Mongolian Academy of Medical science

Ulaanbaatar, Mongolia

Mongolian Academy of Medical science

Ulaanbaatar, Mongolia
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Tohma K.,Tohoku University | Suzuki A.,Tohoku University | Oshitani H.,Tohoku University | Nymadawa P.,Mongolian Academy of Medical science
Japanese Journal of Infectious Diseases | Year: 2012

Human adenoviruses (HAdVs) are responsible for approximately 5z-10z of acute respiratory infections. The serotypes of commonly detected respiratory HAdV in Asian countries are diverse. However, there are no well-documented reports of circulating HAdV serotypes in Mongolia. Between January 2010 and May 2011, 1,950 influenza-negative samples from patients with influenzalike illness, including eye swabs from patients with eye symptoms, were screened for HAdV, and 40 samples (2.1z) were positive for HAdVs. Among these 40 samples, 31 samples were positive for the hexon gene used in phylogenetic analysis, as determined by PCR. We identified 7 different serotypes. We constructed the phylogenetic trees of HAdV-B7 and HAdV-B3, the 2 most commonly detected serotypes in this study. All detected HAdV-B7 and -B3 Mongolian strains had identical sequences. HAdVD8, known to be associated with epidemic keratoconjunctivitis (EKC), was detected from nasopharyngeal and eye swabs. There was no difference between the amino acid sequences of the hexon and fiber genes that may affect tissue tropism in Mongolian strains and those in EKC-causing strains.

Xiang Z.,Chinese Academy of Sciences | Fuji N.,Tohoku University | Khulan J.,National University of Mongolia | Oshitani H.,Tohoku University | And 2 more authors.
Japanese Journal of Infectious Diseases | Year: 2015

Rhinovirus infections are common in all age groups world-wide, and they occur throughout the year. In this study, we examined 2,689 nasopharyngeal swabs collected in Mongolia during 2008–2013. Human rhinoviruses (HRVs) were detected in 295 (11.0z) samples, and 85 (28.8z) patients were co-infected with other respiratory viruses. HRV was co-detected with bocavirus, human coronavirus, and respiratory syncytial virus in 21 (24.7z), 17 (20.0z), and 14 (16.5z), respectively. We tested 170 (57.6z) of the 295 HRV-positive samples: 117 HRV strains were typed by using the VP4/VP2 method and 53 by using 5'UTR method. We found HVR-A, HVR-C, and HVR-B infections in 80 (47.1z), 76 (44.7z), and 14 (8.2z) samples, respectively. © 2015, National Institute of Health. All rights reserved.

PubMed | University of Tirana, Armenian National Academy of Sciences, Kuban State Medical University, Academy of Sciences of Uzbekistan and 39 more.
Type: Journal Article | Journal: Nature | Year: 2016

High-coverage whole-genome sequence studies have so far focused on a limited number of geographically restricted populations, or been targeted at specific diseases, such as cancer. Nevertheless, the availability of high-resolution genomic data has led to the development of new methodologies for inferring population history and refuelled the debate on the mutation rate in humans. Here we present the Estonian Biocentre Human Genome Diversity Panel (EGDP), a dataset of 483 high-coverage human genomes from 148 populations worldwide, including 379 new genomes from 125 populations, which we group into diversity and selection sets. We analyse this dataset to refine estimates of continent-wide patterns of heterozygosity, long- and short-distance gene flow, archaic admixture, and changes in effective population size through time as well as for signals of positive or balancing selection. We find a genetic signature in present-day Papuans that suggests that at least 2% of their genome originates from an early and largely extinct expansion of anatomically modern humans (AMHs) out of Africa. Together with evidence from the western Asian fossil record, and admixture between AMHs and Neanderthals predating the main Eurasian expansion, our results contribute to the mounting evidence for the presence of AMHs out of Africa earlier than 75,000 years ago.

Nukiwa-Souma N.,Tohoku University | Burmaa A.,National Influenza Center | Kamigaki T.,Tohoku University | Od I.,Baganuur District | And 6 more authors.
PLoS ONE | Year: 2012

