The number of tick borne diseases is increasing in the world. More than 100000 tick borne encephalitis, tick borne encephalitis cases were registered every year. It occurred in 29 Europien, 4 Asian countries and became public health concern [1]. In our country, virus, tick detection started since 1980 with collaboration Russian scientists. From 1998, collaborative team of Public Health Institute (PHI), National centre for communicable diseases (NCCD), National center for infectious diseases with natural foci (NCIDNF) and Rssian scientists started study of tick prevalence and infection of tick borne encephalitis in Khuvsgul, Khentii, Bulgan, Orkhon, Tuv province. In study of B.Byambaa, M.Dash (1994), 18 species tick were found in Mongolia. Ticks found in 27 soums of 7 provinces. TBE virus infection of tick was 1.2-16.7% in I.persulcatus, 13.7-20% in D.nutalli. Far eastern subtype founded from patient, Siberian subtype founded from tick in Bulgan province of Mongolia. TBEV infection was 1.1-39% among population; highest infection was in Bugan, Khuder soum of Selenge province, Dadаl soum of Khentii provinces. 57.2-59.4% of population was tick bitten and 21-73.7% of them were developed clinical symptoms during surveillance. Symptoms include redness, fever, headache, skin rash, join paint. Most TBE cases were developed fever, headache, vomiting, stiff neck, paralysis. 96% of them typical, 4.4% of them atypical, 60% of them fever, 13.3% meningial, 10% meningoencephalitis among 90 cases in 1998-2004. In review, clinical symptoms of TBE cases that occurred Mongolia similar to cases caused Sibirein subtype.

Background: Medical geography deals with the application of major concepts and theories derived from human and physical geography to issues of health and disease. Between1970-1980, Russian scientists were first figured landscape, geographical distribution of TBE in Mongolia. Since human cases of TBD were registered from 2005, around 2000 cases of TBD were registered. From 15% of diseases and 78% of fatal cases were tick-borne encephalitis. Therefore, were tried to create current geographical distribution of TBE in Mongolia and detect risk areas. Мaterials and Methods: 287 TBE cases data, information of TBE positive tick and human data were analyzed which registered in NCZD between 2005-2017. Arc GIS 9 were used for create map. Mongolian map was divided by 5 landscape range such as forest-taiga, forest-steppe, steppe, steppe-desert, gobi and high mountain. Result: In forest-taiga range, 57% of TBE cases and incidence was 9.51 per 10000 population. 56.4% of I.persulcatus tick, 1.9% of D.nuttalli tick were found and infection rate of tick was Ixodes persulcatus-6.97%, Dermacentor nuttalli-5.2%. Seroprevalence of TBE was 25±12.1 among population.
In forest-steppe range, 40% of TBE cases and incidence was 0.56 per 10000 population. 43.6% of I.persulcatus tick, 44.3% of D.nuttalli, 24.4% of D.silvarum tick tick were found and infection rate of tick was Ixodes persulcatus-3.08%, D.silvarum-1.56% and D.nuttalli-1.56%. Seroprevalence of TBE was 14.5±11 among population.
In steppe range, 0.7% of TBE cases and incidence was 0.12 per 10000 population. 62.2% of D.silvarum tick, 23.9% of D.nuttalli tick were found and infection rate of tick was D.nuttalli-2.81% and D.silvarum-1.2%. Seroprevalence of TBE was 16.3±6.5 among population.
In other range including steppe-desert, gobi and high mountain, 2.8% of TBE cases and incidence was 0.1-0.27 per 10000 population. 62.2% of D.silvarum tick, 47.6% of D.nuttalli tick were found and infection rate of tick was D.nuttalli-0.84%. Seroprevalence of TBE was 2.5-13.1 among population. Conclusion Natural foci of tick-borne encephalitis have been registered in all landscape ranges of Mongolia and higher risk area of those ranges were forest-taiga and forest-steppe. Dermacentor silvarum, Dermacentor nuttalli tick becoming dominant vector of TBE in steppe range.