The impact of Gibe III hydroelectric dam on the situation of livestock diseases with particular emphasis on bovine trypanosomosis in Southern Ethiopia

This study was initiated to explore the impact of Gibe III dam on the situation of livestock diseases with emphasis on trypanosomosis in upstream and downstream districts. Focus group discussions with 15 groups each with 6-20 members were conducted using participatory research approach. Data were collected through simple ranking, proportional piling and matrix scoring. Level of agreement among groups analyzed was determined by Kendell’s coeffi cient concordance (W). Proportional piling revealed that bovine trypanosomosis ranked fi rst followed by blackleg and anthrax. Study participants identifi ed livestock diseases by name and described the most salient features of each disease. Community perception on clinical signs, disease transmission, seasonality, of tsetse vectors, socio-economic impacts, control methods commonly of trypanosomosis was in a good agreement (W > 0.38***; p<0.001). Livestock disease outbreaks and the challenge from tsetse and trypanosomosis were perceived signifi cantly reduced after dam construction in the upstream villages whereas dam construction and the artifi cial lake created thereof had little impact on the situation of trypanosomosis and the tsetse population in the downstream villages along the Omo river. Therefore, any tsetse and trypanosomosis control program should take into account the basic differences in the two sites and accordingly provide customized services. Research Article The impact of Gibe III hydroelectric dam on the situation of livestock diseases with particular emphasis on bovine trypanosomosis in Southern Ethiopia Solomon Mekuria1,2, Hoges Ashenafi 2, Nigatu Kebede3, Tadesse Eyasu1, Saifemichael Ushecho1 and Getachew Terefe2* 1Faculty of Veterinary Medicine, Hawassa university, Hawassa, Ethiopia 2Department of Pathology and Parasitology, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu/Debre Zeit, Ethiopia 3Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia Received: 27 July, 2020 Accepted: 03 September, 2020 Published: 05 September, 2020 *Corresponding author: Getachew Terefe, Department of Pathology and Parasitology, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu/Debre Zeit, Ethiopia, E-mail:


Introduction
Under mixed crop-livestock production system, livestock production plays signifi cant roles not only as a main source of draught power for crop production but also for meat and milk production and means of income generation and household insurance. However, the contribution of livestock in Ethiopia is often undermined by production limiting factors such as shortage of feed and rampant diseases. African animal trypanosomosis is one of the diseases severely affecting cattle production in the West, Northwest and Southern part of the country [1].
Because they live under the treats of plethora of livestock Citation: Mekuria  diseases, farmers often have their own local names for each of the most important diseases and are able to describe associated signs, their impacts and for some of them traditional remedies. More importantly, their knowledge and experiences to differentiate among the many diseases is essential in the ranking of livestock diseases according to their level of importance/impact. The information and data collected from a community with little formal education is best reliable when obtained through focus group discussions by using the method of participatory epidemiology. In complex situations like for livestock diseases, individual farmers are less likely to provide actual data and hence, group discussion could provide relatively better information than a questionnaire survey [2]. Participatory epidemiology uses a combination of practitioner communication skills and participatory methods to improve the involvement of animal keepers in the analysis of animal disease problems and the design, implementation and evaluation of disease control programs and policies [3,4].
Farmers in Kindo Didaye and Loma districts depend on mixed crop-livestock production system, like in most part of Ethiopia. The two districts are in the Southern Nations, Nationalities and People Regional State (SNNPRS) of Ethiopia. In these two districts, there is a hydro-electric dam (Gibe III), where an artifi cial Lake that covers 200km 2 area of land has been created. Dam construction was started in 2006 [6] and completed in 2016. Human activity due to dam construction has changed the natural fauna and fl ora and consequently human settlement and livestock distribution both in areas surrounding the dam and along the banks of the Omo River on which the dam was constructed. The area is also known to have animal trypanosomosis [7][8][9] since long time. The distribution of this disease is expected to change with the negative or positive changes in the tsetse vector distribution as a result of the change in the ecology of the area which is caused by the presence of the dam. The economic impact of bovine trypanosomosis on crop production is severe in tsetse infested areas, where cattle population reduces by up to 37-70%, and milk and meat off-take reduces by about 50% [10].
In this regards, participatory epidemiological techniques are believed to generate valuable information on the perception and ranking of communities, residing in the upstream and downstream from the dam, on the situation of livestock diseases in general and bovine trypanosomosis in particular before and after the construction of the dam. Understanding community perception on major livestock diseases, their socio-economic impact and control methods are paramount important to complement conventional epidemiological diagnostic methods for further intervention activities [2,3,11,12]. The objective of this study was therefore, to assess community perception and knowledge on the relative importance of livestock diseases and socio-economic impact of bovine trypanosomosis through participatory epidemiological technique.

