Reactivity of Schistosoma japonicum and S. mansoni antigen preparations in indirect haemagglutination (IHA) with sera of patients with homologous and heterologous schistosomiasis

Role of a schistosoma haematobium specific microRNA as a predictive and prognostic tool for bilharzial bladder cancer in Egypt

Urinary bladder cancer is a common malignancy in Egypt, thus reliable methodologies are required for screening and early detection. In this study, we analyzed the gene expression of a Schistosoma hematobium specific microRNA "Sha-miR-71a" and mitogen-associated protein kinase-3 (MAPK-3) in the urine samples of 50 bladder cancer patients and 50 patients with benign bilharzial cystitis. Fifty control subjects were also tested. Indirect hemagglutination test (IHA) diagnosed 70% of studied cancer cases as bilharzial associated bladder cancer (BBC), while histopathological examination detected only 18%. Urinary Sha-miR-71a & MAPK-3 revealed enhanced expression in BBC (p-value = 0.001) compared to non-bilharzial bladder cancer (NBBC) cases. Patients with chronic bilharzial cystitis exhibited a significant increase in gene expression compared to those with acute infection (p-value = 0.001). Sha-miR-71a and MAPK-3 showed good sensitivity and specificity in the diagnosis of BBC when analyzed by the receiver operating characteristic (ROC) curve. They were also prognostic regarding malignancy grade. Both biomarkers showed a positive correlation. Our results revealed that IHA is a reliable test in the diagnosis of bilharziasis associated with bladder cancer, and that Sha-miR-71a and MAPK-3 provide non-invasive specific biomarkers to diagnose BBC, as well as a potential role in testing bilharzial patients for risk to develop cancer.

Identification and validation of a novel autophagy gene expression signature for human bladder cancer patients

We sought to identify and validate a novel urinary autophagy transcript signature in patients with bladder cancer and evaluate its clinical utility. We performed an initial screening for seven autophagy transcript-based panel (autophagy-related protein 12 (ATG12); WD repeat domain, phosphoinositide interacting 2 (WIPI2); FYVE and coiled-coil domain-containing protein 1 (FYCO1); microtubule-associated protein light chain (MAPLC3); RB1-inducible coiled-coil 1 (RB1CC1); tachylectin-II-like beta-propeller domain 1 (TECPR1); and Unc-51-like kinase (ULK1)) that was identified based on bioinformatics analysis followed by SYBR Green-based polymerase chain reaction array validation in paired tissue and urine samples. Afterward, we evaluated the expression of differentially expressed autophagy transcripts in an independent validation set with reverse transcription quantitative real-time polymerase chain reaction in urine sediments of 140 patients with bladder cancer, 68 patients with benign urological lesions, and 74 healthy controls (age and sex matched). The expression levels of ATG12, FYCO1, TECPR1, and ULK1 in paired bladder tissue and urine samples were significantly lower in bladder cancer than in control group (p < 0.001). In the validation set, the receiver-operating characteristic curve analyses demonstrated that each urinary autophagy transcripts showed high sensitivity and specificity for distinguishing bladder cancer from non-bladder cancer patients (ATG12, 75.4% and 86.1%; FYCO1, 87% and 75.7%; ULK1, 85.5% and 75.6%; and TECPR1, 90% and 81.9%). We document and validate a novel autophagy transcript signature for human bladder cancer diagnosis: bilharzial and non-bilharzial types.

Rapid detection of urinary long non-coding RNA urothelial carcinoma associated one using a PCR-free nanoparticle-based assay

We developed a specific hybridization assay for direct detection of long non-coding RNA urothelial carcinoma associated-1 (lncRNA-UCA1). Total RNA was extracted from urine pellet samples (bladder carcinoma patients and controls). Then, we compared the developed nanoassay with quantitative real time polymerase chain reaction (qRT-PCR) results in detection of urine UCA1 in bladder cancer and control samples. The sensitivity and the specificity of UCA1 nanoassay were 92.1% and 93.3%, respectively. The concordance of the two methods was 98%. Interestingly, all bilharzial benign cases showed negative lncRNA-UCA1 using both methods. UCA1-nanoassay is a valid test for direct detection of urine UCA1 for bladder cancer detection.

