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Nickel B, Krebs C, Ruf MT, Anuar NS, Noordin R. An evaluation of a lateral flow rapid diagnostic test for Strongyloides stercoralis infection. Acta Trop 2024; 258:107336. [PMID: 39098752 DOI: 10.1016/j.actatropica.2024.107336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 06/04/2024] [Accepted: 07/25/2024] [Indexed: 08/06/2024]
Abstract
Strongyloides stercoralis in humans often presents as a chronic asymptomatic infection. Diagnosis can be challenging due to the limited sensitivity of faecal-based parasitological techniques. A prototype lateral flow rapid diagnostic test (RDT) for the detection of specific antibodies against Strongyloides stercoralis (SsRapid) was evaluated using 143 samples from the serum bank of the Swiss Tropical and Public Health Institute. Group 1 (n = 30) comprised serum samples from larvae-positive individuals; the RDT's diagnostic sensitivity was 97 % (29/30). Group II comprised serum samples from patients with other parasitic infections (n = 86) and Swiss blood donors (n = 27); the RDT's diagnostic specificity for this group was 90 % (102/113). The RDT showed good diagnostic performance and is a promising point-of-care test for detecting human Strongyloides stercoralis infection.
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Affiliation(s)
- Beatrice Nickel
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123 Allschwil, Switzerland; University of Basel, Basel, Switzerland
| | - Christina Krebs
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123 Allschwil, Switzerland; University of Basel, Basel, Switzerland
| | - Marie-Therese Ruf
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123 Allschwil, Switzerland; University of Basel, Basel, Switzerland
| | - Nor Suhada Anuar
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang, 11800, Malaysia
| | - Rahmah Noordin
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, 56000, Malaysia.
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Santarém VA, Pinto GLB, Ferreira IB, Ribeiro J, Filho RTDS, Meisel DMC, Gryschek RCB, Lescano SAZ, Giuffrida R, Kmetiuk LB, de Paula FM, Biondo AW. A silent threat behind bars: Serosurvey and associated risk factors for strongyloidiasis in female inmates and correctional officers. Acta Trop 2024; 257:107301. [PMID: 38955318 DOI: 10.1016/j.actatropica.2024.107301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 06/04/2024] [Accepted: 06/21/2024] [Indexed: 07/04/2024]
Abstract
Strongyloidiasis has been a neglected parasitic infection caused by Strongyloides genus parasites. Despite assessment of S. stercoralis exposure in different vulnerable populations, seroprevalence in inmates worldwide remains to be fully established. Due to poor sanitation and lack of personal hygienic practices, incarcerated individuals have been considered prone to spread infectious illnesses. Accordingly, the present study has assessed exposure and associated risk factors for strongyloidiasis in women inmates and correctional officers at the Women's State Penitentiary of Parana, part of the third largest incarceration complex in Brazil at the time. Blood samplings were performed in 2020 and 2021from a total of 503 women inmates and 92 correctional officers. Participants voluntarily responded to an epidemiological questionnaire to assess associated risk factors to strongyloidiasis. Serological analysis was performed by ELISA for anti-S. stercoralis IgG detection. Statistical analysis was performed using R software, adopting a 5% level of significance. The data were submitted to univariate analysis by chi-square or Fisher´s Exact test for assessing the association among seropositivity and the variables. The variables with p-value < 0.2 in the univariate analysis were considered fit to be included in the logistic regression. In overall, 356/503 (70.8%; 95% CI: 66.7-74.6) inmates were seropositive for anti-S. stercoralis antibodies, with no statistically associated risk factor to seropositivity. A total of 57/92 (62.0%; 95% CI: 51.8-71.2) correctional officers were seropositive, and logistic regression revealed that individuals older than 50 years were more likely seropositive. In conclusion, the high endemicity observed herein has indicated a history of previous exposure to S. stercoralis and warned for a systematic strongyloidiasis screening for inmates, to prevent long term morbidity and disseminated infection during incarceration.
