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1. State transitions in the Morris-Lecar model under stable L\'evy noise

Author

Cai, Rui, Liu, Yancai, Duan, Jinqiao, and Abebe, Almaz Tesfay

Subjects
Mathematics - Dynamical Systems, Nonlinear Sciences - Adaptation and Self-Organizing Systems, Nonlinear Sciences - Chaotic Dynamics
Abstract

This paper considers the state transition of the stochastic Morris-Lecar neuronal model driven by symmetric $\alpha$-stable L\'evy noise. The considered system is bistable: a stable fixed point (resting state) and a stable limit cycle (oscillating state), and there is an unstable limit cycle (borderline state) between them. Small disturbances may cause a transition between the two stable states, thus a deterministic quantity, namely the maximal likely trajectory, is used to analyze the transition phenomena in non-Gaussian stochastic environment. According to the numerical experiment, we find that smaller jumps of the L\'evy motion and smaller noise intensity can promote such transition from the sustained oscillating state to the resting state. It also can be seen that larger jumps of the L\'evy motion and higher noise intensity are conducive for the transition from the borderline state to the sustained oscillating state. As a comparison, Brownian motion is also taken into account. The results show that whether it is the oscillating state or the borderline state, the system disturbed by Brownian motion will be transferred to the resting state under the selected noise intensity.

Published
2019

2. Most Probable Dynamics of the Single-Species with Allee Effect under Jump-Diffusion Noise.

Author

Abebe, Almaz T., Yuan, Shenglan, Tesfay, Daniel, and Brannan, James

Subjects
*ALLEE effect, *FOKKER-Planck equation, *RANDOM noise theory, *STOCHASTIC models, *POPULATION dynamics, *NOISE, *DYNAMICAL systems
Abstract

We explore the most probable phase portrait (MPPP) of a stochastic single-species model incorporating the Allee effect by utilizing the nonlocal Fokker–Planck equation (FPE). This stochastic model incorporates both non-Gaussian and Gaussian noise sources. It has three fixed points in the deterministic case. One is the unstable state, which lies between the two stable equilibria. Our primary focus is on elucidating the transition pathways from extinction to the upper stable state in this single-species model, particularly under the influence of jump-diffusion noise. This helps us to study the biological behavior of species. The identification of the most probable path relies on solving the nonlocal FPE tailored to the population dynamics of the single-species model. This enables us to pinpoint the corresponding maximum possible stable equilibrium state. Additionally, we derive the Onsager–Machlup function for the stochastic model and employ it to determine the corresponding most probable paths. Numerical simulations manifest three key insights: (i) when non-Gaussian noise is present in the system, the peak of the stationary density function aligns with the most probable stable equilibrium state; (ii) if the initial value rises from extinction to the upper stable state, then the most probable trajectory converges towards the maximally probable equilibrium state, situated approximately between 9 and 10; and (iii) the most probable paths exhibit a rapid ascent towards the stable state, then maintain a sustained near-constant level, gradually approaching the upper stable equilibrium as time goes on. These numerical findings pave the way for further experimental investigations aiming to deepen our comprehension of dynamical systems within the context of biological modeling. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Sero-prevalence of yellow fever and related Flavi viruses in Ethiopia: a public health perspective

Author

Mengesha Tsegaye, Mesfin, Beyene, Berhane, Ayele, Workenesh, Abebe, Almaz, Tareke, Israel, Sall, Amadou, Yactayo, Sergio, Shibeshi, Messeret E., Staples, Erin, Belay, Desalegn, Lilay, Abrham, Alemu, Abebe, Alemu, Emana, Kume, Adugna, H/Mariam, Alemnesh, Ronveaux, Olivier, Tefera, Mesfin, Kassa, Woubayehu, Bekele Weyessa, Abyot, Jima, Daddi, Kebede, Amha, and Tayachew, Adamu

Published
2018
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7. Decline in prevalence of HIV-1 infection and syphilis among young women attending antenatal care clinics in Addis Ababa, Ethiopia: results from sentinel surveillance, 1995-2001

Author

Tsegaye, Aster, Wit, Tobias F. Rinke de, Mekonnen, Yared, Beyene, Asfaw, Aklilu, Mathias, Messele, Tsehaynesh, Abebe, Almaz, Coutinho, Roel, Sanders, Eduard, and Fontanet, Arnaud L.

