Researchers from the Walter and Eliza Hall Institute (Parkville, Australia), Pasteur Institute (Paris, France) and Ehime University (Matsuyama, Japan) have developed a new tool that could be used to monitor the spread of infectious diseases.
The tool, a newly developed blood test, provides information regarding an individuals’ immunity to an infectious disease, indicating whether and when they have been exposed. Originally developed to track cases of Plasmodium vivax malaria, researchers are working to adapt the tool to identify previous exposure to SARS-CoV-2, the virus responsible for the COVID-19 pandemic.
In response to infection, the human body generates antibodies as a part of the immune response. Depending on the infection, antibodies can remain circulating in the blood for years. Many immunity tests detect the presence or absence of antibodies circulating in the human blood stream.
The research, published in Nature Medicine, details the development and validation of a new blood test that could improve infectious disease surveillance and response. In the study, scientists sought to evaluate the changes in the type and number of antibodies present in the blood over time and use this information to determine whether an individual was exposed to infection and when this took place.
Lead researcher, Ivo Mueller (Walter and Eliza Hall Institute and Pasteur Institute) explained: “Many tests for immunity give a simple ‘yes or no’ answer to whether someone has antibodies to the infectious agent. In contrast, our test – which was initially developed to look at malaria infections – can pinpoint how long ago a person was exposed to an infection.”
The researchers intend for the blood test to be used to retrospectively assess the spread of P. vivax malaria, evaluate the success of infection control programs and prepare for possible disease resurgence.
In light of the current global COVID-19 pandemic, the team are now adapting the blood test to detect immunity to SARS-CoV-2. Mueller explained: “We have already started to study the blood of people who have had COVID-19 infections to document the types of antibodies they carry. In the next 6 months we hope to have discovered how these antibodies change over time, meaning we can use this information to explore immunity in wider groups in the community.”
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Mueller clarified that the test will not be used to diagnose individuals, instead it will be used to monitor COVID-19 disease spread in populations, explaining that: “In countries in the Asia-Pacific, Africa or Latin America, it is possible that COVID-19 will be spreading undetected in some regions for the coming year – especially as governments try to loosen shutdown restrictions. This test could be invaluable for informing these decisions.”
The team originally validated the test for P. vivax infections using samples from individuals in malaria-endemic regions of Thailand, Brazil and the Solomon Islands. The results of study confirm the tests ability to detect those infected with P. vivax in the previous 9 months and identify individuals at risk of recurring infections.
Mueller added: “We will be working with the Australian biotech company Axxin (Victoria, Australia) to develop a diagnostic test for malaria that can be deployed in the field, based on the immune markers our laboratory testing identified.”
The team hope that the new blood test will facilitate improved surveillance and deployment of resources to better manage the outbreak and recurrence of infectious diseases.
Sources: Longley RJ, White MT, Takashima E et al. Development and validation of serological markers for detecting recent Plasmodium vivax infection. Nat. Med. 26, 741–749 (2020); www.wehi.edu.au/news/blood-test-potential-new-tool-controlling-infections