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Affiliation(s)
- Vamilton Alvares Santarém
- Graduate College in Animal Sciences, University of Western São Paulo (UNOESTE), Presidente Prudente, SP 19050-920, Brazil
| | - Gabriel Luís Brucinski Pinto
- Graduate College of Cell and Molecular Biology, Department of Veterinary Medicine, Federal University of Paraná (UFPR), Rua dos Funcionários, 1540, Juvevê, Curitiba, PR 80035-050, Brazil
| | - Isabella Braghin Ferreira
- Graduate College in Animal Sciences, University of Western São Paulo (UNOESTE), Presidente Prudente, SP 19050-920, Brazil
| | - Juliano Ribeiro
- Graduate College of Cell and Molecular Biology, Department of Veterinary Medicine, Federal University of Paraná (UFPR), Rua dos Funcionários, 1540, Juvevê, Curitiba, PR 80035-050, Brazil
| | | | - Dirce Mary Correa Meisel
- Laboratory of Medical Investigation (LIM/06), Clinical Hospital of the University of São Paulo, SP, Brazil
| | | | | | - Rogério Giuffrida
- Graduate College in Animal Sciences, University of Western São Paulo (UNOESTE), Presidente Prudente, SP 19050-920, Brazil
| | - Louise Bach Kmetiuk
- Zoonoses Surveillance Unit, Municipal Secretary of Health, Curitiba, PR, Brazil
| | - Fabiana Martins de Paula
- Laboratory of Medical Investigation (LIM/06), Clinical Hospital of the University of São Paulo, SP, Brazil
| | - Alexander Welker Biondo
- Graduate College of Cell and Molecular Biology, Department of Veterinary Medicine, Federal University of Paraná (UFPR), Rua dos Funcionários, 1540, Juvevê, Curitiba, PR 80035-050, Brazil.
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Screening of Schistosomiasis, Strongyloidiasis and Sexually Transmitted Infections in Nigerian Female Sex Workers Living in Rome. Pathogens 2023; 12:pathogens12020274. [PMID: 36839546 PMCID: PMC9961054 DOI: 10.3390/pathogens12020274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/28/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023] Open
Abstract
BACKGROUND Female Sex Workers (FSWs) are at high risk for acquisition and transmission of sexually transmission infections (STIs). Although several studies investigated the diffusion of STIs in this population, none of them investigated the occurrence of helminth infections in FSW coming from endemic regions. This study aims to assess the prevalence of STIs and helminth infections in a cohort of FSWs. METHOD authors conducted a prevalent, observational, and descriptive study on 97 Nigerian FSWs aged 17 to 52 years from January to December 2020. RESULTS a total of 97 FSWs were recruited. Of these, only 82 had completed screening for hepatitis B, C, syphilis, and HIV, while all 97 were screened for schistosomiasis and strongyloidiasis. The prevalence of STIs among FSWs in Rome was lower than in other European countries. The overall prevalence of HIV and HBsAg were 1.2%, (1/82) and 2.4% (2/82), respectively, while no case of hepatitis C and syphilis was found. Regarding parasitological screening, the overall prevalence of schistosoma species was 4.1% (4/97) while 5.15% (5/97) were positive for strongyloidiasis. CONCLUSIONS our study shows a low prevalence of STIs in Nigerian FSWs except for Hepatitis B and a higher prevalence of schistosomiasis and strongyloidiasis. The permanent monitoring of STI and parasitic infections in sex workers coming from Africa is strongly warranted, especially for hepatitis B, schistosomiasis and strongyloidiasis, to allow a timely diagnosis and treatment, and to plan preventive strategies.
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Dishnica K, Piubelli C, Manfredi M, Kondaveeti RT, Longoni SS, Degani M, Buonfrate D, Giorgetti A, Tiberti N. Novel insights into the somatic proteome of Strongyloides stercoralis infective third-stage larvae. Parasit Vectors 2023; 16:45. [PMID: 36721249 PMCID: PMC9890704 DOI: 10.1186/s13071-023-05675-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 01/18/2023] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Strongyloidiasis is a neglected tropical disease affecting an estimated 600 million people, particularly in resource-limited settings. The infection can persist lifelong due to unusual auto-infective cycle of Strongyloides stercoralis. The lack of a diagnostic gold standard and limited knowledge of the mechanisms underpinning this chronic infection are key issues in disease management. To date, only a few proteomics studies have been conducted to elucidate the molecular mechanisms associated with Strongyloides parasitism or to highlight novel immunological markers, with the result that our knowledge of S. stercoralis proteome remains limited. This study aims at expanding the characterization of S. stercoralis infective larvae (iL3) in order to further explore the mechanisms of parasitism and to highlight possible novel targets for serodiagnosis. METHODS iL3 obtained from an infected subject were analysed by high-throughput tandem mass spectrometry. To achieve a more comprehensive characterization of the iL3 proteome we analysed the experimental dataset using an automatic search strategy combined with manual annotation, which included gene ontology (GO) analysis, InterPro annotation, assessment of the homology with Homo sapiens and other pathogens of clinical importance and B-cell epitope prediction. RESULTS Our pipeline identified 430 S. stercoralis proteins, 187 (43%) of which were uncharacterized. Oxidoreductases and peptidases were amongst the most represented protein categories, as highlighted by molecular function GO analyses, while membrane and mitochondrial proteins were the most represented cellular component GO categories. A high proportion of proteins bearing the CAP, SCP or thioredoxin domain or belonging to cysteine-rich secretory, transthyretin-like or peptidase protein families were also identified. Additionally, we highlighted nine proteins displaying low homology with H. sapiens or other related pathogens and bearing amino acid sequences with immunogenic properties. CONCLUSIONS Our comprehensive description and annotation of the S. stercoralis iL3 proteome contribute to expanding the 'omics characterization of this parasite and provide experimental evidence on the most represented proteins associated with S. stercoralis parasitism, as inferred from genomic and transcriptomic data. Moreover, novel candidate immunogenic proteins to be evaluated as novel serological diagnostic markers are highlighted.
