Cauldrons of Bronze Age nomads reveals 2700 year old yak milk and the deep antiquity of food preparation techniques.

Cauldrons, vessels that are simultaneously common and enigmatic, offer insights into past cultural and social traditions. While assumed to possess a special function, what these cauldrons contained is still largely mysterious. These vessels, such as those made from bronze or copper alloys, function as reservoirs for ancient organics through the antibacterial qualities provided by the metal surfaces. Here we show, through protein analysis, that cauldrons from the Final Bronze Age (ca. 2700 BP) were primarily used to collect blood from ruminants, primarily caprines, likely for the production of sausages in a manner similar to contemporary practices in Mongolia's rural countryside. Our findings present a different function from the recent findings of cooked meat in copper-alloy vessels from the northern Caucasus 2000 years earlier, exposing the diversity in food preparation techniques. Our secondary findings of bovine milk within the cauldron, including peptides specific to Bos mutus, pushes back their regional domestication into the Bronze Age.

Aridity-dependent shifts in biodiversity-stability relationships but not in underlying mechanisms.

Climate change will affect the way biodiversity influences the stability of plant communities. Although biodiversity, associated species asynchrony, and species stability could enhance community stability, the understanding of potential nonlinear shifts in the biodiversity-stability relationship across a wide range of aridity (measured as the aridity index, the precipitation/potential evapotranspiration ratio) gradients and the underlying mechanisms remain limited. Using an 8-year dataset from 687 sites in Mongolia, which included 5496 records of vegetation and productivity, we found that the temporal stability of plant communities decreased more rapidly in more arid areas than in less arid areas. The result suggests that future aridification across terrestrial ecosystems may adversely affect community stability. Additionally, we identified nonlinear shifts in the effects of species richness and species synchrony on temporal community stability along the aridity gradient. Species synchrony was a primary driver of community stability, which was consistently negatively affected by species richness while being positively affected by the synchrony between C3 and C4 species across the aridity gradient. These results highlight the crucial role of C4 species in stabilizing communities through differential responses to interannual climate variations between C3 and C4 species. Notably, species richness and the synchrony between C3 and C4 species independently regulated species synchrony, ultimately affecting community stability. We propose that maintaining plant communities with a high diversity of C3 and C4 species will be key to enhancing community stability across Mongolian grasslands. Moreover, species synchrony, species stability, species richness and the synchrony between C3 and C4 species across the aridity gradient consistently mediated the impacts of aridity on community stability. Hence, strategies aimed at promoting the maintenance of biological diversity and composition will help ecosystems adapt to climate change or mitigate its adverse effects on ecosystem stability.

Core health system measures response to COVID-19 among East Asian countries.

Objective: The purpose of this study is to summarize the health system response to COVID-19 in four East Asian countries, analyze the effectiveness of their health system response, and provide lessons for other countries to control the epidemic and optimize their health system response. Methods: This study investigated and summarized COVID-19 data and health system response in four East Asian countries, China, Japan, Mongolia, and South Korea from national governments and ministries of health, WHO country offices, and official websites of international organizations, to assess the effectiveness of health system measures. Result: As of June 30, 2022, all four countries are in a declining portion of COVID-19. China has two waves, and new cases increased slowly, with the total cases per million remaining within 4, indicating a low level. Japan has experienced six waves, with case growth at an all-time high, total cases per million of 250.994. Mongolia started the epidemic later, but also experienced four waves, with total cases per million of 632.658, the highest of the four countries. South Korea has seen an increasing number of new cases per wave, with a total case per million of 473.759. Conclusion: In containment strategies adopted by China and Mongolia, and mitigation strategies adopted by Japan and South Korea, health systems have played important roles in COVID-19 prevention and control. While promoting vaccination, countries should pay attention to non-pharmaceutical health system measures, as evidenced by: focusing on public information campaigns to lead public minds; strengthening detection capabilities for early detection and identification; using technical ways to participate in contact tracing, and promoting precise judging isolation.

