Search

Although the potential significance of hepatitis B surface antigen (HBsAg) mutants for failure of immunization has been studied in some endemic countries, whether the “a” determinant variants are responsible for vaccine failure in Mongolia remains unknown. Fifty-nine HBsAg-positive children (age: 8.8 ± 0.9 years) who had been observed during the nationwide survey of vaccinated cohorts conducted in 2004 were subjected to molecular analyses of hepatitis B virus (HBV). Partial S gene sequences encoding amino acids (aa) 40–171 of HBsAg were determined in 57 children (96.6%) who had detectable HBV DNA. Phylogenetic analysis of the S gene sequences revealed that genotype D accounted for 93.0% and genotype A for 5.3%. Only one child (1.7%) had HBVs of genotypes A and D. HBsAg mutations were found in 17 (29.8%) children ranging from 1 to 4 aa per subject (mean ± SD, 1.6 ± 0.9 aa). Pro127Thr and Thr118Ala were the most common substitutions, which occurred in 6 (10.5%) and 3 (5.3%) subjects, respectively; none had Gly145Arg. There were no significant associations in the prevalence of HBsAg mutations with age, sex, residential area, or vaccination status against hepatitis B. Analysis of the deduced amino acid sequence of the entire preS1/preS2/S gene revealed that eight genotype D isolates and one genotype A isolate were quite similar to previously-reported wild-type isolates, suggesting that they are essentially wild-type, but not vaccine-induced mutants. In conclusion, the results demonstrate that hepatitis B surface gene mutants do not play a significant role in vaccination failure in Mongolia. [ABSTRACT FROM AUTHOR]

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. A questionnaire was used to identify the risk factors for hepatitis virus infections, and the seromarkers were measured using immunoassay kits., Results: Among all participants, the prevalence of HBV, HCV, and HDV was 15.6%, 36.6%, and 14.3%, respectively. The infection rates were significantly higher in females and participants with a lower education level, rural residence, older age, and a history of blood transfusion. HBV and HCV co-infection was found in 120 (5.2%) participants and HBV, HCV, and HDV triple infection was detected in 67 (2.9%) participants. The prevalence of elevated AFP was 2.7%, 5.5%, and 2.6% higher in participants who were seropositive for HBsAg (p=0.01), anti-HCV (p<0.001), and anti-HDV (p=0.022), respectively. Elevated AFP was more prevalent in participants co-infected with HBV and HCV (5.8%, p=0.023), HBV and HDV (6.0%, p<0.001), and triple-infected with HBV, HCV, and HDV (7.5%) than in uninfected individuals., Conclusions: Nearly half (49.8%) of the study population aged ≥40 years were infected with HBV, HCV, or HDV, and 22.4% had dual or triple infections.

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. The prevalence of metabolic syndrome, as defined by International Diabetes Federation criteria, was determined. Alcohol consumption, smoking habits, and physical activity were evaluated. Education, marital status, income, and occupation were also examined as factors of socioeconomic status (SES). Their association with metabolic syndrome was determined by logistic regression models., Results: The prevalence of metabolic syndrome was significantly higher in women (n=488, 40.6%) than in men (n=138, 19.4%). The prevalence of metabolic syndrome was high, especially in the Khangai region, in women. Moderate-to-high alcohol consumption was a significantly positively associated factor of metabolic syndrome in men [odds ratio (OR)=2.01; 95% confidence interval (CI) 1.15-3.51; adjusted odds ratio (AOR)=2.41; 95% CI 1.31-4.44] and widowed status was a significantly positively associated factor of metabolic syndrome in women (OR=1.61, 95% CI 1.18-2.18; AOR=1.49, 95% CI 1.07-2.08)., Conclusions: Metabolic syndrome was prevalent in women compared with men among Mongolian adults. Preventive strategies aimed at men with a higher alcohol consumption and women with widowed status may help reduce metabolic syndrome, thereby improving cardiovascular health conditions in Mongolia.