Integrative functional genetic-epigenetic approach for selecting genes as urine biomarkers for bladder cancer diagnosis

Early screening for bladder cancer (BC) holds the key to combat and control the increasing global burden of BC mortality. We presented a simple approach to characterize, analyze, and validate a panel of biomarkers in BC and their relationship to bilharziasis. We investigated voided urine and blood samples from patients with bladder cancer (n = 94), benign bladder lesions (n = 60), and age-matched normal controls (n = 56). This study was divided into the following phases. (1) We analyzed the expression of urinary Hyaluronoglucosaminidase 1 (HYAL1) protein in BC and control samples by zymography. (2) We performed bioinformatics analysis to retrieve a set of epigenetic regulators of HYAL1. (3) This set of three selected genes [long non-coding RNA-urothelial cancer associated 1(lncRNA-UCA1), microRNA-210, and microRNA-96] was then analyzed in the same urine samples used in phase I by quantitative real-time PCR. (4) A high reproducibility of gene selection results was also determined from statistical validation. The urinary expression of HYAL1 protein and its epigenetic regulators were higher in BC patients (P < .001). The receiver-operating characteristic curve analyses demonstrated that each one had good sensitivity and specificity for distinguishing BC patients from non-BC ones (HYAL1, 89.4 and 91.2 %; miR-210, 76.6 and 93 %; miR-96, 76.6 and 89.4 %; and lncRNA-UCA1, 91.5 and 96.5 %). There was a significant positive correlation between HYAL1 and the selected epigenetic biomarkers. The performance of this urine biomarker panel reached 100 % sensitivity and 89.5 % specificity for bladder cancer diagnosis.

Evaluation of urinary microRNA panel in bladder cancer diagnosis: relation to bilharziasis

We assessed the differential expression of a urinary panel of microRNAs (miRs) in terms of potential application as diagnostic markers of bladder cancer (BC) and relationship to bilharziasis. We investigated voided urine samples and blood from patients with BC (n = 188), benign bladder lesions (n = 88), and age-matched controls (n = 92). Five miRs (miR-210, miR-10b, miR-29c, miR-221, and miR-23a) were selected from previous microarray signature profiling (released by miR2Disease). Afterward, they were validated using polymerase chain reaction array. The expression levels of miR-210, miR-10b, and miR-29c in the urine samples were significantly higher in BC (P < 0.001). The receiver-operating characteristic curve analyses demonstrated that each miR had good sensitivity and specificity for distinguishing patients with BC from patients without BC (miR-210, 71.3% and 91.1%; miR-10b, 80.9% and 91.1%; and miR-183, 71.3% and 88.9%). On combining the 3 miR detection data with the urinary cytology, the results sensitivity increased to 95.2%. Relative quantity mean rank of the miR-29c was significantly higher in the bilharzial-positive patients compared with bilharzial-negative patients. To conclude, urine miR-210, miR-10b, and miR-29c are promising tumor markers for BC: bilharzial and nonbilharzial.

Evaluation of urinary miRNA-96 as a potential biomarker for bladder cancer diagnosis

For bladder cancer, a new diagnostic marker is needed to avoid painful cystoscopy. The aim of this study was to explore the efficacy of urinary miRNA-96 as molecular marker in bladder cancer diagnosis and its relation to bilharziasis. Urine cytology, serologic assessment of schistosomiasis and estimation of miRNA-96 by real-time PCR were carried out for 94 bladder cancer patients, 30 benign bladder lesions and 60 healthy individuals. Expression of miRNA-96 showed a significant difference among the three tested groups and also between benign and malignant bilharzial cases. Urinary miRNA-96 is a good noninvasive diagnostic biomarker for bladder cancer.

Evaluation of urinary HURP mRNA as a marker for detection of bladder cancer: relation to bilharziasis

This study was carried out to assess the efficacy of urinary hepatoma up-regulated protein (HURP) RNA in bladder cancer diagnosis and its relation to bilharziasis. Voided urine samples and blood were collected from 344 consecutive participants: 211 patients diagnosed with bladder cancer, 71 patients with benign urological disorders and 62 healthy volunteers. Serologic assessment of schistosomiasis antibody in sera, urine cytology and estimation of HURP RNA by reverse transcription polymerase chain reaction in urothelial cells was carried out in all samples. HURP RNA expression showed a significant difference among the three investigated groups. The best cutoff point for HURP RNA was determined as 0.0132 at 78.67 % sensitivity and 94 % specificity. The sensitivity of urine cytology was improved when combined with HURP RNA in detection of early stage (77.3 %), low grade (85.3 %) and bilharzial bladder cancer (78.1 %). Detection of urinary HURP RNA is a useful non-invasive test for early detection of bladder cancer and bilharzial bladder cancer and it improves sensitivity of urine cytology up to 91 %.