Subjects
Epidemiology -- Statistics, Epidemiology -- Research, HIV patients -- Demographic aspects, HIV patients -- Health aspects, HIV patients -- Care and treatment, HIV infection -- Demographic aspects, HIV infection -- Prevention, HIV infection -- Research, HIV infection -- Health aspects, Syphilis -- Care and treatment, Syphilis -- Prevention, Syphilis -- Health aspects, Syphilis -- Demographic aspects, Young women -- Demographic aspects, Young women -- Health aspects, Young women -- Diseases, Health surveys -- Analysis, Health
Abstract

Research has been comnducted on the trends in the HIV infection and syphilis prevalence in young women attending antenatal care clinics in Addis Ababa, Ethiopia. Results indicate that the declininmg trends in HIV infection and syphilis among young women are encouraging but no change ha been observed in older age groups.

Published
2002

9. HIV-1 subtype C in commercial sex workers in Addis Ababa, Ethiopia

Author

Hussein, Mintewab, Abebe, Almaz, Pollakis, Georgios, Brouwer, Margreet, Petros, Beyene, Fontanet, Arnaud L., and Rinke de Wit, Tobias F.

Subjects
HIV (Viruses) -- Genetic aspects, HIV infection -- Ethiopia, Prostitutes -- Diseases, Health
Abstract

HIV-1 subtype C continues to be the predominant subtype in Ethiopian prostitutes. Of 150 prostitutes tested, 67 were HIV-positive and 66 had subtype C. The remaining prostitute was infected with subtype D.

Published
2000

11. Rotavirus-associated acute diarrhea outbreak in West Shewa Zone of Oromia Regional State, Ethiopia, 2017

Author

Woyessa, Abyot Bekele, Abebe, Almaz, Beyene, Berhane, Tefera, Mesfin, Assefa, Esete, Ketema, Hiwot, Teshome, Birke, Bekele, Ayenachew, Dugasa, Yohanis, Habebe, Shambel, Assefa, Zewdu, Sufa, Diriba, Alemu, Dagnachew, Tilahun, Habtamu, Biru, Mengistu, and Shume, Gemechu

Subjects
Adult, Diarrhea, Male, Rotavirus, Vaccination Coverage, Adolescent, Genotype, Rotavirus Infections, Disease Outbreaks, Immunoenzyme Techniques, Feces, Young Adult, vaccine, Humans, Child, outbreak, Reverse Transcriptase Polymerase Chain Reaction, Research, Infant, Newborn, Rotavirus Vaccines, Infant, Middle Aged, Child, Preschool, Acute Disease, Female, Ethiopia
Abstract

Introduction Rotavirus causes severe-diarrheal diseases in infants. An estimation of 138 million rotavirus-associated diarrheal cases and 215,000 deaths occur every year globally. In December 2016, West-Shewa zone in Ethiopia reported unidentified gastrointestinal diarrhea outbreak. We investigated to identify the causative agent of the outbreak to support response operations. Methods Medical records were reviewed, and the daily line list was collected from health facilities. Descriptive data analysis was done by time, person and place. Stool specimens were first tested by antigen capture enzyme immunoassay (EIA) technique and further confirmed by reverse-transcription polymerase chain reaction (RT-PCR) as a gold standard. The product of RT-PCR was genotyped for each gene using G1-G4, G8-G9 and G12 primers for VP7 gene and P(4), P(6), P(8) and P(14) primers for VP4 gene. Results A total of 1,987 diarrheal cases (5.7 per 1000) and five deaths (case-fatality rate 0.25%) were identified and epidemiologically-linked to confirmed rotavirus from December 2016 to February 2017. Among the cases, 1,946 (98%) were < 5 children. Fourteen (74%) of the 19 tested stool specimens were positive for rotavirus by EIA and RT-PCR. Majority of strains detected were G12P(6) (25%) and G-negative P(8) (25%) followed by G9P(8) (19%), G1P(8) (13%) and G3/G2 P(8), G12P(8), and G-negative P(6) (6% each). Conclusion Diarrheal outbreak which occurred in West-Shewa zone of Ethiopia was associated with rotavirus and relatively more affected districts with low vaccination coverage. Routine rotavirus vaccination quality and coverage should be evaluated and the surveillance system needs to be strengthened to detect, prevent and control a similar outbreak.

