Wednesday, 13 November 2013

Can African Farmers Detect Cancer-Causing Toxin With An App?

aflatoxin-bean
A smartphone app developed by a University of Colorado associate professor could be a cheap way for African farming communities to manage aflatoxin, a cancer-causing toxin produced by a fungus that grows on crops, according to a report in AllAfrica.

After users photograph a test strip with a smartphone, the app calculates the pixel density of the colored band. The result shows how much aflatoxin is present within a certain threshold, rather than giving a positive or negative result.
The Lab-on-Mobile-Device (LMD) platform can detect aflatoxins in the field as accurately as a lab test, but at a fraction of the cost using a smartphone camera, AllAfrica reports.
Lab tests run about $15. Each LMD test will cost about $2 to $3, the report said.
Donald Cooper of the University of Colorado co-founded Mobile Assay, the company that developed the smartphone app technology.

Field trials began in September in five East Africa locations in collaboration with regional research universities and institutions with a grant from the Bill & Melinda Gates Foundation.
The fungus that produces aflatoxin grows on crops including corn and peanuts in warm climates. The World Health Organization has identified it as a carcinogen.
The problem affects a quarter of food crops worldwide, according to the Food and Agriculture Organization. About five billion people in the developing world are likely to be exposed to aflatoxins, according to the Partnership for Aflatoxin Control in Africa.

Efforts to control aflatoxin have been hampered by a lack of adequate diagnostics, said Benoit Gnonlonfin, a food safety researcher working for a research initiative Biosciences Eastern and Central Africa.
Lab tests that can identify the toxin are expensive – at least $15 per test – Gnonlonfin said. Transporting samples from remote areas is an added challenge. As a result, local regulatory agencies often use cheaper immunoassay tests, which operate in a similar way to over-the-counter pregnancy tests, for on-location screening.
But these can only indicate a positive or negative result via a color change on test strips and do not indicate the level of health threat.

“The immunoassay tests are semi-qualitative techniques and they are not very appropriate for making decisions about whether a batch of food is fit for consumption,” Gnonlonfin said. “We need more-advanced technologies that are also affordable.”
Immunoassay tests are also prone to human error. Some require precise timing and low concentrations of aflatoxin might not trigger a colored response, Cooper said. He said LMD reduces these risks by analyzing shades of the colored bands on test strips via a digital phone image.
LMD is more sensitive than the human eye, boosting accuracy of traditional immunoassay tests by a factor of 100, Cooper said.

Data from the tests will also be automatically uploaded online to create real-time, open-access maps of aflatoxin outbreaks for research.
“Our goal is to be able to use the big data component of this,” Cooper said. He hopes that once a critical mass of people are using the app in various regions, he will be able to correlate those findings with other information such as climate data to build models that predict aflatoxin prevalence.
Gnonlonfin said it would be helpful to have a risk map.
Despite the relatively low test cost ($2 to $3,) the need to own a smartphone with a camera means LMD may not be a tool for every farmer but rather as a more-accurate, on-site test for agricultural co-operatives and regulatory bodies, Cooper said.


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