Sensitive and simultaneous detection of different disease markers using multiplexed gold nanorods

A multiplexed bioanalytical assay is produced by incorporating two types of gold nanorods (GNRs). Besides retaining the desirable features of common GNRs LSPR sensors, this sensor is easy to fabricate and requires only a visible-NIR spectrometer for detection. This assay can simultaneously detect different acceptor-ligand pairs by choosing the proper GNRs possessing various LPWs in a wide detection wavelength range and can be developed into a high-throughput detection method. This bioanalytical assay allows easy detection of human serum specimens infected by S. japonicum and tuberculosis (TB) from human serum specimens (human serum/Tris-HCl buffer ratio=1:10(4)) without the need for sample pretreatment. The technique is very sensitive compared to other standard methods such as indirect hemagglutination assays (IHA) that require a serum concentration ratio of larger than 1:20 and enzyme-linked immunosorbent assays (ELISA) requiring a ratio larger than 1:100. This methodology can be readily extended to other immunoassays to realize wider diagnostic applications.

Detection of hyaluronidase RNA and activity in urine of schistosomal and non-schistosomal bladder cancer

Diagnosis of bladder cancer is done by cystoscopy and cytology. In the last decade, many urine-based tests for bladder cancer have been developed and tested in different populations. Hence, it was relevant to assess the diagnostic significance of urinary hyaluronidase RNA and its enzyme activity in bladder cancer. Seventy patients with bladder cancer, 56 patients with benign bladder lesions, and 49 healthy controls were enrolled in this study. Voided urine samples from all subjects were used for estimation of urinary HAase RNA by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and determination of its enzymatic activity by zymography. There was a significant difference in the mean ranks and positivity rates of HAase RNA expression (P < 0.01) and its enzymatic activity among the three investigated groups: malignant, benign, and normal (P < 0.01). In detecting bladder cancer, the sensitivity of urine cytology (42.83 %) was improved to 100 % when combined with urinary Hyal RNA or Hyal enzyme activity. Detection of urinary Hyal RNA and its enzyme activity is promising noninvasive tests with high sensitivities and specificities for detection of bladder cancer.

Evaluation of eight serological tests for diagnosis of imported schistosomiasis

The diagnosis of schistosomiasis in individuals from countries where the disease is not endemic is challenging, and few data are available on the accuracy of serological diagnosis in those patients. We evaluated the performance of eight serological assays, including four commercial kits, in the diagnosis of imported schistosomiasis in individuals from areas where the disease is not endemic, including six enzyme-linked immunosorbent assays using three different antigens, an indirect hemagglutination assay, and an indirect immunofluorescent-antibody test. To analyze the assays, we used a total of 141 serum samples, with 121 derived from patients with various parasitic infections (among which were 37 cases of schistosomiasis) and 20 taken from healthy volunteers. The sensitivity values for detection of schistosomiasis cases ranged from 41% to 78% and were higher for Schistosoma mansoni than for S. haematobium infections. Specificity values ranged from 76% to 100%; false-positive results were most frequent for samples from patients with cestode infections. By combining two or more tests, sensitivity improved markedly and specificity decreased only moderately. Serological tests are useful instruments for diagnosing imported schistosomiasis in countries where the disease is not endemic, but due to limitations in test sensitivities, we recommend the use of two or more assays in parallel.

A piezoelectric immunosensor using hybrid self-assembled monolayers for detection of Schistosoma japonicum

BACKGROUND

The parasite Schistosoma japonicum causes schistosomiasis disease, which threatens human life and hampers economic and social development in some Asian countries. An important lesson learned from efforts to reduce the occurrence of schistosomiasis is that the diagnostic approach must be altered as further progress is made towards the control and ultimate elimination of the disease.