Published
2019

14. Enteric pathogens and associated risk factors among under-five children with and without diarrhea in Wegera District, Northwestern Ethiopia

Author

Feleke, Hailemariam, Medhin, Girmay, Abebe, Almaz, Beyene, Birhan, Kloos, Helmut, and Asrat, Daniel

Subjects
Diarrhea, Giardiasis, Male, Acute diarrhea, animal diseases, Enzyme-Linked Immunosorbent Assay, enteric pathogens, Rotavirus Infections, fluids and secretions, Risk Factors, Salmonella, parasitic diseases, Humans, sociodemographic and environmental factors, Dysentery, Bacillary, Research, rotavirus vaccination, Infant, Acute diarrhea, under-five children, enteric pathogens, rotavirus vaccination, sociodemographic and environmental factors, Ethiopia, Anti-Bacterial Agents, Cross-Sectional Studies, Child, Preschool, Salmonella Infections, Female, Ethiopia, Shigella, under-five children
Abstract

Introduction: Childhood diarrhea is highly prevalent in slums in developing countries, but it remains understudied. The objectives of this study were to explore the prevalence of Giardia, rotavirus and bacterial enteropathogens among diarrheic and non-diarrheic children and investigate socio-environmental determinants of diarrhea in two Ethiopian towns. Methods: A cross-sectional study was conducted from June to October 2016. Prevalence of childhood diarrhea was established using information gathered during interviews with mothers/guardians. Saline wet mounts of fresh stool samples were used to test for the presence of Giardia. Stool samples were cultured on MacConkey agar and suspected colonies were characterized using biochemical tests. Susceptibility testing was done by the disk diffusion method. ELISA was used to screen for rotavirus. Results: A total of 225 children were included in this study. Four enteropathogens (Giardia, rotavirus, Shigella and Salmonella) were identified from 31% (35/112) diarrheic and 12% (14/113) from non-diarrheic children (p < 0.001). The prevalence of rotavirus infection was 18.0% among diarrheic children and 3.3% among non-diarrheic children unvaccinated against rotavirus (p < 0.01). The prevalence of Giardia was 21.0% among diarrheic and 8.0% among non-diarrheic children (p < 0.01). Diarrheic children had significantly higher rates of bloody stool (p < 0.02), vomiting, fever and breastfeeding for children beyond 23 months of age (p < 0.001). Giardia and rotavirus were identified in more diarrheic than nondiarrheic children. Conclusion: The high prevalence of Giardia and rotavirus in the study area indicates the need for coordinated healthcare activities in the two communities. Vaccination against rotavirus infections and educational interventions are recommended.

Published
2018

15. Impact of rotavirus vaccine introduction and genotypic characteristics of rotavirus strains in children less than 5 years of age with gastroenteritis in Ethiopia: 2011–2016

Author

Abebe, Almaz, primary, Getahun, Mekonen, additional, Mapaseka, Seheri L., additional, Beyene, Berhane, additional, Assefa, Essete, additional, Teshome, Birke, additional, Tefera, Mesfin, additional, Kebede, Ferehiwot, additional, Habtamu, Abebe, additional, Haile-Mariam, Tewodros, additional, Jeffrey Mphahlele, M., additional, Teshager, Fasil, additional, Ademe, Ayesheshem, additional, Teka, Telahun, additional, Weldegebriel, Goitom G., additional, and Mwenda, Jason M., additional

Published
2018
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18. Whole Genome Analysis of African G12P[6] and G12P[8] Rotaviruses Provides Evidence of Porcine-Human Reassortment at NSP2, NSP3, and NSP4.

Author

Mokoena, Fortunate, Esona, Mathew Dioh, Seheri, Luyanda Mapaseka, Nyaga, Martin Munene, Magagula, Nonkululelo Bonakele, Mukaratirwa, Arnold, Mulindwa, Augustine, Abebe, Almaz, Boula, Angeline, Tsolenyanu, Enyonam, Simwaka, Julia, Rakau, Kebareng Giliking, Peenze, Ina, Mwenda, Jason Mathiu, Mphahlele, Maphahlaganye Jeffrey, and Steele, Andrew Duncan

Subjects
ROTAVIRUSES, NUCLEOTIDE sequencing, ZOONOSES, GENOTYPES, GENOMES, GASTROENTERITIS
Abstract