Background: Knowledge of how influenza viruses spread in a community is important for planning and implementation of effective interventions, including social distancing measures. Households and schools are implicated as the major sites for influenza virus transmission. However, the overall picture of community transmission is not well defined during actual outbreaks. We conducted a community-based prospective cohort study to describe the transmission characteristics of influenza in Mongolia. Methods and Findings: A total of 5,655 residents in 1,343 households were included in this cohort study. An active search for cases of influenza-like illness (ILI) was performed between October 2010 and April 2011. Data collected during a community outbreak of influenza A(H3N2) were analyzed. Total 282 ILI cases occurred during this period, and 73% of the subjects were aged <15 years. The highest attack rate (20.4%) was in those aged 1-4 years, whereas the attack rate in those aged 5-9 years was 10.8%. Fifty-one secondary cases occurred among 900 household contacts from 43 households (43 index cases), giving an overall crude household secondary attack rate (SAR) of 5.7%. SAR was significantly higher in younger household contacts (relative risk for those aged <1 year: 9.90, 1-4 years: 5.59, and 5-9 years: 6.43). We analyzed the transmission patterns among households and a community and repeated transmissions were detected between households, preschools, and schools. Children aged 1-4 years played an important role in influenza transmission in households and in the community at large. Working-age adults were also a source of influenza in households, whereas elderly cases (aged ≥65 years) had no link with household transmission. Conclusions: Repeated transmissions between households, preschools, and schools were observed during an influenza A(H3N2) outbreak period in Mongolia, where subjects aged 1-4 years played an important role in influenza transmission. © 2012 Nukiwa-Souma et al.

Burmaa A.,National Influenza Center | Tsatsral S.,National Influenza Center | Odagiri T.,Tohoku University | Suzuki A.,Tohoku University | And 3 more authors.
Influenza and other Respiratory Viruses | Year: 2012

Background Large community outbreaks of pandemic A (H1N1) 2009 occurred between October and December 2009 in Mongolia. A serological study was conducted among the general population by testing paired sera collected before and after the first wave of pandemic in Selenghe province, Mongolia. None of the study participants had been vaccinated for pandemic A (H1N1) 2009 before the second samples were collected. Objective The objective of this study was to estimate cumulative incidence of pandemic A (H1N1) 2009 in different age-groups of Selenghe province residents. Methods After informed consent was obtained from apparently healthy volunteers, the paired sera and background information were collected. Antibody titers were measured using hemagglutinin inhibition (HI) and microneutralization (MN) assays for A/California/07/2009pdm. A fourfold rise in antibody titers was regarded as the evidence of infection. Results The overall cumulative incidences in the study group for all ages were 28·8% (76/264) by HI, 35·2% (93/264) by MN, and 25·0% (66/264) by both HI and MN. Cumulative incidences of infection varied among age-groups, with children aged 2-4 and 5-9years having high cumulative incidence of infection. Overall cumulative incidences of infection in the whole population were estimated to be 23·0% (4946/21460) by HI, 30·2% (6473/21460) by MN, and 18·8% (4036/21460) by both HI and MN. Conclusions This study indicates that about one-fourth of the total population in Selenghe province was infected with pandemic A (H1N1) 2009 virus during the first wave of the pandemic. © 2012 Blackwell Publishing Ltd.

Burmaa A.,National Influenza Center | Kamigaki T.,Tohoku University | Darmaa B.,National Influenza Center | Nymadawa P.,National Influenza Center | And 2 more authors.
Influenza and other Respiratory Viruses | Year: 2014

Background: Mongolia's Health Service began to conduct surveillance for influenza in the 1970s. This surveillance has become more comprehensive over time and now includes 155 sentinel sites in Mongolia. In this study, we analyzed the epidemiological characteristics and impact of influenza using data from influenza surveillance in Mongolia. Materials and methods: The data were collected by the National Influenza Center, Mongolia (NIC). Incidence rates of influenza-like illness (ILI) and severe acute respiratory infections (sARI) were calculated as the proportion of the number of ILI and sARI cases to the total population in the studied areas. Nasopharyngeal samples were collected and tested using real-time reverse transcription polymerase chain reaction [(rt)-RT-PCR]. Selected samples negative for influenza were tested for other respiratory pathogens by multiplex rt-RT-PCR. Results: Averages of 14·0 ILI and 0·8 sARI episodes per 100 population per year were observed during the five influenza seasons. The highest incidences of influenza associated with ILI and sARI were observed among children 0-4 years old. The number of ILI cases showed a clear seasonality, generally peaking between December and February. In contrast, sARI incidence peaked twice during each season. Influenza B was most prevalent during 2007-2008 and 2011-2012, influenza A (H3N2) during 2010-2011, seasonal A (H1N1) during 2008-2009, and A (H1N1) pdm09 during 2009-2010. Conclusions: Additional data on the epidemiology and impact of influenza including socioeconomic impact and vaccine effectiveness are required to develop a national influenza control policy, including a vaccination strategy. Our results provide useful data for developing such a policy. © 2014 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

PubMed | University of Tirana, Kuban State Medical University, Stanford University, Estonian Academy of Sciences and 39 more.
Type: Journal Article | Journal: Genome research | Year: 2015

It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50-100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192-307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47-52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males.

PubMed | Evolutionary Biology group, Mongolian Academy of Medical science, North-Eastern Federal University, University of Cambridge and 12 more.
Type: Historical Article | Journal: PLoS genetics | Year: 2015

The Turkic peoples represent a diverse collection of ethnic groups defined by the Turkic languages. These groups have dispersed across a vast area, including Siberia, Northwest China, Central Asia, East Europe, the Caucasus, Anatolia, the Middle East, and Afghanistan. The origin and early dispersal history of the Turkic peoples is disputed, with candidates for their ancient homeland ranging from the Transcaspian steppe to Manchuria in Northeast Asia. Previous genetic studies have not identified a clear-cut unifying genetic signal for the Turkic peoples, which lends support for language replacement rather than demic diffusion as the model for the Turkic languages expansion. We addressed the genetic origin of 373 individuals from 22 Turkic-speaking populations, representing their current geographic range, by analyzing genome-wide high-density genotype data. In agreement with the elite dominance model of language expansion most of the Turkic peoples studied genetically resemble their geographic neighbors. However, western Turkic peoples sampled across West Eurasia shared an excess of long chromosomal tracts that are identical by descent (IBD) with populations from present-day South Siberia and Mongolia (SSM), an area where historians center a series of early Turkic and non-Turkic steppe polities. While SSM matching IBD tracts (> 1cM) are also observed in non-Turkic populations, Turkic peoples demonstrate a higher percentage of such tracts (p-values 0.01) compared to their non-Turkic neighbors. Finally, we used the ALDER method and inferred admixture dates (~9th-17th centuries) that overlap with the Turkic migrations of the 5th-16th centuries. Thus, our results indicate historical admixture among Turkic peoples, and the recent shared ancestry with modern populations in SSM supports one of the hypothesized homelands for their nomadic Turkic and related Mongolic ancestors.

PubMed | Gene by Gene Ltd., Nazarbayev University, Mongolian Academy of Medical science, Armenian National Academy of Sciences and 7 more.
Type: Journal Article | Journal: PloS one | Year: 2015

Y-chromosomal haplogroup G1 is a minor component of the overall gene pool of South-West and Central Asia but reaches up to 80% frequency in some populations scattered within this area. We have genotyped the G1-defining marker M285 in 27 Eurasian populations (n= 5,346), analyzed 367 M285-positive samples using 17 Y-STRs, and sequenced ~11 Mb of the Y-chromosome in 20 of these samples to an average coverage of 67X. This allowed detailed phylogenetic reconstruction. We identified five branches, all with high geographical specificity: G1-L1323 in Kazakhs, the closely related G1-GG1 in Mongols, G1-GG265 in Armenians and its distant brother clade G1-GG162 in Bashkirs, and G1-GG362 in West Indians. The haplotype diversity, which decreased from West Iran to Central Asia, allows us to hypothesize that this rare haplogroup could have been carried by the expansion of Iranic speakers northwards to the Eurasian steppe and via founder effects became a predominant genetic component of some populations, including the Argyn tribe of the Kazakhs. The remarkable agreement between genetic and genealogical trees of Argyns allowed us to calibrate the molecular clock using a historical date (1405 AD) of the most recent common genealogical ancestor. The mutation rate for Y-chromosomal sequence data obtained was 0.7810-9 per bp per year, falling within the range of published rates. The mutation rate for Y-chromosomal STRs was 0.0022 per locus per generation, very close to the so-called genealogical rate. The clan-based approach to estimating the mutation rate provides a third, middle way between direct farther-to-son comparisons and using archeologically known migrations, whose dates are subject to revision and of uncertain relationship to genetic events.

PubMed | Mongolian Academy of Medical science, Stanford University, University of Turin, University of Hong Kong and 4 more.
Type: Journal Article | Journal: BMJ open gastroenterology | Year: 2016

According to Globocan, Mongolia has the highest worldwide hepatocellular carcinoma (HCC) incidence (78.1/100000, 3.5 higher than China).We conducted an anonymous survey of physicians from major provinces who attended an educational liver symposium, analysing their demography, practice, knowledge, perceptions and proposed solutions. Multivariate logistic regression was used to estimate OR relating demography and practice factors with higher provider knowledge and improvement.Of the 121 attendees, 44-95 (36-79%) responded to each question. Most were female (87%), young (79% age <50), subspecialists (81%), university-affiliated (74%), and practised in urban areas (61%). The mean pretest and post-test scores per physician were 60.420.4 and 65.621.3, with no observed significant predictors for baseline knowledge or improvement. Most (>80%) noted that <50% of patients who need hepatitis or HCC screening receive it. The main perceived barriers to screening were inability to pay for tests, lack of guidelines and poor patient awareness. Hepatitis treatment rates were low; 83% treated hepatitis C virus in <10 patients in the past year, and 86% treated hepatitis B virus in <10 patients/month. Treatment barriers were multifactorial, with cost as a principal barrier. Proposed solutions were universal screening policies (46%), removal of financial barriers (28%) and provider education (20%).Physicians from major regions of Mongolia noted low screening for viral hepatitis, even lower treatment rates, financial barriers and the need for increased educational efforts. We advocate broad-based medical education tailored to local needs and based on needs assessment and outcome measurements.

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