AAU Institutional Repository (AAU-ETD)
Addis Ababa University Institutional repository is an open access repository that collects,preserves, and disseminates scholarly outputs of the university. AAU-ETD archives' collection of master's theses, doctoral dissertations and preprints showcase the wide range of academic research undertaken by AAU students over the course of the University's long history.
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The repository contains scholarly work, both unpublished and published, by current or former AAU faculty, staff, and students, including Works by AAU students as part of their masters, doctoral, or post-doctoral research
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Recent Submissions
Status of Honey Production in Hidabu Abote District of North Shoa Zone Oromia Regional State Ethiopia
(Addis Ababa University, 2025) Kiso Gari; Emana Getu
Beekeeping is a management of honeybee colonies for the production of honey, beeswax, royal jelly, bee venom and other pro ucts. Honey is the sweets substance produced by honeybees from the nectar of blossoms or secretions on living plants; which the bees collect, transform and store in honey combs. The study was conducted in Hidabu Abote District, which is located in North Shoa Zone of Oromia Regional State to study on status of honey production. The main objective of this study was to assess the factors that affect honey production in the study area and to give recommendations for mitigating the challenges in honey production practices in the study area. To address these objective questionnaires and interview were used to collect primary data. We employed a descriptive study design technique and data were gathered from 191 people via questionnaires and interviews using random and a purposive sampling procedure. The data were organized and analyzed using statistical software for the social sciences (SPSS, version 20). The result of the study showed that 60% of beekeepers used purely traditional beehives, 1.9% used transitional beehives, 3.1% used modern beehives, 10% used traditional and transitional beehives, 20% used traditional and modern beehives, and 5% used all three types of beehives. The result also showed that honey production activity is mainly undertaken by younger people. Furthermore, about 51.9% of the beekeepers had not formal education, and about 16.3% took informal adult education. In 2017 E.C., the average honey yield from one traditional beehive was less than 10kg, from one transitional beehive 16-25kg, and from one modern beehive 20- 30kg. Majority of the beekeepers (60%) managed their colonies by visiting and inspection monthly, with 15% doing so per two weeks. The major pests or predators that affecting honey production in the study area were 29.4% ants, 18.1% spiders, 16.3% birds, 15.6% wax moth, 12.5% lizard, and 8.1% Honey badger, respectively ranked 1st to 6th. Furthermore, the widespread use of agrochemicals (94.4%), lack of training (93.1%), and lack of professional support (95%) in beekeeping and the beekeeping activities of the district were dominated by the traditional system, resulted in low honey production, all had an impact on honey production
practices in the study area.
Determination of Selected Essential Metals in Wheat Triticum Aestivum Samples Collected from Shiretigray Ethiopia Using Atomic Absorption Spectroscopy
(Addis Ababa University, 2025) Ashebrom Beletew; Merid Tessema
In this study, the concentrations of essential metals, copper, iron, zinc, and magnesium were determined in wheat grain samples collected from the local market in Shire, Ethiopia, using flame atomic absorption spectroscopy. Sample preparation involved washing, drying, grinding, sieving, and digestion with a mixture of nitric acid and perchloric acid under optimized conditions (15 ml acid mixture, 250°C, 3 hrs.). The average concentrations of Cu (7.72 ppm), Fe (43.27 ppm), Zn (28.43 ppm), and Mg (436.56 ppm) were assessed against permissible limits set by the World Food Programme (WFP), the Food and Agriculture Organization (FAO), and literature values. The concentrations of copper and magnesium were found to be well below both WFP and FAO limits, and aligned with literature values, indicating no risk of toxicity. Zinc concentration was slightly below the maximum permissible levels and consistent with typical literature ranges, suggesting adequate dietary contribution. However, the iron concentration exceeded the WFP permissible limit of 40 ppm, though it remained within the FAO upper limit of 50 ppm. This elevated level may reflect iron-rich soil or agricultural practices, and it raises potential concerns for individuals with iron metabolism disorders. Recovery studies yielded acceptable values—79.4% for Cu, 85.1% for Fe, 115.4% for Zn, and 112.18% for Mg—thereby confirming the reliability of the analytical method. Overall, the study concludes that wheat grains contain safe and nutritionally beneficial levels of Fe, Zn, and Mg. However, the borderline recovery observed for Cu, while potentially acceptable at lower concentration levels, indicates that further validation or method optimization may be necessary.