Group A rotaviruses (RVA) represent the most common cause of pediatric gastroenteritis in children <5 years, worldwide. There has been an increase in global detection and reported cases of acute gastroenteritis caused by RVA genotype G12 strains, particularly in Africa. This study sought to characterize the genomic relationship between African G12 strains and determine the possible origin of these strains. Whole genome sequencing of 34 RVA G12P[6] and G12P[8] strains detected from the continent including southern (South Africa, Zambia, Zimbabwe), eastern (Ethiopia, Uganda), central (Cameroon), and western (Togo) African regions, were sequenced using the Ion Torrent PGM method. The majority of the strains possessed a Wa-like backbone with consensus genotype constellation of G12-P[6]/P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1, while a single strain from Ethiopia displayed a DS-1-like genetic constellation of G12-P[6]-I2-R2-C2-M2-A2-N2-T2-E2-H2. In addition, three Ethiopian and one South African strains exhibited a genotype 2 reassortment of the NSP3 gene, with genetic constellation of G12-P[8]-I1-R1-C1-M1-A1-N1-T2-E1-H1. Overall, 10 gene segments (VP1–VP4, VP6, and NSP1–NSP5) of African G12 strains were determined to be genetically related to cognate gene sequences from globally circulating human Wa-like G12, G9, and G1 strains with nucleotide (amino acid) identities in the range of 94.1–99.9% (96.5–100%), 88.5–98.5% (93–99.1%), and 89.8–99.0% (88.7–100%), respectively. Phylogenetic analysis showed that the Ethiopian G12P[6] possessing a DS-1-like backbone consistently clustered with G2P[4] strains from Senegal and G3P[6] from Ethiopia with the VP1, VP2, VP6, and NSP1–NSP4 genes. Notably, the NSP2, NSP3, and NSP4 of most of the study strains exhibited the closest relationship with porcine strains suggesting the occurrence of reassortment between human and porcine strains. Our results add to the understanding of potential roles that interspecies transmission play in generating human rotavirus diversity through reassortment events and provide insights into the evolutionary dynamics of G12 strains spreading across selected sub-Saharan Africa regions. [ABSTRACT FROM AUTHOR]

Published
2021
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20. Four-Gene Pan-African Blood Signature Predicts Progression to Tuberculosis

Author

Suliman, Sara, primary, Thompson, Ethan G., additional, Sutherland, Jayne, additional, Weiner, January, additional, Ota, Martin O. C., additional, Shankar, Smitha, additional, Penn-Nicholson, Adam, additional, Thiel, Bonnie, additional, Erasmus, Mzwandile, additional, Maertzdorf, Jeroen, additional, Duffy, Fergal J., additional, Hill, Philip C., additional, Hughes, E. Jane, additional, Stanley, Kim, additional, Downing, Katrina, additional, Fisher, Michelle L., additional, Valvo, Joe, additional, Parida, Shreemanta K., additional, van der Spuy, Gian, additional, Tromp, Gerard, additional, Adetifa, Ifedayo M. O., additional, Donkor, Simon, additional, Howe, Rawleigh, additional, Mayanja-Kizza, Harriet, additional, Boom, W. Henry, additional, Dockrell, Hazel M., additional, Ottenhoff, Tom H. M., additional, Hatherill, Mark, additional, Aderem, Alan, additional, Hanekom, Willem A., additional, Scriba, Thomas J., additional, Kaufmann, Stefan H. E., additional, Zak, Daniel E., additional, Walzl, Gerhard, additional, Black, Gillian F., additional, Kriel, Magdalena, additional, Du Plessis, Nelita, additional, Nene, Nonhlanhla, additional, Roberts, Teri, additional, Kleynhans, Leanie, additional, Gutschmidt, Andrea, additional, Smith, Bronwyn, additional, Loxton, Andre G., additional, Chegou, Novel N., additional, Tromp, Gerhardus, additional, Tabb, David, additional, Klein, Michel R., additional, Haks, Marielle C., additional, Franken, Kees L. M. C., additional, Geluk, Annemieke, additional, van Meijgaarden, Krista E., additional, Joosten, Simone A., additional, Joloba, Moses, additional, Zalwango, Sarah, additional, Nsereko, Mary, additional, Okwera, Brenda, additional, Kisingo, Hussein, additional, Golinski, Robert, additional, Jacobson, Marc, additional, Dockrell, Hazel, additional, Smith, Steven, additional, Gorak-Stolinska, Patricia, additional, Hur, Yun-Gyoung, additional, Lalor, Maeve, additional, Lee, Ji-Sook, additional, Crampin, Amelia C., additional, French, Neil, additional, Ngwira, Bagrey, additional, Ben-Smith, Anne, additional, Watkins, Kate, additional, Ambrose, Lyn, additional, Simukonda, Felanji, additional, Mvula, Hazzie, additional, Chilongo, Femia, additional, Saul, Jacky, additional, Branson, Keith, additional, Suliman, Sara, additional, Mahomed, Hassan, additional, Bilek, Nicole, additional, Xasa, Onke, additional, Veldsman, Ashley, additional, Fisher, Michelle, additional, Mulenga, Humphrey, additional, Abel, Brian, additional, Bowmaker, Mark, additional, Kagina, Benjamin, additional, Chung, William Kwong, additional, Sadoff, Jerry, additional, Sizemore, Donata, additional, Ramachandran, S., additional, Barker, Lew, additional, Brennan, Michael, additional, Weichold, Frank, additional, Muller, Stefanie, additional, Geiter, Larry, additional, Kassa, Desta, additional, Abebe, Almaz, additional, Mesele, Tsehayenesh, additional, Tegbaru, Belete, additional, Baarle, Debbie van, additional, Miedema, Frank, additional, Mihret, Adane, additional, Aseffa, Abraham, additional, Bekele, Yonas, additional, Iwnetu, Rachel, additional, Tafesse, Mesfin, additional, Yamuah, Lawrence, additional, Ota, Martin, additional, Hill, Philip, additional, Adegbola, Richard, additional, Corrah, Tumani, additional, Antonio, Martin, additional, Togun, Toyin, additional, Adetifa, Ifedayo, additional, Andersen, Peter, additional, Rosenkrands, Ida, additional, Doherty, Mark, additional, Weldingh, Karin, additional, Schoolnik, Gary, additional, Dolganov, Gregory, additional, Van, Tran, additional, Kafaar, Fazlin, additional, Workman, Leslie, additional, Cloete, Yolundi, additional, Abrahams, Deborah, additional, Moyo, Sizulu, additional, Gelderbloem, Sebastian, additional, Tameris, Michele, additional, Geldenhuys, Hennie, additional, Hanekom, Willem, additional, Hussey, Gregory, additional, Ehrlich, Rodney, additional, and Verver, Suzanne, additional

