Skip to main content Accessibility help
×
Home

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

  • J. RUSSELL STOTHARD (a1), BETTY NABATTE (a2), JOSE C. SOUSA-FIGUEIREDO (a3) and NARCIS B. KABATEREINE (a2)

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.

Copyright

Corresponding author

*Corresponding author. Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK. E-mail: r.stothard@liverpool.ac.uk

References

Hide All
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.
Armitage, P. and Berry, G. (1994). Statistical Methods in Medical Research, 3rd Edn. Blackwell Scientific, Oxford, UK.
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, 573580.
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, S17S29.
Bates, I., Bekoe, V. and Asamoa-Adu, A. (2004). Improving the accuracy of malaria-related laboratory tests in Ghana. Malaria Journal 3, 38.
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, 682695.
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, 18801890.
Bland, J. M. and Altman, D. G. (1986). Regression analysis. Lancet 327, 908909.
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, 18111818.
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, 113117.
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, 1624.
Hanscheid, T. (1999). Diagnosis of malaria: a review of alternatives to conventional microscopy. Clinical and Laboratory Haematology 21, 235245.
Harper, R. and Reeves, B. (1999). Reporting of precision of estimates for diagnostic accuracy: a review. British Medical Journal 318, 13221323.
Jones, D., Nyalwidhe, J., Tetley, L. and Barrett, M. P. (2007). McArthur revisited: fluorescence microscopes for field diagnostics. Trends in Parasitology 23, 468469.
Longmore, J. M. (1983). Bedside hematology – new facility in general practice. British Medical Journal 287, 18491851.
Longmore, J. M. (1986). Community laboratory work and hand held microscopes. Transactions of the Royal Society of Tropical Medicine and Hygiene 80, 849850.
McArthur, J. (1984). Range of accessories for the McArthur microscope. Transactions of the Royal Society of Tropical Medicine and Hygiene 78, 274.
Mouatcho, J. C. and Goldring, J. P. D. (2013). Malaria rapid diagnostic tests: challenges and prospects. Journal of Medical Microbiology 62, 14911505.
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, 583584.
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.
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.
Wernsdorfer, W. (2009). The use of rapid diagnostic tools – the end of traditional microscopic diagnosis of malaria? Tropical Medicine and International Health 14, 2828.
Wernsdorfer, W. H. (2012). Global challenges of changing epidemiological patterns of malaria. Acta Tropica 121, 158165.
WHO (2009). Malaria. Microscopy Quality Assurance Manual. Version 1. World Health Organization, Geneva, Switzerland.
WHO (2010). Basic Malaria Microscopy. Part I. Learner's Guide, 2nd Edn. World Health Organization, Geneva, Switzerland.
WHO (2012). T3: Test, Treat and Track. Scaling Up Diagnostic Testing, Treatment and Surveillance of Malaria. World Health Organization, Geneva, Switzerland.
WHO (2013). Pocket Book of Hospital Care for Children: Second Edition Guidelines for the Management of Common Childhood Illnesses. World Health Organization, Geneva, Switzerland.

Keywords

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

  • J. RUSSELL STOTHARD (a1), BETTY NABATTE (a2), JOSE C. SOUSA-FIGUEIREDO (a3) and NARCIS B. KABATEREINE (a2)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed