1.0TBE Bookhttps://tbenews.com/tbeIThttps://tbenews.com/tbe/author/brianong/rich600338<blockquote class="wp-embedded-content" data-secret="B11dCVILpc"><a href="https://tbenews.com/tbe/13-22-9/">Mongolia</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://tbenews.com/tbe/13-22-9/embed/#?secret=B11dCVILpc" width="600" height="338" title="“Mongolia” — TBE Book" data-secret="B11dCVILpc" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe><script> /*! This file is auto-generated */ !function(d,l){"use strict";l.querySelector&&d.addEventListener&&"undefined"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!/[^a-zA-Z0-9]/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),o=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),c=new RegExp("^https?:$","i"),i=0;i<o.length;i++)o[i].style.display="none";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute("style"),"height"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):"link"===t.message&&(r=new URL(s.getAttribute("src")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener("message",d.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",function(){for(var e,t,s=l.querySelectorAll("iframe.wp-embedded-content"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute("data-secret"))||(t=Math.random().toString(36).substring(2,12),e.src+="#?secret="+t,e.setAttribute("data-secret",t)),e.contentWindow.postMessage({message:"ready",secret:t},"*")},!1)))}(window,document); //# sourceURL=https://tbenews.com/tbe/wp-includes/js/wp-embed.min.js </script> https://tbenews.com/tbe/wp-content/uploads/2019/03/Mongolia.jpg1180250TBE in Mongolia Tserennorov Damdindorj, Uyanga Baasandagva, Uranshagai Narankhuu, Tsogbadrakh Nyamdorj, Burmaajav Badrakh and Burmaa Khoroljav E-CDC risk status: endemic (last edited in June 2026, update for 2024 and 2025: no cases) History and current situation In Mongolia, tick-borne encephalitis virus was first isolated (Kraminskii V.A) from marmot liver in Dornod province in 1979, while the Ixodes persulcatus tick was identified in 1987 by M. Dash.1,2 Ixodes persulcatus is a taiga tick distributed in coniferous forests consisting mostly of pines, spruces and larches.3 Much of northern Mongolia is covered in coniferous forest, and the southern edge of the Siberian taiga is located along the Khangai and Khentii mountains. In the 1980s, Mongolian scientists worked together with researchers from the Institute of Epidemiology and Microbiology of Irkutsk, Russia to investigate the spread of ticks carrying the TBEV in the forest areas of Khuvsgul, Khentii, Bulgan, Selenge, Orkhon, Central, Dornod, Arkhangai and Uvurkhangai provinces, which had been identified as TBEV-endemic regions.4 Finally, in 1989, following available local information on diseases suspected to be TBE, Abmed et al. documented natural foci of the TBEV in the administrative districts of Zelter, Bugant and Khuder in the Selenge province and noted that it is important to plan and implement preventive measures.5 The physician of the Khuder district in the province of Selenge remembers that she had treated more than 400 patients with clinical signs of tick-borne infections from 1993–2000. Five of them had died and had been recorded as “viral infections“. This is the first evidence to indicate that TBE was prevalent at that time.6 The Selenge province was found to carry the highest counts of I. persulcatus ticks frequently infected with the TBEV. I. persulcatus ticks were also found to be abundant in the Bulgan, Tuv, Khuvsgul and Orkhon provinces of Mongolia.1,7,10 Human cases of TBE have been officially registered at the national level since 2005. During 2005-2023, 405 confirmed cases have been registered in Arkhangai, Bayankhongor, Bulgan, Darkhan-Uul, Dundgobi, Dornod, Orkhon, Uvurkhangai, Selenge, Tuv, Uvs, Khunsgul, Khentii, Bayan-Ulgii provinces and Ulaanbaatar city. Most patients remembered a tick bite to have occurred in the areas of Selenge (78%) and the Bulgan (12%) provinces. There were 21 fatal cases (CFR 4.85%) attributed to severe meningoencephalitis (Figure 1). Since 2005, prevention measures such as vaccination, training and advocation among the population