Background Acute respiratory tract infection (ARI) is one of the leading causes of illness and mortality in children under the age of five worldwide. Pneumonia, which is caused by a respiratory tract infection, kills about 1.9 million children under the age of 5 years around the world. The majority of these deaths occur in underdeveloped countries. According to the 2016 Ethiopia Demographic and Health Survey (EDHS), the prevalence rate of ARI in Ethiopia was 7%. Prevalence is defined as the number of infectious diseases present at a given period in relation to the total number of children under the age of five who have been exposed to ARI. The goal of this study was to determine the risk factors for acute respiratory infection among children under the age of five in Ethiopia. Methods To provide representative samples of the population, a community-based cross-sectional sampling scheme was designed. Bayesian multilevel approach was employed to assess factors associated with the prevalence of ARI among children under age five in Ethiopia. The data was collected from 10,641 children under the age of 5 years out of which 9918 children were considered in this study. Results The ARI prevalence rate in children under the age of 5 years was assessed to be 8.4%, somewhat higher than the country’s anticipated prevalence rate. Children whose mothers did not have a high level of education had the highest prevalence of ARI. The key health, environmental, and nutritional factors influencing the proportion of children with ARI differed by area. Tigray (15.3%) and Oromia (14.4%) had the highest prevalence of ARI, while Benishangul Gumuz had the lowest prevalence (2.6%). The use of vitamin A was investigated, and the results revealed that roughly 43.1% of those who received vitamin A had the lowest prevalence of ARI (7.7%) as compared to those who did not receive vitamin A. Diarrhea affected 11.1% of children under the age of five, with the highest frequency of ARI (24.6%) and the highest prevalence of ARI reported in children whose drinking water source was unprotected/unimproved (9.4%). Conclusions The prevalence of ARI among children under the age of 5 years was found to be strongly affected by the child’s age, household wealth index, mother’s educational level, vitamin A supplement, history of diarrhea, maternal work, stunting, and drinking water source. The study also found that the incidence of ARI varies significantly between and within Ethiopian areas. When intending to improve the health status of Ethiopian children, those predictive variables should be taken into consideration.

Background: HIV/AIDS epidemic continues to be the main challenge in the world. According to United Nations Program on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) reports of 2013, 35 million people were living with HIV worldwide, with 2.1 million new infections and with 1.5 million deaths occurred each year. Among these, 24.7 million lived in sub-Saharan Africa with 1.5 million new infections and 1.1 million AIDS deaths.Method: The main objective of this study is finding factors affecting HIV/AIDS disease progression. This study was conducted to investigate the effect of factors on HIV/AIDS disease progression. Patient follow-up data is obtained at Yirgalim General Hospital. A sample of 370 Patient data from a follow-up cohort is obtained at Yirgalim General Hospital. Multivariate generalized hazard regression model was employed to investigate the disease progression using both time independent and time dependent covariates. Result: The study revealed that the risk of transition differs by patient's body mass index. Increase in the body mass index reduces the risk of transiting into the next worst states. The effects of sex, weight, age and body mass index of patients are significantly associated with AIDS disease progression. The risk of transition differs by patient's body mass index. Increase in the body mass index reduces the risk of transiting into the next worst states. The effect of sex, weight, age and body mass index of patients are significantly associated with AIDS disease progression. The results further revealed that the semi-Markov model with Weibull waiting time distribution has smaller log likelihood and AIC values compared to a semi-Markov model with exponential waiting time distribution.Conclusion: Transition probabilities are highly dependent on the choice of waiting times. We recommend that while choosing waiting time distributions for semi-Marko models one should consider appropriate distributions as waiting time distribution effect have a significant change on the estimated model parameters. In addition, this study recommends that concerned bodies should look at deferent contributing factors of AIDS diseases progression in addition to the ART services administered for slowing the current level of high diseased population in the country.

Background: Acute respiratory tract infection (ARI) is a leading cause of morbidity and mortality in children under the age of five years in the world. ARIs, principally pneumonia, account for approximately 1.9 million (1.6 - 2.2 million) deaths globally in children under the age of five years in Ethiopia. Among these deaths majority occur in the developing world. The share for low and middle-income countries takes the highest indeed. In Ethiopia, the prevalence rate of ARI was 7% according to 2016 EDHS estimates. Method: Bayesian multilevel approach was employed to assess possible factors associated with the prevalence of acute respiratory infection (ARI) among under-five children in Ethiopia. The data was collected from 10,641 children under the age of five years out of which 9,918 children were considered in this study. Result: The ARI prevalence rate for children under five years was estimated as 8.4%, which was slightly higher than the estimated prevalence level of the country. The highest proportion of the prevalence of ARI was observed for children whose mothers had no education. The major health, environmental and nutritional related background characteristics of the proportion of children who had ARI varied from one region to another. The highest prevalence of ARI was observed in Tigray (15.31%) followed by Oromia (14.40%) as opposed to the low prevalence which was recorded in Benishangul Gumuz (2.58%). The utilization of vitamin A was analyzed and the results shows that about 43.10% who received vitamin A had the lowest proportion on the prevalence of ARI (7.75%) compared to not having vitamin A. About 11.13% of under-five children had Diarrhea with the highest prevalence of ARI (24.64%) and the highest prevalence of ARI was observed for the child whose source of drinking water were unprotected/unimproved (9.39%). Conclusion: The age of the child, household wealth index, mother educational level, and vitamin A supplement, history of diarrhea, maternal work, stunting and source of drinking water were found to be significantly affecting the prevalence of ARI among children under five years. Furthermore, the study revealed that there is a significant variation of incidence of ARI between and within the regions of Ethiopia. Attention should be given to those predictor variables while planning to increase the health status of children in Ethiopia.