and the respective NCC or CE sera counterpart. The diagnostic accuracy of this assay was compared with two commercial ELISA tests, Novalisa and Ridascreen, widely used in the routine diagnosis of cysticercosis and CE, respectively. Main findings For the diagnosis of NCC, sensitivity ranged from 57.94–63.49% for the rT24H-MBA, and 40.48–46.03% for Novalisa ELISA depending on exclusion or inclusion of sera having equivocal results on ELISA from the analysis; specificities ranged from 90.87–91.30% and 70.43–76.96%, respectively. AUC values of the ROC curve were 0.783 (rT24H) and 0.619 (Novalisa) (p-value < 0.001). For the diagnosis of CE, the sensitivity of the r2B2t-MBA ranged from 68.87–69.77% and of Ridascreen ELISA from 50.00–57.62%; specificities from 92.47–92.68% and from 74.15–80.98%, respectively. AUC values were 0.717 and 0.760, respectively. Conclusions/Significance Overall, the recombinant antigens tested with the bead-based technology showed better diagnostic accuracy than the commercial assays, particularly for the diagnosis of NCC. The possibility of testing the same serum sample simultaneously for the presence of antibodies against both antigens is an added value particularly in seroprevalence studies for cysticercosis linked to control programs in endemic areas where these two parasites coexist.

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High Prevalence of Strongyloidiasis in Spain: A Hospital-Based Study

10.1101/852558 ◽

2019 ◽

Author(s):

Ana Requena-Méndez ◽

Joaquin Salas-Coronas ◽

Fernando Salvador ◽

Joan Gomez-Junyent ◽

Judith Villar-Garcia ◽

...

Keyword(s):

Latin America ◽

Immune System ◽

Strongyloides Stercoralis ◽

Cross Sectional Study ◽

Serological Tests ◽

Cross Sectional ◽

Systematic Screening ◽

Migrant Populations ◽

Immunosuppressed Patients ◽

Endemic Areas

AbstractStrongyloidiasis is a prevailing helminth infection ubiquitous in tropical and subtropical areas. However, prevalence data are scarce in migrant populations.This study aims at evaluating the prevalence of S. stercoralis at hospital level in migrant populations or long term travellers being attended in out-patient and in-patient units as part of a systematic screening implemented in 6 Spanish hospitals. A cross-sectional study was conducted and systematic screening for S. stercoralis infection using serological tests was offered to all eligible participants. The overall seroprevalence of S. stercoralis was 9.04% (95% confidence interval [95%CI] 7.76 −10.31). The seroprevalence of people with a risk of infection acquired in Africa and Latin America was 9.35% (95%CI 7.01-11.69), 9.22% (7.5-10.93), respectively. The number of individuals coming from Asian countries was significantly smaller and the overall prevalence in these countries was 2.9% (95%CI −0.3; −6.2). There was only one case (1/14 (7.14%) from an individual from East European countries. The seroprevalence in units attending potentially immunosuppressed patients was significantly lower (5.64%) compared with the seroprevalence in other units of the hospital (10.20%) or Tropical diseases units (13.33%) (p<0.001). Conclusions: We report a hospital-based systematic screening of strongyloidiasis with a seroprevalence of almost 10% in a mobile population coming from endemic areas suggesting the need of implementing strongyloidiasis screening in hospitalized patients coming from endemic areas, particularly if they are at risk of immunosuppression.Author summaryStrongyloidiasis is an infection caused by the helminth Strongyloides stercoralis which is ubiquitous in tropical and subtropical areas. In the rest of the countries, it is also frequent in migrants coming from tropical and subtropical areas. The disease is more severe when an infected subject has an impaired immune system. Within this study we have evaluated the prevalence of this infection in people being attended in six Spanish hospitals. The prevalence was around 9%, being higher in Africa and Latin America compared with other regions. In addition, the prevalence in patients with an impaired immune system (immunosuppression) was lower compared with people non suffering immunosuppression. These results suggest that the prevalence of strongyloidiasis is quite high among migrants living in Spain and that a screening programme should be designed, particularly in immunosuppressed patients that are at more risk of suffering severe complications of the infection.

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High Incidence of Zika or Chikungunya Infection among Pregnant Women Hospitalized Due to Obstetrical Complications in Northeastern Brazil—Implications for Laboratory Screening in Arbovirus Endemic Area

Viruses ◽

10.3390/v13050744 ◽

2021 ◽

Vol 13 (5) ◽

pp. 744

Author(s):

Iracema J. A. A. Jacques ◽

Leila Katz ◽

Marília A. Sena ◽

Ana B. G. Guimarães ◽

Yasmim L. Silva ◽

...

