Journal Article

Highly Sensitive Detection of Malaria Parasitemia in a Malaria-Endemic Setting: Performance of a New Loop-Mediated Isothermal Amplification Kit in a Remote Clinic in Uganda

Heidi Hopkins, Iveth J. González, Spencer D. Polley, Patrick Angutoko, John Ategeka, Caroline Asiimwe, Bosco Agaba, Daniel J. Kyabayinze, Colin J. Sutherland, Mark D. Perkins and David Bell

in The Journal of Infectious Diseases

Published on behalf of Infectious Diseases Society of America

Volume 208, issue 4, pages 645-652
Published in print August 2013 | ISSN: 0022-1899
Published online April 2013 | e-ISSN: 1537-6613 | DOI: https://dx.doi.org/10.1093/infdis/jit184

More Like This

Show all results sharing these subjects:

  • Infectious Diseases
  • Immunology
  • Public Health and Epidemiology
  • Microbiology

GO

Show Summary Details

Preview

Background. Current malaria diagnostic tests, including microscopy and antigen-detecting rapid tests, cannot reliably detect low-density infections. Molecular methods such as polymerase chain reaction (PCR) are highly sensitive but remain too complex for field deployment. A new commercial molecular assay based on loop-mediated isothermal amplification (LAMP) was assessed for field use.

Methods. Malaria LAMP (Eiken Chemical, Japan) was evaluated for samples from 272 outpatients at a rural Ugandan clinic and compared with expert microscopy, nested PCR, and quantitative PCR (qPCR). Two technicians performed the assay after 3 days of training, using 2 alternative blood sample–preparation methods and visual interpretation of results by fluorescence assay.

Results. Compared with 3-well nested PCR, the sensitivity of both LAMP and single-well nested PCR was 90%; the microscopy sensitivity was 51%. For samples with a Plasmodium falciparum qPCR titer of ≥2 parasites/µL, LAMP sensitivity was 97.8% (95% confidence interval, 93.7%–99.5%). Most false-negative LAMP results involved samples with parasitemia levels detectable by 3-well nested PCR but very low or undetectable by qPCR.

Conclusions. Malaria LAMP in a remote Ugandan clinic achieved sensitivity similar to that of single-well nested PCR in a United Kingdom reference laboratory. LAMP dramatically lowers the detection threshold achievable in malaria-endemic settings, providing a new tool for diagnosis, surveillance, and screening in elimination strategies.

Keywords: malaria; diagnosis; LAMP; loop-mediated isothermal amplification; sensitivity and specificity; PCR; polymerase chain reaction; molecular diagnosis; DNA; Plasmodium falciparum; Uganda; Africa

Journal Article.  5205 words.  Illustrated.

Subjects: Infectious Diseases ; Immunology ; Public Health and Epidemiology ; Microbiology

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content. subscribe or login to access all content.