Browsing by Author "Tekie, Habte (PhD)"

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    A Comparative Study on the Ecology of Tsetse Flies (Diptera: Glossinidae) in the Wabe and Walga River Systems
    (Addis Ababa University, 2006-04) Desie, Fikru; Tekie, Habte (PhD); Mebrate, Assefa (PhD)
    The ecology of tsetse flies of the Wabe and Walga River Systems (southwest Ethiopia) was assessed and compared in the present study. Biconical flytraps baited with cow-urine were employed in both areas. No tsetse flies were detected in Wabe River System. However, di-species composition and bi-phasic diel activity of Glossina morsitans and G. pallidipes in Walga River System were determined. The nature of fly abundance and distribution in relation to season and vegetation types were studied. As the dry season progressed, fly distribution was almost restricted to riverine vegetation, but in rainy and early dry season (August, September and December) fly distribution in riverine and bushy grassland vegetation was almost comparable. The infestation of flies in Borer (at Walga River System) was 24.7% and 26.5% for G. morsitans and G. pallidipes, respectively. There was no significant difference in proportion of infestation between the two fly species (P>0.05). Despite no flies were detected in Serite (at Wabe River System), cattle infection was observed at both study sites, and no significant differences were observed between proportions of infected cattle at the two sites (P>0.05). One established fact from the mean packed cell volume (PCV) analysis was that even if the proportion of negative cattle was significantly higher than the proportion of positive cattle in both sites (P<0.05), however there was no significant difference between the mean PCV of negative and positive cattle at both sites. The infection in both flies and cattle was due to Trypanosoma congolense, except in Borer 25% of cattle infection was due to T. vivax. Key words/phrases: Trypanosomiasis, Glossina morsitans, Glossina pallidipes, Serite, Borer, fly infection rate, cattle infection rate.
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    Ecology of Noorda Blitealis (Walker) (Lepidoptera: Crambidae) and Its Management Using Botanicals in Konso Special Woreda
    (Addis Ababa University, 2005-06) Yifrashewa, Negusu; Tekie, Habte (PhD)
    Some ecological aspects of Noorda blitealis as the major defoliating pest of Moringa stenopetala, were studied in Konso area, Ethiopia. The density of immature stages of Noorda blitealis on Moringa trees were investigated in different months of the year. In addition, the host range, major predators of the pest and control aspect of this pest using botanical extract from seeds of Melia azedarach has been conducted The result showed significant (P < 0.05) difference on the egg densities of the pest on the host trees during the study period, with maximum and minimum numbers recorded during March and February, respectively. The difference in the number of caterpillars per host plant in different months was significant (P < 0.05), where heavy infestation was recorded in April and relatively minimum infestation in February. Pupal density of the pest showed significant (P < 0.05) difference during the study period, where the maximum number was found during February and the minimum number during April. The relationship between pest density and weather factors was significant (P < 0.05) and positive correlations (r = 0.899; r = 0.823) of rainfall and relative humidity respectively with larval density. In the contrary, significant (P < 0.05) but negative correlations (r = - 0.992; r = -0.885) of rainfall and relative humidity respectively with pupal density was observed. Noorda blitealis was found to have only one host plant, Moringa stenopetala in the study area. In this study, Myrmicaria sp. and praying mantids were found to be the larval predators of the pest where significant (P < 0.05) difference was observed in the number of larvae between Myrmicaria sp. nested trees and trees where this species were not nested. However, the number of larvae recorded between the Hymenopodidae nestedand the Hymenopodidae non nested host trees was not significant (P > 0.05). Melia seed water extracts of different concentrations; (the 50g L-1, the 75g L-1) and 2ml L-1 (Dursban 48% EC) showed significant (P < 0.05) difference from the untreated control, for their oviposition deterrence on the moths, and repellent activities against the caterpillars. However, there was no significant difference (P > 0.05) among the Melia and insecticide treatments. Melia seed extracts at 25g L-1 was not found to be significantly different (P > 0.05) from the control. The toxicity effects of all the concentrations of these extracts on filter paper showed no significant difference from the control while the chemical pesticide showed significant (P < 0.05) difference. All the concentrations of the Melia seed extracts were not significantly different from the control in causing mortality on the predatory ants, where as significantly (P < 0.05) different mortality of the predatory ants was observed on the insecticide treated filter paper. Key words: Botanicals, Extract, Melia azedarach, Moringa stenopetala, Noorda blitealis, Predators,
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    Evaluation of the larvicidal effects of Annona squamosa and Tagetes minuta essential oils and crude extracts against Anopheles mosquito larvae under laboratory and semi field conditions
    (Addis Ababa University, 2011-06) Assefa, Tigist; Seyoum, Emiru (PhD); Tekie, Habte (PhD)
    The larvicidal activity of solvent extracts of Annona squamosa, Tagetes minuta and essential oils of both plants were evaluated against laboratory colonies and field collected larvae of Anopheles. Shade dried and grounded seed from A. squamosa and floral part of T. minuta were sequentially extracted with acetone, hexane, ethanol and distilled water. A series of concentration of the extracts ranging from 6.25ppm to 100ppm were tested against 3rd-4th instar larvae of An. arabiensis and their percentage mortalities were recorded. The acetone and hexane extracted A. squamosa showed very high larvicidal activity, where 96% and 98% mortality were recorded respectively in the laboratory and 90% and 87.5% mortality respectively in semi- field at a concentration of 100ppm. In the laboratory, the LC50 values of different solvent extracts tested ranged from 13.3ppm to 574.9ppm against An. arabiensis. Similarly, the LC90 values ranged from 48.35ppm to 916.1ppm. However, acetone and hexane extracted A. squamosa with LC50 of 13.3ppm; 23.3ppm and LC90 59.9ppm, 48ppm respectively showed strong larvicidal activity against An. arabiensis under laboratory condition after 24hrs exposure. On the other hand, the field LC50 and LC90 values of tested solvent extracted plants ranged from 28.0ppm to 410.2ppm and 82.45ppm to 656.1ppm, respectively and Acetone and Hexane extracted A. squamosa was the most effective with LC50 28.0ppm;32ppm and LC90 84ppm;82ppm, respectively. Also A. squamosa and T. minutia of essential oils in the present study exhibited a larvicidal activity against 3rd - 4th instar larvae of An. arabiensis. Annona squamosa essential oils exhibited 99% and 71% larval mortality both in the laboratory and semi-field conditions respectively at the concentration of 66.67ppm than T. minuta essential oils. Moreover, of the two tested essential oils, A. squamosa oil induced highest larvicidal effects both in the laboratory and in field with LC50 41.5ppm; 31.5ppm and LC90 79.2ppm; 32.9ppm, respectively. The results suggest that the investigated plant extracts are promising as larvicides against An. arabiensis and could be useful in the search for new and biodegradable plant derived larvicide’s products.