Study area
The study was conducted between November 2018 and June 2019 in Loma and Kindo Didaye districts near to Ghibe-III hydro-electric dam in SNNPRS Ethiopia. The study area classifi ed as upstream and downstream in reference to the dam, where Loma (upstream) located near to created Lake whereas Kindodidaye(downstream) is located immediately below the dam. The average annual rainfall at Ghibe III basin is 1,426 mm. High rainfalls recorded from May to September. Mean annual temperature is 20.4°C [6]. The altitude of the downstream ranges between 672m to 1200 m a.s.l.; whereas, the altitude of upstream ranges between 830m and 1250 m a.s.l. The created Lake has occupied about 200km 2 areas. Five Peasant Associations (PAs), located near the Ghibe III dam reservoir and natural river bank, were selected. Zima waruma, Subotulema and Deneba Bolla PAs of the Loma district, whereas Zero and Bereda PAs of Kindo Didaye district in the downstream ( Figure 1).

Data collection methods
Participatory epidemiology tools: Participatory epidemiology tools were used as described by Catley, et al. [2] and Catley [4] which included proportional piling, matrix scoring on assessments of socio-economic impact, disease control methods and seasonality. Fifteen focus group discussions (FGD) were employed using bean-sized stones as counter for scoring and ranking purposes. Only those key informants willing to participate in the study were enrolled in the discussion and equal chance was given to refl ect their opinion to avoid biasness toward the dominant discussant. Facilitators have monitored the discussion until participant's agreed on each discussion point. Finally, upon agreement, stones were piled, the number of which refl ects the weight given by the focus group discussants and those piled stones were counted and recorded.
Proportional piling: Proportional piling was used to estimate the relative livestock population in the area and the most important cattle diseases encountered. A total of fi fteen groups (6-20 members/group) were used: eight groups from Kindo Didaye and seven groups from Loma districts. At the beginning of the discussion, participants were allowed to list types of livestock kept in their area and then share 100 stones according to the estimated number of livestock species kept in the area. This was followed by listing and ranking of cattle diseases and proportional piling of stones according to disease importance (severity and/or occurrence) [4].
Matrix scoring: Matrix scoring method was used to understand community perception about the clinical signs, socio-economic impact, seasonality, age variability and control methods of the diseases as described by [2] and Catley, et al. [4]. This method was implemented to verify how well they were associating specifi c indicators or with specifi c cattle disease.
Diseases that were commonly known by facilitators and participants were included as control diseases to cross check respondents knowledge about bovine trypanosomosis [5] as already described by Catley, et al. [4]. Participants' responses were compared with descriptions in standard veterinary text books [14]. Following adequate discussion, FGD participants were allowed to pile stones the number of which shows the degree of association between the selected indicators and Citation: Mekuria  the diseases. The level of agreement across the groups was analyzed using Kendall's coeffi cient of concordance [15].
Triangulation: Triangulation was made using laboratory confi rmation [4,11] to demonstrate the parasite from suspected animal as indicated by clinical signs in the matrix score.
Participants were allowed to select trypanosomosis suspected animals (based on agreed up on clinical sign) from the nearby cattle herd. A total of 50 cattle were used for triangulation.
The selected animals were bled and examined fi rst with wet fi lm and then thin smear prepared and fi xed with methanol from positive ones. Fixed slides were transported to Soddo Regional Veterinary Laboratory for Giemsa stain and species identifi cation.

Type of livestock and their proportion
The focus group discussions in Loma and Kindo Didaye districts gave a general picture on types of livestock kept and their relative proportion in the area. According to median score results in both districts, Mizza (cattle) ranked fi rst followed by Desha (goat), Quttuwa (Poultry), Dorsa (sheep) and Harria (equine) consecutively, as shown in Table 1.
Livestock management system differs in two districts. Kindo didaye farmers keep their animals overnight in the house and allow grazing in open land the whole day. On the contrary, in the selected village of Loma district, farmers keep milking cow tethered at home whereas other cattle herds are kept far away from home near to Ghibe-III water reservoir. Except recently born calves, lambs and kids, sheep and goat are also managed together with cattle. Grazing land, and land covered by forest, bushes and shrubs are much wider in Loma than in Kindo-Didaye district.

Major livestock diseases
Participants' in focus group discussion have listed a number of diseases in local names by describing clinical signs, severity and lesions. The seven most frequently mentioned and one other (with no agreement between groups) diseases were used for further matrices. The local name of each disease described by the group was translated by the facilitator: Accordingly, Shulula (Trypanosomosis), Tilikia (Blackleg), were ranked in the fi rst and second place, respectively (Table 2). Though, major diseases ranking varied between the districts, the type of diseases mentioned by respondents were similar except that Aheeraa/tick born or tick associated disease was mentioned only in Kindo Didaye and Gerenda (pasteurellosis) only in Loma. Proportional piling score was calculated for median score, minimum and maximum range. Trypanosomosis ranked the highest among other diseases. Their main reason for high proportion piling was because of the disease impact throughout the year and its effect on reducing milk yield and bodyweight.
In addition, cost of treatment for trypanosomosis was reported as being very high.

Matrix scoring
Perception of participants about clinical signs for each major disease listed above were assessed in both Loma and Kindo didaye districts using matrix scoring technique with 15 focus group discussants' as shown in Figure 2. Particular emphasis was given to trypanosomosis as it was ranked the most important problem and other diseases are taken as controls in the description of clinical signs. Diseases which were not common to the two districts were excluded.
The fi nding shows clinical signs that were scored against trypanosomosis were generally in agreement with the descriptions in reference books [14,16]. The scores allocated to the control diseases indicated that informants understood the scoring method and their reasonable ability to differentiate cattle diseases from one another based on clinical descriptions.
For instance, mange mite received high scores for itching and alopecia; diarrheal syndrome/GIT parasite received high scores for diarrhea. No itching sign in trypanosomosis case. They have also clearly differentiated blackleg from anthrax, where they said lameness, shivering and skin swelling is a common sign in blackleg whereas sudden death is common in anthrax.
Disease sign of trypanosomosis was indicated mainly by signs of "emaciation, starring coat, diarrhea and inappetance were among other signs, with good level of agreement (W=0.8***; p<0.001). As shown in Table 3 all focus group piled more proportion of stones for trypanosomosis clinical signs than other diseases. Whereas other clinical signs more dominantly indicated for the control diseases mentioned. Table 3. Summarized matrix scoring (median scores with ranges in parenthesis) of disease signs based on FGD outputs.

Disease transmission
Trypanosomosis being the center of interest and Black leg and mange serving as control diseases, participants' *local names are in italics and Silla/Belgo or long rainy season which extend from July to September. Trypanosomosis and tsetse/biting fl ies were shown to have high occurrence in the rainy season as median score indicates in Table 5, whereas the lowest was indicated to be in dry season. Participants also mentioned that though tsetse fl ies are low during dry season, animals are unable to clear infection and signs reoccur every 3 weeks due to poor body condition of the animals arising from lack of adequate feed.

Trypanosomosis occurrence in different age groups
Informants categorize cattle ages into three categories: Mara (calf), Mirgowa (bull/heifer) and Bora/ Mizza (adult ox or cow) according to their own local names. Chances were given for group participants to allocate bean sized 30 stones in different age category, according to the occurrence of trypanosomosis in different age groups. The score allocated by fi fteen groups were calculated for median and range score as shown in Table  5. Median score in both districts indicates the occurrence of trypanosomosis increases as animal age increases. Majority of participants from both study districts have given higher score for high prevalence of tsetse vectors and the disease trypanosomosis in the long rainy season compared to dry or short rainy season.

Socio-economic impact of diseases
Community perception on the impact of trypanosomosis was revolved around indicators such as milk yield, body weight loss, poor skin quality, unfi tness for dowry, cause of abortion, reduction in selling price, cost of treatment and cause of sudden death as indicated by local name (Table 6). To verify whether the responses were in line with the target disease, mange, anthrax diseases were included as shown in Table 6.   Participants agreed that trypanosomosis reduces milk and meat production, causes abortion and is responsible for high cost of treatment compared to other diseases (W=0.61***; p<0.001). Whereas the impact of anthrax was unanimously agreed for sudden death (wores), the impacts of external parasites such as tick infestation and mange indicated by poor quality hide and skin followed by reduction in body weight. The response of focus group discussion signifi es how well experienced the community on livestock diseases in their area.

Trend of trypanosomosis and related events before and after Ghibe III dam construction
The fi ndings of the focus group discussion held with community representatives from both Loma and Kindo Didaye districts suggest that situational changes after Ghibe III dam construction have affected both study sites differently.
According to the focus group discussion, animal health post establishment and veterinary services improved after dam construction as a result of betterment in access to the area and livestock population was also increased. As a positive outcome, disease outbreak, cattle trypanosomosis and tsetse population perceived to have been signifi cantly reduced mainly in the upstream (Loma) district. On the other hand, discussants reiterated that vegetation cover and wild life population have declined in upstream areas. Downstream, after dam construction was completed, tsetse fl y infestation and some wildlife were reported to regain their habitat because of reduced human activity as a result of demolition of construction camps from the site. However, study participants affi rmed that the change in the situation of trypanosomosis in this area was minimal (Table 7).

