Influenza – or flu – is a respiratory illness that is caused by influenza viruses. Influenza viruses type A and type B cause seasonal epidemics in human beings on an annual basis. Furthermore, influenza A is also responsible for the pandemics that periodically appear, the most recent one being that which was caused by a H1N1 strain in 2009.
The illnesses range from mild to severe. According to WHO, the annual epidemics result in several million cases of severe illnesses and approximately 250,000 to 500,000 deaths per year worldwide. Severe cases and deaths mostly occur among the people in high-risk groups, e.g. young children, pregnant women, people aged over 65 years and those who suffer from certain medical conditions.
Influenza diagnostic tests are based on various technologies from viral isolation to immunodiagnostic and molecular diagnostic methods. Immunodiagnostic tests, especially rapid influenza diagnostic tests (RIDTs) that utilize monoclonal antibodies (MAbs) are often the test of choice due to their ease-of-use and low cost, although the sensitivities of the tests do vary significantly.