Keyword(s):

Pregnant Women ◽

Clinical Data ◽

Obstetric Complications ◽

Northeastern Brazil ◽

Serological Tests ◽

Pregnancy And Childbirth ◽

Obstetrical Complications ◽

Risk Pregnancy ◽

Endemic Areas ◽

A Prospective Study

The diagnostic of arbovirus-related obstetric complications in high-risk pregnancy and childbirth care is challenging, especially in endemic areas. We conducted a prospective study to track active or recent Zika (ZIKV), dengue (DENV), or chikungunya (CHIKV) virus infection among hospitalized pregnant women (PW) with obstetric complications in a hospital at the epicenter of Zika outbreak and ZIKV-related microcephaly in Brazil. Clinical data and blood samples were collected at enrollment and 10 days after the admission of study participants, between October 2018 and May 2019. Further clinical data were extracted from medical records. Samples were screened by molecular and serological tests. Out of 780 participants, 93.1% (95% CI: 91.1–94.7%) presented previous DENV exposure (IgG). ZIKV, CHIKV, and/or DENV laboratory markers of recent or active infection were detected in 130 PW, yielding a prevalence of 16.6% (95% CI: 14.2–19.5%); 9.4% (95% CI: 7.4–11.7%), 7.4% (95% CI: 5.7–9.7%), and 0.38% (95% CI: 0.1–1.2%) of CHIKV, ZIKV, and DENV infections, respectively. Most ZIKV infections were detected by molecular assays (89.6%), while CHIKV infections were detected by serology (95.9%). Our findings highlight the need for arbovirus infections screening in PW with obstetrical complications, potentially associated to these infections in endemic areas regardless of the signs or symptoms suggestive of arboviral disease.

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Standard echocardiography versus handheld echocardiography for the detection of subclinical rheumatic heart disease: a systematic review and meta-analysis of diagnostic accuracy

BMJ Open ◽

10.1136/bmjopen-2020-038449 ◽

2020 ◽

Vol 10 (10) ◽

pp. e038449

Author(s):

Lisa Helen Telford ◽

Leila Hussein Abdullahi ◽

Eleanor Atieno Ochodo ◽

Liesl Joanna Zuhlke ◽

Mark Emmanuel Engel

Keyword(s):

Systematic Review ◽

Heart Disease ◽

Diagnostic Accuracy ◽

Receiver Operating Characteristic ◽

Rheumatic Heart Disease ◽

Operating Characteristic ◽

Meta Analysis ◽

Endemic Areas ◽

Rheumatic Heart ◽

Receiver Operating

ObjectiveTo summarise the accuracy of handheld echocardiography (HAND) which, if shown to be sufficiently similar to that of standard echocardiography (STAND), could usher in a new age of rheumatic heart disease (RHD) screening in endemic areas.DesignSystematic review and meta-analysis.Data sourcesPubMed, Scopus, EBSCOHost and ISI Web of Science were initially searched on 27 September 2017 and again on 3 March 2020 for studies published from 2012 onwards.Eligibility criteriaStudies assessing the accuracy of HAND compared with STAND when performed by an experienced cardiologist in conjunction with the 2012 World Heart Federation criteria among populations of children and adolescents living in endemic areas were included.Data extraction and synthesisTwo reviewers independently extracted data and assessed the methodological quality of included studies against review-specific Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 criteria. A meta-analysis using the hierarchical summary receiver operating characteristic model was conducted to produce summary results of sensitivity and specificity. Forest plots and scatter plots in receiver operating characteristic space in combination with subgroup analyses were used to investigate heterogeneity. Publication bias was not investigated.ResultsSix studies (N=4208) were included in the analysis. For any RHD detection, the pooled results from six studies were as follows: sensitivity: 81.56% (95% CI 76.52% to 86.61%) and specificity: 89.75% (84.48% to 95.01%). Meta-analytical results from five of the six included studies were as follows: sensitivity: 91.06% (80.46% to 100%) and specificity: 91.96% (85.57% to 98.36%) for the detection of definite RHD only and sensitivity: 62.01% (31.80% to 92.22%) and specificity: 82.33% (65.15% to 99.52%) for the detection of borderline RHD only.ConclusionsHAND displayed good accuracy for detecting definite RHD only and modest accuracy for detecting any RHD but demonstrated poor accuracy for the detection of borderline RHD alone. Findings from this review provide some evidence for the potential of HAND to increase access to echocardiographic screening for RHD in resource-limited and remote settings; however, further research into feasibility and cost-effectiveness of wide-scale screening is still needed.PROSPERO registration numberCRD42016051261.

