Estimating Asymptomatic and Symptomatic Transmission of the COVID-19 First Few Cases in Selenge Province, Mongolia.

Background: Following the first locally transmitted case in Sukhbaatar soum, Selenge Province, we aimed to investigate the ultimate scale of the epidemic in the scenario of uninterrupted transmission.

Methods: This was a prospective case study following the locally modified WHO FFX cases generic protocol. A rapid response team collected data from November 14 to 29, 2020.

RBD-specific antibody response after two doses of different SARS-CoV-2 vaccines during the mass vaccination campaign in Mongolia.

The SARS-CoV-2 vaccination campaign began in February 2021 and achieved a high rate of 62.7% of the total population fully vaccinated by August 16, 2021, in Mongolia. We aimed to assess the initial protective antibody production after two doses of a variety of types of SARS-CoV-2 vaccines in the Mongolian pre-vaccine antibody-naïve adult population.

Hepatitis B, C, and D Virus Infection among Population Aged 10-64 Years in Mongolia: Baseline Survey Data of a Nationwide Cancer Cohort Study.

Hepatitis B, C, and D virus infections are a major public health problem, and Mongolia has one of the highest prevalences of dual and triple infections in the world. We aimed to determine the seroprevalence of hepatitis infection and dual or triple hepatitis infections among 10-64-year-olds. A questionnaire was used to identify risk factors for hepatitis infection, and seromarkers were measured by the fully automated immunologic analyzer HISCL-5000.

Hepatitis B, C, and D Virus Infections and AFP Tumor Marker Prevalence Among the Elderly Population in Mongolia: A Nationwide Survey.

Objectives: Infections with hepatitis B, C, and D virus (HBV, HCV, and HDV) are a major public health problem and lead to serious complications such as cirrhosis and hepatocellular carcinoma. We aimed to determine the seroprevalence of hepatitis B surface antigen (HBsAg), anti-HCV, anti-HDV immunoglobulin G, alpha-fetoprotein (AFP), and dual and triple hepatitis virus infections in Mongolia.

Methods: A total of 2313 participants from urban and rural regions were randomly recruited for this cross-sectional study.

Factors Associated with COVID-19 Vaccine Hesitancy in Mongolia: A Web-Based Cross-Sectional Survey.

Vaccine acceptance in the general public is essential in controlling the coronavirus disease 2019 (COVID-19) pandemic. The study aimed to assess the COVID-19 vaccine hesitancy in the adult population of Mongolia, and determine the associated factors. A total of 2875 individuals from urban and rural areas were recruited, and completed an online survey.

SARS-CoV-2 seroprevalence in Mongolia: Results from a national population survey.

Background: With the global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in early 2020, Mongolia implemented rapid emergency measures and did not report local transmission until November 2020. We conducted a national seroprevalence survey to monitor the burden of SARS-CoV-2 in Mongolia in the months surrounding the first local transmission.

Methods: During October-December 2020, participants were randomly selected using age stratification and invited for interviews and blood samples at local primary health centres.

Associations of Breast Cancer Risk Factors with Premenopausal Sex Hormones in Women with Very Low Breast Cancer Risk.

Breast cancer incidence rates are low but rising in urban Mongolia. We collected reproductive and lifestyle factor information and measured anthropometrics and serum sex steroid concentrations among 314 premenopausal women living in Ulaanbaatar, Mongolia. Mean differences in hormone concentrations by these factors were calculated using age-adjusted quadratic regression splines.

A cohort study of chronic diseases for Mongolian people: Outline with baseline data of the Moncohort study.

Many Mongolian people suffer from non-communicable chronic diseases. In order to plan preventive strategies against such diseases, we designed a community-based prospective cohort study of chronic diseases, called the Moncohort study, in Mongolia. This is the first nationwide large-scale cohort study of chronic diseases.

Epidemiologic features of metabolic syndrome in a general Mongolian population.

Background: Although cardiovascular health is a crucial problem for Mongolian people, little information about metabolic syndrome, which is well known to be associated with the development of cardiovascular disease, is available in Mongolia. The aim of this study was to observe the epidemiological features of metabolic syndrome in a general Mongolian population.

Methods: This cross-sectional study was performed in 1911 general Mongolian subjects (717 men, 1194 women), who were ≥40 years old and free of ischemic heart disease, by using a dataset from a nationwide population-based cohort study in Mongolia.

Seroprevalence survey of brucellosis among rural people in Mongolia.

Background: After the transition from socialism to a market economy in 1990, human brucellosis re-emerged in Mongolia. The aim of our study was to estimate a representative seroprevalence of Brucella spp. and to determine risk factors for brucellosis seropositivity among rural people.

The role of hormones in the differences in the incidence of breast cancer between Mongolia and the United Kingdom.

Background: There are striking differences in breast cancer incidence between Asian and western women. Rates vary substantially within Asia also, with Mongolia's even lower than China's. These profound differences have been speculated to be due in part to diet, mediated by circulating hormone concentrations.

Vitamin D deficiency in reproductive age Mongolian women: a cross sectional study.