Published
2018
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21. Molecular typing and drug sensitivity testing of Mycobacterium tuberculosis isolated by a community-based survey in Ethiopia

Author

Getahun, Muluwork, primary, Ameni, Gobena, additional, Kebede, Abebaw, additional, Yaregal, Zelalem, additional, Hailu, Elena, additional, Medihn, Grimay, additional, Demssie, Daniel, additional, Girmachew, Feven, additional, Fiseha, Yetnebersh, additional, Meaza, Abyot, additional, Dirse, Nathneal, additional, Agonafir, Mulualem, additional, Dana, Feleke, additional, Tsegaye, Fasil, additional, Alebachew, Zeleke, additional, Abebe, Almaz, additional, Kebede, Amha, additional, and Lemma, Eshetu, additional

Published
2015
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23. Dilution testing using rapid diagnostic tests in a HIV diagnostic algorithm: a novel alternative for confirmation testing in resource limited settings

Author

Shanks, Leslie, primary, Siddiqui, M. Ruby, additional, Abebe, Almaz, additional, Piriou, Erwan, additional, Pearce, Neil, additional, Ariti, Cono, additional, Masiga, Johnson, additional, Muluneh, Libsework, additional, Wazome, Joseph, additional, Ritmeijer, Koert, additional, and Klarkowski, Derryck, additional

Published
2015
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24. Evaluation of HIV testing algorithms in Ethiopia: the role of the tie-breaker algorithm and weakly reacting test lines in contributing to a high rate of false positive HIV diagnoses

Author

Shanks, Leslie, primary, Siddiqui, M Ruby, additional, Kliescikova, Jarmila, additional, Pearce, Neil, additional, Ariti, Cono, additional, Muluneh, Libsework, additional, Pirou, Erwan, additional, Ritmeijer, Koert, additional, Masiga, Johnson, additional, and Abebe, Almaz, additional

Published
2015
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25. Metals Exposures of Residents Living Near the Akaki River in Addis Ababa, Ethiopia: A Cross-Sectional Study

Author

Yard, Ellen, primary, Bayleyegn, Tesfaye, additional, Abebe, Almaz, additional, Mekonnen, Andualem, additional, Murphy, Matthew, additional, Caldwell, Kathleen L., additional, Luce, Richard, additional, Hunt, Danielle Rentz, additional, Tesfaye, Kirubel, additional, Abate, Moa, additional, Assefa, Tsigereda, additional, Abera, Firehiwot, additional, Habte, Kifle, additional, Chala, Feyissa, additional, Lewis, Lauren, additional, and Kebede, Amha, additional

Published
2015
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26. Hospital-based Surveillance for Rotavirus Gastroenteritis in Children Younger Than 5 Years of Age in Ethiopia

Author

Abebe, Almaz, primary, Teka, Telahun, additional, Kassa, Tassew, additional, Seheri, Mapaseka, additional, Beyene, Berhane, additional, Teshome, Birke, additional, Kebede, Ferehiwot, additional, Habtamu, Abebe, additional, Maake, Lorens, additional, Kassahun, Aron, additional, Getahun, Mekonnen, additional, Mitiku, Kassahun, additional, and Mwenda, Jason M., additional

