Purpose: To review the potential relationship between vitamin B12 and colorectal cancer, with particular emphasis on its involvement in one-carbon metabolism and epigenetic regulation.Methods: This narrative review summarises current evidence on the biological mechanisms and epidemiological associations linking vitamin B12 status with colorectal cancer risk.Results: Available evidence indicates a biologically plausible but epidemiologically inconsistent relationship between vitamin B12 and colorectal cancer. Studies assessing dietary intake frequently report an inverse association, particularly for rectal cancer, whereas analyses of circulating vitamin B12 concentrations yield heterogeneous, and often conflicting findings.Conclusion: Vitamin B12 does not act as an isolated protective factor but as part of a complex metabolic and nutritional system. Although its potential protective role in colorectal carcinogenesis is biologically based, it remains insufficiently confirmed, emphasising the need for further integrated research.

Introduction: Legionella spp. is opportunistic pathogenic bacteria that cause two forms of the disease: more severe, more frequently diagnosed - Legionnaires' disease, and milder, less frequently diagnosed Pontiac fever. Research objectives: The primary objective of the study was to examine the presence of Legionella spp. in the air conditioning systems of the studied facilities. Methods: The study was conducted in the Sarajevo Canton, Federation of Bosnia and Herzegovina. The research included air conditioning systems in public facilities. Sampling was carried out over a two-year period. Water samples and samples collected using the wet swab method were obtained. The samples were laboratory analyzed for the presence of Legionella spp. in accordance with a standard method. During the period of sample analysis, the laboratory was undergoing accreditation in accordance with the relevant standard. A survey was also conducted in the included facilities. Results: Legionella spp. was detected in air conditioning devices of 8 (21%) facilities. No relation was established between knowledge, external education and management with bacterial colonization. Internal training of employees is carried out in three (37.5%) facilities compared to eight facilities in which bacteria were detected (p<0.05). Also, bacteria detected in 4 (40%) facilities where employee absenteeism was associated with respiratory diseases (p<0.05). Conclusion: The results emphasize the need for a systemic approach to risk management and the improvement of practices that contribute to safer stay of users and employees in the air-conditioned spaces of public facilities in the Sarajevo Canton. Keywords: Legionella, Bacterial Colonization, Education, Risk Factors, Facility Users

Because man strives to ensure the comfort in living and working spaces, there is a lot of air conditioning devices to achieve the desired temperature. Bacteria from the genus Legionella is a pathogenic bacterium that can cause the disease to occur in very severe form. It most often inhabits water systems created by human activity, among which are air conditioning devices, which is why there is a need to test factors that favors bacteria colonization. The study included 79 facilities from the territory of the Federation of Bosnia and Herzegovina, of which 42 or 53.2% facilities with centralized, and 37 or 46.8% facilities with individual air conditioning devices. Data were collected using a survey and laboratory analysis of samples. The analysis was performed individually, taking into account the different requirements and complexity of the two types of air conditioning devices. The objectives were related to the correlation between the age, distribution installation material, project, the maintenance dynamics and the need to use the air conditioner with Legionella spp. colonization. The results indicate a positive influence of the air conditioner age and steel distribution installation on the Legionella spp. colonization. Significant correlation was not observed between the collected survey responses (project, maintenance and the air conditioner use frequency) and the Legionella spp. colonization. The identification of factors that positively correlate with the presence of Legionella spp. in air conditioning devices has significant public health and technical contribution, especially in the context of legionellosis prevention, the implementation of adequate monitoring and maintenance.