Vitamin D production is critical not only for rickets prevention but for its role in several chronic diseases of adulthood. Maternal vitamin D status also has consequences for the developing fetus. This study assessed the prevalence of vitamin D deficiency (serum 25-hydroxyvitamin D [25(OH)D]<20ng/ml) and insufficiency [25(OH)D=20-29ng/ml] in spring, among reproductive age Mongolian women.

A comparison of migrants to, and women born in, urban Mongolia: demographic, reproductive, anthropometric and lifestyle characteristics.

Background: Mongolia has experienced vast migration from rural to urban areas since the 1950s. We hypothesized that women migrating to Ulaanbaatar, the capital, would differ in factors related to future chronic disease risk compared with women who were born in Ulaanbaatar.

Methods: Premenopausal mothers (aged <44 years) of children attending two schools (one in the city centre and one in the outskirts) in Ulaanbaatar were recruited for the study.

Hypertension in Mongolia: an overview.

Objectives: Although hypertension is the primary cause of morbidity and mortality from cardiovascular diseases in Mongolia, reviews about hypertension in this country have not been reported, to our knowledge. Information on the overview of this disease may be useful to establish measures and policy to prevent hypertension and its related complications. The aim of our article is to summarize the current situation vis-à-vis hypertension in Mongolia.

Ischemic heart disease and its related factors in Mongolia: a nationwide survey.

Ischemic heart disease (IHD) remains one of the most important disorders associated with disability and mortality worldwide, and is one of the major causes of cardiovascular diseases in Mongolia. The objective of the current study was to determine the prevalence of IHD and its related factors in a general population in Mongolia. We conducted a nationwide cross-sectional survey between March and September, 2009.

Breast cancer incidence in Mongolia.

Purpose: Data on international variation in breast cancer incidence may help to identify additional risk factors. Substantially lower breast cancer rates in Asia than in North America and Western Europe are established, but differences within Asia have been largely ignored despite heterogeneity in lifestyles and environments. Mongolia's breast cancer experience is of interest because of its shared genetics but vastly different diet compared with other parts of Asia.

Kawasaki disease in Mongolia: results from 2 nationwide retrospective surveys, 1996-2008.

Background: Kawasaki disease (KD) has been reported in many countries. However, the incidence of KD in Mongolia is not known. This is the first report of incident cases of KD in Mongolia, which were identified using data from 2 nationwide surveys.

Hepatitis A and E virus infections among children in Mongolia.

To compare the epidemiologic profiles of hepatitis A virus (HAV) and hepatitis E virus (HEV) infections in children in Mongolia, the prevalence of HAV and HEV infections was studied serologically and molecularly among 520 apparently healthy children 7-12 years of age (mean +/- standard deviation, 8.5 +/- 0.8 years) using serum samples obtained in 2004.

Administration of hepatitis B vaccine in winter as a significant predictor of the poor effectiveness of vaccination in rural Mongolia: evidence from a nationwide survey.

Background: Universal hepatitis B (HB) immunisation is the most effective means for prevention of hepatitis B virus (HBV) infection worldwide. Maintaining the vaccine cold chain is an essential part of a successful immunisation programme. Our recent nationwide survey in Mongolia has observed significant urban-rural differences in the prevalence of HBV infection among vaccinated cohorts.

Impact of the universal hepatitis B immunization program in Mongolia: achievements and challenges.

Background: The impact of the universal infant hepatitis B (HB) immunization program initiated in 1991 in Mongolia is still unclear.

Methods: A nationwide school-based cross-sectional serosurvey was conducted in 2004, with stratified, multistage, random cluster sampling from all public elementary schools (n=593) in Mongolia. All children were tested for serological markers of hepatitis B virus (HBV).

Seroepidemiology of hepatitis B virus infection among children in Mongolia: results of a nationwide survey.

Background: Because Mongolia is one of the highly endemic countries for hepatitis B virus (HBV) infection in the world, hepatitis B (HB) vaccine was introduced into the National Expanded Program on Immunization in 1991. However, relatively few data are available concerning HBV infection among children born after the start of the program, so far. The aim of the present paper was to describe the seroepidemiology of HBV infection among primary school children using representative national data.

Hepatitis delta virus infection in mongolia: analyses of geographic distribution, risk factors, and disease severity.

The prevalence and risk factors for hepatitis delta virus (HDV) infection among Mongolian school children were assessed by detecting the antibody against HDV and HDV RNA, and through structured interviews. The study subjects consisted of 181 children with the past or ongoing hepatitis B virus infection who were investigated during the nationwide serosurvey conducted in 2004. The prevalence of antibody to HDV was 6.

Prevalence and risk factors for hepatitis C virus infection in Mongolian children: Findings from a nationwide survey.

Although the hepatitis C virus (HCV) infection is one of the major causes of chronic hepatitis and hepatocellular carcinoma (HCC) in Mongolia, its prevalence among children and routes of transmission are largely unknown. The aim of the study was to determine the prevalence of anti-HCV antibodies and the possible risk factors for transmission among school children using representative national data. A nationwide cross-sectional survey among elementary school children was conducted in four main geographical regions and the metropolitan area of Mongolia, through multistage, stratified, random cluster sampling.