Introduction: Hearing loss is an important public health issue that negatively affects children’s speech, cognitive development, academic performance, and social interaction. Even mild hearing impairment may lead to adverse developmental outcomes. However, data on hearing loss among primary school children in Mongolia remain limited. Goals: To determine the prevalence, type, and severity of hearing loss among primary school students in Ulaanbaatar and to assess associated socio-demographic factors. Material and Method: A school-based cross-sectional study was conducted among 1,254 primary school students. Hearing screening was performed using pure-tone audiometry following a standardized protocol. Students who failed the screening were referred for confirmatory diagnostic audiometry. Hearing loss was classified as mild (21–35 dB), moderate (36–50 dB), and severe (≥50 dB). Socio-demographic data were collected using a structured questionnaire. Statistical analysis data were analyzed using RStudio software. Descriptive statistics were used to summarize participant characteristics. Associations between hearing loss and independent variables were examined using chi-square tests and logistic regression analysis. Variables with p<0.20 in univariate analysis were included in the multivariable logistic regression model. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported, and p<0.05 was considered statistically significant. Ethical considerations: The study protocol was approved by the Institutional Ethics Committee (Approval No. 2024/3 06). Written informed consent was obtained from parents or legal guardians, and assent was obtained from participating students prior to data collection. Results: Of the 1,254 students, 116 (9.2%) required further evaluation, and hearing loss was confirmed in 23 students (1.8%). Most cases were mild in severity. Paternal education level was significantly associated with hearing loss (p=0.028), whereas no significant associations were observed for sex or household income. Conclusion The prevalence of hearing loss among primary school students in Ulaanbaatar was 1.8%, with most cases being mild and unilateral. These findings highlight the importance of implementing regular school-based hearing screening programs and improving parental awareness of children’s hearing health.

Introduction: Hearing loss adversely impacts communication, cognitive function, and quality of life, yet early detection among adults remains inadequate. Despite the availability of portable, cost effective tablet-based audiometric screening tools, national-level prevalence data on adult hearing loss in Mongolia are scarce, and no large-scale screening studies in primary health care settings have been conducted to date. Goal: This study aimed to determine the prevalence of screen-detected hearing loss among adults in Ulaanbaatar, evaluate its association with age and test frequency, and identify associated factors. Material and Methods: A cross-sectional study was conducted at primary health care clinics across nine districts of Ulaanbaatar (2024–2025), enrolling 2,335 adults (≥18 years). Hearing screening was performed using the MAICO easyTone device with DD65 v2A headphones at 500–6000 Hz (30 dB HL at 500 Hz; 20 dB HL at remaining frequencies), with ambient noise monitored per ANSI S3.1-2008. Each ear was classified as Pass or Refer at each frequency. Outcomes included screen-detected hearing loss (SD-HL), speech-frequency hearing loss (SD SFHL, 500–2000 Hz), and high-frequency hearing loss (SD-HFHL, 4000–6000 Hz), each categorized as bilateral or unilateral. Associated factors were assessed by univariable and multivariable logistic regression. Results: SD-HL was identified in 37.2% of participants (bilateral: 31.5%; unilateral: 5.7%), SD-SFHL in 30.6%, and SD-HFHL in 36.3%. Prevalence increased markedly with age, from 29.9% (40–49 years) to 96.6% (≥70 years) (p<0.001). On multivariable logistic regression, male sex was inversely associated with a positive screening result (OR=0.65, 95% CI: 0.42–0.99, p=0.049). Conclusion The findings of this study confirm that the MAICO easyTone tablet-based hearing screening device is a feasible and appropriate tool for the early detection of hearing loss among adults in routine primary health care settings in Ulaanbaatar. The high prevalence of screening-detected hearing loss underscores the urgent need to establish adult hearing screening programs in Mongolia. Future studies should include standard audiometric confirmation in participants with positive screening results to determine the diagnostic validity of this hearing screening approach.