Soil environmental anomalies dominate the responses of net ecosystem productivity to heatwaves in three Mongolian grasslands.

Climate change is causing more frequent and intense heatwaves. Therefore, it is important to understand how heatwaves affect the terrestrial carbon cycle, especially in grasslands, which are especially susceptible to climate extremes. This study assessed the impact of naturally occurring, simultaneous short-term heatwaves on CO2 fluxes in three ecosystems on the Mongolia Plateau: meadow steppe (MDW), typical steppe (TPL), and shrub-grassland (SHB). During three heatwaves, net ecosystem productivity (NEP) was reduced by 86 %, 178 %, and 172 % at MDW, TPL, and SHB, respectively. The changes in ecosystem respiration, gross primary production, evapotranspiration, and water use efficiency were divergent, indicating the mechanisms underlying the observed NEP decreases among the sites. The impact of the heatwave in MDW was mitigated by the high soil water content, which enhanced evapotranspiration and subsequent cooling effects. However, at TPL, insufficient soil water led to combined thermal and drought stress and low resilience. At SHB, the ecosystem's low tolerance to an August heatwave was heavily influenced by species phenology, as it coincided with the key phenological growing phase of plants. The potential key mechanism of divergent NEP response to heatwaves lies in the divergent stability and varying importance of environmental factors, combined with the specific sensitivity of NEP to each factor in ecosystems. Furthermore, our findings suggest that anomalies in soil environment, rather than atmospheric anomalies, are the primary determinants of NEP anomalies during heatwaves. This challenges the conventional understanding of heatwaves as a discrete and ephemeral periods of high air temperatures. Instead, heatwaves should be viewed as chronologically variable, compound, and time-sensitive environmental stressors. The ultimate impact of heatwaves on ecosystems is co-determined by a complex interplay of environmental, biological, and heatwave features.

The effect of outcome-based education on clinical performance and perception of pediatric care of the third-year nursing students in Mongolia.

BACKGROUND: Mongolian government has set improvement of clinical proficiency of nursing students as one of its priorities. Nursing professionals have the sentinel role in providing healthcare services in rural areas. Outcome-based education (OBE) offers a promising pedagogical approach to actively mentally engage students to strengthen their clinical proficiencies. We implemented a pilot project with the objective of comparing students' clinical performance under OBE with our traditional didactic techniques. METHODS: The researchers implemented a non-equivalent two-armed quasi-experimental post-test-only' design approach study. The intervention arm (n = 34) received OBE pediatric training, while the control arm (n = 32) received the traditional pedagogical pediatric nursing training. Each arm of the study completed 16 hours of theory, 32 hours of clinical skills practice and 32 hours of seminars in pediatric nursing care. Data were collected using a five-section instrument, Demographic, Competency Inventory, Nursing Students' Satisfaction, Course Experience, and Objective Structured Clinical Examination. Performance and knowledge proficiencies were evaluated by applying the two-sided independent T-test. The distributions of categorical variables were assessed by Fisher's exact test or chi-squared test of significance. RESULTS: The intervention arm had higher mean score value in the competency inventory ([Formula: see text] = 238.70, SD = ± 23.07) compared to the control arm ([Formula: see text] = 222.11, SD = ± 39.94) (P = 0.04); similarly, the mean value for nursing students' satisfaction was higher for the intervention arm ([Formula: see text] = 117.87, SD = ± 15.94) compared to the control group ([Formula: see text] = 109.76, SD = ± 16.94) (P = 0.049). Additionally, the difference in the mean value for course experience questionnaire between the intervention arm ([Formula: see text] = 125.33, SD = ± 19.30) and the control arm ([Formula: see text] = 110.41, SD = ± 11.28) was statistically significant (P = 0.0001). Finally, the intervention arm had a higher mean value ([Formula: see text] = 85.40, SD = ± 6.11) for objective structural clinical examination compared to the control arm ([Formula: see text] = 81.56, SD = ± 7.01) (P = 0.023). CONCLUSION: OBE pedagogical approach offers promising benefits to improving nursing students' clinical competencies; additionally, the OBE approach seems to increase students' satisfactions with their clinical curriculum.