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Affiliation(s)
- Klevia Dishnica
- grid.5611.30000 0004 1763 1124Department of Biotechnology, University of Verona, Verona, Italy
| | - Chiara Piubelli
- grid.416422.70000 0004 1760 2489Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar Di Valpolicella, Italy
| | - Marcello Manfredi
- grid.16563.370000000121663741Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Ravi Teja Kondaveeti
- grid.416422.70000 0004 1760 2489Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar Di Valpolicella, Italy
| | - Silvia Stefania Longoni
- grid.416422.70000 0004 1760 2489Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar Di Valpolicella, Italy
| | - Monica Degani
- grid.416422.70000 0004 1760 2489Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar Di Valpolicella, Italy
| | - Dora Buonfrate
- grid.416422.70000 0004 1760 2489Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar Di Valpolicella, Italy
| | - Alejandro Giorgetti
- grid.5611.30000 0004 1763 1124Department of Biotechnology, University of Verona, Verona, Italy
| | - Natalia Tiberti
- grid.416422.70000 0004 1760 2489Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar Di Valpolicella, Italy
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Fatal Case of Autochthonous Strongyloides stercoralis Hyperinfection in an Immunosuppressed Calabrian Patient. REPORTS 2022. [DOI: 10.3390/reports5040047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Strongyloides stercoralis is an intestinal nematode that can induce disseminated infection in immunocompromised patients. It is most commonly acquired in tropical and subtropical countries; however, foci of the infection have also been reported in temperate geographic areas. In non-endemic areas, the diagnosis of an S. stercoralis infection is challenging due to the variety of clinical symptoms. Herein, we report the case of a patient, born and raised in the Calabria region of Southern Italy, who presented with melanoma and S. stercoralis hyperinfection, which is characterized by dyspnea, productive cough, inappetence, marked asthenia, weight loss, and Klebsiella pneumoniae bacteremia. He worked as a farmer and never traveled to another country known to be endemic for S. stercoralis. Despite the prompt identification of the parasite with sputum microscopy and the initiation of therapy with ivermectin and piperacillin–tazobactam, the patient later died. This case underscores the continued risk for S. stercoralis infection even in geographic areas that were previously considered non-endemic for the nematode and indicates that the geographic distribution of S. stercoralis may be expanding in Italy.
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Buonfrate D, Tamarozzi F, Paradies P, Watts MR, Bradbury RS, Bisoffi Z. The diagnosis of human and companion animal Strongyloides stercoralis infection: Challenges and solutions. A scoping review. ADVANCES IN PARASITOLOGY 2022; 118:1-84. [PMID: 36088083 DOI: 10.1016/bs.apar.2022.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Strongyloidiasis is the infection caused by soil-transmitted nematodes of Strongyloides species, infecting humans and some animals. Strongyloides stercoralis is the species with most clinical and epidemiological relevance in humans and dogs, due to its high prevalence and its capacity of inducing a life-threatening hyperinfection. Diagnosis of strongyloidiasis is challenging, due to the absence of a single reference standard test with high sensitivity and specificity, which also hampers the estimation of the accuracy of other diagnostic tests. In this chapter, we review the deployment and performance of the parasitological, immunological, molecular tests for the diagnosis of strongyloidiasis in humans and in dogs. Further, we comment the available evidence from genotyping studies that have addressed the zoonotic potential of S. stercoralis. Finally, we discuss the use of different diagnostic methods in relation to the purpose (i.e., screening, individual diagnosis, inclusion in a clinical trial) and the setting (endemic/non-endemic areas) and report the accuracy figures reported by systematic reviews on either parasitological, serological or molecular techniques published in literature.
