How much do you know about influenza viruses?
Influenza, abbreviated as flu, is an acute respiratory infectious disease caused by influenza viruses. It is highly contagious and has the characteristics of strong infectivity, rapid transmission speed, and the ability to affect both the upper and lower respiratory tracts. Influenza viruses possess a high degree of antigenic variability and rapid transmission ability. They trigger seasonal epidemics globally every year and may even lead to pandemics. With a relatively high incidence rate, they pose a significant threat to human health.
Influenza viruses are mainly classified into three types: A, B, and C. Among them, influenza A viruses are particularly prone to mutation. Influenza can spread from person to person through droplets and the air. Mild cases may cause symptoms such as fever, cough, sore throat, headache, and chills. Some children may also experience vomiting, abdominal pain, and diarrhea. In severe cases, it can even cause pneumonia, nervous system damage, heart damage, myositis, rhabdomyolysis syndrome, and septic shock, etc.
Globally, the number of confirmed influenza cases reaches one billion each year, with 3 to 5 million severe cases and 290,000 to 650,000 deaths. On average, in China, there are over 3 million influenza-related outpatient visits each year, 2.35 million severe cases, and 90,000 deaths. The winter season is especially a peak period for influenza viruses.
Rapid and Accurate Etiological Diagnosis
In recent years, metagenomic next-generation sequencing (mNGS) and targeted next-generation sequencing (tNGS) methods of high-throughput sequencing have been highly favored. Based on the TargetSeq® liquid-phase probe capture technology, iGeneTech has developed an influenza liquid-phase capture kit. Using the full-length genomic sequences of influenza A (taxid: 11320), influenza B (taxid: 11520), and influenza C (taxid: 11552) viruses from the National Center for Biotechnology Information (NCBI) over the past decade as the target regions, a total of 33,609 probes were designed. Then, the sequences of these probes were compared and analyzed. Redundant probes with high similarity were removed, and the remaining probes were retained to cover the entire genome of the influenza virus. Moreover, a high-density coverage of the highly variable regions of the virus was achieved, enabling precise genotyping of the influenza virus and more accurate detection of newly emerged mutations.
Figure 1. Design Concept of iGeneTech's Influenza Virus Probes
Powerful Data Support
Influenza viruses mutate relatively rapidly. Therefore, conducting a comprehensive analysis of their genomes and designing specific probes are crucial for monitoring the epidemic trends and mutation situations of influenza viruses. In order to cover as many influenza virus variants as possible and still enable effective detection at low viral loads, we designed probes using nearly ten thousand full-length sequences of influenza viruses as templates. A total of more than thirty thousand probes were designed, which can cover the full-length sequences of influenza viruses over the past decade.
The data this time are the results of influenza virus capture sequencing performed by iGeneTech's partners using iGeneTech's complete library preparation and hybridization capture kits (released with authorization). The results show excellent performance in terms of data alignment rate, coverage, uniformity, and other aspects.
Figure 2. Results of the Total reads mapping rate, Coverage rate, and T 20%X coverage rate of the Test Samples
Figure 3: Evolutionary Tree of HA Types Identified by Alignment on NCBI
Figure 4: Evolutionary Tree of NA Types Identified by Alignment on NCBI
After years of research and development, iGeneTech has launched a variety of kit products. It can provide a full set of kits for influenza virus extraction, library preparation, and capture, which are compatible with automated liquid handling workstations. Meanwhile, iGeneTech offers a range of predefined products for whole-genome capture of various pathogens along with their supporting kits, providing a one-stop solution to meet multiple needs.
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