Mycotoxins Contaminations In Red Pepper Powder Produced At Households In Addis Ababa
(Addis Ababa University, 2025) Tsegaye Bunaro; Abebe Ayelign; Paulos Getachew
Red pepper (Capsicum annuum L.) is the most important world spice crop and the second largest consumed spice throughout the world, after black pepper. Apart
from its nutritional importance, red pepper has a huge economic value in many countries including Ethiopia. Despite the role of red pepper in nutrition, income
and national economy, it has been susceptible from the risks of mycotoxin contamination. Therefore, this study aimed to evaluate the level of mycotoxin in
powder red pepper produced at households in Addis Ababa. Sociodemographic information, knowledge and practices related to mycotoxin in red pepper from
124 households were collected using pretested questionnaires. One hundred twenty-four (124) red pepper powder samples at the time of proessing and after
six months storage at house holds in three subcites in Addis Ababa were collected. From the 124 samples collected, 40 composite red pepper powder
samples were produced both at baseline and after six months storage and the level of 26 mycotoxins were determined using a validated UHPLC-MS/MS method.
Out of 26, ten mycotoxins were detected in the red pepper powder samples both at baseline and after six months storage. The ten mycotoxins were detected in all the
samples at concentrations ranging from < LOD to 154 µg/kg and < LOD to 89.7 µg/kg at baseline after six months storage respectively. In this study, 92.5% of the
red pepper powder samples at baseline (during processing) and 75% after six months storage was contaminated with AFB1 above the EU limit and Ethiopian
standard of 5 µg/kg. Further, the mean levels of AFB1, AFB2, AFG1, and AFG2, Beauvericin, Enniatin B and Enniatin B1 decreased significantly after six months
of storage. This might be some spices, like garlic, ginger, and cardamom, have antioxidant and anti-fungal properties, which can potentially inhibit aflatoxin
production or degradation. Overall, mycotoxins (such as AFB1, AFB2, AFG1, and AFG2, Ochratoxin A, Beauvericin, Enniatin A1, Enniatin B and Enniatin B1)
were widespread contaminants of red pepper powder produced at households in the Addis Ababa intended for human consumption. Therefore, awreness creation
among stakeholders about proper preparation methods of red pepper powder and health impacts of mycotoxins is warranted.
Water Sanitation and Hygiene Role in Childhood Intestinal Parasitic Infection and Reinfection in Rural Dire Dawa Eastern Ethiopia
(Addis Ababa University, 2025-09-01) Heroda Gebru; Negussie Deyessa; Girmay Medhin; Helmut Kloos
Background: Numerous infectious disorders brought on by parasitic worms, such as Schistosoma and soil-transmitted helminths, or pathogenic intestinal protozoa, have been grouped as neglected tropical diseases (NTDs). Parasitic illnesses still pose a serious and challenging threat to public health in developing countries. Worldwide, intestinal parasite infections (IPIs) affect about 3 billion individuals. Sanitation and hygiene are crucial to avoid intestinal parasite infections. Children are particularly vulnerable due to their frequent exposure to unhygienic environment and inability to keep adequate personal hygine. Inadequate water quantity limites basic hygienic practices such as hand hygiene and also poor water quality favours the direct transmission of IPIs. Pathogens transmitted through drinking water are mainly of fecal origin and are called enteric pathogens. Eventhough substantial progress has been made in Ethiopia in expanding access to safe drinking water, a significant challenge remains. Approximately 56.7% of the population faced a shortage of clean water. In rural areas, open defecation practices were common, and there was frequent sharing of water sources with animals. All these conditions facilitate fecal contamination of water and poor hygienic practices that favours IPI transmition. Children living in unsanitary and unhygienic environments are often trapped in a vicious cycle of infection and reinfection with intestinal parasites. This recurrent exposure can lead to chronic health issues like malnutrition, stunted growth, impaired cognitive development, and reduced school performance. Moreover, the burden of parasitic infections can persist across generations, reinforcing a cycle of poverty and poor health. In light of this, the present study evaluates the associations between water quality, sanitation, hygiene (WASH) practices, and the occurrence and recurrence of intestinal parasitic infections among children. Objectives: The objectives of this study are to assess the prevalence of intestinal parasitic infections (IPIs) among children aged 1–14 years and to identify associated risk factors related to sanitation and hygiene practices at the community level. In addition, the study examines the microbial quality of point-of-use drinking water in households with children and evaluates its association with the prevalence of IPIs. Furthermore, to determine the six-month reinfection rate of IPIs among previously treated children and to assess the relationship between their sanitation and hygiene practices and the likelihood of reinfection. Methods: From April to May 2021, a community-based cross-sectional study was carried out. Nine rural kebeles were randomly selected by the lottery method from a total of 38 kebeles. A total of 778 children aged 1-14 years participated in the survey. Data were collected using a pretested structured questionnaire administered through interviews to the participants parent or caregiver. Stool samples were taken for analysis using the direct wet mount method in the field and theformol-ether concentration technique at the institution, respectivly. Descriptive statistics and logistic regression analysis were performed using the Statistical Package for the Social Sciences (SPSS) version 23 to addres the first specific objective.