METHODOLOGY/PRINCIPAL FINDINGS

Using mixed self-assembled monolayer membrane (mixed SAM) technology, a mixture of mercaptopropionic acid (MPA) and mercaptoethanol (ME) was self-assembled on the surface of quartz crystals by gold-sulphur-bonds. Soluble egg antigens (SEA) of S. japonicum were then cross-linked to the quartz crystal using a special coupling agent. As compared with the traditional single self-assembled monolayer immobilization method, S. japonicum antigen (SjAg) immobilization using mixed self-assembled monolayers exhibits much greater immunoreactivity. Under optimal experimental conditions, the detection range is 1:1500 to 1:60 (infected rabbit serum dilution ratios). We measured several infected rabbit serum samples with varying S. japonicum antibody (SjAb) concentrations using both immunosensor and ELISA techniques and then produced a correlation analysis. The correlation coefficients reached 0.973.

CONCLUSIONS/SIGNIFICANCE

We have developed a new, simple, sensitive, and reusable piezoelectric immunosensor that directly detects SjAb in the serum. This method may represent an alternative to the current diagnostic methods for S. japonicum infection in the clinical laboratory or for analysis outside the laboratory.

Urinary retinoic acid receptor-β2 gene promoter methylation and hyaluronidase activity as noninvasive tests for diagnosis of bladder cancer

OBJECTIVES

We evaluated the significance of urinary retinoic acid receptor-β2 (RAR-β2) gene promoter methylation and hyaluronidase activity in comparison with voided urine cytology (VUC) in diagnosis of bladder cancer.

DESIGN AND METHODS

This study included 100 patients diagnosed with bladder cancer, 65 patients with benign urological disorders and 51 healthy volunteers. Urine supernatant was used for determining hyaluronidase activity by zymography while urine sediment was used for cytology and detection of methylated RAR-β2 gene promoter by methylation specific nested PCR.

RESULTS

The sensitivity and specificity were 53% and 90.5% for VUC, 65% and 89.7% for percent methylation fraction of RAR-β2 gene promoter, and 89% and 90.5% for hyaluronidase activity; combination of the three parameters increased sensitivity to 95%. A significant association was observed between investigated markers and advanced grade tumor.

CONCLUSIONS

Combined use of RAR-β2 gene promoter methylation, hyaluronidase activity and VUC is promising non-invasive tool for bladder cancer detection.

Combination of Kato-Katz faecal examinations and ELISA to improve accuracy of diagnosis of intestinal schistosomiasis in a low-endemic setting in Brazil

Considering the decrease of disease burden caused by intestinal schistosomiasis in many endemic settings, more sensitive diagnostic methods are needed to plan and monitor control measures. We conducted a cross-sectional survey in a rural community in northeast Brazil (317 inhabitants). A combined approach including repeated faecal examinations and ELISA testing was applied. In a first round, single stool samples were collected from 305 (96.2%) participants. Three Kato-Katz (KK) smears were prepared from each sample, and IgG ELISA was performed from serum samples. In the 85 cases of negative KK smears, but positive ELISA results, three additional faecal samples were collected in a second round, and another five KK smears prepared. In the first round of KK analysis, 11/287 (3.8%; 95% confidence interval; 1.92-6.75) were positive. After examining up to eight smears per individual (second round), prevalence of schistosomiasis increased to 8.7% (95% confidence interval: 5.9-12.5). In total, 96/287 (33.4%, 95% confidence interval: 28.0-39.2) samples were positive by ELISA testing. There were no false negative ELISA results. Specificity, positive and negative predictive values of ELISA as compared to up to eight KK smears from three stool samples (reference diagnosis) were 72.9%, 26.0% and 100%, respectively. A single KK smear detected only 12% of the 25 infections; this increased to 44% (three smears, one stool sample), 84% (five smears, three stool samples) and 96% (six smears, four stool samples). We conclude that in low-endemic areas in Brazil the use of KK continues being an important tool. The additional benefit of preparing more than six KK smears from repeated stool samples is negligible. ELISA may be useful for screening populations, with subsequent confirmation of diagnosis by KK or other more sensitive, but highly specific methods.

Aberrant methylation of RARbeta2 and APC genes in voided urine as molecular markers for early detection of bilharzial and nonbilharzial bladder cancer

BACKGROUND

Bladder cancer cells illustrate major disruptions in their DNA methylation patterns as compared with normal ones. Authors aimed to identify epigenetic molecular markers in urine for early detection of bladder cancer.

MATERIALS AND METHODS

We retrospectively analyzed the methylation status of RARβ(2) and APC genes in urine samples from 210 bladder cancer patients, 61 patients with benign urological diseases, and 49 healthy volunteers by using methylation-specific PCR.