Published
2014
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27. Field expansion of DNA polymerase chain reaction for early infant diagnosis of HIV-1: The Ethiopian experience

Author

Fonjungo, Peter, primary, Girma, Mulu, additional, Melaku, Zenebe, additional, Mekonen, Teferi, additional, Tanuri, Amilcar, additional, Hailegiorgis, Bereket, additional, Tegbaru, Belete, additional, Mengistu, Yohannes, additional, Ashenafi, Aytenew, additional, Mamo, Wubshet, additional, Abreha, Tesfay, additional, Tibesso, Gudetta, additional, Ramos, Artur, additional, Ayana, Gonfa, additional, Freeman, Richard, additional, Nkengasong, John N., additional, Zewdu, Solomon, additional, Kebede, Yenew, additional, Abebe, Almaz, additional, Kenyon, Thomas A., additional, and Messele, Tsehaynesh, additional

Published
2013
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32. Development of a Nucleic Acid Sequence-Based Amplification Assay That Uses gag -Based Molecular Beacons To Distinguish between Human Immunodeficiency Virus Type 1 Subtype C and C′ Infections in Ethiopia

Author

Ayele, Workenesh, primary, Pollakis, Georgios, additional, Abebe, Almaz, additional, Fisseha, Bitew, additional, Tegbaru, Belete, additional, Tesfaye, Girma, additional, Mengistu, Yohannes, additional, Wolday, Dawit, additional, van Gemen, Bob, additional, Goudsmit, Jaap, additional, Dorigo-Zetsma, Wendelien, additional, and de Baar, Michel P., additional

Published
2004
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33. Phenotypic and Genotypic Comparisons of CCR5- and CXCR4-Tropic Human Immunodeficiency Virus Type 1 Biological Clones Isolated from Subtype C-Infected Individuals

Author

Pollakis, Georgios, primary, Abebe, Almaz, additional, Kliphuis, Aletta, additional, Chalaby, Moustapha I. M., additional, Bakker, Margreet, additional, Mengistu, Yohannes, additional, Brouwer, Margreet, additional, Goudsmit, Jaap, additional, Schuitemaker, Hanneke, additional, and Paxton, William A., additional

Published
2004
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34. Rapid CD4+ T-Lymphocyte Depletion in Rhesus Monkeys Infected with a Simian–Human Immunodeficiency Virus Expressing the Envelope Glycoproteins of a Primary Dual-Tropic Ethiopian Clade C HIV Type 1 Isolate

Author

Cayabyab, Mark, primary, Rohne, Daniela, additional, Pollakis, Georgios, additional, Mische, Claudia, additional, Messele, Tseyanish, additional, Abebe, Almaz, additional, Etemad-Moghadam, Bijan, additional, Yang, Peter, additional, Henson, Scott, additional, Axthelm, Michael, additional, Goudsmit, Jaap, additional, Letvin, Norman L., additional, and Sodroski, Joseph, additional

Published
2004
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35. Recombination of HIV Type 1C (C′/C″) in Ethiopia: Possible Link of EthHIV-1C′ to Subtype C Sequences from the High-Prevalence Epidemics in India and Southern Africa

Author

Pollakis, Georgios, primary, Abebe, Almaz, additional, Kliphuis, Aletta, additional, de Wit, Tobias F. Rinke, additional, Fisseha, Bitew, additional, Tegbaru, Belete, additional, Tesfaye, Girma, additional, Negassa, Hailu, additional, Mengistu, Yohannes, additional, Fontanet, Arnaud L., additional, Cornelissen, Marion, additional, and Goudsmit, Jaap, additional

Published
2003
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40. HIV Type 1 Subtype C in Addis Ababa, Ethiopia

Author

ABEBE, ALMAZ, primary, KUIKEN, CARLA L., additional, GOUDSMIT, JAAP, additional, VALK, MARGREETH, additional, MESSELE, TSEHAYNESH, additional, SAHLU, TEFERA, additional, YENENEH, HAILU, additional, FONTANET, ARNAUD, additional, DE WOLF, FRANK, additional, and DE WIT, TOBIAS F. RINKE, additional

Published
1997
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42. Intrauterine Fetal Death due to Echovirus 11

Author

Johansson, Mats E., primary, Holmström, Stefan, additional, Abebe, Almaz, additional, Jacobsson, Björn, additional, Ekman, Gunvor, additional, Samuelson, Agneta, additional, and Wirgart, Benita Zweygberg, additional

Published
1992
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44. Toxicity study and evaluation of biochemical markers towards the identification of the causative agent for an outbreak of liver disease in Tahtay Koraro Woreda, Tigray.

