A portable test being developed by biodetection expert Stratophase could soon enable farmers and vets to accurately detect highly contagious diseases such as bovine TB and foot and mouth in the field, reducing false alarms and containment time and enabling remedial action to be taken more quickly.

A total of 2,030 cases of Foot and Mouth Disease (FMD) were confirmed in Great Britain between February and September 2001.* Millions of cows were slaughtered during the eradication programme and large swathes of the British countryside fenced off and declared out of bounds to the public for fear of further spread of the infection.

Stratophase is working with other British experts to develop a new detector system using immunoassay diagnosis - a biochemical test that detects or quantifies the amount of pathogen present by using an immunological reaction.

The sensor system will collect pathogens from the air and put them into a liquid stream. The liquid will then be analysed 'in the field' using Stratophase's optical sensor technology. The optical chips are coated with antibodies designed to attract specific antigens, such as those for TB or foot and mouth. If the targeted agent is present, it sticks to the surface and the chip undergoes a detectable change in optical spectrum, confirming the presence of the disease.

The Portable Direct Immunoassay Diagnosis Device for Animals and Humans (PDIDDAH) will be significantly more sensitive and accurate than the field deployable antibody based lateral flow tests (similar to those used for home pregnancy tests) presently available. Laboratory based techniques such as DNA replication and tagging (often used in forensic science applications) is currently the most commonly used test but, although this is highly sensitive, processing (sample transport, analysis and results) can take several days or even weeks.

Dr Devaki Bhatta, project leader from Stratophase, said, One of the most important developments that will be realised in this system is the ability to collect and identify airborne pathogens. This will remove the need for swabs and blood samples.

This project is to develop a foot and mouth detection unit, but using different antibodies the system could be used to identify TB and a range of other serious illnesses that affect livestock.

The collaborative development project, which is being co-funded by the UK government-sponsored Technology Strategy Board, will bring together teams from Stratophase, the University of Cambridge, Bristol Industrial and Research Associates Limited and Chelsea Technologies Group.

Initially developed for counter-bioterrorism applications, the Stratophase SpectroSens technology has also proved to be well suited to pharmaceutical manufacturing, food and beverage manufacturing, industrial process control and drug discovery applications.

* Data from Department for Environment, Food and Rural Affairs