Onchocerciasis in Gilgel Ghibe River valley Southwest Ethiopia

Objective: To determine the prevalence of onchocerciasis and the entomological transmission indices such as the parous rate and annual transmission potential (ATP).Setting: Gilgel Ghibe village, Gilgel Ghibe River Valley Southwest Ethiopia between April 1994 and March 1995.Subjects: Two hundred twenty eight subjects of the total 400 population in Gilgel Ghibe village were subjected to parasitological and clinical examinations.Method: Two skin snips per person were taken and examined for microfilariae of Onchocerca volvulus. Fly collections were done from dawn to dusk from human baits seated in pairs at four representative sites at the river bank and away from the river bank. Flies were dissected for parity and infections with O. volvulus larvae.Results: Among the 228 people examined, the prevalence of the disease was low (17%), being higher in males (19%) than in females (14%). The geometric mean of microfilarial density was 11.1 (range, 1-132) mf per skin snip. Itching followed by pigmentary changes were the most common clinical signs and symptoms. The predominant anthropophilic blackfly species was Simulium (Edwardsellum) damnosum s.l. The annual parous rate and ATP were 74.7% and 1669.5, respectively, being higher at the river bank than at sites further away suggesting a greater risk of infection by the river side.Conclusion: The low prevalence of onchocerciasis in Gilgel Ghibe area vis-a-vis the high ATP level could be due to the possible presence of bovine onchocerciasis in the area. Further studies employing molecular techniques are thus required to identify O. volvulus from other filariae in flies

Aspergillus species and aflatoxin contamination in pepper (Capsicum annuum l.) in West Gojjam, Ethiopia

Pepper (Capsicum annuum L.) is an important spice and source of income for smallholder producers in Ethiopia. Since the larger proportion is for the market, it takes a significant share of the national income from export commodity. However, often the product was rejected by some of the European Union markets due to the maximum aflatoxin level accumulations beyond their acceptable limits. So, the present study was carried out to highlight the importance of Aspergillus species invasion in pepper, and levels of aflatoxin contamination at maturity in the field (pod form), farmers' storage and local market (powder form) in West Gojjam, Ethiopia. A total of 135 pepper samples were collected from three districts of West Gojjam (Burie, Jabitehnan, and Fnoteselam), Ethiopia for fungal and aflatoxin analysis. The producers used a pre-validated structured questionnaire to obtain information on pepper production practices. Aspergillus species isolates were recovered using potato dextrose agar (PDA) medium and counting was through dilution method (cfu g-1). The pepper pods were ground to a fine powder for aflatoxin analysis using Enzyme-Linked Immunosorbent Assay (ELISA). The prevalence of infected samples revealed that, pre-harvest samples (51%) were less infected by Aspergillus species, compared to local markets (65 %) and storage (79 %). Aspergillus flavus species were recovered in pre-harvest samples, whilst A. niger were found in local market samples. Aflatoxin contamination at pre-harvest, storage, and local market were 10, 47, and 42 % with levels which ranged from non-detected to 10.6, 0.3 - 17.1 and 3.1 - 19.2 ppb, respectively. The mean aflatoxin concentration detected from storage samples (10.6 ppb) and local market (12.6 ppb) were found to be above the tolerable limits set by EU (5 ppb) in pepper products. From the findings in this study, proper drying, physical separation of molded pods and use of clean storage structures should be implemented along the production chain in order to reduce aflatoxin contamination in pepper in Ethiopia

Heterosis in locally adapted sorghum genotypes and potential of hybrids for increased productivity in contrasting environments in Ethiopia

Increased productivity in sorghum has been achieved in the developed world using hybrids. Despite their yield advantage, introduced hybrids have not been adopted in Ethiopia due to the lack of adaptive traits, their short plant stature and small grain size. This study was conducted to investigate hybrid performance and the magnitude of heterosis of locally adapted genotypes in addition to introduced hybrids in three contrasting environments in Ethiopia. In total, 139 hybrids, derived from introduced seed parents crossed with locally adapted genotypes and introduced R lines, were evaluated. Overall, the hybrids matured earlier than the adapted parents, but had higher grain yield, plant height, grain number and grain weight in all environments. The lowland adapted hybrids displayed a mean better parent heterosis (BPH) of 19%, equating to 1160 kg ha− 1 and a 29% mean increase in grain yield, in addition to increased plant height and grain weight, in comparison to the hybrids derived from the introduced R lines. The mean BPH for grain yield for the highland adapted hybrids was 16% in the highland and 52% in the intermediate environment equating to 698 kg ha− 1 and 2031 kg ha− 1, respectively, in addition to increased grain weight. The magnitude of heterosis observed for each hybrid group was related to the genetic distance between the parental lines. The majority of hybrids also showed superiority over the standard check varieties. In general, hybrids from locally adapted genotypes were superior in grain yield, plant height and grain weight compared to the high parents and introduced hybrids indicating the potential for hybrids to increase productivity while addressing farmers' required traits

Beneficial plant-microbial interactions in agroecosystems: deciphering the rhizosphere microbial community in two field grown crops

Non-Peer Reviewe

Epidemiology of Mycobacterium tuberculosis lineages and strain clustering within urban and peri-urban settings in Ethiopia