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A case of fatal disseminated strongyloidiasis accompanied with intestinal obstruction

Oxford Medical Case Reports ◽

10.1093/omcr/omz087 ◽

2019 ◽

Vol 2019 (10) ◽

Author(s):

Peyman Heydarian ◽

Iraj Mobedi ◽

Mohamad Ali Mohaghegh ◽

Abozar Hosseini ◽

Fatemeh Goudarzvand Chegini ◽

...

Keyword(s):

Intestinal Obstruction ◽

Signs And Symptoms ◽

Strongyloides Stercoralis ◽

Final Diagnosis ◽

High Humidity ◽

Important Message ◽

Disseminated Strongyloidiasis ◽

Endemic Areas

Abstract Strongyloides stercoralis is an endemic parasite in some regions including the tropical and subtropical areas with high humidity. Most infections are asymptomatic with nonspecific signs and symptoms, making the final diagnosis complicated. Here, we report a patient referred to our hospital with signs consistent with sepsis, intestine obstruction, which finally died with the diagnosis of strongyloidiasis. The patient was from northern parts of Iran which are considered as endemic areas for S. stercoralis. In conclusion, there is an important message in this history, i.e. physicians should be aware of specific and non-specific signs of strongyloidiasis especially in people living in endemic areas to make an accurate final diagnosis by proper clinical and paraclinical examinations.

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Occurrence of antibodies against Neospora caninum and/or Toxoplasma gondii in dogs with neurological signs

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612011000300004 ◽

2011 ◽

Vol 20 (3) ◽

pp. 202-206 ◽

Cited By ~ 8

Author(s):

Nicolle Fridlund Plugge ◽

Fabiano Montiani Ferreira ◽

Rosária Regina Tesoni de Barros Richartz ◽

Adriana de Siqueira ◽

Rosangela Locatelli Dittrich

Keyword(s):

Toxoplasma Gondii ◽

Neospora Caninum ◽

Neurological Diseases ◽

Fluorescent Antibody ◽

Antibody Test ◽

Metropolitan Region ◽

Serological Tests ◽

Stray Dogs ◽

Neurological Signs ◽

Significant Difference

This study aimed to evaluate occurrences of antibodies against Neospora caninum and Toxoplasma gondii in dogs with neurological signs. Blood samples from 147 dogs were collected: 127 from owned dogs (attended at the Veterinary Teaching Hospital of the Federal University of Paraná (HV-UFPR) and at private veterinary clinics in the city of Curitiba), and 20 from stray dogs found in Curitiba's metropolitan region. The dogs presented one or more of the following neurological signs: seizures, paresis or paralysis, ataxia, behavioral abnormalities, sensory and somatic disorders and chorioretinitis. The samples were analyzed by means of the indirect fluorescent antibody test (IFAT), at a cutoff dilution of 1:50. Out of the 147 samples obtained, 17 (11.56%) were seropositive for N. caninum, 31 (21.08%) for T. gondii and four (2.72%) for both protozoa. Serum titration on the positive animals showed that 54.83% (17/31) and 41.18% (7/17) had titers > 1:200 against T. gondii and N. caninum, respectively. A significant difference in seropositivity for T. gondii (P = 0.021; OR = 2.87; CI = 1.1 > 2.8 > 7.4) was observed between owned dogs (18.11%) and stray dogs (40%). Inclusion of serological tests for neosporosis and toxoplasmosis is recommended in diagnosing neurological diseases in dogs.