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    The Identification of cereal volatile compounds that attract gravid malaria mosquito, Anopheles Aabiensis Patton (Diptera: Culicidae)
    (Addis Ababa University, 2016-07) Wondwoson, Betelehem; Tekie, Habte (PhD)
    Malaria is a mosquito-vectored infectious disease, which causes serious human health problems in many endemic areas. The dominant malaria vectors in sub-Saharan countries are Anopheles gambiae, Anopheles coluzzii, Anopheles funestus and Anopheles arabiensis. Of these, An. arabiensis is the most widely distributed, versatile and opportunistic vector. The distribution of this vector is frequently correlated with a preference for larval habitats associated with natural and domesticated grasses (Poaceae). Over the past ten thousand years, humans have successfully cultivated grasses and altered the landscape, creating An. arabiensis favourable environments that contain excellent habitats for both larvae and adults. This may indicate that a pre-existing adaptation or preference by An. arabiensis for grass habitats may have co-evolved with human agriculture; to create highly suitable conditions for both the vector and malaria transmission. The distribution and dispersal of An. arabiensis among various larval habitats is mainly driven by the choice of the gravid mosquito for an egg-laying site. To maximise the fitness of their offspring, female mosquitoes should carefully search for habitats with high nutriment, minimal competition and reduced risk of predation. Selection of oviposition site impacts on the survival and development stages of the immature mosquitoes, since larvae are minimally mobile and mature without parental care. The larval habitats also affect adult density, distribution and vectorial capacity. Several cues from the breeding site, such as visual, tactile and olfactory signals, assist gravid mosquitoes to select a suitable oviposition site. Among these, the olfactory cues play a major role in the breeding site selection process, similar to that which has been documented for in other fitness-related activities, such as blood host seeking and sugar feeding. xvii However, few studies have documented the odour-mediated oviposition behaviour of malaria vector mosquitoes. The present studies investigated the effect of olfactory cues emanating from breeding sites associated with the domesticated grasses, rice, maize and sugarcane, on the oviposition preference of An. arabiensis. The volatile compounds associated with the plants and pollen of these grasses were collected by headspace volatile collection, from the above-ground plant tissues of two cultivars of rice (MR1 and MR2), and the pollen of two cultivars of both maize (Bako hybrid-660 and Melkassa 2-521) and sugarcane (Coll-48 and EAK 71-402). Behavioural responses of gravid An. arabiensis to the collected headspace volatile extracts were tested under laboratory conditions, using a two-port olfactometer and a two-choice oviposition bioassay. Headspace volatiles from both cultivars of rice plants as well as maize and sugarcane pollen attracted gravid An. arabiensis and stimulated oviposition. However, the response of the mosquitoes to the volatiles of each crop differed, indicating that females prefer the volatile profiles of specific cultivars. Through combined gas chromatography and electroantennographic detection (GC-EAD) analyses of the headspace volatiles extracts of MR3 rice, BH-660 pollen and sugarcane pollen revealed eight, five and seventeen bioactive compounds, respectively. These compounds were identified using combined gas chromatography and mass spectrometries (GC-MS), revealing that only α-pinene and nonanal were shared among each cereal. Synthetic blends of MR3 rice, BH-660 pollen and sugarcane pollen odour elicited significant attraction and oviposition stimulation of gravid An. arabiensis. Subtractive blends were inferior to that of the full synthetic blends. The synthetic blend of MR3 rice was also tested under semi-field xviii conditions showing gravid An. arabiensis are significantly attracted to the full blend when compared to a solvent control. The results show that gravid An. arabiensis prefer oviposition sites associated with domesticated grasses and that this selection is driven by olfactory cues. Synthetic blends were demonstrated to elicit the complete behavioural repertoire of gravid An. arabiensis mosquitoes. The synthetic blends identified in the present studies are novel for malaria vectors and show great potential to be integrated with other components of Integrated Vector Management (IVM). Key words: An. arabiensis, attraction, stimulation, cultivars, gravid, oviposition
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    Isolation and Identification of Microflora From the Midgut and Salivary Glands of Laboratory Reared and Field Collected Anopheles Species from Some Malaria Endemic Areas of Ethiopia
    (Addis Ababa University, 2018-04-01) Berhanu, Abib; Tekie, Habte (PhD); Dugassa, Sisay (PhD)
    Anopheles mosquitoes are of great importance to human health. They transmit pathogens including malaria parasites, filarial worms, and O'nyong-nyong and rift valley viruses. The numbers of studies have shown that, midgut and salivary gland microflora have an impact on malaria parasite burden through colonization mechanisms, involving either direct Plasmodium microbiota interaction or bacterial mediated induction of mosquito immune response. The objective of this study was to isolate and identify the microflora from the midgut and salivary gland of laboratory reared and field collected Anopheles species in some malaria endemic areas of Ethiopia. A total of twenty pools of mosquitoes, ten per pool (insectary), and ten pools, thirty per pool (field collected) were anesthetized by chloroform and dissected. 70% of ethanol was used for surface sterilization of mosquitoes followed by washing of each pool four times by 1x PBS and the environment. Each pool of dissected midgut and salivary gland samples was transferred in 3ml phosphate buffer saline, squashed and incubated in water bath until enriched in tryptic soya broth for 24hrs at 35±2oc. After enrichment, a loopful of each sample was taken and inoculated on Blood, Chocolate, Mac Conkey and Sabouraud dextrose agar for 24 hrs. at 35±2oc. Finally, the microbiota was isolated based on their colony characteristics and identified by conventional biochemical tests and automated VITEK 2 Compact Analyzer. All identified microbiota was stored in 20% tryptic soya broth with glycerol at -80 oc. From all field collected and insectaries, Pseudomonas 38 (29%) was found to be the dominant microbiota from all species. Anopheles gambiae s.l 77 (50.33%) had got the largest number of microbiota identified and An. arabiensis had identified diversified types of microbiota from the rest species. From this report, 40 genera of microbiota were identified and can be a milestone for studying relationship between microbiota and mosquitoes and for the development of a new malaria control strategy.
