Complications

The course of an influenza infection depends on factors relating to both the virus itself and the infected organism. The following factors influence the course of infection: physiological status of the patient in relation to age, nutritional status, history of the patient with respect to disease/health and related burden of chronic diseases, and level of disease resistance including both non-specific resistance (antiviral inhibitors contained in the saliva and in secretions of the respiratory tract mucosa) and specific resistance (antibodies in the serum, IgA and IgG immunoglobulin present in the respiratory tract). Influenza complications are associated with severe clinical forms of influenza virus infection or with other pathological processes not related to influenza virus infection. The influenza virus shows affinity primarily for respiratory epithelium, but can also be responsible for cytotoxic reactions occurring in muscle cells, neurons, or cells in the vascular media, leading to pneumonia, encephalomyelitis, myocarditis, and inflammation of other organs. During the course of influenza infection, bacterial infections of various aetiologies may also occur, leading to bacterial infection of vital organs (lungs, vessels, sinuses and others). In addition, influenza can be associated with heart failure or deterioration and cardiovascular problems