RESULTS

Methylated RARβ(2) and APC were significantly higher in bladder cancer patients (62.8%, 59.5%) than benign (16.4%, 5%) but not detected in healthy volunteers (0%) at (P < 0.0001). Both methylated genes showed no significant difference among clinicopathologic factors; however, they were detected in all grades and stages. Among the 128 patients with bilharzial bladder cancer, 94 (73.4%) showed methylated RARβ(2) and 86 (67.2%) showed methylated APC. Homoplasmic methylation pattern of both genes were only detected in bilharzial bladder cancer cases. Both sensitivities and specificities of the methylated genes for bladder cancer detection were superior to urine cytology and when altogether combined, the sensitivities improved to (91.8%), (93.5%), (91.9%), and (80.9%) in detection of: bladder cancer, non-muscle invasive bladder cancer, low-grade tumors, and bilharzial associated bladder cancer, respectively.

CONCLUSION

Thus, methylated RARβ(2) and APC genes might be valuable urinary molecular markers for early detection of bilharzial and nonbilharzial bladder cancer.

Expression of HYAL1 and survivin RNA as diagnostic molecular markers for bladder cancer

PURPOSE

Urinary tumor markers that help in the early detection of bladder cancer promise a significant improvement in sensitivity, specificity and convenience over conventional, invasive diagnostic tests. We assessed the diagnostic efficacy of hyaluronidase (HYAL1) and survivin for early bladder cancer detection.

MATERIALS AND METHODS

The study included 166 patients diagnosed with bladder carcinoma, 112 with benign bladder lesions and 100 healthy volunteers who served as controls. All underwent serological assessment of schistosomiasis antibody, urine cytology, and hyaluronidase (HYAL1) and survivin RNA estimation by qualitative and semiquantitative reverse transcriptase-polymerase chain reaction in urothelial cells from voided urine.

RESULTS

Positivity rates of HYAL1 RNA and survivin RNA on qualitative reverse transcriptase-polymerase chain reaction were significantly different among the 3 groups. Mean rank using semiquantitative method was increased in the malignant vs the other groups. The best cutoff for HYAL1 and survivin RNA was 0.25 each. Using these cutoffs HYAL1 and survivin RNA sensitivity was 91% and 75%, respectively, with absolute specificity. HYAL1 RNA detected all patients with stages 0 and I bladder cancer (p <0.037). Urine cytology sensitivity improved when combined with hyaluronidase or survivin RNA on semiquantitative reverse transcriptase-polymerase chain reaction.

CONCLUSIONS

The detection of urinary HYAL1 and survivin RNA is a promising noninvasive test for bladder cancer early detection. HYAL1 RNA was more sensitive and specific than urine cytology. Semiquantitative reverse transcriptase-polymerase chain reaction is favored for its high sensitivity and specificity.

Diagnostic value of fibronectin and mutant p53 in the urine of patients with bladder cancer: impact on clinicopathological features and disease recurrence

Development of new methods for bladder cancer detection is required because cystoscopy is invasive, and voided urine cytology (VUC) has low sensitivity. The aim of this study was to evaluate the diagnostic performance of urinary fibronectin and mutant p53 in comparison with VUC in the detection of bladder cancer. This study included 100 patients diagnosed with bladder cancer, 93 patients with benign urological disorders and 47 healthy volunteers. The urine supernatant was used for determination of fibronectin by ELISA, while urine sediment was used for cytology and detection of mutant p53 by PCR-SSCP followed by DNA sequencing. The sensitivity and specificity were 59% and 91.4% for VUC, 82% and 84.3% for fibronectin, and 37% and 100% for mutant p53; combination of the three parameters increased sensitivity to 95% but specificity was only 78.6%. A significant association was observed between disease recurrence and mutant p53, stage and lymph node involvement. Our results indicate that fibronectin had the highest sensitivity compared to VUC and mutant p53 in bladder cancer detection; however, mutant p53 had superior specificity compared to VUC and fibronectin. Mutant p53 is associated with disease recurrence and hence it has a significant prognostic role in bladder cancer.