Background: Overconsumption of unhealthy foods and beverages, namely those high in sugar, salt, and saturated or trans fats, is observed among children and is associated with poorer health outcomes. The global trend of increasing consumption of foods with high energy and low nutrient density, including refined foods such as sugary and savory snacks, is reflected across all socioeconomic groups. Unhealthy food consumption increases the risk of overweight and obesity, and consequently elevates the risk of developing non-communicable diseases (NCDs) [1]. Therefore, it is necessary to assess the level of unhealthy food consumption among general education school students, disseminate the findings to the public, and develop and implement evidence-based interventions accordingly. Material and Methods: A cross-sectional analytical study design was employed. A total of 5,578 students were randomly selected from 33 schools operating in Övцrkhangai Province and included in the study. Quantitative data were analyzed using IBM SPSS Statistics version 23.
The prevalence of unhealthy food consumption and oral hygiene status among students was expressed as frequencies and percentages. The association between two variables was assessed using Pearson’s Chi-square test, and a p-value of less than 0.05 was considered statistically significant.
The internal consistency reliability of the questionnaire was determined using Cronbach’s alpha coefficient. Results: Among the participating students, 92.7% reported regularly consuming fast food, and 75.8% consumed it more than three times per week. The main reasons for consuming unhealthy foods included “being quick and convenient” (53.9%), “craving” (43.6%), and “the widespread availability of such foods nearby” (6.9%). Consumption of all types of sugary and processed foods showed a statistically significant association with dental caries (p=0.0001), indicating that these products contribute to the development of tooth decay. Furthermore, the prevalence of healthy teeth was highest (84.1%) among students who brushed their teeth at least twice a day, whereas dental caries was more common among students who brushed once daily or did not brush at all. This suggests that increased frequency of toothbrushing is associated with lower rates of dental caries, and this relationship was statistically significant (p<0.000). Conclusion The majority of students participating in the study regularly consume unhealthy foods such as fast food, carbonated beverages, sugary products, ice cream, and chocolate, and 58.6% were found to have dental caries. When comparing by location, both the frequency of unhealthy food consumption and the prevalence of dental caries were higher in the provincial center and in larger or roadside soums.

Background: Although childhood cancer accounts for a small percentage of total cancer cases globally, it remains a critical public health issue. Studying the incidence of childhood and adolescent cancer in Ulaanbaatar, where nearly half of Mongolia's population resides, is essential for improving diagnosis and treatment quality. Objective: To investigate the patterns and trends of new childhood and adolescent cancer cases in Ulaanbaatar from 2015 to 2024. Material and Method: A descriptive cross-sectional study was conducted. Based on statistical data from the Center for Health Development, incidence rates per 100,000 population were calculated and analyzed using STATA 14.2 software. Results: A total of 516 new cases were recorded during the study period, with an average incidence rate of 9.0 per 100,000 population. The incidence increased by 35.2%, rising from 8.8 in 2015 to 11.9 in 2022. Regarding cancer types, hematological and lymphoid malignancies dominated (50%). The highest incidence was observed in the 0–4 age group (12.5). The male-to-female ratio was 1.4, showing a male predominance. By district, the highest overall incidence rates were observed in Bayangol (10.3 per 100,000), Songinokhairkhan (9.6), and Bayanzurkh (9.4), while the lowest rates were observed in Nalaikh (4.7) and Bagakhangai (0.0). Conclusion The incidence of childhood cancer in Ulaanbaatar has shown an increasing trend over the last decade. The patterns of cancer types, age, and sex distribution are consistent with international and Asian regional trends.

