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Towards malaria microscopy at the point-of-contact: an assessment of the diagnostic performance of the Newton Nm1 microscope in Uganda

Published online by Cambridge University Press:  04 August 2014

J. RUSSELL STOTHARD ,
BETTY NABATTE ,
JOSE C. SOUSA-FIGUEIREDO  and
NARCIS B. KABATEREINE
J. RUSSELL STOTHARD*
Affiliation:
Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
BETTY NABATTE
Affiliation:
Vector Control Division, Ministry of Health, P.O. Box 1661, Kampala, Uganda
JOSE C. SOUSA-FIGUEIREDO
Affiliation:
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
NARCIS B. KABATEREINE
Affiliation:
Vector Control Division, Ministry of Health, P.O. Box 1661, Kampala, Uganda
*
*Corresponding author. Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK. E-mail: [email protected]
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Summary

Malaria microscopy in sub-Saharan Africa is often restricted by access to light microscopes. To address this gap, a novel portable inverted monocular microscope, the Newton Nm1, was designed and is now commercially available. Its diagnostic performance was assessed in a blinded-slide trial at ×1000 (oil) of Giemsa-stained thick blood films against a conventional microscope as undertaken by four Ugandan Ministry of Health technicians. With the Newton Nm1, diagnostic performance was: sensitivity 93·5% (95% confidence interval (CI) 78·6–99·2%), specificity 100·0% (95% CI 82·4–100·0%), positive predictive value 100·0% (95% CI 88·1–100·0%) and negative predictive value 90·5% (95% CI 69·6–98·8%). Discordance was due to a systematic error underestimating parasitaemia by ~45%; when counting Plasmodium parasites against 200 white blood cells, blood films with low parasitaemia (i.e. <100 μL−1 of blood) could be overlooked and misclassified. By contrast, specificity was excellent with no false positives encountered. Whilst proven useful, especially in resource-poor environments, it is still unclear how we can ensure the uptake of the Newton Nm1 within sub-Saharan Africa.

Keywords

McArthur microscopemalariadiagnosismicroscopyBland-Altmanevaluation
Type
Special Issue Article
Information
Parasitology , Volume 141 , Issue 14: Symposia of the British Society for Parasitology Volume 52 Advances in diagnostics for parasitic diseases , December 2014 , pp. 1819 - 1825
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Copyright
Copyright © Cambridge University Press 2014 

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References

REFERENCES

Abdulla, S., Alonso, P., Binka, F., Graves, P., Greenwood, B., Leke, R., Malik, E., Marsh, K., Meek, S., Mendis, K., Schapira, A., Slutsker, L., Tanner, M., Valecha, N., White, N., Bosman, A., Cibulskis, R., D'Souza, B., Lynch, M., MacDonald, M., Mintcheva, R., Mnzava, A., Newman, R., Ringwald, P., Szilagyi, Z. and Wongsrichanalai, C. (2013). Malaria policy advisory committee to the WHO: conclusions and recommendations of September 2013 meeting. Malaria Journal 12, 456.Google Scholar
Armitage, P. and Berry, G. (1994). Statistical Methods in Medical Research, 3rd Edn. Blackwell Scientific, Oxford, UK.Google Scholar
Bailey, J. W., Williams, J., Bain, B. J., Parker-Williams, J. and Chiodini, P. L. (2013). Guideline: the laboratory diagnosis of malaria. British Journal of Haematology 163, 573–580.CrossRefGoogle ScholarPubMed
Banoo, S., Bell, D., Bossuyt, P., Herring, A., Mabey, D., Poole, F., Smith, P. G., Sriram, N., Wongsrichanalai, C., Linke, R., O'Brien, R., Perkins, M., Cunningham, J., Matsoso, P., Nathanson, C. M., Olliaro, P., Peeling, R. W. and Ramsay, A. (2010). Evaluation of diagnostic tests for infectious diseases: general principles. Nature Reviews Microbiology 8, S17–S29.Google Scholar
Bates, I., Bekoe, V. and Asamoa-Adu, A. (2004). Improving the accuracy of malaria-related laboratory tests in Ghana. Malaria Journal 3, 38.Google Scholar
Bell, D., Wongsrichanalai, C. and Barnwell, J. W. (2006). Ensuring quality and access for malaria diagnosis: how can it be achieved? Nature Reviews Microbiology 4, 682–695.CrossRefGoogle ScholarPubMed
Betson, M., Sousa-Figueiredo, J. C., Atuhaire, A., Arinaitwe, M., Adriko, M., Mwesigwa, G., Nabonge, J., Kabatereine, N. B., Sutherland, C. J. and Stothard, J. R. (2014). Detection of persistent Plasmodium spp. infections in Ugandan children after artemether-lumefantrine treatment. Parasitology. 141, 1880–1890.Google Scholar
Bland, J. M. and Altman, D. G. (1986). Regression analysis. Lancet 327, 908–909.Google Scholar
Bogoch, I. I., Coulibaly, J. T., Andrews, J. R., Speich, B., Keiser, J., Stothard, J. R., N'Goran, E. K. and Utzinger, J. (2014). Evaluation of portable microscopic devices for the diagnosis of Schistosoma and soil-transmitted helminth infection. Parasitology. 141, 1811–1818.Google Scholar
Collier, J. A. B. and Longmore, J. M. (1983). The reliability of the microscopic diagnosis of malaria in the field and in the laboratory. Annals of Tropical Medicine and Parasitology 77, 113–117.Google Scholar
Dunning, K. and Stothard, J. R. (2007). From the McArthur to the Millennium Health Microscope (MHM): future developments in microscope miniaturisation for international health. Infocus 6, 16–24.Google Scholar
Hanscheid, T. (1999). Diagnosis of malaria: a review of alternatives to conventional microscopy. Clinical and Laboratory Haematology 21, 235–245.CrossRefGoogle ScholarPubMed
Harper, R. and Reeves, B. (1999). Reporting of precision of estimates for diagnostic accuracy: a review. British Medical Journal 318, 1322–1323.Google Scholar
Jones, D., Nyalwidhe, J., Tetley, L. and Barrett, M. P. (2007). McArthur revisited: fluorescence microscopes for field diagnostics. Trends in Parasitology 23, 468–469.Google Scholar
Longmore, J. M. (1983). Bedside hematology – new facility in general practice. British Medical Journal 287, 1849–1851.CrossRefGoogle ScholarPubMed
Longmore, J. M. (1986). Community laboratory work and hand held microscopes. Transactions of the Royal Society of Tropical Medicine and Hygiene 80, 849–850.Google Scholar
McArthur, J. (1984). Range of accessories for the McArthur microscope. Transactions of the Royal Society of Tropical Medicine and Hygiene 78, 274.Google Scholar
Mouatcho, J. C. and Goldring, J. P. D. (2013). Malaria rapid diagnostic tests: challenges and prospects. Journal of Medical Microbiology 62, 1491–1505.Google Scholar
Mundy, C., Ngwira, M., Kadewele, G., Bates, I., Squire, S. B. and Gilks, C. F. (2000). Evaluation of microscope condition in Malawi. Transactions of the Royal Society of Tropical Medicine and Hygiene 94, 583–584.CrossRefGoogle ScholarPubMed
Opoku-Okrah, C., Rumble, R., Bedu-Addo, G. and Bates, I. (2000). Improving microscope quality is a good investment for under-resourced laboratories. Transactions of the Royal Society of Tropical Medicine and Hygiene 94, 582.Google Scholar
Sousa-Figueiredo, J. C., Oguttu, D., Adriko, M., Besigye, F., Nankasi, A., Arinaitwe, M., Namukuta, A., Betson, M., Kabatereine, N. B. and Stothard, J. R. (2010). Investigating portable fluorescent microscopy (CyScope (R)) as an alternative rapid diagnostic test for malaria in children and women of child-bearing age. Malaria Journal 9, 245.Google Scholar
Wernsdorfer, W. (2009). The use of rapid diagnostic tools – the end of traditional microscopic diagnosis of malaria? Tropical Medicine and International Health 14, 28–28.Google Scholar
Wernsdorfer, W. H. (2012). Global challenges of changing epidemiological patterns of malaria. Acta Tropica 121, 158–165.CrossRefGoogle ScholarPubMed
WHO (2009). Malaria. Microscopy Quality Assurance Manual. Version 1. World Health Organization, Geneva, Switzerland.Google Scholar
WHO (2010). Basic Malaria Microscopy. Part I. Learner's Guide, 2nd Edn. World Health Organization, Geneva, Switzerland.Google Scholar
WHO (2012). T3: Test, Treat and Track. Scaling Up Diagnostic Testing, Treatment and Surveillance of Malaria. World Health Organization, Geneva, Switzerland.Google Scholar
WHO (2013). Pocket Book of Hospital Care for Children: Second Edition Guidelines for the Management of Common Childhood Illnesses. World Health Organization, Geneva, Switzerland.Google Scholar