Author

Debella A, Abebe D, Tekabe F, Mamo H, Abebe A, Tsegaye B, Ayana G, Degefa A, Negussie P, Yimer E, Challa F, Lemma E, Tefera A, Mekonnen Y, Afework N, Mudie K, Tadele A, Kidanemariam T, Muchie B, and Dadi N

Subjects
Animals, Biomarkers analysis, Ethiopia epidemiology, Female, Humans, Male, Models, Animal, Disease Outbreaks statistics & numerical data, Liver Diseases epidemiology, Liver Diseases etiology, Water Pollution adverse effects
Abstract

Background: A team of experts of the Faculty of Medicine, Addis Ababa University reported the emergence of unidentified fatal liver disease in Tahtay Koraro Woreda, Tigray in the mid of December 2005. The EHNRI has been then instructed to investigate the possible etiological agent that are likely to be responsible in triggering the health problem and a field survey team consisting of experts were went to the affected area to investigate the situations surrounding the disease., Objectives: This investigation was conducted to determine the possible etiological agent(s) for the stated health problem in the affected village., Method: Acute toxicity study was performed on animal model for the various samples used in human consumption, which was followed by histopathological examination of the liver of the sacrificed laboratory animals. In order to facilitate the elucidation of the causative agent for the alleged health problem further tests for clinical markers and antigens were also performed on the serum collected from affected persons., Result: Neither death nor toxic symptoms manifestations were observed on laboratory animals when feeding the consumable samples for a period of two weeks, however histopathological examination of the liver of the sacrificed animals that were given the unprotected pond water and Tela samples from the affected village as a drink revealed severe hepatoic necrosis. Biochemical test results of the serum samples revealed raised level of some clinical markers that are highly significant for detecting liver abnormality of toxic origin. Serological test for surface antigen ruled out the possible causes of infectious origin such as viral hepatitis., Conclusion: The overall results confirmed that the causative agent for the outbreak of the liver disease was of toxic origin rather than due to infectious agent and this was found to be associated with consumption of contaminated water as well as Tela.

Published
2012

45. Human herpesvirus 8 infection in HIV-1-infected and uninfected pregnant women in Ethiopia.

Author

Lemma E, Constantine NT, Kassa D, Messele T, Mindaye T, Taye G, Abebe A, Tamene W, Tebje M, Gebremeskel W, Adane A, and Gezahegn N

Subjects
Adolescent, Adult, Cross-Sectional Studies, Ethiopia epidemiology, Female, Humans, Middle Aged, Pregnancy, Pregnancy Complications, Infectious virology, Sarcoma, Kaposi prevention & control, Seroepidemiologic Studies, Syphilis epidemiology, HIV Infections epidemiology, HIV-1, Herpesvirus 8, Human, Pregnancy Complications, Infectious epidemiology, Sarcoma, Kaposi epidemiology
Abstract

Background: Human Herpes Virus (HHV-8) is related to Kaposi Saracoma, an opportunistic infection occurring with HIV infection. Little is known about the seroepidemiology of Human Herpesvirus 8 (HHV-8) infection among Ethiopian women, even though women are a major HIV risk group in Ethiopia., Objectives: This study aimed at determining the seroprevalence of HHV-8 infection in HIV-1-infected and uninfected pregnant women in five selected regions of Ethiopia., Methods: A cross-sectional study was conducted from December 2006 to June 2007 where pregnant women were recruited after age-matching in groups. A total of 400 pregnant women were enrolled, with 200 being HIV-infected and 200 being HIV-uninfected Sera were screened for IgG lytic antibody to HHV-8 using an Indirect Fluorescence Assay (IFA) in Virology Unit of Ethiopian Health and Nutrition Research Institute (EHNR1)., Results: Of 400 pregnant women attending antenatal clinic (ANC) testing sites of five regions in Ethiopia, 212 (53.0%) were positive for HHV-8 IgG lytic antibody. There was a high prevalence of HHV-8 infection among HIV-1-infected pregnant women (138, 69.0%) as compared with HIV-1-uninfected pregnant women (74, 37.0%)., Conclusion: The study shows a high prevalence of HHV-8 infection among HIV-1-infected pregnant women as compared with HIV-1-uninfected pregnant women. Therefore, creating awareness and educating women on safe sexual practice and avoiding deep kissing may be a fundamental ways to limit the roots of transmission. Moreover, initiating strong antiretroviral therapy (ART) for HIV infected women would be best treatment prior to the development of Kaposi's sarcoma (KS).

