Development of novel mesoporous silica nanoparticle sensing sprays for rapid field detection of foot-and-mouth disease (FMD)

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Among the challenges agriculture and food production has to face in the future, is the long-term management of sustainable food production for the growing world population. A crucial factor in this respect is the control of diseases and improvement of animal health as a basis for safe, efficient, and high-quality production. The impact of disease on global animal production and thus food security are measured in the £billions. Globalisation and climate change are driving the unprecedented increase of emerging and re-emerging animal diseases and zoonotics. Therefore improving animal health systems by providing tools to enable early detection and control of economically important global livestock diseases is the most effective response to this alarming situation. Foot-and-mouth disease (FMD) is a livestock disease of great economic importance, caused by the highly contagious foot-and-mouth disease virus (FMDV). The disease circulates in 77% of the global livestock population, costing ~between $5 -21 billion in production losses and control measures. The greatest overall economic loss by region is China totalling more than 2 billion USD, whereas the direct financial impacts as a result of production losses are greatest in Africa with an estimated loss of $815 million. Countries where FMD is endemic pose a great threat to disease free countries such as the UK for example the 2001 outbreak cost more than £8bn to control. FMD results in these huge economic losses through production losses (producers, markets, slaughterhouses, food processors, and consumers), disease eradication losses (quarantine enforcement, euthanisation, disposal of carcases, compensation, disinfection) and trade losses (restriction of trade to FMD free countries). Routine laboratory tests are widely used for FMD diagnosis and although relatively quick, the speed of result reporting is confounded by the time delays associated with sending samples from the farm to the laboratory. These delays have direct impacts upon the quality of evidence that can be used to support immediate diagnostic decisions in the event of suspect cases of FMD. The lack of a quick test result is particularly important for suspect FMD cases in sheep and goats, since diagnosis based solely on clinical signs can be very challenging in these species. These factors have driven the development of rapid tests which can be used in situ. In fact, the use of such rapid diagnostic assays was recommended in major reports following the UK 2001 FMD outbreak. Simple pen-side diagnostics which can be deployed on farm to rapidly detect viral antigen have been developed in the form of lateral flow devices (LFD's) for detection of FMDV, however the sensitivity of these tests is less than that of molecular methods. Therefore, research was focused on transfering real-time rRT-PCR into the field, but with the cost of most platforms being expensive and the need for decontamination of the equipment, emphasis has shifted to alternative assays such as loop-mediated isothermal amplification (LAMP). However, at present LAMP still requires expensive reagents and equipment, multiple pipetting steps and a skilled operator to perform and interpret the test. Safe-guarding of animal health through prevention and control of animal diseases is therefore of paramount importance for sustainable food production and veterinary public health. This project will see the development and validation of the first 'diagnostic FMDV sensing spray' which we anticipate can be applied non-invasively to the mouth, feet, nasal and teat area of animals suspected of displaying clinical signs of FMDV. Using an innovative approach a non-toxic dye which can be detected by the naked eye will be released from nanoparticles which only respond when they either come into contact with the whole FMDV virus or with enzymes released by the virus.