Diverse responses of surface biogeophysical parameters to accelerated development and senescence of vegetation on the Mongolian Plateau.

Vegetation dynamics is essential for characterizing surface biogeophysical parameters. Speeds of vegetation development and senescence are well documented, however, the effects of vegetation growth rates on surface parameters during different growth stages remains unclear. By using such methods as trend analyses and correlation analyses, this study examines the variations and interactive relationships of leaf area index (LAI) and surface parameters including Albedo, evapotranspiration (ET), and land surface temperature (LST), derived from Moderate Resolution Imaging Spectroradiometer (MODIS), during the intra-growing season (April-October, GS) on the Mongolian Plateau (MP). Generally, LAI exhibited a significant upward trend across GS months. Significant changes in VLAI (the difference in LAI between 2 consecutive months) in April-May and September-October indicated that the vegetation change rates were accelerated in the early GS (April-June) and late GS (September-October). The effect of vegetation activity on surface parameters varies over time and space. The effects of VLAI on the speed of surface parameters were inconsistent during the intra-GS. As a result of the significant changes in LAI, VET (the difference in ET between 2 consecutive months) displayed a significant upward trend during the early GS but a significant downward trend during the late GS. With acceleration of vegetation activity, the effects of VET and VAlbedo (the difference in Albedo between 2 consecutive months) on LST could offset each other at different stages of the GS. In addition, the effect of VLAI on the speed of surface parameters varied significantly by vegetation types. Our findings imply that clarifying the impact of vegetation activity on surface parameters at different growth stages can advance our understanding of vegetation responses and feedbacks to climate change.

The Metabolic Functional Feature of Gut Microbiota in Mongolian Patients with Type 2 Diabetes.

The accumulating evidence substantiates the indispensable role of gut microbiota in modulating the pathogenesis of type 2 diabetes. Uncovering the intricacies of the mechanism is imperative in aiding disease control efforts. Revealing key bacterial species, their metabolites and/or metabolic pathways from the vast array of gut microorganisms can significantly contribute to precise treatment of the disease. With a high prevalence of type 2 diabetes in Inner Mongolia, China, we recruited volunteers from among the Mongolian population to investigate the relationship between gut microbiota and the disease. Fecal samples were collected from the Volunteers of Mongolia with Type 2 Diabetes group and a Control group, and detected by metagenomic analysis and untargeted metabolomics analysis. The findings suggest that Firmicutes and Bacteroidetes phyla are the predominant gut microorganisms that exert significant influence on the pathogenesis of type 2 diabetes in the Mongolian population. In the disease group, despite an increase in the quantity of most gut microbial metabolic enzymes, there was a concomitant weakening of gut metabolic function, suggesting that the gut microbiota may be in a compensatory state during the disease stage. ß-Tocotrienol may serve as a pivotal gut metabolite produced by gut microorganisms and a potential biomarker for type 2 diabetes. The metabolic biosynthesis pathways of ubiquinone and other terpenoid quinones could be the crucial mechanism through which the gut microbiota regulates type 2 diabetes. Additionally, certain Clostridium gut species may play a pivotal role in the progression of the disease.

Respiratory Syncytial Virus and Influenza Infections in Children in Ulaanbaatar, Mongolia, 2015-2021.

