Highly Multiplexed Broad Pathogen Assay Detects Infectious Diseases

Identifying the causative agent in an acute febrile illness can be challenging diagnostically, especially when organisms in a particular region have overlapping clinical presentation or when that pathogen’s presence is unexpected.

Rapid pathogen identification during an acute febrile illness is a critical first step for providing appropriate clinical care and patient isolation. Primary screening using sensitive and specific assays, such as real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assays (ELISAs), can rapidly test for known circulating infectious diseases.

Scientists at the United States Army Medical Research Institute of Infectious Diseases (Fort Detrick, MD, USA) developed a highly multiplexed assay designed to detect 164 different viruses, bacteria, and parasites using the NanoString nCounter platform. Included in this assay were high consequence pathogens such as Ebola virus, highly endemic organisms including several Plasmodium species, and a large number of less prevalent pathogens to ensure a broad coverage of potential human pathogens.

The team used the Broad Pathogen Detection Assay (BPDA) for use with the NanoString nCounter platform in order to quickly screen a sample for multiple pathogens in a single tube reaction. Mock clinical samples were prepared in order to evaluate the ability of the BPDA to detect samples that had been extracted from whole human blood. Evaluation of the panel resulted in positive detection of 113 (encompassing 98 different human pathogen types) of the 126 organisms available to us including the medically important Ebola virus, Lassa virus, dengue virus serotypes 1–4, Chikungunya virus, yellow fever virus, and Plasmodium falciparum.

The authors concluded that the hands on time and sample volume requirement are minimal for the BPDA. The assay performed well in mock clinical and human clinical samples, demonstrating the clinical utility of this assay in cases where the initial diagnostic testing results in negative results. Overall, this assay could improve infectious disease diagnostics and biosurveillance efforts as a quick, highly multiplexed, and easy to use pathogen-screening tool. The study was published on November 5, 2018, in the journal Public Library of Science Neglected Tropical Diseases.

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United States Army Medical Research Institute of Infectious Diseases