Animal influenza viruses
The animal influenza virus is distinct from human seasonal influenza viruses and doesn’t transmit between humans. However, zoonotic influenza(flu) or respiratory disorder viruses – animal influenza(flu)viruses that will often infect humans through direct or indirect contact – will cause disease in humans starting from a mild illness to death.
Birds are the natural hosts for avian influenza(flu) viruses. Once a deadly disease (H5N1) virus in 1997 in poultry in Hong Kong SAR, China, since 2003, These avian and different influenza viruses have spread from Asia to Europe and Africa.
In 2013, human infections with influenza (flu) A(H7N9) virus were reported in China.
Most influenza viruses don’t cause sickness in humans. However, some countries have reported cases of human infection from certain influenza viruses.
Close proximity to infected pigs or visiting locations wherever pigs are exhibited has been reported for many human cases; however, some limited human-to-human transmission has occurred. Just like birds and pigs, other animals like horses and dogs, maybe infected with their flu viruses (canine flu viruses, equine flu viruses, etc.).
Pathogen And Cause of Influenza
There are four kinds of influenza(flu) viruses: types A, B, C, and D.
Influenza viruses infect humans and lots of completely different animals. The emergence of a brand new and exceptionally completely different influenza virus with the ability to affect individuals and have sustained human to human transmission Will cause an influenza pandemic.
Influenza B viruses flow into among humans and cause seasonal epidemics. Recent the information showed seals could also be infected.
Influenza C viruses will infect both humans and pigs; however, infections are usually gentle and are rarely reported.
Influenza D viruses primarily affect cows and aren’t known to infect or cause illness in people. Influenza type infections are of most significance to public health because of their potential to cause an influenza pandemic.
Influenza group An infections are classified into subtypes consistent with the combinations of various virus surface proteins Hemagglutinin (HA) and neuraminidase (NA).
Depending on the origin host, influenza viruses may be classified as avian influenza, swine influenza, or different varieties of animal influenza viruses.
Signs and symptoms in humans
Avian, swine, and different flu infections in humans could cause disease starting from mild higher respiratory tract infection to rapid progression to severe pneumonia, Acute respiratory distress syndrome, shock, and even death.
Gastrointestinal symptoms like nausea, vomiting, and diarrhea are reported a lot of frequently in A(H5N1) infection. Conjunctivitis has also been reported in influenza A(H7).
Disease features like the period, the severity of symptoms, and clinical outcome varies by the virus causing infection, however, primarily manifests with respiratory symptoms.
In several patients affected by A(H5) or A(H7N9) avian influenza viruses, the disease has an aggressive clinical course. Common initial symptoms are high fever (greater than or up to 38°C) and cough followed by signs of lower respiratory tract involvement, Including dyspnea or difficulty respiration.
More upper respiratory tract symptoms like sore throat or coryza are less common. Different symptoms like diarrhea, vomiting, abdominal pain, bleeding from the nose or gums, cephalitis, and chest pain have also been reported within the clinical course of some patients.
Complications of infection include severe pneumonia, hypoxemic metabolic process failure, multi-organ dysfunction, septic shock, and secondary bacterial and fungus infections.
The case death rate for A(H5) and A(H7N9) subtype virus infections among humans is much over that of seasonal respiratory disorder infections.
For human infections with avian influenza A(H7N7) and A(H9N2) viruses, the disease is usually delicate or subclinical. Only one fatal A(H7N7) human infection has been reported within the Netherlands so far. For human infections with swine flu viruses, most cases are mild with some cases hospitalized and very few reports of deaths resulting from disease.