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    The Prevalence of Malaria and Associated Risk Factors in Outpatients Visiting Shewarobit Health Center, North Central Ethiopia
    (Addis Ababa University, 2018-09-09) Teshome, Tadegew; Tekie, Habte (PhD)
    Malaria is one of the major public health problems in many tropical developing countries including Ethiopia. The objective of this study was to determine the prevalence of malaria parasite infections and to assess the people's knowledge and practices about malaria transmission, prevention and control measures in Shewarobit town, central Ethiopia. A total of 33,932 outpatients with malaria symptoms gave blood films for malaria diagnosis in the past five years (2013-2017) in Shewarobit Health Center. Among 33,932 cases, 4705 (13.9%) microscopically confirmed malaria cases were reported at the Health Center. Males were more affected than females by malaria infections in each year. Out of 4705 positive individuals 3074 (65.3%) were males and 1631(34.7%) were females. There were fluctuations in trends of the malaria transmission in different months in the study area, with the peak malaria transmission reported from September up to November and from June up to August. A total of 384 outpatients with malaria symptoms were selected and gave blood films for malaria diagnosis from October 2017 up to April 2018. From this cross sectional survey, a total of 73 (19.0%) microscopically confirmed malaria cases were recorded. In multivariate analysis, the association between the prevalence of malaria and age groups of the participants were statistically significant (AOR = 4.340, 95% CI: 1.628-11.565, p=0.003). The Kebeles that the participants lived have associations with the infections of malaria (AOR = 9.300, 95% CI: 2.352-36.774, p=0.001). The association between the prevalence of malaria and income level of the participants were statistically significant (AOR = 2.285, 95% CI: 1.071-4.874, p=0.033). The relationship between the prevalence of malaria and long lasting insecticidal nets were statistically significant (AOR = 0.083, 95% CI: 0.045-0.155, p=0.000). Furthermore between the prevalence of malaria and IRS were statistically significant (AOR = 0.490, 95% CI: 0.255-0.941, p=0.032). Finally the association between mosquito breeding sites and the prevalence of malaria were highly significant in the study area (AOR = 2.573, 95% CI: 1.364-4.854, p=0.004).
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    Restance in maize genotypes to the spotted stem borer, Chilo pm-tellus (Swinhoe) (Lepidoptera: Crambldae)
    (Addis Ababa University, 2006-07) Beredin, Seifedin; Tekie, Habte (PhD)
    In the current study, 134 maize genotypes were screened against C. partelhls at Melkasa Agricultural Research Center (MARC) under field and laboratory conditions. Initially, 134 maize lines against Chilo partelhls were screened based on the number of leaf infestation and dead heart. From 134 lines tested in the field, 34 lines (.'010% infestation) showed promising in terms of C. partelhls resistance, 74 (11-25% infestation) lines were intermediate and the rest 20 lines (>25% infestation) were susceptible. From each category four lines were randomly selected and planted in tlu'ee replication using completely randomized design (CRD) to verify the plantsresult obtained under field screening. Number of egg masses and leaf infestation per plant were recorded and then dissected to check for number of borer density, larvae exist holes and tunnel length. There were significant differences for all parameters were observed among the three categories. Furthered more, the results confirmed the presence of similar trends with field screening result in leaf infestation with screen house outcome. Finally, the growth and development of the borer were measured on the most susceptible and resistant maize lines which were de!ermined under natural, and m1ificial infestations. These maizelines were examined for their relative resistance to the C. parfel!us (Swinhoe) in relation to feeding. Freshly hatched larvae of C. parfel!/ls were allowed to grow on the leaf sheath and stem cuts of the two lines separately. The rate of growth, egg lying, egg hatchability, pupation, and adult emergence were studied. The insects showed better growth when reared on susceptible maize line than on the resistant line. The majority of Ethiopian farmers have small land holdings. For these reasons, and the hazards associated with insecticide applications, there is a great need to develop varieties that can resist pest attack with out requiring any traditional expenditure by the farmers.
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    The Role of Grasses in Natural Breeding Habitats of Gravid Female Anopheles Mosquitoes (Diptera: Culicidae) on Oviposition Preference as Well as Larval Development and Survival
    (Addis Ababa University, 2017-08) Asmare, Yelfwagash; Tekie, Habte (PhD)
    The malaria vectors Anopheles arabiensis and Anopheles coluzzii are widely distributed in sub- Saharan Africa, the region with the highest malaria burden in the tropics. Previous research findings show both positive and negative correlations between Anopheles larvae productivity and vegetation in and close to breeding habitats. The aim of the present studies is to determine species specific association between Anopheles mosquitoes and grasses in natural habitats. Larval sampling in natural breeding sites associated with grasses was used as a proxy to identify the link between grasses and oviposition preference in Anopheles mosquitoes. Grasses have their own impacts on the life cycle and oviposition behavior of mosquitoes and exploiting their potential in vector control is a novel approach. Oviposition behaviour of Anopheles mosquitoes is odour-mediated and behavioural response of An. arabiensis and An. gambiae/An. coluzzi to volatile extracts of grasses using oviposition and attraction bioassays were investigated. The results showed that grass volatiles affect differentially oviposition site selection by Anopheles mosquitoes. Both the larval Anopheles in natural breeding habitats and gravid female of An. arabiensis and An. coluzzi in laboratory demonstrated strong preference to Poaceae grasses than Typhaceae and Cyperaceae grasses (P < 0.05). The dietary effects of grasses pollen was studied to test why gravid Anopheles mosquitoes and their larvae show preference hierarchy to grasses. The hypothesis that dietary effect of pollen of grasses is based on the quality of pollens and this is characterized by C: N ratio and grain size of pollens. The results showed that there were significant differences between pollen from grasses by their C: N ratio and grain size (P < 0.0001), and these differences demonstrated differential effects on development rate and survival of larval An. arabiensis (P < 0.05). The pollens from all xvii the grasses enhanced pupation rate more than the nitrogen rich artificial diet TetraMin®. The small grained and carbon rich Typha latifolia and Pennisetum setaceum pollens resulted in more enhanced development rate of larval An. arabiensis than the large grainedcarbon-rich Zea mays pollen, nitrogen-rich TetraMin® fish food and Echnocloa pyramidalis pollen. Zea mays pollen, and TetraMin® fish food equivalently increased survival of larval An. arabiensis develop in to adulthood. The effects of grass pollens in larval diets were more pronounced in the females of An. arabiensis. This is similar with previous studies, indicate that male anophelines develop faster and emerge sooner than females. The effect of grasses oils on