London: Danish researchers have developed a novel test that can detect HIV, hepatitis B and hepatitis C from a single drop of blood. The team from Copenhagen University Hospital in Denmark developed a dried blood spot test, in which a single spot of blood is tested for nucleic acid from the three viruses. "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," said Stephen Nilsson-Moller at the varsity's Department of Clinical Microbiology.
"Blood samples need to be analysed within six hours when kept at room temperature, while dried blood spots can last for nine months without refrigeration," he added. To do the test, the individual's finger is pricked and a few spots of blood collected on filter paper and allowed to dry. The Hologic Panther System - testing equipment widely found in public health laboratories - then uses a technique called transcription mediated amplification to analyse one of the blood spots for genetic material from the three viruses.
The analysis is designed to be, and is normally, run on liquid samples of plasma or serum - not the dried samples used here. Twenty samples with known amounts of HIV, hepatitis B and hepatitis C were analysed via the dried blood spot method (60 in total) and the viruses were detected in all of the samples. The plasma was also diluted to determine the lower limit of detection. This showed that it was possible to detect the viruses at levels that are much lower than are normally found in untreated patients.
"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 centres and homeless shelters," Nilsson-Moller said. "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 analyse it," he noted.
The findings will be presented at this year's European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) to be held in Copenhagen from April 15 to 18. More than one million people a year are killed by hepatitis B or hepatitis C. About 650,000 people die from HIV-related causes annually and 1.5 million acquire HIV. The World Health Organization has made the elimination of all three viruses by 2030 one of its global health strategies but new tests are necessary if case numbers are to be reduced. (IANS)