BACKGROUND: Data available for RSV and influenza infections among children < 2 years in Mongolia are limited. We present data from four districts of Ulaanbaatar from April 2015 to June 2021. METHODS: This study was nested in an enhanced surveillance project evaluating pneumococcal conjugate vaccine (PCV13) impact on the incidence of hospitalized lower respiratory tract infections (LRTIs). Our study was restricted to children aged < 2 years with arterial O2 saturation < 93% and children with radiological pneumonia. Nasopharyngeal (NP) swabs collected at admission were tested for RSV and influenza using qRT-PCR. NP swabs of all patients with radiological pneumonia and of a subset of randomly selected NP swabs were tested for S. pneumoniae (S.p.) by qPCR and for serotypes by culture and DNA microarray. RESULTS: Among 5705 patients, 2113 (37.0%) and 386 (6.8%) had RSV and influenza infections, respectively. Children aged 2-6 months had a higher percentage of very severe RSV infection compared to those older than 6 months (42.2% versus 31.4%, p-value Fisher's exact = 0.001). S.p. carriage was detected in 1073/2281 (47.0%) patients. Among S.p. carriage cases, 363/1073 (33.8%) had S.p. and RSV codetection, and 82/1073 (7.6%) had S.p. and influenza codetection. S.p. codetection with RSV/influenza was not associated with more severe LRTIs, compared to only RSV/influenza cases. CONCLUSION: In Mongolia, RSV is an important pathogen causing more severe LRTI in children under 6 months of age. Codetection of RSV or influenza virus and S.p. was not associated with increased severity.

Analysis of the Correlation between FH and PCSK9 and APOB Gene Mutations in Han and Mongolian Populations of the Hulunbuir.

BACKGROUND: The goal of the study was to provide an individual and precise genetic and molecular biological basis for the early prevention, diagnosis, and treatment of local FH by analyzing the risk factors for the development of FH in Han and Mongolian patients in the Hulunbuir, comparing the lipid levels of FH patients of the two ethnicities, and assessing differences in mutations to two genes between the two ethnic groups. METHODS: Twenty cases each of Han Chinese and Mongolian healthy controls and fifty patients who each met the inclusion criteria from November 2021 to December 2022 in five general hospitals in Hulunbuir were selected. Multifactor logistic analysis was used to analyze the risk factors associated with the development of FH. We used t-tests to analyze statistical differences in lipid levels between the groups, and Sanger sequencing to detect the dis-tribution of common mutation sites of PCSK9 and APOB in all study subjects. The mutation rates and differences between regions and ethnic groups were summarized and compared. RESULTS: 1) Gender, age, alcohol consumption, dietary status, and a family history of FH were risk factors associated with the development of FH. 2) TC, LDL-C, and APOB were significantly higher in Mongolian cases than Han cases (p < 0.05). sdLDL-C was not statistically different between the two ethnicities (p > 0.05). 3) We detected four (8%) heterozygous mutations at the PCSK9 gene E670G mutation site in the Han case group and a total of nine (18%) mutations at this site in the Mongolian cases, including one (2%) homozygous and eight (16%) heterozygous mutations. One case of a heterozygous mutation was detected in the Mongolian control group. We detected a total of ten (20%) mutations at the APOB gene rs1367117 mutation site in the Han case group, including eight (16%) heterozygous and two (4%) homozygous mutations, 11 cases (22%) of heterozygous mutations in the Mongolian case group, two cases of heterozygous mutations in the Han control group, and one case of a heterozygous mutation in the Mongolian control group. 4) The D374Y and S127R mutation sites of PCSK9 and the R3500Q mutation site of APOB were not detected in any of the study subjects. CONCLUSIONS: The mutation sites of the PCSK9 and APOB genes in FH patients in Hulunbuir are different from other regions, and the mutation rate is higher than in other regions. Therefore, we recommend that the mutation sites of the PCSK9 and APOB genes described herein be used as clinical detection indicators to assist the diagnosis of FH in this region.

Acceptance of Self-Sampling and Knowledge about Human Papillomavirus among Women in Mongolia.