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Systematic Review into Diagnostics for Post-Kala-Azar Dermal Leishmaniasis (PKDL)

Journal of Tropical Medicine ◽

10.1155/2013/150746 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 16

Author(s):

Emily R. Adams ◽

Inge Versteeg ◽

Mariska M. G. Leeflang

Keyword(s):

Diagnostic Accuracy ◽

Clinical Symptoms ◽

Statistical Modelling ◽

Study Quality ◽

Serological Tests ◽

Molecular Tests ◽

Kala Azar ◽

Valid Estimate ◽

Low Sensitivity ◽

Control Designs

Identification of post-kala-azar dermal leishmaniasis (PKDL) is important due to the long and toxic treatment and the fact that PKDL patients may serve as a reservoir for visceral leishmaniasis (VL). We summarized the published literature about the accuracy of diagnostic tests for PKDL. We searched Medline for eligible studies investigating the diagnostic accuracy of any test for PKDL. Study quality was assessed using QUADAS-2. Data were extracted from 21 articles including 43 separate studies. Twenty-seven studies evaluated serological tests (rK39 dipstick, ELISA, DAT, and leishmanin tests), six studies molecular tests, eight microscopy, and two cultures. Only a few of these studies reported a valid estimate of diagnostic accuracy, as most were case-control designs or used a reference standard with low sensitivity. The included studies were very heterogeneous, for example, due to a large variety of reference standards used. Hence, no summary estimates of sensitivity or specificity could be made. We recommend well-designed diagnostic accuracy trials that evaluate, side-by-side, all currently available diagnostics, including clinical symptoms, serological, antigen, molecular, and parasitological tests and possible use of statistical modelling to evaluate diagnostics when there is no suitable gold standard.

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Using Tuning-Fork Tests in Diagnosing Fractures

Journal of Athletic Training ◽

10.4085/1062-6050-51.7.06 ◽

2016 ◽

Vol 51 (6) ◽

pp. 498-499 ◽

Cited By ~ 4

Author(s):

Chelsey M. Toney ◽

Kenneth E. Games ◽

Zachary K. Winkelmann ◽

Lindsey E. Eberman

Keyword(s):

Magnetic Resonance Imaging ◽

Clinical Practice ◽

Magnetic Resonance ◽

Diagnostic Accuracy ◽

Strong Evidence ◽

Bone Scan ◽

Tuning Fork ◽

Reference Standard ◽

Resonance Imaging ◽

Likelihood Ratios

Reference/Citation: Mugunthan K, Doust J, Kurz B, Glasziou P. Is there sufficient evidence for tuning fork tests in diagnosing fractures? A systematic review. BMJ Open. 2014;4(8):e005238. Clinical Question: Does evidence support the use of tuning-fork tests in the diagnosis of fractures in clinical practice? Data Sources: The authors performed a comprehensive literature search of AMED, CAB Abstracts, CINAHL, EMBASE, MEDLINE, SPORTDiscus, and Web of Science from each database's start to November 2012. In addition, they manually searched reference lists from the initial search result to identify relevant studies. The following key words were used independently or in combination: auscultation, barford test, exp fractures, fracture, tf test, tuning fork. Study Selection: Studies were eligible based on the following criteria: (1) primary studies that assessed the diagnostic accuracy of tuning forks; (2) measured against a recognized reference standard such as magnetic resonance imaging, radiography, or bone scan; and (3) the outcome was reported using pain or reduction of sound. Studies included patients of all ages in all clinical settings with no exclusion for language of publication. Studies were not eligible if they were case series, case-control studies, or narrative review papers. Data Extraction: Potentially eligible studies were independently assessed by 2 researchers. All relevant articles were included and assessed for inclusion criteria and value using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool, and relevant data were extracted. The QUADAS-2 is an updated version of the original QUADAS and focuses on both the risk of bias and applicability of a study through a series of questions. A third researcher was consulted if the 2 initial reviewers did not reach consensus. Data for the primary outcome measure (accuracy of the test) were presented in a 2 × 2 contingency table to show sensitivity and specificity (using the Wilson score method) and positive and negative likelihood ratios with 95% confidence intervals. Main Results: A total of 62 citations were initially identified. Six primary studies (329 patients) were included in the review. The 6 studies assessed the accuracy of 2 tuning-fork test methods (pain induction and reduction of sound transmission). The patients ranged in age from 7 to 84 years. The prevalence of fracture in these patients ranged from 10% to 80% using a reference standard such as magnetic resonance imaging, radiography, or bone scan. The sensitivity of the tuning-fork tests was high, ranging from 75% to 92%. The specificity of the tuning-fork tests had a wide range of 18% to 94%. The positive likelihood ratios ranged from 1.1 to 16.5; the negative likelihood ratios ranged from 0.09 to 0.49. Conclusions: The studies included in this review demonstrated that tuning-fork tests have some value in ruling out fractures. However, strong evidence is lacking to support the use of current tuning-fork tests to rule in a fracture in clinical practice. Similarly, the tuning-fork tests were not statistically accurate in the diagnosis of fractures for widespread clinical use. Despite the lack of strong evidence for diagnosing all fractures, tuning-fork tests may be appropriate in rural and remote settings in which access to the gold standards for diagnosis of fractures is limited.