Background: Water is essential in air conditioning processes, where it is used for cooling or heating. Its longer retention in the tanks and pipes of air conditioning devices can lead to physical and chemical changes that favor the appearance and reproduction of Legionella spp. This pathogen causes diseases that arise from inhalation of contaminated aerosol. The research was conducted in the Federation of Bosnia and Herzegovina, Bosnia and Herzegovina during 2023-2024. and included 30 public facilities where 54 water samples were collected from air conditioning devices. Objective: The main goal of the research was to determine the presence of Legionella spp. in water from air conditioning devices, and to examine correlation of physical and chemical parameters (temperature, residual chlorine, ph value, iron, zinc and copper) with the pathogen presence. An additional goal of the research was to examine the relationship between the physical and chemical parameters of water. Methods: The research was conducted at the territory of the Federation of Bosnia and Herzegovina (FBiH), Bosnia and Herzegovina (BiH) in the period 2023-2024. The samples were analysed in an authorized laboratory in Sarajevo, using standard microbiological and chemical methods. The water of the air conditioning units was analysed for presence of L. spp., the detection of the bacteria and the determination of the relationship between the examined physical and chemical factors and the settlement of pathogens in the air conditioning units. Results: Legionella spp. was isolated in 7 (13%) of 54 analysed samples. A correlation between higher temperature, lower residual chlorine, and higher concentrations of iron and copper with the bacteria appearance was established. Among the analysed parameters, several significant mutually positive correlations were recorded. Out of a total of 54 analysed samples from air conditioning devices, L. spp. was isolated in seven. The results showed that there is a relation between higher temperature and lower concentration of residual chlorine, as well as higher concentrations of Fe and Cu, with the occurrence of L. spp. in air conditioning devices. No statistically significant association between the presence of bacteria and Zn concentration or water pH was confirmed. By analysing the mutual relations between the tested physical and chemical parameters, the relation of Fe with Zn and Cu, and Zn with Cu and Ph value was determined. The limitation of this study refers to the fact that during the testing the so-called dead pipes in the system was not detected nor present, nor was there a test for the presence of biofilm inside the installation. Conclusion: The results indicate the importance of regular monitoring of water parameters in air conditioning devices in order to reduce the risk of Legionella spp. colonization and to improve preventive measures in public health and air conditioning engineering.

Objective – The aim of the study was to establish the prevalence of hearing and sight impairment, and the differences in relation to school grade and sex in school children in the area of the Jajce municipality.Materials and Methods – Screening of sight and hearing impairment in school children took place in 2018 and 2019. Vision screening covered a total of 1002 students from 1st to 5th grades, and hearing screening 768 students from 2nd to 5th grades in all central and district (rural) schools in the area of the municipality of Jajce.Results – Of the total number of students covered by the vision screening, in 163 (16%) some impairment was noticed, and they were sent for further diagnostic testing by a specialist. In relation to sex, there was a higher percentage of girls, 60%, than boys, 40%. In relation to screening of hearing, 44 (6%) of the students were sent for further diagnostics, of which 57% were boys and 43% girls. During the vision screening, 5% of the students were wearing dioptric glasses. In relation to age, the largest number of students were in first grade, 14 (27%), then in second grade, 10 students (19%). Conclusion – In this study, the results showed that a large percentage of school children were found with hearing and vision impairment, which indicates the pressing need to continue running these preventive programmes.

Background: Healthcare workers at all levels of the healthcare system are at the front line of the response to the COVID-19 epidemic and are consequently more exposed to risk of infection. To examine the characteristics of the healthcare workers morbidity during the COVID-19 pandemic in the area of Central Bosnia Canton.Methods: This research includes all healthcare workers of this Canton (n=2276) in the period from March 2020 to March 2022. A total of 666 health workers tested positive (RT-PCR method) for severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) in healthcare institutions.Results: The average age of the patients was 45.16 (±11.93) (range 18-77 years old), with a median of 45 years old. Of the total number of positive patients, 68.2% were women, 165 or 24.77% were doctors, and 57.80% were other medical workers. Interactions with infected colleagues accounted for 28.4% of infections, 22.2% of infections occurred during patient care, 36.3% outside a healthcare facility, and in 13.1% the mode of infection was not confirmed. Due to the severity of the clinical status, a total of 74 people were hospitalized with a hospitalization rate of 11.11 (95% CI 8.78-13.87). The second positivity of the test (by RT-PCR method) was after 12.34 months from the first infection (mean=12.34: SD±4.270; median=13).Conclusions: High rates of morbidity among healthcare workers certainly have a significant, long-term impact on the healthcare provision, especially in healthcare systems where there is a pronounced lack of professional workers. 

