Development of a fully automated malaria diagnostic system and field evaluation for practical use
  • Awarded Year
    2015
  • Awarded Amount
    $964,500
  • Disease
    Malaria
  • Intervention
    Diagnostics
  • Development Stage
    Product Validation
  • Collaboration Partners
    Institute of Tropical Medicine (NEKKEN) Nagasaki University , Juntendo University, Kenya Medical Research Institute (KEMRI-CGHR), Malaria No More Japan (MNMJ), National Institute of Advanced Industrial Science and Technology, Panasonic Corporation

Introduction and Background of the Project

Introduction

Light microscopy is widely used for malaria diagnosis. Stained parasites are directly observed and counted under a microscope; however, the method requires considerable preparation time and skills. Nowadays, the number of skilled technicians is not enough, and remote health facilities seldom have them. The method also requires a stable light source. Electric light is an ideal source for the method, but stable electricity is often unavailable in malaria endemic areas. On the other hand, rapid diagnostic test (RDT) kits are increasing popular in these days because of their simplicity and cost performance. The disadvantages of RDT are a qualitative result and frequent false positives. Therefore, the currently available RDTs should not be used for monitoring patients treated with drugs. Moreover, asymptomatic malaria infection is an obstacle to controlling and eliminating malaria, because the majority of asymptomatic cases are under the detection limits by microscopy and RDT. Molecular methods such as PCR (polymerase chain reaction) are sensitive enough to detect most asymptomatic cases, but the procedure is time-consuming and not cost effective. Currently we are developing a new diagnostic system to overcome these problems. The prototype of this system has already showed greater performance compared to the conventional methods. The system is ready for further improvement through laboratory and field tests in malaria endemic areas.

 

Project objective

A majority of asymptomatic malaria infections is under the detection limit by microscopy and/or RDT (Fig. 1). Although RDTs are useful for first line screening to support treatment, they should not be used for monitoring the effectiveness of treatment and an elimination program because of the low sensitivity and specificity. The main project objective is to develop a simple and fast malaria diagnostic system with high performance. Health workers should be able to use this system without considerable training. This system should be cost effective and operational in remote health facilities. The system can be used not only for diagnosis but also for monitoring patients and eliminating malaria. The specific objectives that we are aiming during this funded period are 1) to integrate multiple functions or components to one system, 2) to increase sensitivity for detecting at least 0.0005% parasitemia (the system will be able to detect infection even though only 0.0005% of red blood cells are infected. We will try to improve it to 0.00005% after this project, which is 100 times greater than RDT. ), 3) to reduce false positives nearly zero by enhancing the quantification technology, 4) to improve the system to handle at least 10 blood samples simultaneously, 5) to make all procedure automated (it should require only a single keyboard or mouse action after applying blood samples), 6) to display summary test results on a monitor within 10 minutes, and 7) to make the system portable and battery operated. .

 

Fig. 1. This new malaria diagnostic system will have high sensitivity.

 

Project design

This malaria diagnosis system has three main functions or components, filtering red blood cells, spreading red blood cells to a single layer for accurate detection of Plasmodium parasites, and quantifying them in the blood cells. We will integrate these functions to one system. For filtering function, we will design a disposal compact polystyrene container (cell microarray chip) and a compact disc that can host multiple cell chips. As the disc will rotate in a device resembled to a DVD driver, blood will migrate toward a small opening of the cell chip. A filter at the opening will separate only red blood cells from the other blood components, and red blood cells will enter inside the chip. Then, red blood cells will form a single layer and will be stained with fluorescent dyes in the chip. We will also add functions of detecting and quantifying parasites in the blood cells applying the modern digital imaging technology. After integrating these functions mechanically, we will write a software program to automate the procedure. We will also design a function for displaying test results on a monitor. In the lab, we will evaluate this integrated system using infected red blood cells with cultured parasites. Once confirmed that this system works properly and satisfies our numerical targets, we will evaluate this system with blood samples from residents in malaria endemic areas in Africa. Then, we will make the system operational in local health facilities.

How can your partnership (project) address global health challenges?

This system can dramatically improve the current situation of malaria diagnosis and treatment in endemic areas. Microscopy and RDT for routine diagnosis may be replaced with this system. In particular, this will make a great contribution in rural health facilities with an insufficient number of health workers and little equipment. When a health facility receives a large number of patients during a malaria season, the system will help both health workers and patients by handling multiple samples. The superior ability to quantify parasites will lead to accurate diagnoses and proper treatments, which may eventually reduce medical costs. Moreover, this system will be operational with solar energy in an area without electricity. With its portability this system will be also useful for mobile clinics. As this system requires little training, it will become handy for health facilities without skilled microscopists and training budget. Global efforts to combat malaria in the past decade achieved substantial reduction of deaths. Now several endemic countries are targeting malaria elimination. In the era of elimination, malaria prevalence will become extremely low; the number of malaria parasites in a person may become lower than the detection limit of microscopy. On the other hand, individuals with low parasitemia still become a source of parasites for others, and identifying infected individuals is indispensable to achieve malaria elimination. In this regard, this diagnostic system can be best fit for such situation.

What sort of innovation are you bringing in your project?

This diagnostic system is built with a totally different concept from the currently available tools. The system is built with some highly innovative technologies. To improve sensitivity and specificity, this system needs to separate red blood cells from the other blood components. Without the other blood components (or noise), it is able to detect and quantify parasites in the blood cells, which reduces errors such as false positive. The filter invented with SiO2 nano-fibers made this possible. Another innovative future is forming mono-layer of red blood cells. As red blood cells are arranged in a single layer, parasites in the cells will be detected correctly. This requires only 2 μl of blood. For detecting and quantifying parasites in red blood cells, this diagnostic system uses the latest digital image reading technology with a DVD type scan disc. Then, through a computer monitor, health workers actually are able to see malaria parasites in red blood cells. This process will be automated and require less than 10 minutes.

 

Fig 2. Proposed malaria diagnosis system with a CD type scan disc and an image reader.

 

Role and Responsibility of Each Partner

Panasonic will be the overall project leader and principle investigator overseeing the progress of the project. Panasonic will also lead the development of blood cells separation device, the cell chip for plasmodia detection, and fluorescent detector. Juntendo University will work with AIST on the development of principle for high sensitive technology and field testing.   Juntendo University will also be responsible for discriminate malaria specifics, extract issues for diagnosis, and perform statistical evaluation of field data. National Institute of Advanced Industrial Science and Technology (AIST) will work with Juntendo University on the development of principle for high sensitive technology. AIST will also be responsible for discriminating species of plasmodia and will work on chip PCR technology. Institute of Tropical Medicine at Nagasaki University will work with partners on the evaluation of the technology in the field trials. The Institute of Tropical Medicine will work with partners to manage field trials in Kenya, conduct field test of the diagnostic system and detecting problems and control ethics on site, and conduct preclinical testing. Malaria No More Japan (MNMJ) will provide partners with consultation for field testing and conduct marketing effort in Africa. Kenya Medical Research Institute (KEMRI-CGHR) will work with partners on conducting the field trails and preclinical trials. Kenya Medical Research Institute (KEMRI-CGHR) will also work with partners on detecting problems and control ethics on site.