i.5 Innovative Technology to Address the Elimination of Morbidity of Soil-Transmitted Helminth (STH)

Statement of need:

Intestinal worms negatively affect the nutrition and development of children and pregnant women, and are estimated to infect over a billion people worldwide.  Every year several hundred million people around the world are offered deworming medicine to control the effects of intestinal worms. The World Health Organization (WHO) considers STH a public health problem in areas where >2% of the at-risk population has moderate-to-high intensity infection – as measured by the number of eggs per gram of stool and diagnosed by microscopic examination of stool. Fortunately, intestinal worm infections are preventable and treatable. STH control requires the delivery of one or more interventions, such as drug treatment, sanitation provision and personal hygiene promotion. The programs have been successful in reducing the global worm burden and intestinal worms are no longer ubiquitous in the tropics. In order to target programmatic effort and donated medicine to those who are still infected with STH, and not give medicine to people who are not infected, quality diagnostics are required. To diagnose intestinal worms (also known as soil transmitted helminths or STH) a known quantity of stool is examined microscopically for the presence of worm eggs using a technique known as Kato-Katz that was first popularized over 50 years ago. Managing the collection of stool samples from a population-based survey, preparing the microscope slides for examination, and reading the slides with the naked eye is time-consuming, expensive, and moderately unpleasant. The world would benefit from an automated system in which stool samples can be accurately machine read and scarce program resources can be directed to those populations still at risk of sickness from worms, and redirected away from those who do not need it.

Overview of prior work:

The current STH diagnostic process performed by lab technicians in developing areas is not sensitive or consistent enough for accurate diagnosis of community-wide infection. These issues are due to poor visibility of parasitic eggs on the prepared microscope slide, human error in manual egg counting, and the occurrence of analyst fatigue due to the need to process a high volume of STH slides.

This project is a continuation of work done in the Fall 2021 Semester by Team Paradigm.  Paradigm developed a compact portable device, the ParaViewer. It has two main components: 1) the process improvements of the stool slide preparation and 2) the housing module in combination with phone microscopy. Ultimately, the ParaViewer standardizes a novel, wet-protocol procedure for preparing stool samples that decreases slide preparation time, increases throughput, and potentially decreases lab technician fatigue.

The housing module consists of a multi-part device that has a base, inner wheel, slide disc, lid, and phone. The ParaViewer functions by using a rotation mechanism to display 4 donor samples that are plated onto a slide disc adapted with 8 sample chambers. These chambers eliminate the Kato-Katz thick smear challenges. The ParaViewer houses a rechargeable LED light suitable for low light and power blackouts. A cell phone camera was adapted  with a reverse lens rests on the ParaViewer lid and produces high-quality, magnified images of stool containing low to high intensity infection. The slide disk is then rotated manually with a key to display the next sample.

Although the ParaViewer represents a significant paradigm shift over Kato-Katz methods, further development is needed to expand the system from analyzing 8 samples at a time to hundreds of samples in a high-throughput manner.  Your team’s task would be to further adapt the existing device to allow automated slide loading and scanning for rapid high-throughput sample analysis. 

Why should I be interested?

This seemingly straightforward challenge is remarkably complex. It will require multiple high-capacity people to solve. Due to the difficulty of bringing stool samples with parasite eggs in them into the USA there will be a need to field test in Africa or Asia.

If you can make this work, it could literally touch the lives of a billion people and change the STH world as we know it today.

Please note that Task Force for Global Health is interested in obtaining the IP assignment to assure continuity of the project towards implementation in the field – please discuss with instructors to understand what this means.