Plasma Concentration of Parasite DNA as a Measure of Disease Severity in Falciparum Malaria

Abstract

In malaria-endemic areas, Plasmodium falciparum parasitemia is common in apparently healthy children and severe malaria is commonly misdiagnosed in patients with incidental parasitemia. We assessed whether the plasma Plasmodium falciparum DNA concentration is a useful datum for distinguishing uncomplicated from severe malaria in African children and Asian adults. P. falciparum DNA concentrations were measured by real-time polymerase chain reaction (PCR) in 224 African children (111 with uncomplicated malaria and 113 with severe malaria) and 211 Asian adults (100 with uncomplicated malaria and 111 with severe malaria) presenting with acute falciparum malaria. The diagnostic accuracy of plasma P. falciparum DNA concentrations in identifying severe malaria was 0.834 for children and 0.788 for adults, similar to that of plasma P. falciparum HRP2 levels and substantially superior to that of parasite densities (P < .0001). The diagnostic accuracy of plasma P. falciparum DNA concentrations plus plasma P. falciparum HRP2 concentrations was significantly greater than that of plasma P. falciparum HRP2 concentrations alone (0.904 for children [P = .004] and 0.847 for adults [P = .003]). Quantitative real-time PCR measurement of parasite DNA in plasma is a useful method for diagnosing severe falciparum malaria on fresh or archived plasma samples.

Molecular Testing for Plasmodium falciparum by Use of Serum or Plasma and Comparison with Microscopy and Rapid Diagnostic Testing in Febrile Nigerian Patients

“…Similarly to the study by Lamikanra et al, we did find a significant correlation between C T values in the DLM assay for patients with P. falciparum malaria and parasite density determined by microscopy (4). Although the clinical utility of quantitative malaria PCR remains unclear, a recent study by Imwong et al showed that the plasma concentration of P. falciparum DNA correlates with disease severity (18). However, quantitative PCR was performed only on patients who had positive microscopy results in this study.…”

Use of a rapid test to assess plasma Plasmodium falciparum HRP2 and guide management of severe febrile illness

“…The performance of the RDT at individual sample dilutions to discriminate severe from uncomplicated malaria was then examined in plasma samples from non-pregnant adults ( ≥ 16-year-old) admitted to hospital with slide- or RDT-confirmed falciparum malaria and enrolled in prospective studies at Chittagong Medical College Hospital, Bangladesh (2011); uncomplicated and severe cases were defined using modified World Health Organization criteria [ 17 ]. ELISA methods and results and issues related to ethical permission for testing these samples have been previously described [ 10 , 18 ].

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A eDNA-qPCR assay to detect the presence of the parasite Schistocephalus solidus inside its threespine stickleback host

“…Our first hypothesis was that S. solidus produces cell-free DNA or cell-bound DNA in the fish abdominal cavity, and that this eDNA could be identified by a PCR approach to correctly detect S. solidus infection in sticklebacks (Bass et al, 2015). eDNA produced by parasites is a common target in epidemiology to detect infection using a PCR approach in organic samples like serum, faeces or plasma (Imwong et al, 2015;Pontes et al, 2002;Xu et al, 2017). eDNA is also used to detect invasive species in aquatic environments (Takahara et al, 2013).…”