Contrasting reservoirs for Schistosoma japonicum between marshland and hilly regions in Anhui, China--a two-year longitudinal parasitological survey

Schistosoma japonicum remains highly endemic in many counties in China and has recently re-emerged, to a large extent, in previously controlled areas. To test the hypothesis that small rodents and less agriculturally important domestic animals such as dogs and cats may play an important role in the transmission and potential re-emergence of this disease, an annual investigation of S. japonicum among humans, domestic animals and rodents, combined with detailed surveys of the snail intermediate host, was performed across 3 marshland villages and 3 hilly villages in Anhui province of China over 2 consecutive years. The highest infection prevalence and intensity observed across all mammals was in rodents in the hilly region; while in the marshland, bovines were suspected as the main reservoirs. However, relatively high infection prevalence levels were also found in dogs and cats in both regions. Such results may have implications for the current human- and bovine-oriented control policy for this medically and veterinarily important disease, particularly within the hilly regions of mainland China.

Comparison of CD44 and cytokeratin 20 mRNA in voided urine samples as diagnostic tools for bladder cancer

OBJECTIVES

We evaluated the diagnostic efficacy of urinary CD44 and cytokeratin 20 (CK20) mRNA in comparison with voided urine cytology (VUC) for the detection of bladder cancer.

DESIGN AND METHODS

A total of 136 Egyptian patients provided a single voided urine sample for CD44, CK20 mRNA and VUC before cystoscopy. Of the 136 cases, 111 were histologically diagnosed as bladder cancer whereas the remaining 25 had benign urological disorders. A group of 20 healthy volunteers was also included in this study. Voided urine was centrifuged and the urine sediment was used for cytology, estimation of CD44 by ELISA and RNA extraction. CK20 mRNA was detected by conventional RT-PCR and quantitative real-time RT-PCR.

RESULTS

The best cutoff values for CD44 and relative CK20 mRNA detected by real-time RT-PCR were calculated by receiver operating characteristic curve. The positivity rates and the mean ranks for CD44 and CK20 mRNA showed significant difference among the three investigated groups (p=0.001). Quantitative real-time RT-PCR results were comparable to conventional RT-PCR for the detection of CK20 mRNA. The positivity rate of CD44 was significantly associated with schistosomiasis and urine cytology. The overall sensitivity and specificity were 52.3% and 88.9% for VUC, 63.1% and 88.9% for CD44, and 82.0% and 97.8% for CK20 mRNA. Combined sensitivity of VUC with CD44 and CK20 mRNA together (95.5%) was higher than either the combined sensitivity of VUC with CD44 (78.4%) or with CK20 mRNA (91.0%) or than that of the biomarker alone.

CONCLUSION

Urinary CD44 and CK20 mRNA had higher sensitivities compared to VUC. However, when the diagnostic efficacy was considered, CK20 mRNA by either conventional RT-PCR or real-time RT-PCR had the highest sensitivity and specificity compared to CD44 and VUC.

Determination of Schistosoma japonicum circulating antigens in dilution serum by piezoelectric immunosensor and S/N enhancement

A piezoelectric immunosensor assay was developed with immobilizing immunoglobulin G (IgG) as a probe to detect Schistosoma japonicum circulating antigens (SjCAg). Analytical strategy utilizes the polyclonal antibodies with broad-spectrum recognition to a complex target with high specificity. The immobilized antibodies were purified from immunized rabbit's sera (im-S) and infected rabbit's sera (inf-S) by S. japonicum. The detection capacities of antibodies were compared between the sera of different phenotypes and purified fractions. The sample dilution ratios were also evaluated and optimized. Additionally, the sera with a variety of infection degrees for validation could be discriminated quantitatively. The linear dose-response relationship indicates that the systematic sensitivity of this method is below 150 Hz and the lowest limit of detectable range is above 500 cercariae of S. japonicum infection for 2 weeks. The novel immunosensor technique is well potential to determine the SjCAg in serum samples for clinical diagnosis of parasitosis in early stage.

Undiagnosed and potentially lethal parasite infections among immigrants and refugees in Australia

Intestinal parasite infections are a major cause of ill health in many resource-poor countries. This study compares the types and rates of these infections and their risk factors in recently arrived and long-term immigrants in Australia. Cross-sectional surveys of 127 East African and 234 Cambodian immigrants and refugees were undertaken in 2000 and 2002, respectively, to assess the burden of intestinal parasites and collect demographic information. Serum samples were assessed for eosinophilia and Strongyloides stercoralis and Schistosoma antibodies, and feces examined for ova, cysts, and parasites. Intestinal parasites were identified in 77/117 fecal samples from East African and in 25/204 samples collected from Cambodian participants. Eleven percent (14/124) of East Africans and 42% (97/230) of Cambodians had positive or equivocal serology for S stercoralis. Schistosoma serology was positive or equivocal in 15% (19/124) of East African participants. Potentially serious intestinal parasite infections are common among recent and longer term immigrants despite multiple visits to health care providers. Immigrants and refugees from high-risk countries would benefit from comprehensive health checks soon after resettlement.

