• 1.

    Girma S, Cheaveau J, Mohon AN, Marasinghe D, Legese R, Balasingam N, Abera A, Feleke SM, Golassa L, Pillai DR, 2019. Prevalence and epidemiological characteristics of asymptomatic malaria based on ultrasensitive diagnostics: a cross-sectional study. Clin Infect Dis 69: 10031010.

    • Search Google Scholar
    • Export Citation
  • 2.

    Awandu SS, Raman J, Bousema T, Birkholtz LM, 2019. Ultralow-density Plasmodium falciparum infections in African settings. Clin Infect Dis 69: 14631464.

    • Search Google Scholar
    • Export Citation
  • 3.

    Taylor SM, Juliano JJ, Trottman PA, Griffin JB, Landis SH, Kitsa P, Tshefu AK, Meshnick SR, 2010. High-throughput pooling and real-time PCR-based strategy for malaria detection. J Clin Microbiol 48: 512519.

    • Search Google Scholar
    • Export Citation
  • 4.

    Beshir KB, Hallett RL, Eziefula AC, Bailey R, Watson J, Wright SG, Chiodini PL, Polley SD, Sutherland CJ, 2010. Measuring the efficacy of anti-malarial drugs in vivo: quantitative PCR measurement of parasite clearance. Malar J 9: 312.

    • Search Google Scholar
    • Export Citation
  • 5.

    Adams M 2015. An ultrasensitive reverse transcription polymerase chain reaction assay to detect asymptomatic low-density Plasmodium falciparum and Plasmodium vivax infections in small volume blood samples. Malar J 14: 520.

    • Search Google Scholar
    • Export Citation
  • 6.

    Zainabadi K, Adams M, Han ZY, Lwin HW, Han KT, Ouattara A, Thura S, Plowe CV, Nyunt MM, 2017. A novel method for extracting nucleic acids from dried blood spots for ultrasensitive detection of low-density Plasmodium falciparum and Plasmodium vivax infections. Malar J 16: 377.

    • Search Google Scholar
    • Export Citation
  • 7.

    Murphy SC 2012. Real-time quantitative reverse transcription PCR for monitoring of blood-stage Plasmodium falciparum infections in malaria human challenge trials. Am J Trop Med Hyg 86: 383394.

    • Search Google Scholar
    • Export Citation
  • 8.

    Bousema T, Okell L, Felger I, Drakeley C, 2014. Asymptomatic malaria infections: detectability, transmissibility and public health relevance. Nat Rev Microbiol 12: 833840.

    • Search Google Scholar
    • Export Citation
  • 9.

    Gruenberg M 2020. Utility of ultra-sensitive qPCR to detect Plasmodium falciparum and Plasmodium vivax infections under different transmission intensities. Malar J 19: 319.

    • Search Google Scholar
    • Export Citation
  • 10.

    Hofmann N, Mwingira F, Shekalaghe S, Robinson LJ, Mueller I, Felger I, 2015. Ultra-sensitive detection of Plasmodium falciparum by amplification of multi-copy subtelomeric targets. PLoS Med 12: e1001788.

    • Search Google Scholar
    • Export Citation
  • 11.

    Hofmann NE 2018. Assessment of ultra-sensitive malaria diagnosis versus standard molecular diagnostics for malaria elimination: an in-depth molecular community cross-sectional study. Lancet Infect Dis 18: 11081116.

    • Search Google Scholar
    • Export Citation
  • 12.

    Golassa L, Cheaveau J, Mohon AN, Pillai DR, 2019. Reply to Awandu et al. Clin Infect Dis 69: 14641465.

  • 13.

    Dalrymple U, Arambepola R, Gething PW, Cameron E, 2018. How long do rapid diagnostic tests remain positive after anti-malarial treatment? Malar J 17: 228.

    • Search Google Scholar
    • Export Citation
  • 14.

    Hanron AE 2017. Multiplex, DNase-free one-step reverse transcription PCR for Plasmodium 18S rRNA and spliced gametocyte-specific mRNAs. Malar J 16: 208.