BACKGROUND: Previous work has shown differential predominance of certain Mycobacterium tuberculosis (M. tb) lineages and sub-lineages among different human populations in diverse geographic regions of Ethiopia. Nevertheless, how strain diversity is evolving under the ongoing rapid socio-economic and environmental changes is poorly understood. The present study investigated factors associated with M. tb lineage predominance and rate of strain clustering within urban and peri-urban settings in Ethiopia. METHODS: Pulmonary Tuberculosis (PTB) and Cervical tuberculous lymphadenitis (TBLN) patients who visited selected health facilities were recruited in the years of 2016 and 2017. A total of 258 M. tb isolates identified from 163 sputa and 95 fine-needle aspirates (FNA) were characterized by spoligotyping and compared with international M.tb spoligotyping patterns registered at the SITVIT2 databases. The molecular data were linked with clinical and demographic data of the patients for further statistical analysis. RESULTS: From a total of 258 M. tb isolates, 84 distinct spoligotype patterns that included 58 known Shared International Type (SIT) patterns and 26 new or orphan patterns were identified. The majority of strains belonged to two major M. tb lineages, L3 (35.7%) and L4 (61.6%). The observed high percentage of isolates with shared patterns (n = 200/258) suggested a substantial rate of overall clustering (77.5%). After adjusting for the effect of geographical variations, clustering rate was significantly lower among individuals co-infected with HIV and other concomitant chronic disease. Compared to L4, the adjusted odds ratio and 95% confidence interval (AOR; 95% CI) indicated that infections with L3 M. tb strains were more likely to be associated with TBLN [3.47 (1.45, 8.29)] and TB-HIV co-infection [2.84 (1.61, 5.55)]. CONCLUSION: Despite the observed difference in strain diversity and geographical distribution of M. tb lineages, compared to earlier studies in Ethiopia, the overall rate of strain clustering suggests higher transmission and warrant more detailed investigations into the molecular epidemiology of TB and related factors

Parthenium weed (Parthenium hysterophorus L.) research in Ethiopia: Investigation of pathogens as biocontrol agents

Parthenium is an exotic invasive weed that now occurs widely in Ethiopia. Surveys to determine the presence and distribution of pathogens associated with parthenium and further evaluation of the pathogens found as potential biocontrol agents were carried out in Ethiopia since 1998. Several fungal isolates of the genus Helminthosporium, Phoma, Curvularia, Chaetomium, Alternaria, and Eurotium were obtained from the seeds and other plant parts. However, all of the isolates tested were non-pathogenic except Helminthosporium isolates. The two most important diseases were the rust, Puccinia abrupta var. partheniicola and the phyllody, caused by a phytoplasma belonging to the species “Candidatus Phytoplasma aurantifolia”. Host specificity tests revealed that the rust, P. abrupta, only sporulates on parthenium while the phyllody infected parthenium, groundnut, sesame, grass pea, lentil, and chickpea. Suspected insect vectors were examined for phytoplasma infection by means of Polymerase Chain Reaction (PCR). The successful acquisition of phytoplasma’s by the leafhopper, Orosius cellulosus Lindberg (Cicadellidae), was determined by molecular detection of phytoplasma. Phytoplasma was also detected from a single bait plant after feeding by the leafhopper. Sequencing data from phytoplasma obtained from parthenium and the above mentioned crops was identical with sequence identities > 98%. The rust was commonly found at 1400 – 2500 m.a.s.l. with disease incidence up to 100% in some locations while phyllody was observed at 900 – 2300 m.a.s.l. with incidence up to 75%. Individual effects of the rust and phyllody diseases on Parthenium in different locations under field condition showed significant reduction on seed and morphological parameters. Seed production was reduced by 42 and 85% due to rust and phyllody, respectively

Dynamics of root-associated fungal community of canola genotypes in Saskatchewan soils

Non-Peer Reviewe

Podoconiosis and soil-transmitted helminths (STHs): double burden of neglected tropical diseases in Wolaita zone, rural southern Ethiopia

Background Both podoconiosis and soil-transmitted helminth (STH) infections occur among barefoot people in areas of extreme poverty; however, their co-morbidity has not previously been investigated. We explored the overlap of STH infection and podoconiosis in Southern Ethiopia and quantified their separate and combined effects on prevalent anemia and hemoglobin levels in podoconiosis patients and health controls from the same area. Methods and Principal Findings A two-part comparative cross-sectional study was conducted in Wolaita zone, southern Ethiopia. Data were collected from adult patients presenting with clinically confirmed podoconiosis, and unmatched adult neighborhood controls living in the same administrative area. Information on demographic and selected lifestyle factors was collected using interviewer-administered questionnaires. Stool samples were collected and examined qualitatively using the modified formalin-ether sedimentation method. Hemoglobin level was determined using two different methods: hemoglobinometer and automated hematology analyzer. A total of 913 study subjects (677 podoconiosis patients and 236 controls) participated. The prevalence of any STH infection was 47.6% among patients and 33.1% among controls (p<0.001). The prevalence of both hookworm and Trichuris trichiura infections was significantly higher in podoconiosis patients than in controls (AOR 1.74, 95% CI 1.25 to2.42, AOR 6.53, 95% CI 2.34 to 18.22, respectively). Not wearing shoes and being a farmer remained significant independent predictors of infection with any STH. There was a significant interaction between STH infection and podoconiosis on reduction of hemoglobin level (interaction p value = 0.002). Conclusions Prevalence of any STH and hookworm infection was higher among podoconiosis patients than among controls. A significant reduction in hemoglobin level was observed among podoconiosis patients co-infected with hookworm and ‘non-hookworm STH’. Promotion of consistent shoe-wearing practices may have double advantages in controlling both podoconiosis and hookworm infection in the study area