larval survival was also studied to test why both gravid Anopheles mosquitoes and their larvae showed lower preferences to Typhacae and Cyperaceae grasses and especially no larvae was found in natural breeding habitats associated with Cyperaceae. The absence of Anopheles larvae in habitats with Cyperaceae grass is due to higher production of natural oil and this could result in mortality of larval Anopheles due to toxic nature of Cyperaceae grasses in addition to the physical nature of oils that causes suffocation. The results showed the rhizome sections of C. papyrus had significantly higher oil content (2.09 ± 0.23) than that of T. latifolia (1.455 ± 0.011) (P <0.05). Oil extracts from both T. latifolia and C. papyrus significantly increased larval mortality on An. arabiensis in a dose dependent manner (P<0.0001). No significant differences were observed between oils of the two grass species (P = 0.624). In contrast, increasing the doses of the oils had significant positive correlation with larval mortality of the tested mosquito (P < 0.0001). Therefore, it is possible to conclude that presence/growing of C. papyrus in breeding habitats could reduce Anopheles mosquito population due to the larvicidal effect of higher amount of natural oil production by its rhizome. xviii Generally grasses close to and in breeding habitats are drivers of vector population dynamics and malaria transmission: grasses volatiles modulate oviposion site selection, grasses pollen has larval nutrition input and grasses oils markedly affect larval survival and development of Anopheles mosquitoes. The findings in this study indicated that Poaceae and Typhaceae grasses are indicators for the availability of suitable breeding habitats for Anopheles mosquito and could help for monitoring malaria vector populations and for planning malaria interventions. In contrast, Cyperaceae grasses can be promising component of integrated malaria vector management as the rhizome had higher amount of oil which could be released directly to the breeding water with larvicidal effects on An. arabiensis. Key words: Anopheles arabiensis, Anopheles coluzzii, gravid mosquitoes, attraction, oviposition, larval survival, grass volatiles, pollen, oils
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    Screening of Sorghum Genotypes Against Spotted Stem Borer, Chilo Partellus (Swinhoe) (Lepidoptera: Crambidae)
    (Addis Ababa University, 1990-06) Kibret, Zerubabel; Tekie, Habte (PhD); Getu, Emana (PhD); Tefera, Tesfaye (PhD)
    Sorghum (Sorghum bicolor (L) Monech) is among the leading cereal grains produced in Africa and it is a staple food for millions of people in the continent. In Ethiopia, sorghum stands third in terms of area coverage after teff and maize, and second in terms of yield per hectare after maize. The spotted stem borer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) is a major constraint limiting production of sorghum in Ethiopia. The present study was conducted at Melkassa Agricultural Research Center experimental field with the main objective of screening sorghum genotypes which are resistant against Chilo partellus. Two hundred one sorghum genotypes were planted at Melkassa Agricultural Research Center in two replications in Randomized Complete Block Design. Twelve of these genotypes were selected for artificial infestation study in screen house pot experiment depending on stem borer percent infestation. The twelve genotypes were four from resistance, four from intermediate and four from susceptible groups and they were planted in pot in screen house in completely randomized design in three replications. Forty mated C. Partellus adults were released in to the set up for artificial infestation of the genotypes. Population growth of C. partellus was also studied on the most resistant and the most susceptible genotypes. The results obtained indicate that there were high level of variability among the genotypes tested both under natural infestation of field condition and artificial infestation of pot-screen house experiment. Significantly (P < 0.05) lower number of egg masses, lower percent hatchability, lower percent pupation and lower percent survival of C. partellus were recorded on A3 X 76 T1 # 23 suggesting that there is a possibility of developing C. partellus resistant varieties. However, further evaluation of the sorghum genotypes, which are found in different adaptation areas are important and there is also a great need to develop varieties by breeders that can resist stem borer attack. Key words: Sorghum bicolor, spotted stem borer, genotypes, artificial infestation, screen
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    Status of Malaria in Wau Town, Western Bahr El Ghazal, South Sudan
    (Addis Ababa University, 2017-03-03) Ngor, Chan; Lakew, Mekuria (PhD); Tekie, Habte (PhD)
    South Sudan, like all other East African Countries through Global Fund had implemented several control programs as per recommendation of WHO and succeeded to reduce malaria transmission from intense to interrupted transmission contributing to the implementation of the elimination/eradication program in the years to come. Investigation of the transmission pattern of the hotspot foci and understanding the dynamics of malaria transmission was essential. Therefore, this study planned Hotspot study on urban epidemiological setting of Wau town/city. Cross sectional studies of the town at 2 months intervals in the dry season and two others in wet season were planned. Sample size was determined, peripheral blood Smear and RDT serological methods were adopted as standard methods of prevalence study, positive in both were considered for determination of the prevalence. Accordingly, four (4) study sites were selected and data collection was completed in Hai Nazareth, just before the unpredicted war between the rebel and the government forces broke in the town. Hence, relying on one time cross sectional study for prevalence study and the retrospective data of the preceding year, 2015, taken from Health clinics and hospitals to establish the parasite prevalence. There was transmission throughout the year and an increase in all age groups in the rainy seasons between June and October with peak August-October. Infected individuals who visited the hospital and were found positive are larger in number in the age groups 6-15 and above 15. The result showed that 35% of infection in those under 5 years is greater than 23% of those between 6-10 years indicating that the under 5 are the high risk groups. The 16.1% in those under 1 year are most vulnerable for at that age they do not have protective immunity ready yet. P. falciparum was the only species diagnosed, accounting for 47.51% of all subjects who visited for any other infections (52.49%), suggesting the health significance of Malaria in the population. Primary data done in May and June showed 32.6% infection rate in the sample population of which 5.2% were children under 5 while the age groups 6-15 and above 15 years had 13 and 14.4% respectively. All were asymptomatic cases. Given the retrospective study that showed a year round transmission with a peak between June and October and then a decline to lowest level in December, the Frequency of infection in Children and age group below 15 is a high level of infection and above 15 had relatively higher infection. The demographic distribution of the study population, Metrological data of the town, age distribution of the parasite prevalence, identification of major and minor vectors were also reflected and their implications in breaking transmission were discussed.