BACKGROUND: Mongolia faces a significant burden of cervical cancer, with the highest prevalence of Human Papillomavirus (HPV) in the region. Cervical cancer ranks as the third most common cancer among women in the country. This study aimed to assess the acceptance of self-sampling among young women in Mongolia and evaluate their knowledge regarding HPV and cervical cancer. METHODS: In this study, participants provided a self-administered vaginal swabs to detect high-risk HPV genotypes. Both acceptability of self-sampling using swabs and participants knowledge regarding HPV and cervical cancer through a scored questionnaire were assessed.  The knowledge scale was categorized into three groups: low (0-2), moderate (3-4) and high (5-6). RESULTS: A total of 203 women aged 24-28 years completed the questionnaire and provided self-administered vaginal swabs. The majority (95.1%) found self-sampling technique using Copan Self Vaginal FLOQSwabs® easy to perform. Additionally, 98.5% indicated that the self-swab instructions were clear and comprehensive, while 94.1% reported no pain during the process. Furthermore, 67.8% of participants expressed a preference for performing the swab in a clinic rather than at home. All respondents chose self-sampling due to greater personal privacy, tranquility, reduced anxiety and time optimization. The questionnaire results revealed an overall low level of knowledge about HPV among participants, with a mean score at 1.9 out of 6 [95%CI 1.67-2.21] and a moderate level of knowledge regarding cervical cancer risks, with a mean score at 3.7 out of 6 [95%CI 3.19-4.21]. This pattern was consistent across both vaccinated and unvaccinated cohorts, indicating a strong demand for enhanced awareness of HPV and cervical cancer. CONCLUSIONS: This study demonstrates the high acceptance of self-sampling among young women aged 24-28 years in Mongolia. However, it also  underscores a significant need for improved awareness initiatives concerning HPV and cervical cancer in Mongolia.

Exploring Alashan Ground Squirrel (Spermophilus alashanicus) Diversity: Metagenomic and Transcriptomic Datasets from the Helan Mountains.

This study investigates the adaptive strategies of the Alashan Ground Squirrel (Spermophilus alashanicus) in response to habitat changes, as rodents are sensitive indicators of ecosystem changes. Despite its ecological importance, the genome and microbiome of this species have not been thoroughly studied. This research fills this gap by presenting the first comprehensive metagenomic and transcriptomic datasets of the species. Transcriptomic data was collected from five tissue types, including heart, liver, cecum, muscle, and blood, resulting in the assembly of 72,156 unigenes. Metagenomic sequencing identified predominant bacterial groups such as Firmicutes, Bacteroidetes, Verrucomicrobia, Urovircota, and Proteobacteria. Our workflow involved RNA and DNA extraction, library preparation, assembly, and annotation, yielding valuable insights into gene discovery, microbial composition, and further genome and microbial function studies. In conclusion, our findings have significant implications for understanding the adaptive mechanisms of this species in response to environmental changes.

Milk processing systems of the Mongolian nomadic Khalkha groups in eastern Mongolia and technique transmission from West Asia.

The purpose of this paper is to understand the milk processing system practiced in the Mongolian nomadic Khalkha groups of Su'qbaatar and Dornod Provinces in eastern Mongolia through a field survey, to compare it with surrounding areas of Qentiy and Dundgowi Provinces, and then to analyze the transmission of processing techniques by further comparison with those of Syria, Jordan, Iran and Iraq in West Asia. The milk processing techniques of fermentation, cream separation and additive coagulation are all used in Su'qbaatar and Dornod Provinces. In fermentation processes, the technique of alcohol fermentation with churning is mainly used for cow milk to process alcoholic sour milk, followed by further processing to spirit, butter oil and non-matured dry cheese. In cream separation processes, the technique of heating/cream separation is used, in which cream is first separated from milk and non-matured dry cheese is processed from skim milk. In additive coagulation processes, the technique of fermented milk coagulation which utilizes lactic acid fermented whey as a coagulant is used to process non-matured dry cheese. These techniques are widely shared in the eastern part of Mongolia. It is characteristic of Su'qbaatar Province that the processing of cow milk is dominated by the technique of fermentation processes, mainly alcohol fermentation with churning. It is presumed that the technique of churning sour milk transmitted from West Asia to eastern Mongolia, and then the function of churning originally for butter processing was converted to allow for alcohol fermentation under the cooler environment in North Asia.