Background: Fascioliasis is a neglected tropical disease (NTD) with a fluctuating global prevalence, recorded at 14% in 2012 and 4.5% in 2022 across endemic regions such as the Andean highlands, Egypt, and Vietnam. Transmission is primarily driven by the consumption of contaminated water, vegetables, or infected livestock products.
In Mongolia, Fasciola hepatica was first identified in 1967, with indigenous livestock infections confirmed in the Kharaa River basin in 2016. Molecular and morphometric analyses have since confirmed the distribution of F. hepatica among various livestock types across the Kharaa, Yeroo, and Selenge river basins. Studies on intermediate hosts have identified diverse gastropod mollusk species within Mongolia's freshwater ecosystems. Recent serological screenings (ELISA) in livestock across the central region revealed high seroprevalence rates, ranging from 6.22% to 51.02%. Despite the documented prevalence in animals, research on human infection and associated risk factors in these high-risk regions remains limited. Materials and Methods: A descriptive, cross-sectional study was conducted among 273 individuals from 130 herder households across selected soums in Selenge, Darkhan-Uul, Tuv, Khovsgol, and Bulgan provinces. Study areas were selected based on proximity to river basins and previous reports of livestock outbreaks. Data and serum samples were collected to evaluate knowledge, risk factors, and infection status. Fascioliasis was determined by detecting specific IgG antibodies using the Enzyme-Linked Immunosorbent Assay (ELISA) at the National Center for Zoonotic Diseases. Statistical analyses, including Chi-square and Fisher’s exact tests, were performed using SPSS, STATA, and R, while spatial distribution was mapped via QGIS. The study protocol was approved by the Ethics Committee of "Ach" Medical University, and all participants provided written informed consent. Results: Out of 273 participants, the overall seroprevalence of Fasciola-specific IgG antibodies was 11.4%. Geographically, the highest prevalence was recorded in Mandal soum (26.0%) and Bayangol soum (11.5%) of Selenge province. While no significant difference was found across age groups, the 50–59 (14.5%) and 30–39 (12.5%) cohorts showed the highest infection rates. Occupational analysis revealed that herders accounted for 14.7% of positive cases, facing a 1.86 times higher risk of infection compared to other occupations (p=0.05). Ultrasonographic examination of the 273 participants revealed pathological changes in 47 individuals, including increased hepatic and pancreatic echogenicity, renal cysts, and prostatic calcification. When comparing increased echogenicity with fascioliasis infection status, infected individuals were 3.85 times more likely to exhibit increased echogenicity (p < 0.001), indicating a statistically significant difference. Regarding awareness, 52.7% of participants had heard of the disease, though only 41.39% correctly identified contaminated water and vegetables as transmission routes. Knowledge levels varied significantly by province (p < 0.001), with the lowest awareness observed among herders in Selenge province. Conclusion The seroprevalence of fascioliasis was determined to be 11.4% among the population of five soums across Bulgan, Darkhan-Uul, Selenge, and Khuvsgul provinces in the central region. Among these, the highest infection rate was recorded in Mandal soum of Selenge province. While no statistically significant differences were observed regarding age and gender among the overall positive cases, men in Mandal soum of Selenge province were 2.63 times more likely to be infected than women. In terms of occupation, the prevalence of infection was notably higher among herders.
Although the overall awareness of fascioliasis among the study population in the central region was 52.7%, knowledge levels varied significantly across provinces. Regarding risk factors, traditional transmission routes such as the use of untreated river or spring water for drinking and swimming in rivers were not identified as primary drivers of infection. Instead, livestock ownership and the consumption of unwashed raw fruits and vegetables were determined to be the significant risk factors for fascioliasis in this population.

Background: The growth, development, and health of preschool children are significantly influenced by the conditions of their living and learning environments. In particular, the sanitary conditions of the outdoor environment of kindergartens play an important role in children’s physical activity, play behavior, psychological well-being, and the prevention of infectious diseases. Since children spend a considerable amount of time in kindergarten settings and actively use playgrounds and outdoor spaces, ensuring that these environments meet hygiene and safety standards is a fundamental requirement for protecting their health (Hills, A.P.et all, 2007) [1]. International studies have demonstrated that the outdoor environment of preschool educational institutions has a direct impact on children’s health and physical activity. According to these studies, the presence of green spaces, open areas, and a variety of playground equipment in kindergarten outdoor environments increases children’s physical activity and promotes their overall well-being [2]. A study conducted in Sweden has shown that the quality of the outdoor environment is associated with children’s health. The findings indicate that improvements in the outdoor conditions of kindergartens are positively associated with children’s body weight, stress levels, and overall well (Baranowski, T. Et all, 1993) [5]. Objective : To conduct a hygiene assessment of the outdoor environments of kindergartens in Bayangol District. Material and Method: This study employed a descriptive cross-sectional design. A total of 39 public kindergartens in Bayangol District, Ulaanbaatar, were selected using a census sampling approach. Data were collected using questionnaires, measurements, observations, and surveys.
Quantitative data collected during the study were coded and analyzed using Microsoft Excel, Word 2016, and SPSS version 27. The total land area of each kindergarten was measured in square meters and calculated per child based on enrollment figures. These values were compared against the MNS 6558:2015 standard to assess adequacy.
Descriptive statistical methods, including mean (x̄ ), standard deviation (SD), frequency, and percentage, were applied to summarize data obtained from observations and questionnaires on environmental conditions, sanitation, and hygiene indicators. The results were presented using tables and graphical representations. Result : The findings indicate that a substantial proportion of kindergartens operate in aging facilities, with 22% functioning for more than 36 years, while newly established institutions remain limited (5%).
Across 39 public kindergartens, the average area per child (18.3 m²) was below the national standard, with more pronounced deficits in ger districts (17.27 m²) compared to apartment areas (18.57m²), representing insufficiencies of 40.5% and 33.1%, respectively.
Although basic infrastructure was generally present, critical gaps were identified in key environmental conditions. Only 40% of playgrounds met required standards, and 8% were absent. Fire safety systems were inadequate in 32% of kindergartens, while 40% lacked proper waste sorting facilities. Playground surfaces were predominantly hard (66.7% cement), posing increased risk of injury.
The mean knowledge score of kindergarten directors on environmental and building standards was 50.6%, reflecting moderate competency with notable deficiencies in waste management, site planning, and safety-related regulations. Conclusion The environmental health conditions of kindergartens in Bayangol district do not fully meet relevant standards. Insufficient space per child and limited playground areas may negatively affect children’s health and safety.
Despite substantial work experience among directors, their knowledge of hygiene standards and environmental requirements is inconsistent and generally inadequate, particularly in technical areas such as waste management and safety regulations.