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    Studies on Salivary Gland Hyperplasia Virus (SGHV) Transmission In Glossina Pallidipes Colony Using Conventional and Molecular Techniques
    (Addis Ababa University, 2007-07) Kiflom, Musie; Tekie, Habte (PhD)
    In Ethiopia five species of tsetse flies were recorded from different parts of the country. Glossina pallidipes is one of the five species which cause a fatal disease to human and animal. Sterile Insect Technique (SIT) as a component for tsetse fly control and eradication programme is one of the successful techniques in some insect pest eradication programmes. However, the presence of salivary gland hyperplasia virus affects the application of SIT technique in tsetsecontrol as it limits the mass rearing activity. It is widely accepted that tsetse plays host to salivary gland hyperplasia virus. This study mainly focused on virus free line establishment and the antiviral drug treatment using more than 1800 G.pallidipes Tororo and 3072 G. pallidipes Arbaminch strains. Prior to the large scale experiments, two preliminary surveys were done on virus free line establishment and antiviral drug treatments. All experiments were analyzed using PCR, dissection and QPCR methods. The preliminary survey on the investigation of the virus free line by dissection showed that 4.45% male flies and 3.09% of female flies were positive for salivary gland hyperplasia, whereas in PCR analysis 95% of the flies were positive for SGHV. In the virus free line establishment a total of 920 female flies were taken by randomly and 13.04% were selected by PCR as positive or negative flies for salivary gland hyperplasia and two out of 120 female flies died. Among 120 flies, 26.7% male and 15% female including the dead flies were negative and 35.8% female and 22.5% male flies were positive by PCR. All screened flies were grouped into four groups as Virus free line I, II, III and IV. In the preliminary survey of the antiviral drug, female flies treated with valacyclovir treated flies produced more pupae than acyclovir treated flies. In the main experiment of the antiviral drugs valacyclovir treated flies showed no significant difference P>.072. But, acyclovir and control showed significant difference P<.000 and P<.005 at P=0.05, respectively. Key words: Glossina pallidipes, SIT, Salivary gland hyperplasia virus, virus free line, Trypanosomosis
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    Studies on Species Composition And Behaviour of Anopheles Mosquitoes (Diptera: Culicidae) and Insecticide Resistance Management Option For The Control of Malaria Vectors in Selected Sites in Butajira Area, Southern Ethiopia
    (Addis Ababa University, 2018-04-03) Kinfe, Esayas; Tekie, Habte (PhD)
    Detection and monitoring of insecticide resistance in malaria vectors is crucial and has to be conducted together with other entomological indices for effective vector control. The aim of this study was to identify species composition of Anopheles mosquitoes, behaviour and feasibility of resistance management using rotation of indoor insecticides spray combined with different insecticide impregnated long lasting insecticidal nets. Monthly larvae and adult Anopheles collections were undertaken from May 2013 to June 2015 in Intervention (Jolie) and Control (Gogete) study sites. Identification of Anopheles species were done using morphological keys under a compound microscope as well as 10% of the adult specimens identified as Anopheles gambiae s.l. also subjected for species-specific polymerase chain reaction (PCR) test for sibling species detection. Abdominal status, host and resting preferences, indoor resting density, parity rate, sporozoite rate, man biting rate and entomological inoculation rate were compared among the Intervention (Jolie) and Control (Gogete) study sites to evaluate the impact of the resistance management option used in Intervention study site (Jolie). Besides, An. gambiae s.l. susceptibility tests result carried out every year throughout the study period (in the month of August 2013, 2014, 2015 and 2016) to determine the susceptibility status of An. gambiae s.l. among the Intervention (Jolie) and Control (Gogete) study sites were compared to observe the impact of the resistance management option. To detect the presence of the L1014S and the L1014F kdr mutation a sub-sample of An. arabiensis and An. gambiae were selected from both study sites and tested using adapted versions of the allele-specific polymerase chain reaction (from October 2016 to April 2017). xx A total of 4118 third and fourth instars larvae of Anopheles mosquitoes used for identification, ten in Intervention study site (Jolie) and eleven in Control (Gogete) Anopheles species were identified. Most of Anopheles larvae (27.5%) were collected from marshy breeding site which served as major breeding sites during the study period, followed by irrigation canals (24.5%), rain pools (20.4%), river pockets (17.6%) and ponds (9.9%). In both Intervention (Jolie) and Control (Gogete) study sites the predominant Anopheles species was An. gambiae s.l. which is the main vector in the country. Statistically significant (p<0.05) seasonal variations were observed in the larval collection of Anopheles larvae in Intervention (Jolie) and Control (Gogete) study sites. In line with this a total of 4461 indoor adult female Anopheles were caught of which 1386 (31.1%) from Intervention (Jolie) and 3075 (68.9%) from Control (Gogete) study site. Out of 1386 of female Anopheles mosquitoes caught from Intervention study site (Jolie) An. gambiae s.l. was the predominant species making up 63.9% followed by An. pharoensis 19%. Similarly, out of 3075 of female Anopheles mosquitoes caught in Control study site (Gogete) also An. gambiae s.l. was the predominant species (64%) followed by An. pharoensis (19.1%). Significant (p<0.05) higher number of An. gambiae s.l. and An. pharoensis were collected in the Control (Gogete) than in the Intervention (Jolie) study site. Out of 239 An. gambiae s.l. subjected for PCR sibling species identification 94.1% were found An. arabiensis and 5.9% An. gambiae. At species level in Intervention study site (Jolie) An. gambiae s.l. showed high tendency to feed on bovine 53.8% followed by human 47.9%, unlike in Control (Gogete) An. gambiae s.l. showed high tendency to feed on human 57.1% followed by bovine 40.6%. xxi Statistically significant differences (p<0.05) with low HBI in Intervention (Jolie) than Control (Gogete) study site were observed in An. gambiae s.l. In Intervention (Jolie) the parity rate for An. gambiae s.l. was 45.8 and in Control (Gogete) 52.6 determined. Statistically significant differences (p<0.05) of parity in An. gambiae s.l. and An. pharoensis were observed among the study sites, that is low parity rate found in Intervention (Jolie) than Control (Gogete) study site. The result of sporozoite rate of An. gambiae s.l. in Intervention study site (Jolie) for Pv-210 was (1.1) and in the Control (Gogete) study site (2.8), however for Pf the same result 1.1 detected in both study sites. Statistical significant differences (p<0.05) were observed between Intervention (Jolie) and Control (Gogete) study sites on indoor resting density in both species of An. gambiae s.l. and An. pharoensis, as well as in man-biting rate of An. gambiae s.l. An. gambiae s.l. resistance to DDT, permethrin, malathion, deltamethrin and bendiocarb were detected in both study sites. However, in Intervention (Jolie) An. gambiae s.l. susceptible populations increased in 2016 than 2013, that is significant (p<0.05) improvement on mortality rates due to the tested seven insecticides observed in the Intervention study site (Jolie), while in Control (Gogete) were not. The L1014F kdr mutation in An. arabiensis detected at a relative high frequency 41.7% in Control study site (Gogete) and 35.9% in Intervention (Jolie). Besides, two in Intervention study site (Jolie) and seven in Control (Gogete) heterozygous alleles for L1014F were found in the tested An. arabiensis specimens. However in An. gambiae both xxii kdr mutations were not detected in both study sites. The L1014S kdr alleles were not found in the two study sites. The breeding habitats of Anopheles mosquitoes in the study sites particularly in the dry season were due to human activities rather than environmental causes that require larval control. In the present study An. gambiae was reported for the first time in addition to An. arabiensis in Ethiopia indicating the presence of the highly efficient vector in Ethiopia, thus establishing appropriate control strategy for this species might be necessary. Anopheles gambiae s.l. resistance to DDT, permethrin, malathion, deltamethrin and bendiocarb insecticides in the study sites is worrying. Moreover, West African kdr mutation was found in a higher rate this kdr mutation was related with high levels of both pyrethroid and DDT resistance than East African mutation and furthermore the presence of the incomplete heterozygous state indicates the continuity of kdr incidence shows the needs to urgently implement resistance management strategies. The observed significant reduction of indoor resting density, human host preference, man biting, parity rate as well as increment of susceptibility in An. gambiae s.l. in 2016 compared to that of 2013 clearly indicates the effectiveness of the selected resistance management option applied in Intervention study site (Jolie).