Disease control methods
Knowledge, perception and practice of the participants were assessed about disease control methods. Trypanosomosis disease in association with other diseases (Blackleg, Anthrax, mange mite, tick and lice, GIT parasite) were compared against control methods, meanwhile response of participants monitored whether discussants responding properly or not. Therefore, treatment, spraying, vaccination and traditional medicine were used as an indicator for control method and analyzed against each disease. Good level of agreement (W= 0.75***; p<0.001) was shown among the groups on vaccination, spray and treatment control method against diseases; whereas moderate level of agreement (W=0.36; p<0.01) was observed between traditional methods against diseases (Table 8). Participants were well aware that control methods for trypanosomosis is only treatment and spray whereas blackleg is reported to be controlled by vaccination and treatment as indicated by median score. According to participants anthrax can only be controlled through vaccination because it causes sudden death before it reaches to the treatment service.     Trypanosomosis was ranked as the most important livestock disease in the area. Recent studies conducted in Dawro zone [8,9] have also indicated that trypanosomosis is a major problem in the study area. Similar fi ndings have also been documented by other studies [18,19] in trypanosomosis infected region of Kenya and Tanzania, respectively. In Kaffa zone, which is adjacent to the areas in this study, 94.1% of questionnaire survey respondents considered bovine trypanosomosis as an economically important cattle disease accounting for 64.6% of the total annual deaths in the year 2011/2012 [20].
In this regards, participants were able to differentiate trypanosomosis from other diseases by giving clinical signs such as rough hair coat, loss of appetite, emaciation and the like, whereas they reported only sudden death for anthrax.
Orma community in Kenya refl ected similar clinical signs for chronic trypanosomosis infection and hemorrhage and sudden death for the acute form of the disease [3]. The response of the communities was in agreement with existing literature [14,21,22]. It was also evident from the discussions that trypanosomesis is more important in adult animals as compared to younger ones. This supports study reports by Catley, et al. [11] in Tana River district of Kenya, by Adama, et al. [23] in Ghana and by Von Wissmann, et al. [24] in west Kenya. This could be explained by the fact that tsetse feeding preferences for adult cattle due to size and olfactory cues [25,26] or an inherent resistance to trypanosome infections in young animals [27] and/or because calves usually remain around homestead where exposure for tsetse fl y is low [28].
Many studies have substantiated that local communities have an accumulated knowledge about their animals and their wellbeing [12]. The strong concordance observed between diseases and clinical symptoms listed for each of them strengthens the above statement. Biting fl ies, mainly the tsetse were incriminated for the transmission of the disease trypanosomosis (Shulala) in cattle whereas direct contact was ranked fi rst for infection by mange mites. This is in agreement with information in various published reports [14,16,22]. It also supports the reports of many studies including those in Serengeti community in Tanzania [29] and in Southern Sudan community [12].
The perceived abundance of fl ies in rainy season may predispose the animals to higher prevalence of trypanosome infections. In rainy season, despite the presence of adequate feed availability, trypanosomosis prevalence could be high due to the increased tsetse fl y challenge [20,30]. The infl uence of rainfall and temperature on tsetse ecology has also been mentioned by other studies [31]. In contrast, a study with Tanzanian communities revealed that study participants perceived higher trypanosomosis challenge in dry season [19].
This could be explained by the fact that in most dry seasons, shortage of feed and water pushes animals to move down to river side where there is high tsetse fl y challenge [32]. On the other hand, the improved access to adequate feed in the rainy season could improve body conditions of animals which may mislead farmers to consider their animals do not have the disease although in real terms they are showing tolerance to the infection due to the good nutrition [33].
Moreover, the list of disease impacts and the possible methods of trypanosomosis control agreed by the study participants implies that any effective intervention program installed to minimize these problems could be easily felt and appreciated by the community. Other studies have shown that more than half of the study participants incriminated draught power reduction and high drug cost to animal trypanosomosis in Metekel and Guji zones of Ethiopia [30,34]. Weight loss and milk reduction were also stated by Nigerian community [35].

Perception of trypanosomosis before and after Ghibe III dam construction
The G.pallidipes and G.fuscipes were the most frequently caught tsetse fl y species in the study area, which are highly dependent on bovid hosts such as bushbuck, buffalo, and antelope [16].
However, as these wild animals evacuated, survival of tsetse will depend on domestic cattle which have also been displaced away from the site and hence most tsetse will starve to death.

Conclusion
This participatory epidemiological study was initiated to explore the impact of Gibe III dam on the situation of livestock diseases with emphasis on trypanosomosis in Loma Therefore, any tsetse and trypanosomosis control program should take into account the basic differences in the two sites and accordingly provide customized services. One should bear in mind that the community has a good understanding of any change, positive or negative, resulting from any intervention program implemented in their locality.

Ethical considerations
The permission to carry out this study was granted by the research ethics review committee of the College of Veterinary PhD research support scheme. Apart from this, the research did not receive any specifi c grant from funding agencies in the public, commercial, or not-for-profi t organizations.