For objective II, a nested case-control study design was used. From April to May 2021, children with positive stool results for IPIs were identified as cases, while those with negative results were selected as controls based on direct wet mount method and formol-ethe concentration technique. A total of 352 water samples were collected 176 from case households and 176 from control households using sterile water sample collection bottles. For each household, 500 ml point of use water was collected from the actual point where water is consumed (cup or jug) by trained water lab staffs, following the standard procedures for water sample collection. In addition to collecting water samples for microbiological analysis, mothers and other caregivers of children were asked to complete pretested structured questionnaires. Data were entered into Epi Info, and exported to SPSS version 23 for analysis to examine the relationship between IPIs and point-of-use microbiological water quality. For objective III a case-control study design was employed. Data were collected from 75 IP reinfected cases and 147 unmatched controls. Fecal specimens were examined for parasities using both the direct smear and formol ether methods. Data entery was performed using EpiInfo, and statistical analysis was conducted using SPSS. Logistic regration analysis was used to identify associations between variables, with statistically significant set at P < 0.05.
Results: The prevalence of 5 intestinal parasites was 33.7% (95% CI = 30.4%-37%). Giardia intestinalis (15.2%) and Hymenolepis nana (11.6%) had the highest prevalence. The odds of IPIs among children of illiterate mothers were 13.1 times higher when compared with children of mothers with secondary education (aOR=13.1, P=.02), and the odds of IPIs among children from households that have unclean latrines were 1.8 times higher when compared with children from
households that have clean latrines. (aOR=1.8, P=.03). Children from households that discard solid waste in open fields had 1.7 times higher odds of having a positive result than children from households that burn their waste (aOR=1.7, P=.03). However, children who didn’t swim in accumulated water (naturally or for irrigation purpose) were 0.4 times less likely to test positive for intestinal parasitic infection compared to those who did. Also, children who were asymptomatic for IPIs at the time of the survey were 0.3 times less likely to be diagnosed with intestinal parasitic infection.
Overall, total coliform was detected from 298 point-of-use water samples (94.3% from cases and 75% from the control group), and E. coli was detected totally from 249 (96.6% from cases and 44.9% from the control group) point-of-use water at the household level. The positivity for IPIs was 12.6 times higher among the study subjects from households with point-of-use water detected with total coliform than their counterparts (P=0.001, 95% CI: 3.8-41). Also, IPIs were 14 times more likely to occur among children from households with point-of-use water detected with E. coli than the reference group. This relation has statistical significance (P=0.001, 95% CI: 6.6-30.2). Among microbial risk categories, water with E. coli counts in the low-risk range (1–10 CFU/100ml) showed a significantly increased infection risk (AOR = 15.3; p = 0.004), suggesting that even low risk contamination levels may pose substantial health threats in vulnerable populations. However, intermediate and high contamination levels did not retain significance after adjustment. Subjects from households that consum water ≥25 l/c/day had lower odds of infection (P=0.029, CI: 0.3–0.9), indicating a protective effect of adequate water consumption The overall IP reinfection rate within 24 weeks after treatment was 33.8% (75/222), with a 95% CI = 27.7%–40.5%. The frequency of intestinal protozoa was 18%, and for helminths, it was 15.8%. Children who swam in polluted water had 3.7 times greater odds of IP reinfection than children who did not swim (P = 0.01, 95% CI: 1.4–10.0). Children who regularly bathed in streams and children who bathed both at home and in streams were found to have 12.6 times and 5.8 times higher odds of IP reinfection than children who bathed regularly at home (P = 0.002, 95% CI: 2.5–64.8) and (P = 0.042, 95% CI: 1.1–31.3), respectively. Children from households that owned domestic animals had 4.2 times higher odds of IP reinfection compared to children from housholds without domestic animals (P = 0.013, 95% CI: 1.3–12.5). Conclusions: The multifaceted nature of intestinal parasite infections and reinfections in children is highlighted in this study, with particular attention paid to the important roles played by environmental exposures, sanitation, hygiene practices, maternal education, and water quality and quantity. Children of illiterate mothers, those living in households with unclean latrines or poor waste management practices, and those exposed to contaminated water sources were more likely to be infected. Additionally, behaviors such as swimming or bathing in contaminated surface waters and close contact with domestic animals