Published
2009

46. HIV type 1 C and C' subclusters based on long terminal repeat sequences in the Ethiopian type 1 subtype C epidemic.

Author

De Baar MP, Abebe A, Kliphuis A, Tesfaye G, Goudsmit J, and Pollakis G

Subjects
Base Sequence, Ethiopia epidemiology, Ethiopia ethnology, HIV Infections epidemiology, HIV Infections ethnology, HIV-1 classification, Humans, Molecular Sequence Data, Phylogeny, Sequence Alignment, HIV Infections virology, HIV Long Terminal Repeat genetics, HIV-1 genetics
Abstract

While the Ethiopian HIV-1 epidemic is dominated by subtype C, two distinguishable cocirculating C genotypes have been identified based on sequences of the C2V3 envelope region. In this study we sequenced and analyzed the long terminal repeat (LTR) sequence from 22 Ethiopian HIV-1-positive individuals. The two phylogenetically distinguishable genotypes C (n = 13) and C' (n = 4) are separated by significant bootstrap values. Nucleotide differences between the two groups were identified in the NF-AT, TCF-1alpha, and SP1 transcription factor binding sites, whereas the NF-kappaB and NRE-core sequences were identical between the two groups. Five isolates that could not be classified C or C' were found to be recombinants within the LTR sequence upon boots can analysis. Comparison of all the LTR sequences with their corresponding C2V3 envelope sequence revealed four intersubtype C/C' recombinant isolates. Thus, the prevalence of C/C' recombinant viruses is well over 40%. Interestingly, the C2V3 envelope sequences of all recombinant viruses belonged to the genotype C', whereas every LTR sequence belonged to the genotype C. This result indicates that recombination between the two genotypes is unidirectional, possibly as the result of evolutionary pressure on the respective biological functions of the LTR promoter and the envelope protein.

Published
2003
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47. Decline in prevalence of HIV-1 infection and syphilis among young women attending antenatal care clinics in Addis Ababa, Ethiopia: results from sentinel surveillance, 1995-2001.

Author

Tsegaye A, Rinke de Wit TF, Mekonnen Y, Beyene A, Aklilu M, Messele T, Abebe A, Coutinho R, Sanders E, and Fontanet AL

Subjects
Adolescent, Adult, Age Factors, Ethiopia epidemiology, Female, Humans, Pregnancy, Sentinel Surveillance, Seroepidemiologic Studies, Time Factors, Ambulatory Care Facilities statistics & numerical data, HIV Infections epidemiology, HIV-1, Prenatal Care statistics & numerical data, Syphilis epidemiology
Abstract

From 1995 to 2001, five rounds of sentinel surveillance were carried out for young women attending antenatal care clinics at four health centers in Addis Ababa, the capital city of Ethiopia, to monitor trends in the prevalence of HIV infection and syphilis. Serum samples were tested for antibodies to HIV (enzyme-linked immunosorbent assay and Western blotting) and antibodies to Treponema pallidum (T. pallidum hemagglutination assay and rapid plasma reagin test). Prevalence ratios for an increase in one calendar year were estimated using log-binomial models. Between 1995 and 2001, the prevalence of HIV infection among young women (age range, 15-24 years) attending antenatal care clinics in inner city health centers declined from 24.2% to 15.1% (prevalence ratio for an increase in one calendar year, 0.91; 95% confidence interval, 0.87-0.95). No change was observed for older age groups or in outer city health centers. The decline in the prevalence of active syphilis (T. pallidum hemagglutination assay and rapid plasma reagin testing positive for antibodies to T. pallidum) was more pronounced among and also restricted to the young age groups (age range, 15-24 years) in the inner city (from 7.6% in 1995 to 1.3% in 2001; prevalence ratio, 0.69; 95% confidence interval, 0.59-0.80). The declining trends in the prevalence of HIV infection and syphilis among young women attending antenatal care clinics in the inner city are encouraging, but these findings require confirmation in future years and for other population groups.

Published
2003

48. Polio and other enterovirus isolation by region in Ethiopia, 2000-2002.

Author

Mentaye BB, Zelalem M, Asha A, Tiruneh Y, Afework A, Tedela M, Bezuneh T, Senbet AG, Oyewole F, Abebe A, Woldemichael T, and Tomori O

Subjects
Ethiopia, Humans, Time Factors, Enterovirus isolation & purification, Feces virology, Poliovirus isolation & purification
Published
2003

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