Influenza+complications

= Influenza complications =

The most common complication of influenza is **viral pneumonia**. This differs from viral influenza, because it involves infection of alveolar epithelium deep in the lungs. Alveolar epithelium are responsible for gas exchange between blood and air when we breath (C02-O2). Mass infection of this epithelial tissue can result in the loss of the gas exchange function and therefore respiratory failure and death15,17]

Secondary **bacterial pneumonia** can coexist with a viral infection or become present post viral infection. As with viral pneumonia this condition is a spread of infection distally (downward) into the lungs affecting gas exchange. Bacterial Pneumonia can be aggressive and fatal if not treated properly. In past Influenza pandemics, secondary bacterial infection has been responsible for a large proportion of deaths. Currently antibiotics are effective in combating bacterial pneumonia and as a result mortality is low 3, 10, 18].

**Ear infections** are also common. This is due to the infection spreading via the pharyngotympanic tube, also known as the Eustachian tube, which connects the middle ear to the nasopharynx 9]

As the virus can enter the blood stream, **disseminated intravascular coagulation** is also possible, though very rare. This condition can cause blood clotting throughout the body. In extreme cases this condition can starve internal organs their blood supply 12, 9].

**Myocarditis** is an inflammation of the heart muscle. The precise cardiac cells that the influenza virus targets is still unclear, though Endomyocardial biopsies and RT-PCR techniques have been used to confirm influenza infection present in cardiac tissue. Influenza-like symptoms may be present and can combine with an irregular heartbeat. Outcome of Myocarditis is dependent on duration and severity. Recovery is possible, though fatal cases are also common 1, 22].

**Myositis** or Myopathy is a direct viral infection of muscle tissue. Severe muscle damage resulting in acute renal failure or myoglobinuria is rare though, as most sufferers recover fully 12].

Influenza can also cause **Enchephalitis** which is an inflammation or swelling of the brain. While rare this condition can result in brain damage and in extreme cases, result in death. Treatments include antiviral and antibiotic drugs 12].