Objective: To assess the effectiveness of the Maternal and Child Health (MCH) handbook in Mongolia to increase antenatal clinic attendance, and to enhance health-seeking behaviors and other health outcomes., Methods: A cluster randomized trial was conducted using the translated MCH handbook in Bulgan, Mongolia to assess its effectiveness in promoting antenatal care attendance. Pregnant women were recruited from 18 randomly allocated districts using shuffled, sealed envelopes. The handbook was implemented immediately for women at their first antenatal visit in the intervention group, and nine months later in the control group. The primary outcome was the number of antenatal care visits of all women residing in the selected districts. Cluster effects were adjusted for using generalized estimation equation. Masking was not possible among care providers, pregnant women and assessors., Findings: Nine districts were allocated to the intervention group and the remainder to the control group. The intervention group (253 women) attended antenatal clinics on average 6•9 times, while the control group (248 women) attended 6•2 times. Socioeconomic status affected the frequency of clinic attendance: women of higher socioeconomic status visited antenatal clinics more often. Pregnancy complications were more likely to be detected among women using the handbook., Conclusion: The MCH handbook promotes continuous care and showed an increase in antenatal visits among the intervention group. The intervention will help to identify maternal morbidities during pregnancy and promote health-seeking behaviors., Trial Registration: UMIN Clinical Trial Registry UMIN000001748.

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. General participants were recruited from urban to rural regions in a multistage random cluster sampling method. The diagnosis of IHD was based on the Rose questionnaire (World Health Organization) and electrocardiographic findings. A total of 369 (16.2 %) subjects with IHD were diagnosed among 2,280 participants. The prevalence of subjects with IHD was significantly increased by age: from 9.9 % in individuals age 40-44 years compared to 17.7 % in those over 60 years. Smoking habits (former and current) and non-frequent intake of fruits and vegetables were significantly positively associated with IHD in men, while heavy alcohol drinking habits and lower education period of time were significantly positively associated with IHD in women. IHD was found to be prevalent, especially among people aged over 40 years, in Mongolia. Statistical factors related to IHD were found to be significantly different based on sex. The current data may provide relevant information to prevent IHD in the Mongolian population.

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., Methods: Population-based studies that provided relevant information on hypertension in Mongolia were searched through PubMed, abstract books of the Mongolian Medical University resources from cardiologists, epidemiological databases and reliable websites of national organizations. Available articles from 1970 to present were selected., Results: A high prevalence of hypertension, which varied according to geographic location, exists among Mongolian people. The prevalence of hypertension may be influenced by nutritional factors, sedentary lifestyle, socioeconomic status and environmental factors in particular., Conclusions: The high prevalence of hypertension among Mongolian people can be a serious health problem in this country. Defining ethnic features of hypertension and related conditions will be the initial step that may lead to prevention of this disease. Further research and positive efforts to prevent hypertension appear necessary for Mongolians.

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., Methods: Two nationwide retrospective surveys were conducted: medical histories were collected from patients aged 0 to 16 years who were hospitalized countrywide between 1996 and 2008. Hospital records for these patients were also reviewed. Nationwide training seminars on KD were conducted before each survey., Results: For the nationwide surveys, the participation rates among all hospitals with pediatric wards were 97% and 94%. Inpatient medical histories from 1996 through 2008 were reviewed, and, among children younger than 16 years, 9 patients with KD were investigated. The age of KD patients ranged from 1.4 to 14 years; 7 of 9 patients were male. Six (67%) patients fulfilled all 6 clinical diagnostic criteria; the other 3 (33%) were defined as having KD based on the presence of 5 such criteria. Fever persisting 5 or more days, bilateral conjunctival congestion, and changes of the lips and oral cavity were the most common symptoms, and cervical lymphadenopathy was the least common symptom. Cardiac sequelae developed in 5 of the patients, 4 of whom were older than 10 years., Conclusions: The results of these nationwide surveys reveal that KD cases do exist in Mongolia. However, knowledge of KD among Mongolian pediatricians is likely to be poor. Thus, there is a need to augment their understanding to improve management of KD patients. Further studies are crucial to clarify the epidemiologic characteristics of KD 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. Total antibody against HAV (anti-HAV) was detected in 438 children (84.2%), whereas IgG antibody against HEV (anti-HEV IgG) was detected in only three subjects (0.6%). All three subjects with anti-HEV IgG were negative for anti-HEV IgM and HEV RNA. The presence of HAV RNA was tested in all 520 subjects, and one child (9-year-old girl) was found to have detectable HAV RNA (subgenotype IA). In conclusion, HEV infection was uncommon, but subclinical HAV infection was highly prevalent among children in Mongolia.