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    Studies on the Effect of Intercropping and Application of Livestock Manure on the Infestation and Damage of Kale (Brassica Oleracea L. Var Acephala) By Diamondback Moth, Plutella Xylostella (Lepidoptera: Plutelliddae) in A Bio-Farming Systems.
    (Addis Ababa University, 2007-05) Beyene, Belay; Tekie, Habte (PhD); Tikubet, Getachew (PhD)
    Kale (Brassica oleracea var. acephala) is an important source of income to many small-scale farmers in Ethiopia and is a major dietary component for many Ethiopians. The production of kale is, however, constrained by several pests among which diamondback moth (Plutella xylostella) is the major insect pest. Control of diamondback moth has mainly been by pesticides, which has resulted in pest resistance and pollution of the environment. This study attempts to look into alternative environmentally friendly ways of controlling diamondback moth larvae on kale in selected site in Ethiopia. Field studies and Screen house experiments were conducted to determine the effect of intercropping and livestock manure on the diamondback moth larval density and damage on kale. Parasitoid species and percentage parasitism are also determined. Intercropping kale and onion (Allium cepa) both with and without manure significantly reduced (P<0.05) the densities of P. xylostella larvae and damage on kale leaves compared to control plots. The lowest larval densities and damage on leaves were recorded in kale- onion intercropping with manure application. In addition significant reduction (P<0.05) in leaf damage was observed in Screen house experiments of kale grown on manure applied soil. Moreover, significantly higher marketable leaf weights were recoded in kale monocrop with the application of livestock manure as compared to kale monocrop without manure application. Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae) which is larval-pupal parasitoid and Apanteles spp. (Hymenoptera: Braconidae) which is larval parasitoid were recorded on diamondback moth during the study. Parasitism in diamondback moth larvae and pupae by these parasitoids were 16.33%. with O. sokolowski 9.96% and Apanteles spp. 6.37%. The results in the present study indicate that intercropping kale with onions can be effectively used to suppress diamondback moth larval density, reduce leaf damage and improve yield of kales.
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    Studies on the Prevalence of Malaria and Utilization of Mosquito Nets in Dubti Woreda, North East Ethiopia
    (Addis Ababa University, 2019-05-05) Wogderes, Andualem; Tekie, Habte (PhD)
    Malaria is a major health and socio-economic problem in developing countries of the world including Ethiopia. This study was aimed to determine the prevalence of malaria infection in patients who visited Dubti Health Center for the last five years (2006 – 2010 E.C). A retrospective study was conducted to determine the prevalence of malaria infection from laboratory registered records in Dubti Health Center and 274 household heads were purposely selected from Kebele 01 of Dubti town and rural Kebele Ayrolaf to assess the knowledge, possession and utilization of mosquito nets. Examination for malaria parasites was carried out using light microscope and rapid diagnostic test. Structured questionnaires were administered to gather relevant information on socio-demographic, associated risk factors of malaria infection, possession and utilization of mosquito nets in households. Data were entered and analyzed using Microsoft Excel 2010 and SPSS version 20. Prevalence of the disease was 9.1% and 3.3% in males and females, respectively. During the past five years, a total of 47,651 thick and thin Giemsa stained blood films were examined for malaria diagnosis in Dubti health center and 4153 (8.7%) microscopically confirmed malaria cases were reported with slightly lower in magnitude from 2006 to 2009 E.C, and slightly increased in 2010 E.C. The overall prevalence of malaria infection was 8.7 %. Prevalence of Plasmodium falciparum, Plasmodium vivax and mixed infection of the two were 91.3%, 8.6%, and 0.2%, respectively. Prevalence of the disease was 62.6% and 37.4% in males and females, respectively. Mixed infection was observed in age groups of 5- 14, and ≥15 years old. The association of prevalence of malaria infection with sex and age was statistically significant (P < 0.05). The apparent fluctuation of malaria trends in the area and the highest peak of malaria cases were reported during the month of February in the last five years. Malaria prevalence was 12.4% and the knowledge of malaria transmission and control was good. The concerned bodies should inspect, follow-up and create awareness of the community about the use of mosquito net for the intended goal in the study area.
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    Studies on the Spatial Ecology of Malaria and the Impact of Mass Trapping of Anopheles Mosquitoes on Malaria Transmission in Southern Ethiopia
    (Addis Ababa University, 2020-07-06) Debebe, Yared; Tekie, Habte (PhD); Ignell, Rickard (Professor); Rose, Sharon (PhD); Hopkins, Richard (Professor); Dugassa, Sisay (PhD)
    The sustainability of current indoor vector control methods is challenged by the emergence of insecticide resistance in malaria mosquito populations and the behavioural shift of vectors, resulting in increased outdoor biting activities. As a result, there is a dire need for novel vector control tools, which complement the existing strategies, particularly targeting the outdoor-active mosquitoes. Effective control of mosquitoes outdoors can be achieved through in-depth understandings of their spatial and behavioural ecology. The effect of landscape elements on the resting site selection of the outdoor Anopheles mosquito population was assessed. Fine-scale characterization of landscape factors within 10 m radius from resting clay pots was conducted and their association with the number of resting anophelines was determined. Canopy cover, distance from the nearest focal house, and land cover type significantly influenced the aggregation of resting mosquitoes. Canopy cover was the strongest predictor for both the number and presence of Anopheles mosquitoes in the clay pots. Female Anopheles were most frequently found resting in the pots placed within the banana plantations, and at sampling points that were ≥75 m from the focal house. To identify the factors underlying hotspots for higher vector densities and malaria incidence, and associated landscape features, monthly entomological monitoring, and fourstage repeated seasonal malaria prevalence surveys were conducted in two rural villages in southern Ethiopia. Moreover, characterization of the landscape features in and around every household of the study villages was conducted. Spatial analyses using Getis-Ord Gi* statistics were used to identify hotspots for malaria incidence, as well as malaria vector density and associated sporozoite prevalence. The result from the regression models revealed that household occupancy, location and housing conditions were the main iv predictors of vector density, entomological inoculation rate, and malaria incidence. The spatial analyses revealed that statistically significant hotspots for malaria vector densities and Plasmodium-infected individuals were identified at village edges. The impact of mass trapping of Anopheles mosquitoes using odour-baited traps was assessed in a controlled before-and-after study design in two rural villages of Southern Ethiopia. Baseline monthly entomological and seasonal cross-sectional malaria prevalence surveys were conducted in the two villages for a year. Then, mass trapping was implemented in one of the villages immediately before the beginning of the rainy season, while the monthly entomological monitoring and the seasonal malaria prevalence surveys continued in both villages for nine months, throughout the long and short rainy seasons. The impact of the mass trapping was then assessed by computing the relative reduction of entomological indices and malaria incidence in the intervention village in a seasonal comparison with the control village. The mass trapping resulted in a significant reduction in the population of the primary malaria vector in the area, An. arabiensis and the associated entomological indices (the human biting-, sporozoite-, and entomological inoculation rates) in the intervention compared to the control village. This resulted in a relative reduction of malaria incidence by 61 %, 44 %, and 49 % in the long rain, short rain, and dry seasons, respectively.