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Affiliation(s)
- Dora Buonfrate
- Department of Infectious Tropical diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Italy.
| | - Francesca Tamarozzi
- Department of Infectious Tropical diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Italy
| | - Paola Paradies
- Department of Emergency and Organs Transplantation, Veterinary Section, Campus of Veterinary Medicine, University of Bari, Bari, Italy
| | - Matthew R Watts
- Centre for Infectious Diseases and Microbiology, Institute of Clinical Pathology and Medical Research - New South Wales Health Pathology and Sydney Institute for Infectious Diseases, Westmead Hospital, University of Sydney, Sydney, New South Wales, Australia
| | - Richard S Bradbury
- School of Health and Life Sciences, Federation University Australia, Berwick, VC, Australia
| | - Zeno Bisoffi
- Department of Infectious Tropical diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Italy; Department of Diagnostics and Public Health, University of Verona, Verona, Italy
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Osman E, Amin NA, Noon TPM, Lahat SNH, Rosli MS, Sham SF, Periyasamy PR, Ghazali N, Manap SNAA, Noordin R. Comparison of Two Serological Assays in Detecting Strongyloides Infection in Immunocompromised Patients. Am J Trop Med Hyg 2022; 107:tpmd220076. [PMID: 35895335 PMCID: PMC9490643 DOI: 10.4269/ajtmh.22-0076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 05/02/2022] [Indexed: 11/07/2022] Open
Abstract
Strongyloides infection may develop into fatal hyperinfection and dissemination syndrome in immunocompromised hosts. Despite suboptimal specificity issues, the detection of IgG antibodies by ELISA has been central in the serodiagnosis of Strongyloides infection. Recently, an IgG4-based lateral-flow test (SsRapid) using recombinant NIE (rNIE) protein with good diagnostic performance has been reported. This study assessed the result concordance between a commercial IgG-ELISA and the SsRapid. Additionally, we determined the Strongyloides seroprevalence and its association with clinical manifestations. Immunocompromised patients (N = 200) were from Hospital Canselor Tuanku Muhriz, Kuala Lumpur, Malaysia, and were diagnosed with HIV/AIDS, hematological malignancy, and solid organ cancers. Their plasma samples were tested using a commercial IgG-ELISA and SsRapid. A fair concordance (κ = 0.27-0.33; P < 0.05) among the tests was demonstrated. The SsRapid exhibited a significantly higher (P < 0.05) seroprevalence (10.5% [21/200]) compared with IgG-ELISA (7.5% [15/200]). After adsorption with rNIE, all SsRapid-positive samples tested negative with the rapid test, thus showing binding specificity. There was no significant association with clinical manifestations. This study revealed that SsRapid is a useful diagnostic tool for Strongyloides infection, and there is a notable seroprevalence among the immunocompromised patients.
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Affiliation(s)
- Emelia Osman
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Nur Azma Amin
- Universiti Kuala Lumpur Institute of Medical Science Technology Selangor, Malaysia
| | - Thieeraporn Phraseart Ma Noon
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Siti Nuratiqah Hanani Lahat
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Mohamad Syairazi Rosli
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Shazia Farhana Sham
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | | | - Nuraffini Ghazali
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Siti Nor Azreen Abd Manap
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Rahmah Noordin
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia (USM), Penang, Malaysia
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Strongyloidiasis in Children Outside the Tropics: Do We Need to Increase Awareness? Microorganisms 2021; 9:microorganisms9091905. [PMID: 34576800 PMCID: PMC8465658 DOI: 10.3390/microorganisms9091905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 09/01/2021] [Accepted: 09/04/2021] [Indexed: 11/16/2022] Open
Abstract
Strongyloidiasis belongs to the group of neglected tropical diseases, due to diagnostic difficulties and the lack of systematic screening. Studies on strongyloidiasis prevalence are often heterogenous and mainly performed in adults in endemic countries. We retrospectively enrolled 2633 children referred to a tertiary care hospital in Italy between 2009 and 2020 and tested for S. stercoralis infection. Sixty-one (2.3%) had a positive serology and for 55 of them, clinical and epidemiological information were available. Thirteen cases (24%) were diagnosed in Italian children without history residency or travel to foreign countries, while the remaining were internationally adopted or migrant children. Seropositive patients were mostly asymptomatic, and often eosinophilia was the only sign of strongyloidiasis. Sero-reactivity to Toxocara canis was found in 1/3 of patients. Ivermectin was used in 37 (75.5%) treated patients. A significant reduction of eosinophil levels and IgG titer was seen after treatment. Our study confirms that strongyloidiasis is usually asymptomatic in children. However, due to the ability of the parasite to cause a life-long infection together with the risk of a severe form in case of immunosuppression, it is important to identify and treat infected children. Special consideration should be reserved to high-risk groups, such as immigrants and international adoptees, where screening for S. stercoralis is indicated. However, the study highlights that sporadic cases of autochthonous strongyloidiasis in Italy may occur. Therefore, pediatricians should be aware of this condition, which is often under-recognized.