have been administered but human cases continue to be registered. Between 2014 and 2017, TBE cases and deaths increased annually, but declined in the last five years (2018–2022). In 2023, human morbidity increased 4.25 times compared to the previous year. TBE cases have also been recorded from areas without the main vector I. persulcatus. Moreover an expansion of natural TBEV-foci has been observed.8-12 Most infections occurred among Individuals between 20–49 years of age, and it was 2.7–4.5 times higher than other age groups. Also, men more frequently contracted the disease (2.3, p<0.001) than women (Fig. 2). The majority of subjects were bitten by ticks when they had been collecting plants and picnicking during May and June.7 According to a survey of long-term neurological symptoms in 37 TBE-recovered individuals in Selenge province, 5 (16.1%) of them manifested with fever, 6 (19.4%) with paralysis, 8 (25.8%) with meningoencephalitis and 12 (38.7%) with meningitis when they were ill. After recovery between one to twelve years, 78.4% of them had headache, 30%–40% of them had fatigue, forgetfulness, decreased ability to concentrate and stiff neck, 10%–20% had hearing loss, paralysis, and a small percentage (3.2%) of them still had mental change, shoulder muscle atrophy, back muscle tone and muscle tremors convulsions.24 Vaccination against TBE has been consistently carried out since 2005 in the risk areas of the country.13-15 A molecular biological study of TBEV was performed in collaboration with researchers from Germany and Russia and determined the prevalent viral subtypes by genetic sequencing.7,15-20,22 Overview of TBE in Mongolia Table 1: TBE in Mongolia Viral subtypes, distribution8,16-21 Far Eastern subtype isolated from fatal cases Siberian subtype isolated from I. persulcatus Reservoir animals Not documented Infected tick species (%)7-8 I. persulcatus (3.18±2.5%)D. silvarum (2.9±2.6%)D. nuttalli (0.6%) Dairy product transmission Not reported Mandatory TBE reporting Patients with clinical suspected TBE are reported to the National Center for Zoonotic Diseases (NCZD) where the diagnosis can be microbiologically confirmed (anti-TBEV-IgG and IgM by ELISA). Any patient with serologically confirmed TBE or by PCR is reported to the Center for Health Development and also to the Ministry of Health, Mongolia.(Source: http://hdc.gov.mn/) Other TBE-surveillance National Center for Zoonotic Diseases and its local branches (15 Centers for zoonotic diseases in provinces) are conducting TBE surveillance in ticks and in the population of endemic areas.4,6,9-11 Special clinical features Clinically, 37.7% of patients have fever only, 34.6% suffer from meningitis, 26.5% from meningoencephalitis and 1.2% from encephalomyelitis. By age, fever dominates in age groups 0–9 and 40–49 years, meningitis in the age groups of 10–39 and 50–59 years and meningoencephalitis in those >60 years.7,11,12 In terms of age and sex, 20–49 year olds (65.6%) and males (69.3%) are the most affected groups. Among all affected males, those aged 10–49 years (81.8%) comprised the majority of male cases.7,8 The overall CFR was 4.85% between 2005 and 2022 with an annual range between 3.1%–20%. Available vaccines Russian vaccine – EnceVir and TBE-Moscow. Vaccination recommendations and reimbursement Persons in a risk population of most endemic provinces can receive TBE vaccination free of personal charge.  Vaccination is also recommended for anybody living in or visiting known endemic areas with a risk for tick bites.  (Source: The Order A160 on 21 April 2017 approved by the Minister of Health Annex 4: Guidelines for prevention and control of tick-borne diseases) Vaccine uptake by age group/ risk group/ general population TBE vaccination is organized since 2005. As of 2017, 51,000 persons from 13 provinces and the capital have been vaccinated, i.e., 2.1% of the total population. Vaccine uptake in endemic provinces ranges between 0.2%–23%.12-15 Name, address/website of TBE National Reference Center National Center for Zoonotic Diseases, Songinokhairkhan dictrict, 20 khoroo, Ulaanbaatar, 18131, Mongolia(Source: www.nczd.gov.mn) Figure 1: Figure 1: