Unknown Influenza Viruses Threatening Us

On this website we closely follow the discovery and progress of several viral influenza-like diseases, like Novel Corona Virus and Influenza A (H7N9) Virus. Both of these have not yet reached pandemic proportions and still seem to linger in some far away country.

Are there other new or previously unknown flu-like threats that could spark a worldwide health scare? The last few years there have seen a few worrying developments.

[Foto: Bioquell.com]

[1] Surfacing in 2003, H5N1 or the infamous Bird Flu to date has infected some 626 people, resulting in 372 deaths. That results in a Case Mortality Rate (CMR) of 59.4%. While this disease is quite deadly, it still doesn't seem to spread that easily between humans and does not qualify for a pandemic.

[2] Since 2005, there are a number triple-reassortant swine flu (variant) viruses (H1N1v, H1N2v and H3N2v) circulating in the United States that created a number of serious infections in humans. So far they have failed to spread efficiently or to produce substantial levels of morbidity. To date 348 cases were reported to the CDC. See the table here.

[3] In November of 2011, substantial numbers of seals died in New England (USA). It was ultimately discovered that the cause was a new mammalian adapted influenza virus: H3N8 avian flu strain, versions of which are known to also infect horses and dogs. This Influenza A virus subtype, H3N8, appears to have a low risk of transmission to humans. News here.

[4] In March of 2012, a new Influenza A subtype was discovered in fruit bats: H17. That was a surprise because up to that moment it was thought that 16 different HA antigens (H1 to H16) and nine different NA antigens (N1 to N9) for influenza A were known. Birds are the natural host for influenza viruses but they had never been isolated in mammals before. New discoveries create new possibilities of infection and reassortment. News here.

[5] H6N1 is normally circulating in ducks. In May 2013 a 20-year old female was admitted to a hospital in Taiwan. After conducting whole genome sequencing, the National Influenza Center (NIC) at Taiwan CDC identified the virus to be a novel avian-origin influenza A (H6N1) virus. The patient recovered. See here.