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Tamarozzi F, Longoni SS, Mazzi C, Pettene S, Montresor A, Mahanty S, Bisoffi Z, Buonfrate D. 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. Parasit Vectors 2021; 14:412. [PMID: 34407876 PMCID: PMC8375122 DOI: 10.1186/s13071-021-04916-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/02/2021] [Indexed: 11/12/2022] Open
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 ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04916-x.
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Affiliation(s)
- Francesca Tamarozzi
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Negrar di Valpolicella, Italy
| | - Silvia Stefania Longoni
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Negrar di Valpolicella, Italy
| | - Cristina Mazzi
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Negrar di Valpolicella, Italy
| | - Sofia Pettene
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Negrar di Valpolicella, Italy.,University of Ferrara, Ferrara, Italy
| | - Antonio Montresor
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Siddhartha Mahanty
- Department of Infectious Diseases, The Peter Doherty Institute for Infection and Immunity, University of Melbourne and The Royal Melbourne Hospital, Melbourne, VIC, 3052, Australia
| | - Zeno Bisoffi
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Negrar di Valpolicella, Italy.,Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - Dora Buonfrate
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Negrar di Valpolicella, Italy.
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Lashnits E, Neupane P, Bradley JM, Richardson T, Maggi RG, Breitschwerdt EB. Comparison of Serological and Molecular Assays for Bartonella Species in Dogs with Hemangiosarcoma. Pathogens 2021; 10:pathogens10070794. [PMID: 34201572 PMCID: PMC8308881 DOI: 10.3390/pathogens10070794] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/18/2021] [Accepted: 06/18/2021] [Indexed: 11/23/2022] Open
Abstract
Currently, a gold standard diagnostic test for Bartonella infection in dogs is lacking. This represents a critical limitation for the development and evaluation of new diagnostic tests, as well as for the diagnosis of, and research on, bartonellosis in dogs. This retrospective observational study aims to compare the results of commonly performed and newly-reported Bartonella spp. diagnostic tests in banked clinical specimens from 90 dogs with hemangiosarcoma (HSA) using composite reference standard (CRS) and random effects latent class analysis (RE-LCA) techniques. Samples from each dog were tested using six serological or molecular diagnostic assays, including indirect fluorescent antibody (IFA) and Western blot (WB) for the detection of antibodies in serum, and qPCR and droplet digital PCR (ddPCR) in blood and fresh frozen tissue biopsy samples (mainly splenic HSA tumors and histopathologically normal spleen or skin/adipose tissue). Bartonella infection prevalence was estimated to be 78% based on the CRS (parallel testing with all six assays), and 64% based on the RE-LCA model. The assay with the highest diagnostic accuracy was qPCR performed on fresh frozen tissue biopsy samples (sensitivity: 94% by RE-LCA and 80% by CRS; specificity: 100%). When comparing newly-reported to traditional Bartonella diagnostic assays, ddPCR was more sensitive for the detection of Bartonella DNA than qPCR when testing blood samples (36% vs. 0%, p < 0.0001). Dogs that were positive on serological assays alone with negative molecular assays were highly unlikely (<3%) to be classified as infected by the RE-LCA model. These data indicate that Bartonella spp. DNA can be PCR amplified from fresh frozen tissues from a majority of dogs with HSA using both qPCR and ddPCR, supporting the use of these methods for future controlled studies comparing the prevalence of Bartonella spp. DNA in the tissue of dogs with HSA to that of unaffected controls.
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Affiliation(s)
- Erin Lashnits
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53713, USA;
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
| | - Pradeep Neupane
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
| | - Julie M. Bradley
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
| | - Toni Richardson
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
| | - Ricardo G. Maggi
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA
| | - Edward B. Breitschwerdt
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA
- Correspondence:
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