were strongly associated with reinfection. These findings are consistent with both local and international studies, reinforcing the urgent need for integrated, community-based interventions that combine health education, improved water and sanitation services, behavioral change communication, and targeted environmental health strategies to reduce the burden of parasitic diseases among vulnerable populations. Recommendations: To effectively reduce childhood intestinal parasitic infections and reinfections in rural Dire Dawa, a comprehensive approach focusing on water, sanitation, and hygiene (WASH) is essential. To lessen the burden of intestinal parasite infections and reinfections in children, a number of important recommendations are put out in light of the study's findings. First, enhancing community-based health education is essential for promoting safe water management, illness prevention, and better hygiene habits, especially for illiterate mothers. Prioritizing access to clean and sufficient water (≥25 liters per person per day) should be achieved through better infrastructure and encouragement of water treatment and storage at the household level. Community-led total sanitation (CLTS) strategies must discourage openfield waste disposal and encourage routine latrine cleaning in order to improve sanitation and hygiene initiatives. Particularly in high-risk rural areas, it is important to discourage risky activities like swimming and bathing in contaminated surface waters and to encourage safe alternatives. Public health initiatives should also incorporate appropriate domestic animal management, emphasizing the safe disposal of animal waste and minimizing interaction between children and animals. To effectively address the multifactorial causes of intestinal parasitic infections (IPIs), it is essential to establish strong coordination between the health, education, and water sectors
The Effect of Composite Edible Film Coating Technology on the Storage Period and Quality of Tomato
(Addis Ababa University, 2025-06-06) Ibrahim Abebe; Paulos Getachew
Coatings were demonstrated to be possible for application due to their edible , non-reactive,and biodegradable nature. The aim of the study was to investigate the use of edible film coating materials on the extending the shelf life of tomato. Three different coating materials in combined with others and alone were used for the study. The tomatoes sample were subjected to seven experimental groups and coated with edible coating materials. The Physico- chemical analysis, proximate analysis, sensory analysis and the microbial load of the samples were evaluated at five days interval during the storage period. The maximum storage day was recorded 35 and 30 days in bees wax alone and bees wax with pectin (1:1). The weight loss percentages for chitosan with wax coated tomato (1:1), pectin with chitosan, pectin, pectin with wax (1:1) and wax coated samples were recorded as 25.55 %, 22.66 %, 17.81%, 14.04 % and 9.47 % respectively. The Total Soluble Solids (TSS) of tomatoes was increases from 4. 49 to 5.72 in controlled sample within 15 days, bees wax coated tomatoes were increased from 3.98- 5.03 in 35 days of storage period. The acidity of stored tomatoes were decreased from 6.67 to 4.73 in control sample within 15 days, 5.37 to 4.17 in bees wax coated tomato within 30 days, 7.06 to 3.87 in pectin coated tomato within 30 days, chitosan coated decreased from 7.06 to 3.87 within 25 days of storage period, from 7.23 to 4.59 in 1:1 pectin and chitosan coated materials within 30 days of storage period, 5.93 to 3.57 in 1:1 pectin and wax coated tomato within 35 days of storage. The lycopene content of tomatoes were showed that an increment from 14.08 to 18.30, 3.5 to 16.66, 15.77 to 17.53, 7.75 to 11.10, 17.47 to 24.41, 14.83 to 20.58, 11.69 to 14.9 respectively in control, bees wax, chitosan, pectin, pectin with chitosan, pectin with bees wax, chitosan with beeswax. The microbial load (plate count) of the stored tomato at different coating materials such as pectin, chitosan, bees wax and combined with each other were recorded nil or no growth up to 15 days. In control sample 10cfu/ml was recorded in the 15 days of storage. Yeast and mold count growth also nil within 15 days of storage period, while in control (uncoated tomato) 11cfu/ml at dilution factor 10-3. The control treatment has relatively lower scores across all sensory attributes. The values for color (6.18), firmness (5.00), texture (5.09), odor (5.55), appearance (5.45), and overall acceptance (5.45) are among the lowest in comparison to other treatments. The findings showed that all prepared coatings could maintain qualitative features and extend the shelf life of tomatoes. The coatings made from citrus fruit (pectin), shrimp shell (chitosan), and beeswax (bee product) in equal proportions were the best combination of all coatings because they retained maximum quality attributes by inhibiting respiration and minimizing starch conversion into sugar. Therefore, coatings materials plays significant role on the extending shelf life of tomato for several storage days