Unmet Need
Enterotoxigenic Escherichia coli (ETEC), Shigella, Cholera, Typhoid, Campylobacter and Norovirus are the most common causes of illness & diarrhea in low- and middle-income countries, accounting for an aggregate 777.3 million annual cases and 354,230 aggregate deaths globally.
As such, there is a large and fast-growing demand for diagnostics. Global revenues from infectious disease molecular diagnostics are expected to grow from $4.38 billion in 2017 to $9.45 billion by 2022 at a 16.7% CAGR. Gold standard rapid molecular diagnostic tests for detecting infection by illness & diarrhea-causing pathogens – including PCR and immunoassays – are routinely deployed in clinical labs. However, their use is limited in underdeveloped, developing and developed countries where laboratory cold supply chain infrastructure & highly trained personnel are not available.
Therefore, there is a large unmet need for rapid, inexpensive, and simple-to-use diagnostic tests that detect infections caused by bacterial & viral pathogens.
Technology Overview
Johns Hopkins researchers developed a rapid test that detects bacterial or viral pathogens with high sensitivity & specificity in (1) patient derived samples (stool or blood) and (2) environmental and drinking water. The technology – called “Rapid LAMP-based Diagnostic Test” or RLDT Diagnostic Assay – currently detects enterotoxigenic Escherichia coli (ETEC), shigella, cholera, typhoid, campylobacter and norovirus. The total assay (sample preparation + processing time in the device) takes less than an hour (50 minutes). All assay reagents are lyophilized to avoid a cold chain requirement, making it particularly useful if used in underdeveloped & developing countries.
Stage of Development
The inventors have performed a proof-of-principle study for the detection of enterotoxigenic Escherichia coli (ETEC) and Shigella in a cohort of 261 frozen stool samples from diarrhea patients seeking care in a rural health center in Bangladesh and a separate cohort of 136 frozen stool samples from a traveler’s study in Guatemala and Mexico. The lowest detection limit (LOD) of the RLDT assay [10^4CFU/gm of stool for Shigella and 10^5CFU/gm of stool for ETEC] is similar to that of a qPCR assay and could detect <10 bacteria/reaction.
Publications
- Chakraborty S,* Connor S, Velagic M. Development of a simple, rapid, and sensitive diagnostic assay for enterotoxigenic E. coli and Shigella spp applicable to endemic countries. PLoS Negl Trop Dis. 202216(1):e0010180.
- Connor S, Voeglein B, Alam M, Mukhopadhaya A, Dutta S, Wierzba. T, Bougeois. AL, Sack. D, Chakraborty. S*. Evaluation of a novel, simple, sensitive and rapid fieldable detection assay for ETEC and Shigella spp from stool samples. PLoS Negl Trop Dis. 2022 16(2):e0010192.
- A LAMP to Light the way: A rapid diagnostic test for ETEC and Shigella diarrhea (defeatdd.org)