    • Search Google Scholar
    • Export Citation
  • 15.

    Niederwieser I, Felger I, Beck HP, 2000. Plasmodium falciparum: expression of gametocyte-specific genes in monolayer cultures and malaria-positive blood samples. Exp Parasitol 95: 163169.

    • Search Google Scholar
    • Export Citation
  • 16.

    Ngasala B 2019. Detection of the Asymptomatic Plasmodium Falciparum Infectious Reservoir among Schoolchildren in Tanzania using Mosquito Skin Feeding Assays. Poster Presentation at the Annual Meeting of the American Society of Tropical Medicine and Hygiene, National Harbor, MD.

    • Search Google Scholar
    • Export Citation
  • 17.

    Lin JT, Saunders DL, Meshnick SR, 2014. The role of submicroscopic parasitemia in malaria transmission: what is the evidence? Trends Parasitol 30: 183190.

    • Search Google Scholar
    • Export Citation
  • 18.

    Stone W, Gonçalves BP, Bousema T, Drakeley C, 2015. Assessing the infectious reservoir of falciparum malaria: past and future. Trends Parasitol 31: 287296.

    • Search Google Scholar
    • Export Citation
  • 19.

    Slater HC 2019. The temporal dynamics and infectiousness of subpatent Plasmodium falciparum infections in relation to parasite density. Nat Commun 10: 1433.

    • Search Google Scholar
    • Export Citation
  • 20.

    Imwong M 2016. Numerical distributions of parasite densities during asymptomatic malaria. J Infect Dis 213: 13221329.

 

 

 

 

Direct Comparison of Standard and Ultrasensitive PCR for the Detection of Plasmodium falciparum from Dried Blood Spots in Bagamoyo, Tanzania

View More View Less
  • 1 Duke Global Health Institute, Duke University, Durham, North Carolina;
  • 2 Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania;
  • 3 Institute of Global Health and Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, North Carolina;
  • 4 University of Maryland School of Medicine, Baltimore, Maryland

ABSTRACT

Ultrasensitive PCR used in low-transmission malaria-endemic settings has revealed a much higher burden of asymptomatic infections than that detected by rapid diagnostic tests (RDTs) or standard PCR, but there is limited evidence as to whether this is the case in higher transmission settings. Using dried blood spots (DBS) collected among 319 schoolchildren in Bagamoyo, Tanzania, we found good correlation (Pearson’s R = 0.995) between Plasmodium falciparum parasite densities detected by a DNA-based 18s rRNA real-time PCR (qPCR) and an RNA-based ultrasensitive reverse transcriptase (RT)-PCR (usPCR) for the same target. Whereas prevalence by usPCR was higher than that found by qPCR (37% versus 32%), the proportion of additionally detected low-density infections (median parasite density < 0.050 parasites/µL) represented an incremental increase. It remains unclear to what extent these low-density infections may contribute to the infectious reservoir in different malaria transmission settings.

Author Notes

Address correspondence to Jessica T. Lin, Division of Infectious Diseases, University of North Carolina School of Medicine, 130 Mason Farm Rd., Suite 2115, Chapel Hill, NC 27599. E-mail: jessica_lin@med.unc.edu

Authors’ addresses: Christine F. Markwalter and Tonelia Mowatt, Duke Global Health Institute, Duke University, Durham, NC, E-mails: christine.markwalter@duke.edu and toneliamowatt@gmail.com. Billy Ngasala and Mwajabu Loya, Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania, E-mails: bngasala70@yahoo.co.uk and loyamwajabu51@gmail.com. Christopher Basham, Zackary Park, Meredith Muller, and Jessica T. Lin, Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, NC, E-mails: christopher_basham@med.unc.edu, zackarypark@gmail.com, meredith_muller@med.unc.edu, and jessica_lin@med.unc.edu. Christopher Plowe and Myaing Nyunt, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, E-mails: plowe.chris@gmail.com and myaingnyunt@gmail.com.

Save