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    Studies on the Species Composition and Behaviour of Anopheles Mosquitoes in Relation to Malaria Transmission in Doubti Woreda (Afar Region)
    (Addis Ababa University, 2005-06) Kibretu, Misge; Tekie, Habte (PhD); Seyoutn, Aklilu (PhD)
    The species composition and behavior of Anopheles mosquitoes was studied in three selected agriculturally irrigated villages in Doubti Woreda (Afar region ) . Information on the malaria cases were also gathered from Afar Regional Health Bureau and Doubti hospital . The results of malaria case data showed that malaria has perennial transmission and its incidence increased from year to year. Plasmodium falciparum followed by Plasmodium vivax are the most frequently prevalent Plasmodium parasites in this area. Although both males and females are infected with malaria , males are more vulnerable. Age groups above 15 years are more affected followed by age groups 5- 14 years. Larvae collected from different breeding habitats throughout the study period showed the presence of two species: Anopheles arabiensis and Anopheles pharoensis, of which Anopheles arabiensis was predominant and encountered in several breeding habitats throughout the study period. Adult Anophelines collected from different resting places revealed that both Anopheles arabiensis and Anopheles pharoensis predominantly rest indoors than outdoors. Anopheles arabiensis collected indoor by aspirator shows significance difference at %2 = 5.544, P = 0.019. The biting behavior of these two species was predominantly exophagic. Anopheles arabiensis collected by human bait shows significance difference at %2 = 30.0 IP = 0.00. However, CDC light trap collection of this species shows predominantly indoor density at y2 = 65.47, P= 0.000. The parous rate of Anopheles arabiensis was 23.8% where as that of Anopheles pharoensis was 16.6%. The salivary glands dissected for sporozoite rate showed none of which were found infected with sporozoites.
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    Study on the Effects of Manure Application and Host Plant Spacing on the Infestation Level and Damage of Thrips Tabaci Lindeman (Thysanoptera: Thripidae) on onion.
    (Addis Ababa University, 2006-07) Assefa, Thomas; Tekie, Habte (PhD)
    The study on the effect of manure application and other cultural practices on the infestation level and damage of Thrips tabaci on onion was conducted in Cheha Woreda, Luke Kebele of the Gurage Zone from December to April 2005. The field study was on the impact of manure application and plant spacing on the infestation level, damage, size and number of leaf and bulb yield were carried out on the demonstration site, and where as the effect of organic manure application on onion thrips density was based on cage experiments conducted using Complete Randomized Design (CRD) in five replications. The field experiments was performed using a Randomized Complete Block Design (RCBD) involving six treatments from a factorial combination of organic manure application, plant spacing and untreated controls. The results on the effect of organic manure application on onion thrips density indicated that, the lowest number of adult and larvae T. tabaci was obtained from onions planted on soil with manure application before transplanting. The highest density of onion thrips was recorded from the untreated controls. The investigation on the impact of manure application and plant spacing on the infestation, damage levels, size and number of leaves of onion revealed that starting from 45 days after transplanting treatments with before transplanting manure application (BTMA) at 20x30cm and 20x25cm showed lower mean count of thrips per plant, and highest leaf size followed by the treatment at transplanting manure application with 20x30cm plant spacing. The damage level was identified as mild at 15 and 30 days after transplanting and at older stages intermediate damage was recorded on most plants. On the other hand, the control treatments with 20x20cm and 20x25cm plant spacing had the highest infestation, with the smallest leaf sizes and characterized by intermediate damage at early stages and sever attack as the crop matured. The study on the effect of organic manure application in cage experiments, demonstrated that the lowest mean number of larvae and adults were obtained from manure application before transplanting followed by at transplanting manure application and the highest being the control with no manure application. The survey on alternate host range of onion thrips in the study area showed that five cultivated vegetables, a cereal crop and one wild plant were found to harbor the insect pest on their leaves. The highest number of thrips per plant and percent total infestation was recorded from onion followed by Kale (Brassica oleracea L.var acephala) and wild Sorghum (Sorghum arundinaccum). Finally, the survey on impact of the system on the occurance of predatory beneficial insects showed that, three different generalist insects and spiders were encountered in the field feeding on onion thrips larvae and adult. Finally, this study emphasized on a new strategy of managing onion thrips in which host plant spacing and nutrient management were integrated to suppress the pest population and improved the crop health and vigority to withstand the damage to a certain limit.