We investigated the anti-allergic effects of one strain (T120) of a lactic acid bacteria (LAB) isolated from Mongolian fermented milk using atopic dermatitis (AD) model mice (NC/Nga mice). Strain T120 has already been identified as Enterococcus faecium and shown to induce strong production of IL-12 (Kimura et al. 2006). In in vitro studies, strain T120 suppressed total IgE production and induced IL-12 and IFN-gamma production by splenocytes of NC/Nga mice. The additional examination of various neutralization antibodies was performed to elucidate in detail the mechanism of depressed IgE production by strain T120. As a result, it became clear that IL-12 induced by strain T120 increased production of IFN-gamma and total IgE production was mainly controlled by the IFN-gamma. In order to define the cells which produce IL-12 powerfully by this strain, antigen-presenting cells (APCs) such as macrophages and dendritic cells (DCs) were removed from the splenocytes, and the reactivity of these cells to the strain was examined. Induction of IL-12 and IFN-gamma by strain T120 became significantly very low by removal of APCs from splenocytes. Therefore, it was clear that strain T120 acted on APCs and induced production of IL-12. Further, this strain enhanced the production of IL-10 by splenocytes. In in vivo studies, intraperitoneal injection of strain T120 inhibited serum IgE elevation and atopic dermatitis symptoms in NC/Nga mice. These results suggest that an anti-allergic effect of strain T120 depends on the increased production of IL-12 by APCs activated by the strain and following the increased production of IFN-gamma. Further, activation of regulatory T cells by strain T120 may inhibit atopic disease.

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., Objective: To examine whether the administration of HB vaccine in winter contributes to these residential discrepancies on the effectiveness of vaccination., Design and Setting: In 2004, a nationwide serosurvey was carried out covering both urban and rural areas of Mongolia. Sampling was multistage, with random probability from all public schools in the country., Participants: A random sample of 1145 children (51.7% boys; aged 7-12 years), representative of Mongolian elementary school children., Results: Multivariate logistic regression analysis identified that total (past and current) HBV infection (OR 2.31, 95% CI 1.20 to 4.42; p = 0.012) was independently associated with the administration of all HB vaccines in winter. An increased OR for current HBV infection was also observed (OR 2.58, 95% CI 0.87 to 7.68; p = 0.089), but without significance. Interestingly, after stratifying by residence, the association between winter vaccination and total HBV infection was evident for rural (p = 0.008) but not for urban areas (p = 0.294). The frequency of vaccine-induced immunity was significantly (p = 0.007) lower for those who received HB vaccine at birth during winter in rural areas., Conclusion: Administration of HB vaccine during winter is an important predictor of the low effectiveness of vaccination in rural Mongolia. To improve the effectiveness of HB vaccination in remote areas, cold chain control should be addressed with particular attention to the winter season.

