Highly pathogenic avian influenza is a growing public health threat, with the risk of its adaptation for transmission between humans currently elevated. The strain responsible for the ongoing outbreak, H5N1, spreads more easily between mammals than prior avian influenza strains and has spread widely in bird and cow populations.
In March 2024, the first cattle-to-cattle transmission of the virus was confirmed, and the outbreak among cows is now the largest outbreak of avian influenza in a domestic mammal close to humans.
As the infection spreads, testing for H5N1 in milk has become an invaluable public health tool. Genetic sequencing of H5N1 recovered from milk makes it possible to monitor whether the virus is evolving in ways that could make it more transmissible between people. In addition, proactive testing can enable farmers to quickly contain infections among their livestock and protect their employees from exposure.
A strategy for surveillance
The US Department of Agriculture has instituted a voluntary National Milk Testing Strategy, which offers no-cost avian influenza testing to farmers, as well as mandatory testing of animals before they are transported. Through the program, farmers can also receive compensation for veterinary care of infected animals, for lost milk production, and for biosecurity costs. Some states have chosen to mandate avian influenza surveillance in milk. However, because many farmers are reluctant to test, cases of avian influenza remain underreported.
A key concern is economics. Many farmers have reported concern that the combined cost of implementing biosafety measures and reporting positive tests outweigh the cost incurred from an outbreak. This concern may be especially compelling to dairy farmers because the mortality rate of avian influenza is much lower in cattle – at around 4 percent – than it is in poultry.
However, while mortality in cows is low, there are still sizable costs to an outbreak of avian influenza in a dairy that could be reduced if farmers were better able to contain it. In a recent analysis by the American Association of Bovine Practitioners, farmers lose an estimated $900 per infected cow, due to the impact of infection on a cow’s milk production and reproduction long term.
The problem(s) with PCR
Crucially, a delay in time-to-results using traditional testing methods makes it hard for farmers to respond quickly when outbreaks occur. Because the tests used in the USDA milk testing program are PCR based, they require specialized lab equipment and expertise, and must take place in authorized laboratories. As a result, farmers must navigate sample collection and shipping to one of sixty certified labs, and the turnaround time between sample collection and results can take many days. Meanwhile, an avian influenza outbreak becomes more challenging – and costly – to contain.
Slow time-to-detection, compounded with the logistical burden of testing, has led researchers to liken current systems of disease surveillance for avian influenza to the use of a single smoke detector for the fire management of an entire forest.
Switching on LAMP-based surveillance
If a dependence on lab-based testing methods deters farmers from conducting disease surveillance, it’s clear we need an alternative. More efficient methods of testing, which offer valuable, real-time information to farmers, could help rebalance the scales. Farmers equipped with better “smoke detectors” for avian influenza may be more likely to determine that the benefits of containing the virus quickly outweigh the cost of implementing testing measures and reporting outbreaks.
Alternatives to PCR-based testing strategies must allow for real-time results, while being easy, affordable, and similarly accurate. One promising alternative is loop-mediated isothermal amplification (LAMP), which is a fieldable technology that is particularly well suited to remote areas with limited lab facilities.
Unlike PCR, LAMP can be performed at a single temperature, without requiring laboratory instrumentation or specialized expertise. Adding to the method’s simplicity and flexibility, LAMP tests can be assessed by visual inspection. In colorimetric LAMP, a positive result is reflected by a color change. The combination of a simple, fast and easily interpreted molecular diagnostic makes LAMP an optimal candidate for point-of-need testing. In fact, colorimetric LAMP enabled the first molecular diagnostic test approved for at-home use.
Real-time testing: coming soon
While the potential for real-time testing is clear, and the technology to achieve it is available, there are no commercially available point-of-need LAMP tests for avian influenza on the market. The research and development of LAMP-based, real-time diagnostics is underway, but there remains an urgent need for continued development and validation. As of spring 2025, there are a handful of ongoing development efforts.
Paper-based LAMP technology is extremely simple, and assays in development for the detection of avian influenza have been reported to have ten times the detection sensitivity of conventional PCR-based methods. Researchers are in the process of validating paper-based LAMP assays with clinical samples, and assessing the feasibility of implementing real-world testing. Meanwhile, researchers at New England Biolabs have adapted colorimetric LAMP methods for the analysis of milk samples, offering a starting point for the further development of real-time milk testing for avian influenza.
Alveo, a molecular sensing and diagnostics company, is perhaps the closest to bringing tests to market. Alveo has demonstrated in silico that its LAMP-based, hand-held diagnostic for avian influenza can detect the avian influenza H5N1 strain, and is now working to validate the diagnostic for humans, cattle and poultry.
Future opportunities for surveillance of avian influenza might include multiplex LAMP assays that simultaneously test for multiple infections, and colorimetric LAMP tests to integrate with accessible digital technologies, such as smartphone apps, for accessible, accurate, and affordable real-time monitoring and analysis.
Bringing the farmers on board
The successful development of rapid testing for avian influenza is much needed, but will not be a public health panacea. Efforts to develop an approved point-of-need test for avian influenza must be combined with outreach to farmers that address common concerns about avian influenza disease surveillance.
At present, many farmers distrust information about the risks of avian influenza, and believe that testing is economically disadvantageous. Therefore, successful implementation of testing will need to be combined with transparent communication about how to conduct testing, how to respond to an outbreak, and how proactive infectious disease response translates into benefits for livestock, farm employees, and the farmer’s business.
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