A single blood test can now detect the deadly H5N1 bird flu infection in just two hours time. Scientists have for the first time developed the world's most rapid and comprehensive diagnostic kit that can detect all known strains of avian influenza or bird flu (H5N1) through a single blood sample.
In comparison, the WHO World Health Organisation's gold standard test can test for only three of the 10 distinct genetic types of H5N1 virus (clades 1, 2 and 3). To detect all existing strains of H5N1 with the WHO detection method would not be possible. The new made-in-Singapore H5N1 test kit is being called the H5N1 real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR) assay.
The close collaboration between scientists from the Experimental Therapeutics Centre (ETC) under the Agency for Science and Technology Research (A*STAR) and clinicians from Tan Tock Seng Hospital (TTSH) enabled the successful development of the test. With this highly advanced kit, doctors can now rapidly detect all existing strains of the H5N1 viruses in a single test with almost 100% accuracy, within a few hours. Experts say this is a big boost to public healthcare system and a great stride forward in pandemic preparedness against this highly infectious disease worldwide. The bird flu virus, scientifically termed as the Avian Influenza virus, is usually lethal to the birds and normally does not transmit to humans.
However, highly lethal and contagious strains like H5N1 avian influenza A virus that can 'jump' from birds to human have been reported to cause serious infections and even death rates as high as 60% in infected patients. Although anti-viral treatment is available, the potential for H5N1 bird flu virus to spark a pandemic remains a serious threat to public health as most humans do not have immunity to the H5N1 virus. Therefore, to successfully curb the spread of the disease during an outbreak, accuracy and speed of detection on the type of H5N1 virus is of essence for effective infection control intervention and patient management.
Co-developed by Dr Masafumi Inoue, a Senior Research Scientist and Project Director of Technology Development from ETC and Dr Timothy Barkham, a senior consultant of Laboratory Medicine from TTSH, this newly launched H5N1 test kit has been clinically validated by several hospitals in Southeast Asia. "We are excited to be able to contribute to the fight against H5N1 virus with our expertise and know-how. Our technology has greatly simplified and accelerated the process of detection and identification of new H5N1 variants. Such information is especially critical when the virus mutates to become more dangerous, such as in drug resistance." said Dr Inoue. To enhance its usability, this new H5N1 test kit has been designed to be compatible with the previously launched "4-plex" Influenza diagnostic kit.
The latter is already adopted for use by several regional hospitals in Thailand. Using such multiplex assays enables simultaneous detection and differentiation of the different types of influenza infection in a single test, which will save hospital labs and clinicians significant time and cost. "While there have not been any reported H5N1 cases in Singapore, this mutating subtype of influenza virus type A continues to be a concern. The ability to detect and characterise influenza strains remains important in the management of the disease. With this latest H5N1 assay, we can easily combine it with our previous 4-plex Influenza kit to differentiate which strain of Influenza is present with one test, giving a definite diagnosis and faster turnaround for our patients and our colleagues in infection control and public health," said Dr Barkham.
Bird flu has been a big problem for India. It has been reported from various parts of the country including Maharashtra, Gujarat and north eastern states like Tripura. India has also reported many human casualties besides loss in millions due to lost poultry products. a sngle test that can detect all strains can be a real boon for India where genetical tests to identify the strain can take months during which time the deadly influenza virus can spread through backward villages, making containment operations a real problem.