Nose of dog, eye of elk, and wolf's liver: exploring the interconnectedness of Indigenous health and foraging among the Dukha reindeer herders of Mongolia.

Recent studies show that Traditional Ecological Knowledge (TEK) of Indigenous Peoples' food systems and the transfer of that knowledge to their children are critical to physical and mental health, promote the transfer of language and culture, and further resilience. The aim of this exploratory, medical ecological study was to document TEK about foraging and plant use among the Dukha, a small, semi-nomadic reindeer herding community in Northern Mongolia. Field research was conducted at multiple remote camps in 2019 and 2023. Methods included semi-structured, open-ended interviews (N = 16), photo identification, and participant observation (N = 34 families). Study Informants identified 27 foraged plants. Results placed Dukha foraging practices within a framework illustrating the interconnectedness of their worldview and cultural norms, including the physical and spiritual aspects of the landscape, with health, illness, and curing. Dukha curative knowledge of the flora aligns with both Traditional Mongolian Medicine (TMM) and scientific studies on healing and preventative care. Through foraging and plant use, the Dukha balance relationships with the land and spirits, benefit from better nutrition and physical activity, utilise healing qualities of indigenous flora, and foster the intergenerational transfer of language and traditional knowledge.

Phylogenetic analysis of small ruminant lentiviruses in Mongolian sheep supports an ancient east-west split for the genotype A.

The ovine maedi-visna virus (MVV) and caprine arthritis-encephalitis virus (CAEV) are small ruminant lentiviruses (SRLVs) with striking genetic and structural similarities. The presence of SRLV in Mongolian sheep and goats was serologically demonstrated more than a decade ago; however, the viral genotype remains unknown. In total, 329 blood samples were collected from two sheep breeds (i.e., Khalkha and Sumber) in Tov, Govisumber, Arkhangay, Dornogovi, Zavkhan, and Sukhbaatar provinces, Mongolia. Serological and phylogenetic analyses were performed regardless of any apparent clinical signs, although most of the animals appeared healthy. All sheep in three of the six provinces were seronegative, whereas the seroprevalence in the Tov, Govisumber, and Zavkhan provinces averaged 7.9%. Genomic DNA from seropositive animals was tested using hemi-nested polymerase chain reaction, and sub-genomic SRLV sequences were determined from nine samples. Mongolian SRLV sequences clustered within the divergent subtype A22, which was previously found only in Fertile Crescent regions, including Lebanon, Jordan, and Iran, where the first sheep-domestication (Ovis aries) occurred. According to the phylogenetic analysis, genotype A has two ancestors from the ancient Fertile Crescent: (1) Turkish strains and (2) Iranian, Jordanian, and Lebanese strains. The first ancestor spread westward, whereas the second spread eastward, ultimately reaching Mongolia.

Improvement of the anthropogenic emission rate estimate in Ulaanbaatar, Mongolia, for 2020-21 winter.

