COPENHAGEN, Denmark — HIV, the virus that causes AIDS, infects an estimated 1.5 million people annually all over the world. Roughly 650,000 people die every year from HIV-related causes. Hepatitis B (spread via bodily fluids) and hepatitis C (spread via blood), meanwhile, contribute to over one million deaths per year. Now, a groundbreaking new test is capable of detecting HIV, hepatitis B, and hepatitis C using nothing more than a single drop of blood.
Collectively, these three viruses represent a major health concern on a global scale. The World Health Organization has deemed the elimination of all three by 2030 one of its key global health strategies. However, if that goal is going to become a reality, modern science needs new, more efficient detection tests. Right now, the most common way of detecting hepatitis B, hepatitis C, and HIV entails taking a blood sample from a vein via needle. While this approach is accurate, there is also a potentially large reservoir of the three conditions in places where this method is not suitable. For example, prisons, drug rehabilitation centers, and homeless shelters.
In such places, the taking of venous blood samples isn’t always suitable. Additionally, properly shipping and storing blood samples can be difficult in some countries.
Current alternatives include dried blood spot tests, in which scientists test a single spot of blood for nucleic acid from viruses. Researcher Stephen Nilsson-Møller and colleagues from the Department of Clinical Microbiology at Copenhagen University Hospital validated, or assessed, one such test.
To perform this type of test, you simply prick the patient’s finger, collecting a few spots of blood on filter paper and allowing it to dry. Scientists then use the Hologic Panther System (testing equipment widely found in public health laboratories) to perform a technique called transcription mediated amplification, which analyzes one of the blood spots for genetic material from the three viruses.
This analysis typically uses liquid samples of plasma or serum – not the dried samples used by study authors. In all, the team analyzed 20 samples with known amounts of HIV, hepatitis B, and hepatitis C with the dried blood spot method (60 in total). The test detected viruses in all of the samples.
Study authors also diluted plasma to determine the lower limit of detection. This showed that it is indeed possible to detect the viruses at levels that are much lower than typically detected in untreated patients.
“We’ve shown that using existing hospital equipment, it is possible to detect HIV, hepatitis B and hepatitis C from a single drop of blood,” says Nilsson-Møller in a media release. “The dried blood spot test is ideal for places where you don’t want to use a needle for safety reasons or where it is less practical. This includes prisons, drug rehabilitation centers and homeless shelters.”
“It is also suitable for developing countries or places where you run the risk of a blood sample being ruined before it is transferred to a laboratory that can analyze it,” the researcher concludes. “Blood samples need to be analyzed within six hours when kept at room temperature, while dried blood spots can last for nine months without refrigeration.”
The team is presenting their findings at this year’s European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in Copenhagen, Denmark.