Comparison of Schistosoma mansoni Soluble Cercarial Antigens and Soluble Egg Antigens for Serodiagnosing Schistosome Infections

A Schistosoma mansoni cercarial antigen preparation (cercarial transformation fluid – SmCTF) was evaluated for detection of anti-schistosome antibodies in human sera in 4 collaborating laboratories. The performance of SmCTF was compared with that of S. mansoni egg antigens (SmSEA) in an indirect enzyme-immunoassay (ELISA) antigen assay, the latter being used routinely in 3 of the 4 participating laboratories to diagnose S. mansoni and S. haematobium infections. In the fourth laboratory the performance of SmCTF was compared with that of S. japonicum egg antigens (SjSEA) in ELISA for detection of anti-S. japonicum antibodies. In all 4 laboratories the results given by SmCTF in ELISA were very similar to those given by the antigen preparation routinely used in the respective laboratory to detect anti-schistosome antibodies in human infection sera. In so far as the ELISA results from SmCTF are thus so little different from those given by schistosome egg antigens and also cheaper to produce, the former is a potentially useful new diagnostic aid for schistosomiasis

Use of Enzyme-Linked Immunosorbent Assay and Dipstick Assay for Detection of Strongyloides stercoralis Infection in Humans

A homemade enzyme-linked immunosorbent assay (ELISA) (Academic Medical Center ELISA [AMC-ELISA]) and a dipstick assay for the detection of anti-Strongyloides stercoralis antibodies in serum were developed and evaluated together with two commercially available ELISAs (IVD-ELISA [IVD Research, Inc.] and Bordier-ELISA [Bordier Affinity Products SA]) for their use in the serodiagnosis of imported strongyloidiasis. Both commercially available ELISAs have not been evaluated previously. The sensitivities of the assays were evaluated using sera from 90 patients with parasitologically proven intestinal strongyloidiasis and from 9 patients with clinical larva currens. The sensitivities of the AMC-ELISA, dipstick assay, IVD-ELISA, and Bordier-ELISA were 93, 91, 89, and 83%, respectively, for intestinal strongyloidiasis. In all tests, eight of nine sera from patients with larva currens were positive. The specificity was assessed using a large serum bank of 220 sera from patients with various parasitic, bacterial, viral, and fungal infectious diseases; sera containing autoimmune antibodies; and sera from healthy blood donors. The specificities of AMC-ELISA, dipstick assay, IVD-ELISA, and Bordier-ELISA were 95.0, 97.7, 97.2, and 97.2%, respectively. Our data suggest that all four assays are sensitive and specific tests for the diagnosis of both intestinal and cutaneous strongyloidiasis

Diagnosis and subtype analysis of Blastocystis sp. in 442 patients in a hospital setting in the Netherlands

Background: Blastocystis sp. are among the most commonly observed intestinal parasites in routine clinical parasitology. Blastocystis in humans consists of at least 9 genetic subtypes. Different subtypes of Blastocystis may be associated with differences in pathogenicity and symptomatology.Methods: Advanced microscopy on two samples and sequence-confirmed PCR on a third sample from the same individual were used for Blastocystis diagnosis and subtype analyses on routine clinical samples in a university hospital.Results: With a combined gold standard of sequence-confirmed PCR and positive advanced microscopy, 107 out of 442 (24.2%) patients were diagnosed with Blastocystis. infection, which is a high frequency of detection in comparison to previous reports from industrialized countries. The sensitivity of microscopy and sequence-confirmed PCR was 99.1% (106/107) and 96.3% (103/107), respectively.Among 103 typable samples, subtype 3 was most abundant (n = 43, 42%), followed by subtypes 1 and 2 (both n = 23, 22%), subtype 4 (n = 12, 12%), and single samples with subtypes 6 (1%) and subtype 7 (1%). The prevalence of Blastocystis infection was 38% in patients from the Department of Tropical Medicine and 18% in patients from other departments.Conclusions: A high prevalence of Blastocystis infection was found with both advanced microscopy and sequence-confirmed PCR in our patient population. Most cases were caused by subtypes ST1, ST2, ST3 and ST4. A significantly higher prevalence was found among patients with a history of recent travel to tropical countries. © 2013 Bart et al. licensee BioMed Central Ltd.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

NMU: reactivity of sera from the Peoples Republic of China against <i>S. mansoni</i> SEA (SmSEA), <i>S. japonicum</i> SEA (SjSEA) and <i>S. mansoni</i> CTF (SmCTF) in ELISA.

<p>Twenty five sera were from <i>S. japonicum</i> egg-positive subjects and 17 from egg-negative subjects, both groups living in an area endemic for schistosomiasis japonicum, and 20 sera from negative controls living outwith an endemic area. Horizontal lines indicate the mean OD450 values for each antigen in each of the subject groups. • SmSEA ▪ SjSEA ▴ SmCTF.</p

SPDRL: correlation between <i>S. mansoni</i> cercarial transformation fluid (SmCTF) and soluble egg antigen (SmSEA) in ELISA.

<p>Results for sera from 8 subjects previously shown parasitologically to be infected with <i>S. haematobium</i> and 8 subjects suspected to be infected with <i>S. haematobium</i>. ▴ = 2 positive and 6 negative sera from patients that had visited Lake Malawi; □ = patients with <i>S. haematobium</i> eggs in urine; ▪ = control positive sera from patients known to be <i>S. haematobium</i>-infected.</p

SPDRL: correlation between <i>S. mansoni</i> cercarial transformation fluid (SmCTF) and soluble egg antigen (SmSEA) in ELISA.

<p>Results for sera from those subjects in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001815#pntd-0001815-g001" target="_blank">Figure 1</a> that had anti-SmSEA OD450 values of between 0 and 0.3. Vertical and horizontal lines indicate the cut-off values of, respectively, 0.22 for SmSEA and 0.25 for SmCTF.</p

SPDRL: comparison of <i>S. mansoni</i>- and <i>S. haematobium</i>-infection sera in ELISA.

<p>Graph of the greater-than-cut-off OD450 results of <i>S. mansoni</i> infection sera in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001815#pntd-0001815-g001" target="_blank">Figure 1</a> and <i>S. haematobium</i> infection sera in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001815#pntd-0001815-g002" target="_blank">Figure 2</a> reacting against <i>S. mansoni</i> cercarial transformation fluid (SmCTF). Horizontal lines indicate the mean SmCTF OD450 values for each group of sera.</p

LSTM: correlation between <i>S. mansoni</i> cercarial transformation fluid (SmCTF) and soluble egg antigen (SmSEA) in ELISA.

<p>Results for sera from patients infected with <i>S. mansoni</i>.</p

AMC: correlation between <i>S. mansoni</i> cercarial transformation fluid (SmCTF) and soluble egg antigen (SmSEA) in ELISA.

<p>Results for sera from a total of 46 subjects: 21 from patients with parasitologically-proven schistosome infections, 20 sera that were positive in routine serology and 5 negative controls. □ = sera from patients known to be <i>S. mansoni</i>-infected; ○ = sera from patients known to be <i>S. haematobium</i>-infected; ▪ = sera from patients with Katayama fever; • = sera from patients that tested positive for schistosomiasis in routine serology, but were egg-negative; ▴ = control negative sera from patients that tested negative in routine serology.</p