Medical Microbiology

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Browsing Medical Microbiology by Author "Abegaz Woldaregay"

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    Molecular Identification and Characterization of Pathogenic Leptospira from Asymptomatic Humans, Livestock and Water Sources in Peri-Urban Areas of Addis Ababa: A one Health Concept
    (Addis Ababa University, 2021-07) Marrigje Jacoba; Abegaz Woldaregay
    Background Leptospirosis is a neglected zoonotic disease caused by spirochetes, pathogenic Leptospira. It can give a severe disease in humans. Many domestic animals can carry pathogenic Leptospira and Leptospira can survive in environmental water sources. There are barely studies done to investigate the presence of Leptospira in humans, animals or water sources in Ethiopia. Objectives: Identification of the presence of pathogenic Leptospira in asymptomatic humans, livestock and environmental water sources and assessment of knowledge, attitude and practice concerning leptospirosis among households in peri-urban areas of Addis Ababa. Methodology: Urine was collected from asymptomatic humans and livestock in peri-urban areas of Addis Ababa. Water samples were taken from the same areas. After DNA-extraction, real-time PCR and melting curve analysis were performed. Knowledge, attitude and practice (KAP) was assessed with help of a questionnaire. Results: In total, 105 human urine samples, 194 animal urine samples and 32 water samples were collected from 85 households. Pathogenic Leptospira were found in 3 of the 194 animal urine samples (1.5%), characterized as Leptospira borgpetersenii and detected in urine of cattle. No pathogenic Leptospira were found in the human urine samples and in the water samples. Majority (97.6%) of the respondents had never heard about leptospirosis, but knew that water, animals’ urine and rat urine could contain pathogens. Multiple risk factors for the presence of Leptospira were found in the studied households: walking through wet areas without adequate protection (48.2%), rats in (66.3%) or around (63.8%) the house and garbage stored inside the compound (56.1%). No significant relationship was found between risk factors and the positive. Leptospira samples in this study. Conclusion: This study has shown that pathogenic Leptospira are present in peri-urban areas of Addis Ababa. Risk factors for the presence of pathogenic Leptospira and other zoonoses were widespread in the study area. These findings highlight the need to create awareness among livestock-keeping households concerning leptospirosis using a “One Health” concept.
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    Occult Hepatitis B Virus Infection Among Blood Donors at National Blood Bank of Ethiopia, Addis Ababa, Ethiopia.
    (Addis Ababa University, 2021-06) Gemechu Gizachew; Abegaz Woldaregay ; Mihret Adane; Mulu Andargachew
    Background: Occult hepatitis B infection (OBI) is a persistent Hepatitis B virus infection in which serological test fails to detect surface antigen, but viral DNA is detectable at a low level. The HBV screening for blood transfusion is still based only on HBsAg. As a result, OBI remains a potential threat for blood safety. Thus far, there is no data on the magnitude of occult hepatitis among blood donors. Therefore, this study sought to determine the magnitude of occult hepatitis B virus among apparently healthy blood donors in Ethiopia. Objectives: To study the magnitude of OBI and associated risk factors among blood donors at National Blood Bank, Addis Ababa, Ethiopia. Methods: Cross-sectional study was conducted from December 2020 to April 2021 to determine the prevalence of OBI among blood donors. A total of 973 HBsAg negative plasma samples were collected from National Blood Bank. The samples were tested for anti-HBc using an ELISA and viral DNA using quantitative real time PCR [Abbot m2000rt]. Along with plasma samples, demographic data were also retrieved from donor‟s database. Both descriptive and inferential statistics was employed for the analysis of data by SPSS 15. P-value less than (0.05) were considered as statistically significant. Results: Of the total 973 apparently healthy blood donor study participants, 445 (45.7%) were females and mean age was 26.5 years. A total of 144 of the 973 blood samples were anti-HBc reactive (14.8%). Four (0.41% of all and 2.7% of anti HBc+ donations) samples were confirmed as OBI by DNA detection. The mean viral load was 31IU/ml with +/- 12 SD suggesting true occult hepatitis BV infections. Age was found to be risk factors for anti-core positivity and statically significant at (p=0.0001). Conclusion: About 4 in 1000 apparently healthy blood donors screened negative for HBsAg had occult HBV infection. This shows that there is a risk of HBV transmission through blood transfusion in Ethiopia. Therefore, there is a need for further investigation and action to revise blood screening strategy including anti-HBc and HBV nucleic acid testing.