​To find out the severity of a dengue infection, clinicians or researchers typically take blood samples and measure the amount of virus in the blood.   However, this method does not offer detailed information on how the infection is spreading in the body.

Now, a team from Duke-NUS Medical School (Duke-NUS) and Singapore General Hospital (SGH) has found a way to use PET, a technology commonly used to detect tumours, to visualise dengue infection in real-time.

"To our knowledge, this is the very first time PET has been systematically evaluated in the field of acute viral infectious diseases.   We are excited to be able to repurpose this non-invasive technology, and generate such robust images of live dengue infection in the body," commented the lead author of the study, Duke-NUS Assistant Professor Ann-Marie Chacko from the Cancer and Stem Cell Biology Programme, and head of the Duke-NUS for Translational and Molecular Imaging (LTMI).

PET (positron emission tomography) is an imaging technique that shows functional processes in the body. It was already in wide use in the 1990s. PET is often used with fluorodeoxyglucose (FDG), a radioactive version of glucose visible in PET scans.

"Being able to visualise dengue infection in the body potentially transforms how we assess the effectiveness of new dengue therapeutics."
- Prof Subhash Vasudevan, Emerging Infectious Diseases Programme, Duke-NUS

Researchers know that dengue infected mice will usually have inflammation in their intestines, and that inflammation sites absorb more FDG and glucose.   With this in mind, the team used PET-FDG to track the inflammation as indicator of dengue infection in mice models.

Not only did they observe inflammation in the spleen, and small and large intestines, the researchers also saw that the inflammation subsided after they gave the mice antivirals. FDG-PET allows them to see the progression and severity of the infection, as well as effectiveness of treatment.

"Being able to visualise dengue infection in the body potentially transforms how we assess the effectiveness of new dengue therapeutics.   We look forward to collaborating with academic and industry partners who are looking to validate their new dengue therapeutics using this novel approach," said Professor Subhash Vasudevan from the Emerging Infectious Diseases Programme at Duke-NUS and senior author of the publication.

Another SGH/Duke-NUS clinical study is underway to see if this laboratory finding is applicable to dengue patients.   They are currently recruiting volunteers.