Motivation/Background: positive staphylococci (CPS) are common contaminants of raw milk. Before it is used, various heat treatments are applied to destroy microorganisms, inactivate enzymes and improve technological properties and concentration of dry matter of milk. This work aimed to determine the influence of commonly used heat treatments in diary on presence and number CPS in raw milk from Bosnia and Herzegovina area and to affirm whether there is a difference in efficacy between different treatments. Method: Using the standard method, 40 samples of raw milk from farms were inoculated for counting the initial number of CPS in raw milk. Samples were then exposed to heat treatments in vapor sterilizer and CPS number was counted using the same standard method. Results: Applied treatments included heat treatments at: 68 °C/40 s, 70 °C/15 s, 72 °C/without holding, 63 °C/30 min and 72 °C/15 s. CPS presence was detected in all tested samples of raw milk in numbers ranging from 2,82 to 5,32, with an average of 4,30, calculated as log10 /ml. Conclusions: Raw milk samples collected in the field initially registered a high CPS number. The applied heat treatments were effective to a large extent. The initial CPS count of milk seems to be the most important factor determining the number of CPS after heat treatments as well as traits of the strains.

Aim The damage caused by the COVID-19 pandemic has made the prevention of its further spread at the top of the list of priorities of many governments and state institutions responsible for health and civil protection around the world. This prevention implies an effective system of epidemiological surveillance and the application of timely and effective control measures. This research focuses on the application of techniques for modelling and geovisualization of epidemic data with the aim of simple and fast communication of analytical results via geoportal. Methods The paper describes the approach applied through the project of establishing the epidemiological location-intelligence system for monitoring the effectiveness of control measures in preventing the spread of COVID-19 in Bosnia and Herzegovina. Results Epidemic data were processed and the results related to spatio-temporal analysis of the infection spread were presented by compartmental epidemic model, reproduction number R, epi-curve diagrams as well as choropleth maps for different levels of administrative units. Geovisualization of epidemic data enabled the release of numerous information from described models and indicators, providing easier visual communication of the spread of the disease and better recognition of its trend. Conclusion The approach involves the simultaneous application of epidemic models and epidemic data geovisualization, which allows a simple and rapid evaluation of the epidemic situation and the effects of control measures. This contributes to more informative decision-making related to control measures by suggesting their selective application at the local level.

Aims and objectives: This paperwork aims to analyse the knowledge and attitudes on immunisation, subjective perceptions of the risks and decision theory of vaccination amongst the specific female population living in the Federation of Bosnia and Herzegovina. Purpose: The purpose of the research is to point out the significance of parents’ decisions and strengthening of positive attitudes on vaccination. Material and methods: The research was conducted during 2018. Females from different parts of the Federation were asked questions. There were 4000 respondents of different ages ranging from 20 to 50 years old females (approximately 1% of the target population). The respondents were classified according to their place of living (urban/rural), and also being a parent or not. The questionnaire was answered by 2504 respondents being parents with a certain experience with immunisation of their children, but also 1496 future parents who expressed their attitude towards immunisation. For this research, a special questionnaire was used, comprising 18 questions classified into 4 different groups. Results: Most of the respondents (71.2%) who already have children claim they vaccinated their children completely whereas 2.0% respondents from urban areas and 1.3% from rural areas explicitly refuse to vaccinate their children. The rest of the respondents (25.4%) claim they partially vaccinated their children or they are not familiar with the vaccination status of their children. Our research shows that parents are mostly informed about vaccinations and immunisation by some medical workers – paediatricians (36.6%). This research also suggests that respondents are showing a great level of reluctance and scepticism towards some medical workers and that only 40.6% of respondents unconditionally trust their doctor. Additionally, the results show that considering the safety of vaccines there are significant differences amongst urban and rural population. In urban areas, 18.8% of respondents claim that they completely trust vaccines and in rural areas there are 36.2% of respondents trusting them. Conclusion: We may conclude that personal experience, medical system efficiency, trusting medical professionals, vaccine safety and communication in public health community are very important to make decisions on vaccinating children