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    Visceral Leishmaniasis L. Donovani; P. Orientalis Migrant Labourers Rodents Agriculture Fields Thickets of A. Seyal Dense Mixed Forest
    (Addis Ababa University, 2015-06-09) Lemma, Wossenseged; Tekie, Habte (PhD)
    Kala-azar (visceral leishmaniasis; VL), due to Leishmania donovani, is transmitted by Phlebotomus orientalis in Metema Humera lowlands where this disease is a major health problem. The aims of this study were to determine seasonal dynamics, habitat preferences, nocturnal activities, host preferences, and Leishmania infections of P. orientalis in addition to study on sero-prevalence of L. donovani infection in migrant labourers with associated risk factors and the role of rodents as reservoir hosts of VL. Centers for Disease Control and Prevention miniature light traps (CDC traps) (John W. Hock, USA) and/or sticky paper traps were used for sand fly collections. The blood meal sources for P. orientalis were detected by reverse line blot (RLB) of cytochrome b polymerase chain reaction (PCR) amplification products using 11 probes for domestic animals. Polymerase chain reaction amplification of internal transcribed spacer 1 (ITS1) and kinetoplast DNA (kDNA) markers were used to detect Leishmania infections in P. orientalis. Blood for direct agglutination test (DAT) was sampled, randomly, from migrant labourers involved in sesame harvest to study sero-prevalence of L. donovani infection and entomological risk factors. Sherman collapsible rodent traps were used to capture rodents. The rodents were anaesthetized before sacrificed for tissue biopsies from liver, spleen, bone marrow and tip of the nose (skin) in addition to blood for screening of Leishmania infections. The species of the rodents were identified by their morphological characters. The tissues from liver, spleen and skin were macerated in Locke’s solution before transferring them into Novy-McNeal Nicolle (NNN) medium for Leishmaniacultivation. Blood and touch smears of liver, spleen, skin and bone marrow were made on microscope slide and allowed to air dry before fixing using methanol and xix staining by Giemsa stain for microscopy. Polymerase chain reaction technique was also used to identify Leishmania infection in the tissues of the rodents. The studies were conducted from May, 2011 to January, 2014. During study on bionomics of P.orientalis, a total of 376, 441 sand flies using CDC light trap (n=955) and sticky traps (n=5, 551) were collected from May 17, 2011 to June 6, 2012 from agriculture fields, thickets of Acacia seyal and dense mixed forest. Of these sand flies, 313, 055 (80.45%) were Sergentomyia species. The highest mean monthly density of P. orientalis trapped by CDC light traps was found in thickets of Acacia seyal in March (64.11 + 75.87). The corresponding highest mean monthly density of P. orientalis trapped by sicky traps was found in April (58.69 + 85.20) in agricultural field. No P. orientalis were caught in September using CDC traps and July - October using sticky traps. The overall mean monthly density of P. orientalis (female and male) trapped by CDC light traps was 15.78 + 28.93 (n=320) in agricultural field, 19.57 + 36.42 (n=255) in thickets of A. seyal, and 3.81 + 6.45 (n=380) in dense mixed forest. For sticky traps, the overall mean monthly density of P. orientalis was 14.76 ± 38.78 (n=2378) in agricultural fields, 11.45 ± 15.56 (n=1500) in the thickets of A. seyal and 0.95 ± 2.16 (n=1168) in dense mixed forest. Analysis of variance (ANOVA) result has showed statistically significant mean difference (p=0.000) for different habitats. Phlebotomus orientalis, P. papatasi, P. duboscqi, P. bergeroti, P. rodhaini, P. martini and P. alexandri were the Phlebotomus species found in the area. Phlebotomus orientalis was the dominant species (99%) in the extra-domestic study sites. During January to May, 2013 collection of P. orientalis at hourly intervals using 22 CDC light traps, the peak activities of P. orientalis were at 1.00 hr (134.0 ± 7.21) near animal shelters, 3.00 hr (66.33 ± 46.40) in agricultural fields and xx 21:00 hr (40.6 ± 30.06) in thickets of A. seyal. This species was not attracted to the different species of rodents in trials carried out in March and April, 2013. Riverse line blot PCR identified 7 human (28%), 9 mixed (human and cattle) (36%) and 2 cattle (8%) blood meals while 7 were unknown (28%). Molecular screening of 30 pools (1 pool = 5 individual P. orientalis) from dense mixed forest in July (rainy season), 2011, for Leishmania infection, was performed by targeting kDNA in a PCR assay. Five pools (5/30, 16.7%) were positive for Leishmania kDNA PCR. For March–May, 2013 dry season collections, 9/15 pools (60%) were ITS1 PCR positive. Of the total 359 labour migrants screened during October – November (2013), using DAT, 45(12.5%) were seropositive (≥1:800) for L. donovani infections with risk of VL development in 3 (0.8%) individuals who had very high titer (1:12800). Leishmania donovani infection in labour migrants seemed to correlate more with relatively higher density of P. orientalis during the June – August weeding season than the September – October harvest season. Staying in the areas both in the weeding and harvesting seasons (p=0.035; odds ratio (OR) = 2.83) and sleeping in the agricultural fields (p=0.01; OR=15.096) were positively correlated with L. donovani infection. Night harvest (p=0.028; OR=0.133) and knowledge about sign or symptoms (p=0.042; OR=0.383) were negatively associated with this infection. A total of 128 rodents such as Arvicanthis niloticus (n=68), Acomys cahirinus (n=25), Tatera (Gerbilliscus) robustus (n=21), Mastomys erythroleucus (n=3), Mylomys albipes (n=2), Rattus rattus (n=5), Paraechimus aethiopicus (Hedgehog) (n=2) and Xerus erythropus (striped ground squirrel) (n=2) were trapped and screened for Leishmania infections by parasitological, serological and PCR techniques. Of 91 rodents collected from extra-domestic habitats of Beaker and Gelanzeraf (Kafta-Humera district) and xxi analyzed by ITS1 PCR using skin, spleen, liver and bone marrow samples, 6/54 (11.1%) of Arvicanthis nilothicus were positive compared to the infection rates in Acomys cahirinus (3/17 or 17.6%) and Tarera (G) robustus (2/16 or 12.5%). Almost all the PCR infections were found from bone marrow samples (8/48 or 16.7%) compared with 1/91(1.1%) liver, 2/87(2.2%) spleen and 0/87 (0%) skin. Different organs on the same rodent were not found infected. These rodents were negative with NNN-medium, microscopy (Giemsa stains) and direct agglutination tests (DAT) except 2 Arvicanthis niloticus NNN-medium positives spleen samples from Baeker. The remaining 37 Arvicanthis niloticus,Acomys cahirinus, Tatera (G) robustus, Mastomys erythroleucus, Mylomys albipes,Paraechimus aethiopicus (Hodge hoge), Rattus rattus and Xerus erythropus (striped ground squirrel) collected from Baeker, Ademiti, Mayhas and Adijamus (western Tigray)screening using NNN-medium, Giemsa stain and DAT were negative. Agricultural fields and thickets of A. seyal habitats are the breeding sites for P. orientalis in extra-domestic habitats of Kafta Humera lowlands where female P. orientalis can bite humans at any hour of the night with peak biting after mid night. Sleeping in open agricultural fields was related to L. donovani infections in labour migrants. Arvicanthis niloticus, Acomys cahirinus and Tarera (G) robustus might play important role in the transmission cycle of zoonotic VL in endemic lowlands areas of Ethiopia. Further studies are required for L. donovani isolation from rodents in the endemic areas in addition to experimental infection for xenodiagnosis before considering these rodents as reservoir hosts of L. donovani conclusively. Access and proper use of bed nets, especially during crop growing season, are required for reducing the incidence of the infection. Key words:Visceral leishmaniasis; L. donovani; P. orientalis; migrant labourers; rodents; agriculture fields; thickets of A. seyal; dense mixed forest