Background: The average age at menarche (AAM) among girls is influenced by various factors, including the socioeconomic status of the country, geographical location, and anthropometric characteristics. In Mongolia, limited research has been conducted on this topic Aim: This study aimed to compare the mean age at menarche among girls living in Bayanzürkh District of Ulaanbaatar and those in Uvs Province. Materials and Methods: A cross-sectional study was conducted between April and June 2025. The study participants included schoolgirls aged 8 years and older from general education schools located in Bayanzürkh District and Uvs Province. Statistical analyses were performed using R version 4.5.1 (RStudio 2025.05.1-513) Results: A total of 486 girls participated in the study. The mean age at menarche among the participants was 12.23±1.29 years. The mean age at menarche among girls aged 8–18 years in Bayanzürkh District was 11.84±1.19 years, while that among girls aged 8–18 years in Uvs Province was 12.97±1.15 years. Thus, girls in Bayanzürkh District experienced menarche 1.13 years earlier on average than those in Uvs Province. The difference in mean AAM between urban (Ulaanbaatar) and rural (Uvs Province) girls was statistically significant (p<0.0001). Conclusion The mean age at menarche among girls residing in Bayanzürkh District was significantly lower than that of girls living in Uvs Province, indicating a tendency toward earlier onset of menarche in urban areas.

Introduction: Major outbreaks of infectious diseases caused by enteroviruses (EV) have been reported in recent years. As of 2017, in Mongolia, hand, foot and mouth disease, or HFMD, accounts for 13.7% of all infectious diseases. The purpose of this study was to investigate the circulation of EV among healthy children, and clinical characteristics of infection. Materials and Methods : The analysis of EV circulation was conducted on Polio Laboratory data of 1172 specimens, collected in 2013-2018, from 9 districts of UB and 21 provinces of Mongolia. Also specimens of 239 patients, who underwent outpatient and inpatient treatment at the NCCD in 2014-2018, were randomly selected and stool samples were collected. Clinical symptoms of patients were analyzed and virus isolation analysis was performed in order to confirm the diagnosis. Results: Children from 1 month of age to 5 years have participated in the study and the average age was 2 years and 5 months. The enterovirus rate among healthy children was 20.1%. Virus circulation rate was highest in 2013 (37.2%), lowest in 2014 (11.8%). The peak of circulation is observed in May and October, while the minimum rate is in July.
Out of selected patients 52.7% (n=126) were diagnosed with HFMD, rash infection occurred in 28.5% (n=68), acute flaccid paralysis-18.8% (n=45). EV was detected in 56.4% (n=135) of the collected stool samples.
Children from 1 month of age to 5 years have participated in the study and the average age was 2 years and 5 months (95% CI:2.5 ±0.1). 49% (n=578) of participants were female, 50.7% (n=594) were male. The enterovirus rate among healthy children were 20.1% (n=236; 95% CI: 20.1 ± 0.55). Virus circulation rate was highest in 2013 (37.2%), lowest in 2014 (11.8%). The peak of circulation is observed in May and October, while the minimum rate is in July. Although the enterovirus isolation rate was relatively high among children under 3, there was no statistically significant difference (p>0.05), as well as there was no difference in gender (p>0.05). As for the EV circulation by region, the highest prevalence rate is found in Central region (27.5%), while the lowest is in the Eastern region (12.7%) with no statistical significance by regions (p>0.05). Conclusions Among children, HFMD is a common disease, that caused by EV. Enterovirus infection can often cause fever, flu like symptoms as well as spotted, maculopapular rash. The EV isolation rate of 20.1% indicates that the incidence of enterovirus is characterized by symptoms of influenza-like illness or is asymptomatic.

BackgroundIn 1988, the Forty-first World Health Assembly adopted a resolution for the Global Polio Eradication.Since the initiative was launched, number of polio cases has fallen by over 99%. Today, only threecountries in the world, Afghanistan, Pakistan and Nigeria - remain polio-endemic. The Polio Eradicationand Endgame Strategic Plan of 2013-2018 calls for the gradual eradication of wild virus strain and thevaccine virus strain at the same time. In order to prevent the border transmission of wild type poliovirus,virus leakage from laboratories, it is required to conduct inventory of laboratories handling poliovirus andpotential infectious materials every 2 year.GoalTo identify laboratories handling poliovirus and potential infectious materialsMethodsSurvey of laboratories handling poliovirus and potential infectious materials was conducted amongstate, private, clinical, biomedical and environmental testing in total of 127 laboratories operating in21 provinces and 9 districts of Ulaanbaatar city by questionnaire. Survey questionnaire consists of 6sections (general, sample storage, laboratory biosafety, staff knowledge, information source, trainingand etc.). Study results were processed using SPSS-19 statistical programme.Results34.7% of 96 biomedical laboratories were analyzed stool samples. These laboratories were analyzedrotavirus (17.0%), intestinal bacteria (67.0%), Helicobacter (14.3%), parasite and other indicators (1.7%)in stool samples. 43.8% of laboratories were stored stool samples for one day and 3.1% up to oneyear. From 31 environmental testing laboratories 73.3% were bacterialdetection test on environmentalsamples. 60% of wastewater samples were collected from rivers, 16% on entrance to wastewatertreatment plant and after biological treatment combined, and 24% from other sources. Soil sampleswere collected near waste disposal and other sources (46.4%), and from unknown sources (53.6%).24.1% of all laboratories were stored environmental samples for 3 days, 3.4% for 45 days. Accordingto results, surveyed laboratories did not store samples for more than 1 year. Also, none of surveyedlaboratories (100%) were not stored poliovirus and potential infectious materials.Conclusion· The investigated laboratories were not stored poliovirus and potential infectious materials.· The biosafety and biosecurity status of laboratories should be improved in near future throughenhancing knowledge of laboratory workers and organizing training related to biosafetyandbiosecurity.