Serodiagnosis of Schistosoma mansoni infections in an endemic area of Burkina Faso: performance of several immunological tests with different parasite antigens

The performance of indirect haemagglutination assays (IHA), enzyme-linked immunosorbent assays (ELISA) and indirect immunofluorescent antibody tests (IFAT) were compared with 450 sera from a Schistosoma mansoni-endemic area in Burkina Faso. All participants in this survey provided at least one sample each of stool, urine and serum. From those with an egg-negative Kato-Katz thick smear, a second stool sample was examined. IHA was based on either extracts of adult S. mansoni worms (SmIHA) or S. japonicum egg antigen (SjIHA). For ELISA, three antigen preparations were used, namely: (i) soluble S. mansoni adult worm antigens (SWAP); (ii) soluble S. mansoni egg antigens (SEA); and (iii) a cationic exchange fraction of S. mansoni eggs (CEF6). IFAT was performed with S. mansoni male worm sections. Among the egg-excretors, the sensitivity of ELISA was high and egg antigens performed slightly better (SEA, 96%; CEF6, 97%) than worm antigen (94%). Sensitivity of IHA was satisfactory with homologous (Sm, >85%), but not heterologous (Sj, 56%) parasite antigen. In IFAT, the parenchyma-associated fluorescence showed high sensitivity (95%), but gut-associated fluorescence, which is known to be a sensitive diagnostic marker for schistosome-infected European travelers, was observed only in 76% of a sub-sample of 100 of the endemic sera. Among sera from egg-negative individuals, many gave positive reactions in several or all of the tests employed. These reactions (formally "false positive") are considered to represent true infections, since chemotherapy had not yet been delivered to this population. For the purpose of further surveys in Burkina Faso or other resource-poor settings, we suggest IHA as an accurate diagnostic test and propose to further improve its performance by including egg rather than worm antigens.

Hybridoma cell agglutination as a novel test to detect circulating antigen of Schistosoma japonicum

We developed a serodiagnostic test which is based on the agglutination of hybridoma cells. In the presence of specific antigen, agglutination of the fixed and stained cells occurs and can be visualized in analogy to traditional erythrocyte agglutination. The procedures were developed with a murine cell line producing a monoclonal antibody against a schistosome gut protein and sera of patients and mice infected with Schistosoma japonicum. This test is capable of detecting circulating antigen during pre-patency in mice infected with 50 cercariae. Its sensitivity was high with acute schistosomiasis japonica (97%, n = 32) and moderate with chronic cases (75%, n = 57). No positive reactions were obtained with healthy persons (n = 78) or patients infected with other parasites (Chlonorchis sinensis, n = 20; Paragonimus westermani, n = 20; Plasmodium vivax, n = 10) or suffering from lupus erythomatodus (n = 5) or mononucleosis (n = 10).

Serodiagnosis of imported schistosomiasis by a combination of a commercial indirect hemagglutination test with Schistosoma mansoni adult worm antigens and an enzyme-linked immunosorbent assay with S. mansoni egg antigens

