[Incidence of avian flu worldwide and in the Russian Federation. Improvement of surveillance and control of influenza during preparation for potential pandemic].

Problem of influenza and acute respiratory virus infections (ARVI) remains one of the most urgent medical and socio-economic issues in despite of certain achievements in vaccine and chemoprophylaxis. In Russia influenza and ARVI account for up to 90% of the total annual incidence of infectious disease (up to 30 million of sick people; 45-60% of them are children). Economic damage, caused by influenza and ARVI, makes around 86% of total economic damage, caused by infectious diseases. WHO predicts that in the years coming a new antigenic influenza virus will appear, which can lead to development of large pandemia with 4-5 times increase in disease incidence and 5-10 times increase in death rate. During 2005 some changes in animal influenza epidemiology were registered. New cases of people infections are detected, the virus has spread to some new countries. Avian influenza is a high contagious virus infection that can affect all bird species. For birds influenza is enteral infection, it severely affects parenchymatous organs, especially spleen, and lungs. By now it is known that carriers of avian influenza virus H5N1 can be all known species of wild waterfowl and near-water birds. Poultry is highly susceptible to many stocks of influenza virus H5N1, death rate reaches 100%. At that hens, especially chickens, are most susceptible. From January 2004 to 24th November 2005 in the world there were detected 131 cases of influenza, caused by virus A/H5N1/, 68 of them (51%) ended in lethal outcome (Vietnam--92 cases, Thailand--21 cases, Cambodia--4, Indonesia--11, China--3). Most of the described cases of avian influenza resulted from direct contact with infected birds (handling bird internal organs is especially dangerous). In frozen meat of infected birds the virus can remain for about one year. Heating kills virus (no cases of infection caused by use for food of poultry products were detected). In order to prevent wide ranging spread of infection over Russia it is necessary to organize medical monitoring of sea ships, aircraft and train crews, arriving from the countries where influenza H5N1 cases were detected, in case of need to arrange raids to outlets and markets to detect poultry and poultry products brought from these countries. In Russia it is necessary to prepare a reserve of vaccine strains of viruses--potential causative agent of pandemic, including H5N1 and H7N7, that can start to vaccine reproduction immediately in case of pandemic.