Background: Healthcare workers play a key role in the transmission of methicillin-resistant Staphylococcus aureus (MRSA) in healthcare settings. Staphylococcus aureus is a major cause of healthcare associated infections, including surgical site infections, ventilator-associated pneumonia, and bloodstream infections.
The anterior nares serve as an important reservoir for this pathogen, facilitating its spread within healthcare environments. In recent years, the rising prevalence of antimicrobial resistance has become a major public health concern, leading to increased morbidity, mortality, and healthcare costs.
Therefore, assessing nasal carriage and antimicrobial resistance patterns among healthcare workers is essential for effective infection prevention and control. Objective: To detect Staphylococcus aureus from nasal swabs of healthcare workers and to determine its antimicrobial susceptibility profile, with a particular focus on resistant strains. Materials and Methods: This descriptive cross-sectional study included 159 healthcare workers from six private hospitals in Songino Khairkhan district. Nasal vestibule swabs were collected and cultured on 5% blood agar and CHROMagar™ MRSA. Bacterial identification was performed using conventional microbiological techniques and API identification systems. Antimicrobial susceptibility testing was conducted using the disk diffusion method and interpreted according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Statistical analysis was performed using SPSS version 24. The study protocol was submitted to and approved by the Research Ethics Subcommittee of “Ach” Medical University on November 11, 2025. Written informed consent was obtained from all participants prior to sample collection. Results: A total of 159 nasal swabs were collected from healthcare workers, from which 58 (36.5%) bacterial strains were isolated. Staphylococcus aureus was the most prevalent pathogen, accounting for 50 (86.2%) of the total isolates, representing an overall carrier rate of 31.4% (50/159) among the participants. Other identified species included Enterococcus spp. (n=5, 8.6%), Streptococcus viridans (n=2, 3.4%), and Klebsiella pneumoniae (n=1, 1.7%). Antimicrobial susceptibility testing revealed that 76% (n=38) of the S. aureus isolates were Methicillin-Resistant S. aureus (MRSA), and 21% (n=10) were Multi-Drug Resistant (MDR). Additionally, Vancomycin-Resistant S. aureus (VRSA) and Vancomycin-Resistant Enterococci (VRE) were each detected at a rate of 0.6% Conclusion Antibiotic-resistant bacteria were identified in 44 (27.7%) of samples collected from healthcare workers, indicating the presence of multidrug resistance.
The detection of methicillin-resistant Staphylococcus aureus (MRSA), along with vancomycin resistant Staphylococcus aureus (VRSA), among healthcare workers indicates a potential risk for the dissemination of highly resistant pathogens.

Background: Sand play benefits young children’s physical, cognitive, and socio-emotional development and can help meet the WHO’s daily activity recommendation of 180 minutes. Children consider playing with sand as a pleasurable activity, which allows them to interact with materials, explore, and use them creatively to develop their imagination. However, sand provides a favorable environment for the growth and development of microorganisms. Objective: To assess bacterial and parasitic contamination in playground sand and compare the findings with established hygiene standards. Materials and Methods: The study was conducted using a descriptive cross-sectional design. Thirteen kindergartens were selected through simple random sampling from a total of 39 public kindergartens in Bayangol District, Ulaanbaatar. The research was carried out using laboratory analysis methods. Collected data were compiled using Microsoft Excel and Word 2016, and processed with SPSS version 24 Results: The total bacterial contamination of the sand samples collected in the study was 2.2 Ч 10⁵ CFU/g, indicating heavy contamination. The analysis showed that Clostridium perfringens was present in 100% of samples (n=13), Escherichia coli in 92.8% (n=12), Bacillus subtilis in 46.1% (n=6), and Acinetobacter in 7.7% (n=1). Additionally, mold was detected in 38.4% of the samples (n=5). Parasite eggs were found in 54% (n=7) of the samples from the 13 kindergartens. Analysis of the types of parasite eggs revealed that Ascaris lumbricoides was present in 28.5% (n=2), Enterobius vermicularis in 28.5% (n=2), Balantidium coli in 57.1% (n=4), and Toxocara spp. in 14.2% (n=1) of the positive samples. Conclusion Playground sand is highly contaminated with bacteria and parasites, posing infection risks, and is influenced by animal feces, poor sanitation, and environmental conditions.