A commercial indirect hemagglutination (IHA) test using erythrocytes coated with Schistosoma mansoni adult worm antigens (WA) and an enzyme-linked immunosorbent assay (ELISA) with S. mansoni egg antigens (SEA) were assessed for their use in serodiagnosis of imported schistosomiasis (hereafter these tests are designated WA/IHA and SEA/ELISA, respectively). The sensitivity of the tests was evaluated with sera from 75 patients with proven S. mansoni infection, 25 with proven S. haematobium infection, and 10 with clinical Katayama fever. The specificity was assessed with sera from 283 patients with various parasitic, bacterial, viral, and fungal infections and sera containing autoimmune antibodies. Sensitivities of the WA/IHA with a cutoff titer of 1:160 (WA/IHA(160)) in detecting S. mansoni, S. haematobium, S. mansoni and S. haematobium combined, and clinical Katayama fever were 88.0, 80.0, 86.0, and 70.0%, respectively, with a specificity of 98.9%. The WA/IHA with a cutoff of 1:80 (WA/IHA(80)) showed sensitivities of 94.7, 92.0, 94.0, and 90.0%, respectively, with a specificity of 94.7%. The comparable values of SEA/ELISA were 93.3, 92.0, 93.0, and 50.0%, respectively, with a specificity of 98.2%. Combined use of ELISA and WA/IHA(80) gave sensitivities of 100% for S. mansoni, S. haematobium, and S. mansoni and S. haematobium combined and 90% for Katayama fever. The specificity of this combination in detecting schistosomiasis was 92.9%. Combination of SEA/ELISA with WA/IHA(160) gave sensitivities of 98.7, 96.0, 98.0, and 80% with a specificity of 97.2%. Our findings suggest that WA/IHA and SEA/ELISA are each sensitive and specific serological tests that are easy to use for the diagnosis of imported schistosomiasis. The combined use of these two tests enabled the serological diagnosis of schistosomiasis to be achieved with very high degrees of both sensitivity and specificity.

The relationship between hepatitis C virus and schistosomiasis: histopathologic evaluation of liver biopsy specimens

The reported high incidence of anti-HCV seropositivity in the Egyptian population seems surprising. Some suggest that schistosomiasis is the responsible factor, either by producing false positivity for HCV antibodies or by predisposing to actual HCV infection in some way. In an attempt to investigate this unclear relationship on a histological level, we performed a thorough semiquantitative morphological study of liver biopsy specimens from 44 anti-HCV-positive Egyptian patients with chronic liver disease. More than half of these patients (23) had serological evidence of schistosomiasis. The results have shown that all 44 liver biopsy specimens demonstrated the histopathological features known to be characteristic of chronic HCV hepatitis. Statistical analysis showed no significant difference between the schistosomal and nonschistosomal groups regarding the semiquantitative histological scores of these features. This study confirms the presence of definite HCV-induced hepatic pathology in all anti-HCV seropositive cases. More importantly, it shows the lack of enhancement of this pathology in the schistosomal patients.

Schistosomiasis in Australian travellers to Africa

OBJECTIVE

To determine the proportion of Australian travellers to Africa at risk of Schistosoma infection, and the proportion of those infected.

DESIGN AND PARTICIPANTS

Retrospective postal survey of 360 patients who had attended Fairfield Hospital travel clinic in 1994 and stated an intention to travel to Malawi, Zimbabwe or Botswana.

MAIN OUTCOME MEASURES

Self-reported risk status for Schistosoma infection. For those at risk, results of an indirect haemagglutination assay (IHA). For those with IHA titres > or = 1:32, results of enzyme-linked immunosorbent assay, urine microscopy and eosinophil count.

RESULTS

360 letters were sent; 35 were returned to sender. Of the 325 remaining, 250 (77%) either responded or had an IHA test; 19 of these were still overseas or did not travel. 117/231 (51%) returned travellers considered themselves at risk of infection. Significantly fewer older patients reported exposure (chi 2 = 66.6; P < 0.001). 109/117 (93%) of those at risk had IHA tests and 18 had titres > or = 1:32. Subsequent testing indicated infection in 10/117 travellers (8.5%; 95% CI, 4.2%-15.2%).

CONCLUSION

Our findings indicate that a considerable number of Australian travellers to Africa are at risk of schistosomiasis, and some are infected. As complications can be serious, screening is recommended for individuals with any risk of infection, and treatment should be offered to those infected.

Evaluation of a monoclonal antibody-based sandwich-ELISA for detection of circulating Schistosoma japonicum antigen (Sj31/32) in an endemic area of China

A sandwich-ELISA specific for 31/32 kDa schistosome proteins was used to trace infections in a Chinese population living in a low endemicity area for schistosomiasis japonica. The study population included 304 persons for whom records were available from 1992 onwards. In 1994, 2 individuals were positive in the miracidial hatching assay performed with 30 g of stools. The ELISA gave positive results for 8 individuals, including these 2 with active infections. Of the remaining 6 ELISA-positive, 5 had excreted eggs and received praziquantel in 1993 and may have harboured residual worms in 1994. It is concluded that this ELISA is able, in a low prevalence situation, to identify the few infected individuals.