Ulaanbaatar (UB), the fast-growing capital of Mongolia, is known for its world's worst level of particulate matter (PM) concentrations in winter. However, current anthropogenic emission inventories over the UB are based on data from more than fifteen years ago, and satellite observations are scarce because UB is in high latitudes. During the winter of 2020-21, the first period of the Fine Particle Research Initiative in East Asia considering the National Differences (FRIEND), several times higher concentrations of PM in UB compared to other urban sites in East Asia were observed but not reproduced with a chemical transport model mainly due to the underestimated anthropogenic emissions. Therefore, we devised a method for sequentially adjusting emissions based on the reactivity of PM precursors using ground observations. We scaled emission rates for the inert species (CO, elemental carbon (EC), and organic carbon (OC)) to reproduce their observed ambient concentrations, followed by SO2 to reproduce the concentration of SO42-, which was examined to have the least uncertainty based on the abundance of observed NH3, and finally NO and NH3 for NO3-, and NH4+. This improved estimation is compared to regional inventories for Asia and suggests more than an order of magnitude increase in anthropogenic emissions in UB. Using the improved emission inventory, we were able to successfully reproduce independent observation data on PM2.5 concentrations in UB in December 2021 from the U.S. Embassy. During the campaign period, we found more than 50% of the SO42-, NO3-, and NH4+ increased in UB due to the improvement could travel to Beijing, China (BJ), and about 20% of the SO42- could travel to Noto, Japan (NT), more than 3000 km away. Also, the anthropogenic emissions in UB can effectively increase OC, NO3-, and NH4+ concentrations in BJ when Gobi dust storms occur.

Delays in health seeking, diagnosis and treatment for tuberculosis patients in Mongolia: an analysis of surveillance data, 2018-2021.

Early diagnosis and treatment of infectious tuberculosis (TB) is essential to the attainment of global targets specified in the End TB Strategy. Using case-based TB surveillance data, we analysed delays in health seeking, diagnosis and treatment among TB patients in Mongolia from 2018 to 2021. We calculated the median and interquartile range (IQR) for "diagnostic delay," defined as the time from symptom onset to diagnosis, subdivided into "health-seeking delay" (time from symptom onset to first visit to a health facility) and "health facility diagnostic delay" (time from first health facility visit to diagnosis), and for "treatment delay," defined as the time from diagnosis to start of treatment. We also calculated "total delay," defined as the time from symptom onset to treatment start. Based on data for 13 968 registered TB patients, the median total delay was estimated to be 37 days (IQR, 19-76). This was mostly due to health-seeking delay (median, 23 days; IQR, 8-53); in contrast, health facility diagnostic delay and treatment delay were relatively short (median, 1 day; IQR, 0-7; median, 1 day; IQR, 0-7, respectively). In 2021, health-seeking delay did not differ significantly between men and women but was shorter in children than in adults and shorter in clinically diagnosed than in bacteriologically confirmed TB cases. Health-seeking delay was longest in the East region (median, 44.5 days; IQR, 20-87) and shortest in Ulaanbaatar (median, 9; IQR, 14-64). TB treatment delay was similar across sexes, age groups and types of TB diagnosis but slightly longer among retreated cases and people living in Ulaanbaatar. Efforts to reduce TB transmission in Mongolia should prioritize decreasing delays in health seeking.

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. We created a stochastic process to draw many transmission chains from this greater distribution to better understand and make inferences regarding the outbreak under investigation. RESULTS: The majority of the cases involved household transmissions (35, 52.2%), work transmissions (20, 29.9%), index (5, 7.5%), same apartment transmissions (2, 3.0%), school transmissions (2, 3.0%), and random contacts between individuals transmissions (1, 1.5%). The posterior means of the basic reproduction number of both the asymptomatic cases R 0 Asy $$ {R}_0^{Asy} $$ and the presymptomatic cases R 0 Pre $$ {R}_0^{Pre} $$ (1.35 [95% CrI 0.88-1.86] and 1.29 [95% CrI 0.67-2.10], respectively) were lower than that of the symptomatic cases (2.00 [95% Crl 1.38-2.76]). CONCLUSION: Our study highlights the heterogeneity of COVID-19 transmission across different symptom statuses and underscores the importance of early identification and isolation of symptomatic cases in disease control. Our approach, which combines detailed contact tracing data with advanced statistical methods, can be applied to other infectious diseases, facilitating a more nuanced understanding of disease transmission dynamics.