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Diagnostic comparison of Baermann funnel, Koga agar plate culture and polymerase chain reaction for detection of human Strongyloides stercoralis infection in Maluku, Indonesia

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Abstract

Human infection with the nematode Strongyloides stercoralis, which may have a life-threatening course, primarily occurs in tropical settings. Epidemiological data on the occurrence of strongyloidiasis are scarce, and microscopic stool-based detection methods are insensitive. Polymerase chain reaction (PCR) assays have been developed, yet conflicting results have been reported. Our goal was to determine whether there was diagnostic agreement between an in-house PCR and two microscopic techniques, the Baermann funnel (BM) and the Koga agar plate culture (KAP) for the detection of S. stercoralis in stool samples. Eighty ethanol-fixed stool samples stemming from a cross-sectional survey in Maluku, Indonesia, were purposefully selected for PCR analysis. The final sample size comprised four groups, each with 20 samples: group 1, positive for S. stercoralis on both BM and KAP; group 2, positive only by BM; group 3, positive only by KAP; and group 4, negative on both BM and KAP. A Strongyloides-specific PCR targeting the internal transcribed spacer 2 (ITS2) region was carried out in an Indonesian reference laboratory. The overall agreement between PCR and microscopy was 61% (49/80 samples), being highest in group 1 (15/20, 75%) and lowest in group 3 (9/20, 45%). PCR revealed eight additional S. stercoralis infections in group 4. Future studies should elucidate the ‘true’ infection status of samples that are negative by PCR, but positive upon microscopy. Taken together, there is a lack of agreement between microscopy and PCR results for the diagnosis of human S. stercoralis infection in Indonesia. ClinicalTrials.gov (identifier: NCT02105714)

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Acknowledgements

We thank all participants in Maluku Tengah Regency, Maluku, Indonesia, and the staff from the Province Health Office of Maluku who facilitated the field work. We are grateful to the laboratory technicians and research staff involved in the field work both from RSUD Tulehu, Maluku Tengah Regency, Maluku, Indonesia and the Department of Parasitology at Universitas Gadjah Mada, Yogyakarta, for laboratory analyses.

Funding

This work is part of the NIDIAG European research network (Collaborative Project), supported by the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 260260.

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Author notes

  1. Sören L. Becker and E. Elsa Herdiana Murhandarwati contributed equally to this work.

Authors and Affiliations

  1. Postgraduate Programme of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia

    Handriani Kristanti, Mahardika Agus Wijayanti & E. Elsa Herdiana Murhandarwati

  2. Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia

    Fransiska Meyanti, Mahardika Agus Wijayanti, Yodi Mahendradhata & E. Elsa Herdiana Murhandarwati

  3. Department of Parasitology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia

    Mahardika Agus Wijayanti & E. Elsa Herdiana Murhandarwati

  4. Institute of Tropical Medicine, Antwerp, Belgium

    Katja Polman

  5. Division of Tropical and Humanitarian Medicine, Geneva University Hospitals, Geneva, Switzerland

    François Chappuis

  6. Swiss Tropical and Public Health Institute, Basel, Switzerland

    Jürg Utzinger & Sören L. Becker

  7. University of Basel, Basel, Switzerland

    Jürg Utzinger & Sören L. Becker

  8. Institute of Medical Microbiology and Hygiene, Saarland University, Homburg, Germany

    Sören L. Becker

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  1. Handriani Kristanti
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Correspondence to Sören L. Becker or E. Elsa Herdiana Murhandarwati.

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Ethical approval

The protocol for the NIDIAG study on persistent digestive disorders was approved by the institutional review boards (IRBs) of the Institute of Tropical Medicine (ITM; Antwerp, Belgium) and Swiss Tropical and Public Health Institute (Swiss TPH; Basel, Switzerland) prior to external review. Approval in Indonesia was granted by the ethics committee of the Universitas Gadjah Mada (21 November 2013). The NIDIAG study is registered on ClinicalTrials.gov (identifier: NCT02105714). All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

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Kristanti, H., Meyanti, F., Wijayanti, M.A. et al. Diagnostic comparison of Baermann funnel, Koga agar plate culture and polymerase chain reaction for detection of human Strongyloides stercoralis infection in Maluku, Indonesia. Parasitol Res 117, 3229–3235 (2018). https://doi.org/10.1007/s00436-018-6021-5

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