1.Distribution of tick-borne diseases at Bulgan province, Mongolia
Rolomjav L ; Battsetseg J ; Bolorchimeg B ; Otgonbayar B ; Urangerel B ; Ganzorig G ; Natsagdorj D ; Bayar Ts ; Altantogtokh D ; Uyanga B ; Burmaajav B
Mongolian Medical Sciences 2022;199(1):24-33
Background:
Tick-borne encephalitis is human viral infection involving the nervous system and transmitted by the bite of infected tick. The TBE Virus is distributed in different geographical areas by three widespread subtypes of the virus: The Far East, Europe, and Siberia. The Far East type has a mortality rate was 30-35%, the European type has a mortality rate of 2.2%, and the Siberian type has a mortality rate of 6-8% (A.G. Pletnev, 1998) [2].
In recent years, human cases of tick-borne infections have been reported in 19 European countries and four Asian countries (Mongolia, China, Japan, and South Korea) [3].
Human cases of tick-borne encephalitis, tick-borne rickettsiosis, and tick-borne borreliosis have been registered in Mongolia since 2005. Deaths have been reported year by year [5].
During 2005 to 2021, tick-borne rickettsiosis (71.6%), tick-borne encephalitis (17.3%) and tick-borne borreliosis (52.9%) were confirmed by epidemiological, clinical and laboratory tests at the NCZD.
Tick-borne encephalitis was registered in 63 soums of 15 provinces and 9 districts of the capital city, of which 90% were infected with tick bites in Selenge and Bulgan provinces. The average mortality rate is 4.9% (14), of which 28.6% in Bulgan province and 2.7% in Selenge province.
Tick-borne encephalitis is the leading cause of death in Bugat soum of Bulgan province and more infected men about 40 years of age [7].
Purpose :
Collect ticks from selected soums of the provinces, identify tick species, species composition, distribution, tick densities, pathogens of tick-borne diseases, conduct population surveys to assess the risk of tick-borne infections, and identify tick-borne infections.
Material and Method:
Ticks were collected by flag from birch trees in birch forests and meadows with biotope and overgrown berries, determined morphological analyze and molecular biological investigation for detecting tickborne pathogens.
Questionnaires were collected from selected soum residents according to a specially designed randomized epidemiological and clinical survey card, collected information and forms were submitted to soum hospitals with a history of tick bites (according to clinical criteria). Serological tests were performed to detect IgG-specific antibodies to the collected serum mites.
Result and conclusion
Collected 121 ticks (120 I. persulcatus and 1 D. nuttalli) and not wound egg, larvae, nymphs. By molecular biological investigation detected 3.5% of I.persulcatus from Khutag-Undur soum of Bulgan province, 3.5% of anaplasmosis, and 14.1% of I.persulcatus mites from Bugat soum. 1.5% borreliosis, 3.1% anaplasmosis.
Detected DNA of 100% tick-borne rickettsiosis from D.nutalli ticks and determined circulation of infection among tick in Bugat and Khutag-Undur soums of Bulgan province.
247 people were surveyed, 56 blood serum from cases. Detected Q fever, erysipelas, and anaplasmosis, tick-borne borreliosis 3 (5.4%), tick-borne rickettsiosis 26 (46.4%), Japanese encephalitis 3 (5.4%), tick-borne encephalitis tick-borne rickettsiosis 6 (13.0%), tick-borne rickettsiosis tick-borne borreliosis 1 (1.8%), tick’s rickettsiosis Japanese encephalitis 1 (1.8%), tick-borne encephalitis tick-borne borreliosis 1 (1.8%).
By investigation, vaccination (88%) and wearing long-sleeved shirts and pants (81%) were the most effective ways to prevent tick bites (81%) [15]. According to our research, the percent of population knowledge in Bulgan province was insufficient (40.9%) which there is a lack of information, training and advertisement among the population in the province.