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Serological Evaluation of Specific-Antibody Levels in Patients Treated for Chronic Chagas' Disease

Clinical and Vaccine Immunology ◽

10.1128/cvi.00106-07 ◽

2007 ◽

Vol 15 (2) ◽

pp. 297-302 ◽

Cited By ~ 38

Author(s):

Olga Sánchez Negrette ◽

Fernando J. Sánchez Valdéz ◽

Carlos D. Lacunza ◽

María Fernanda García Bustos ◽

María Celia Mora ◽

...

Keyword(s):

Chagas Disease ◽

Treatment Effectiveness ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Serological Tests ◽

Recombinant Antigens ◽

Antibody Titers ◽

Laboratory Procedures ◽

The Individual ◽

Antibody Levels

ABSTRACT Serological tests are the main laboratory procedures used for diagnosis during the indeterminate and chronic stages of Chagas' disease. A serological regression to negativity is the main criterion used to define parasitological cure in treated patients. The aim of this work was to monitor the individual specificities of antibody levels for 3 years posttreatment in 18 adult patients. Conventional serological techniques (hemagglutination assays and enzyme-linked immunosorbent assay [ELISA]) were modified by using recombinant antigens to detect early markers of treatment effectiveness. For this purpose, serum samples were taken before and during treatment and every 6 months after treatment for at least 3 years. When hemagglutination assays were used, a decrease in antibody levels was observed in only one patient. When ELISA with serum dilutions was used, antibody clearance became much more apparent: in 77.7% (14/18) of the patients, antibody titers became negative with time. This was observed at serum dilutions of 1/320 and occurred between the 6th and the 30th months posttreatment. The immune response and the interval for a serological regression to negativity were different for each patient. For some of the recombinant antigens, only 50% (9/18) of the patients reached the serological regression to negativity. Recombinant antigen 13 might be a good marker of treatment effectiveness, since 66.6% (six of nine) of the patients presented with an early regression to negativity for specific antibodies to this antigen (P = 0.002).

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Increased detection of schistosomiasis with Kato-Katz and SWAP-IgG-ELISA in a Northeastern Brazil low-intensity transmission area

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86822012000400019 ◽

2012 ◽

Vol 45 (4) ◽

pp. 510-513 ◽

Cited By ~ 17

Author(s):

Teiliane Rodrigues Carneiro ◽

Marta Cristhiany Cunha Pinheiro ◽

Sara Menezes de Oliveira ◽

Ana Lúcia de Paula Hanemann ◽

José Ajax Nogueira Queiroz ◽

...

Keyword(s):

Serological Test ◽

Laboratory Diagnosis ◽

Elisa Test ◽

Northeastern Brazil ◽

Enzyme Linked Immunosorbent Assay ◽

Serological Tests ◽

Predictive Values ◽

Transmission Area ◽

Elisa Technique ◽

Endemic Areas

INTRODUCTION: The laboratory diagnosis of schistosomiasis is based mainly on the detection of parasite eggs in stool samples through the Kato-Katz (KK) technique, reading one slide by test. However, a widely known limitation of parasitological methods is reduced sensitivity, particularly in low endemic areas. METHODS: To increase sensitivity, we conducted further slide readings from the same stool sample using the parasitological method associated with a serological test. We used the KK method (three slides) and the IgG anti-Schistosoma mansoni-enzyme-linked immunosorbent assay (ELISA) technique to diagnose schistosomiasis in low endemic areas in the Brazilian State of Ceará. Fecal samples and sera from 250 individuals were analyzed. RESULTS: Sixteen percent and 47.2% of samples were positive in parasitological tests and serological tests, respectively. Parasitological methods showed that 32 (80%) individuals tested positive on the first slide, 6 (15%) on the second slide, and 2 (5%) on the third. The performance of the ELISA test in the diagnosis, using the KK method as diagnostic reference, showed a negative predictive value of 100%, with specificity and positive predictive values of 62.8% and 33.9%, respectively. CONCLUSIONS: In this study, the increase from one to three slides analyzed per sample using the KK technique was shown to be a useful procedure for increasing the diagnostic sensitivity of this technique.

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