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., Methods: In 2004, a nationwide school-based cross-sectional serosurvey was carried out throughout Mongolia, covering both urban and rural areas. Serum samples were tested for hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti-HBc) and hepatitis B e antigen (HBeAg) as well as for liver enzymes., Results: A total of 1145 children aged 7-12 years were studied, which represents nearly 2% of the second grade population of elementary schools in Mongolia. The overall prevalence of HBsAg and anti-HBc was 5.2% (95% confidence interval [CI]: 3.9-6.5%) and 15.6% (95%CI: 13.5-17.7%), respectively. Among HBsAg-positive children 67.8% (95%CI: 55.9-79.7%) were also positive for HBeAg. The prevalence of chronic HBV infection increased by age and was significantly higher among children from rural areas compared to those from urban areas (7.7% vs 3.0%; P < 0.001). In the multivariate logistic regression analysis, rural residence (odds ratio [OR]: 2.57; 95%CI: 1.45-4.58), male sex (OR: 1.9; 95%CI: 1.08-3.26) and age (OR: 1.5; 95%CI: 1.10-2.05) were independent demographic predictors for chronic HBV infection., Conclusions: The prevalence of chronic HBV infection has been decreasing in the Mongolian young generation, most likely due to infant HB vaccination. However, significant rural-urban differences in the prevalence of HBV infection were found that demand further investigation to estimate the potential causes.

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)., Results: Serology results were available for 1,145 children (592 boys and 553 girls) aged 7-12 years (survey response rate: 93%). Immunization card was available for 702 (61.3%) children. The coverage of complete HB vaccination was 60.1% and it was increased by birth cohort from 44% to 76%. Significantly higher proportion of children in Metropolitan cities (75.2%) was completely vaccinated with HB compared to those in Province centers (55.7%) and rural areas (59.1%). HBV infection occurred in 5.9%, 13.2%, and 20.8% of complete vaccinees living in Metropolitan, Province centers, and rural areas, respectively; of whom 1.2%, 2.9%, and 8.6% were HB surface antigen (HBsAg) carriers, respectively. Only 17.0% of the children had protective anti-HBs which decreased from 31.1% to 16.3% among 7 to 12-year-olds indicating its decay with time., Conclusions: Prevalence of HBV infection and carriage among young generation meaningfully declined compared with those of previous studies in Mongolia. The coverage of birth dose and complete HB vaccination was significantly low in Province centers and rural areas which should be taken into consideration.

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 6.1%, with the proportion of 13.6% among hepatitis B surface antigen (HBsAg)-positive subjects, all of whom had HDV RNA. Multivariate logistic regression analyses showed that injections (> 11 times) (odds ratio [OR] = 8.31, 95% confidence interval [CI] = 1.28-54.07) and blood sampling (> 3 times) (OR = 5.34, 95% CI = 1.12-25.53) in health care settings, hospitalization (> 3 times) (OR = 6.20, 95% CI = 1.18-32.71), and cohabitating with patients with chronic hepatitis (OR = 4.57, 95% CI = 1.26-16.55) predicted the seropositivity for antibody to HDV. These results suggest that parenteral exposures in health care settings and household transmission are the main routes of HDV transmission among Mongolian children.

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. Serum samples from 1,145 children (response rate, 93%; 592 boys and 553 girls; age range, 7-12 years), which represented nearly 2% of the second grade population in Mongolia, were tested for HCV antibodies with a third-generation immunoradiometric assay (IRMA). Positive samples were further evaluated by a third-generation immunoblot assay (RIBA). A standardized questionnaire concerning the socio-demographic characteristics and potential risk factors was used. Overall, seven subjects were confirmed to be anti-HCV seropositive, giving a prevalence of 0.6% (95% CI: 0.15-1.0%). The prevalence of anti-HCV increased with age. In the multivariate logistic regression analysis, adjusted for age, sex, and residence, the history of dental manipulation (odds ratio [OR] = 15.4; 95% CI: 1.4-164.8) and surgery (OR = 8.3; 95% CI: 1.5-45.6) were associated independently with the presence of anti-HCV. These findings suggest that contaminated equipment used in the dental and surgical manipulations probably played a predominant role in HCV transmission among Mongolian children. Strict guidelines on disinfection and sterilization procedures of medical instruments have to be introduced and should be followed to improve the control of HCV infection in Mongolia., (Copyright 2006 Wiley-Liss, Inc.)