Rationate: In recent years, global warming, climate change, environmental pollution driven by human activities, expansion of settlement areas, and mining operations within the Tuul river basin have been increasingly recognized as major factors affecting the river’s water quality, pollution levels, and flow regime [1, 3].
In particular, air and soil pollution in Ulaanbaatar, the quality and composition of effluent from the central wastewater treatment plant, water use by thermal power plants and boilers, as well as increasing domestic and industrial water consumption, continue to exert pressure on the Tuul river system [4, 6]. In addition, gold mining activities in the Zaamar area further contribute to the deterioration of water quality.
These combined pressures highlight the growing vulnerability of the Tuul river ecosystem and underline the need for detailed, spatially differentiated assessment of water quality along its course, especially within and downstream of urbanized areas. Objective: The objective of this study is to assess and evaluate the level of pollution in the Tuul river by spatially dividing the river into zones based on the results of chemical analysis. Materials and Methods: This study utilized water quality data obtained from laboratory analyses of Tuul River water samples conducted by the Information and Research Institute of Meteorology, Hydrology and Environment between 2022 and 2024. The data were accessed and used with official permission from the relevant authority.
The study was designed as a descriptive cross-sectional analysis. The research area was divided into three zones and 14 monitoring sites. A total of 373 water samples were analyzed based on 15 chemical parameters. Ethics: Before initiating the study, the research methodology and procedures were reviewed and approved by the Ethics Committee of Ach Medical University. An official request was submitted to the National Agency for Meteorology and Environmental Monitoring to obtain permission for the use of research data, and the data were used upon receiving approval.
To assess the water quality of the Tuul river, a statistical analysis was conducted on 15 key parameters across Zones 1, 2, and 3 using SPSS and Microsoft Excel. The study calculated arithmetic means and standard deviations to evaluate the data. A total of 373 samples, collected from 14 monitoring points within these three zones over a three-year period, were included in the analysis. Results: The three-year average concentrations of water quality indicators differed across Zones 1, 2, and 3. In Zones 2 and 3, key indicators including dissolved oxygen, biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonium nitrogen, mineral phosphorus, and chromium corresponded to Class IV and V levels of surface water quality classification, indicating heavy to extreme pollution. Conclusion
1. The chemical indicators reflecting the water quality and pollution level of the Tuul River show clear spatial variation along its course. The upper reach entering the city is relatively unpolluted, the central urban section experiences noticeable contamination, and the downstream section accumulates the highest level of pollution.
2. The main surface water pollution indicators in Zones 2 and 3 fall within heavily polluted (IV) and very heavily polluted (V) categories, indicating a strong influence of human activities and urbanization.
3. The average fluoride concentration in all zones exceeds the permissible limit defined by relevant standards by 2.5–3.9 times. Consumption of surface water with elevated fluoride levels may lead to fluorosis in humans, while livestock drinking water along the Tuul River may experience reduced productivity and disruption of normal bone structure development.

Background: Optimal nutrition during infancy is critical for growth, development, and long-term health outcomes. Globally, child malnutrition remains a major public health concern, with a growing shift from undernutrition to a dual burden that includes overweight and obesity. In Mongolia, national surveys indicate declining undernutrition but rising overnutrition among young children. Objective: To assess the nutritional status and feeding practices of children aged 0–23 months in Kherlen soum Material and Methods: A cross-sectional study was conducted among 166 children aged 0–23 months using systematic random sampling. Data were collected through caregiver questionnaires and anthropometric measurements. Nutritional status was assessed using WHO Anthro software (Z-scores). Statistical analysis was performed using SPSS-26, applying chi-square and t-tests at a 95% confidence level. Results : Early breastfeeding initiation was high (94.6%), but exclusive breastfeeding among 0–5 months was low (43.9%). Continued breastfeeding declined with age (p<0.05). Appropriate complementary feeding frequency was observed in 71%, and 68.8% met minimum dietary diversity. Stunting (1.8%) and wasting (0.6%) were low, with no acute malnutrition. However, 37.8% were at risk of overweight, increasing with age. Conclusion Exclusive breastfeeding rates among infants aged 0–5 months remain suboptimal. Undernutrition (stunting and wasting) is low among children under two years.
A considerable proportion of children are at risk of overweight, indicating a growing double burden of malnutrition