Journal of
Veterinary Medicine and Animal Health

  • Abbreviation: J. Vet. Med. Anim. Health
  • Language: English
  • ISSN: 2141-2529
  • DOI: 10.5897/JVMAH
  • Start Year: 2009
  • Published Articles: 416

Full Length Research Paper

Prevalence and the associated risk factors of bovine trypanosomiasis in nyangatom pastoral woreda, Southern Nation and Nationalities People Region (SNNPR), Ethiopia

Sisay Tadele Kassa*
  • Sisay Tadele Kassa*
  • Gnangatom Livestock and Fishery Development Office, Ethiopia.
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Seblewongel Ayichew Megerssa
  • Seblewongel Ayichew Megerssa
  • School of Veterinary Medicine, Wolita Sodo University, Wolaita Sodo, Ethiopia.
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  •  Received: 10 February 2017
  •  Accepted: 24 March 2017
  •  Published: 30 June 2017

 ABSTRACT

A cross-sectional study was carried out in Nyangatom wereda of South Omo zone, Southern Nation and Nationalities People Region (SNNPR), Ethiopia with the general objectives to find out the prevalence of bovine trypanosomiasis and the risk factors associated with its prevalence from January to June 2015. To identify the protozoa blood samples (n =384) collected from the marginal ear vein of indigenous zebu cattle of more than one year age and both the sexes from three kebeles were examined by buffy coat technique, direct blood smear, thick blood smear and thin blood smear after staining. The overall prevalence of bovine trypanosomaisis was 26.3%. On peasant associations (PA’S) basis Lebere kebele has the highest prevalence 39(30.5%) followed by Shenkora kebele 34 (26.6%) and Ayipa kebele 28 (21.9%). Trypanosoma congolense is the most prevalent species (14.3%) followed by Trypanosoma vivax (5.70%) and Trypanosoma brucei (5.50%). A significant association was observed (P<0.05) between the disease positivity and age, sex and body condition score. The prevalence of trypanosomiasis was 16.20 and 31.50% in young and adult respectively. The prevalence 42.80 and 16.30 % in poor and good body condition score respectively. There was significant association between the risk factors and the species of trypanosomiasis (P<0.05). The result of the present study revealed that trypanosomiasis is the most important problem for animal production in the study area. Strategic control of bovine trypanosomiasis should be strengthened to improve livestock production and agricultural development in the area.

Key words: Bovine, buffy coat, Nyangatom, prevalence, trypanosomiasis.

Abbreviation: ALC, Annual loss from liver condemnation; DACA, Disease Administration and Control Authority; FAO, Food and Agricultural Organization; HAT, Human African Trypanosomiasis; P, Prevalence rate of  the disease  at  the  study  area;  PA, Peasant Association; SNNPR, Southern Nation and Nationalities People Region; SOFEDD, South Omo zone Finance and Economy Development Department; STEP, Southern Tsetse Eradication Program.

 INTRODUCTION

In Ethiopia, tsetse flies (the vector of different species of Trypanosoma)) infest an area  of  approximately  240,000 km2; most of this area is located in the southern region of which; 25,000 km2 is found in  the  southern  rift  valley  of  Ethiopia. About 10 to 14 million heads of cattle in Ethiopia, 4 to 6 million heads of cattle in southern region and 2 to 3 million heads of cattle in the southern rift valley are at risk from trypanosomosis.
 
Trypanosomosis is a complex immunosuppressive disease caused by unicellular, eukaryotic, hetetro specific haemo- parasites (trypanosomes) of blood and other tissues of vertebrates including cattle and man (Uilenberg, 1998; Singla et al., 2009). The disease by flagellated protozoa is transmitted by a number of different arthropod vectors but mainly by biting flies (Kumar et al., 2012; Sharma et al., 2012: Sharma et al., 2015). The disease is coincident with the distribution of the tsetse fly (Glossina spp.) and other flies which acts as a vector for the parasite (Sumbria et al., 2015) and infests an area of some 10 million square kilometer encompassing 36 countries in Africa (Black and Seed, 2002).
 
Trypanosomosis, a disease of major economic importance is caused by several species of trypanosomes, a major constraint to livestock animal production (Urquhart et al., 1996; Aulakhet al., 2005).  Pathogenic species of salivarian trypanosomes are present throughout vast areas of Africa including Ethiopia (Jahnke et al., 1988). The disease in livestock creates great loses in terms of mortality, abortion, reduced fertility, milk and meat production, and working abilities of animals (Juyal et al., 2005). Depending on the species of Trypanosoma the organisms are transmitted cyclically by tsetse flies of the genus Glossina or mechanically by tsetse or other biting flies. The disease is the most economically damaging and widely distributed in most parts of Ethiopia (DACA, 2006).
 
Bovine trypanosomosis, which is one of the most important protozoa diseases of cattle in Ethiopia, affects the health status of animals. In general bovine are susceptible to trypanosome infection such as T. vivax, T. congolese T. brucei and T. evansi (Leak, 1996). Therefore, the objectives of this study were to determine prevalence and risk factors of trypanosomosis in the study area and to identify and define the existing species of Trypanosoma in the study area.


 MATERIALS AND METHODS

Study area
 
The study was conducted from January to June/2015 in the Nyangatom woreda,  Ethiopia located in south omo zone of SNNPR, comprising of 20 (1 urban and 19 rural) kebele administrations. It is one of the eight woredas in south omo zone with an area of 2652 km and is located at 4.850 to 5.670N and 35.750 to 36.230E. It’s bordering with Bench -maji zone and Selamagoworeda in north, Dassenech woreda in south, Hamar woreda in east and Kenya and South Sudan in west (CSA, 2013). The traditional agro ecology of the woreda is kola with an altitude that ranges between 300 and 450 m a.s.l. The mean annual temperature of the woreda ranges between 33 and 42°C. The woreda has a rainfall pattern of bimodal type  (Belg  from  March  to May and Meher from August to October). The mean annual rainfall ranges from 350 to 500 mm. Livestock production is the dominant livelihood source in the woreda. It has an animal resource with an estimate of about 415,292 cattle, 132,604 goats, 109217 sheep, 11218 donkeys and 5474 chicken. There are three ethnic groups in the woreda. Nyangatom is the dominant one followed by Murulle and Koygu (Muguji) (SOFEDD, 2012).
 
Study population
 
The study population was indigenous zebu cattle of more than one year age group, with poor and good body condition and both sex which are found within three kebeles of the study area. Particularly Lebere, Shenkora and Ayipa. A total of 384 cattle were examined to estimate the existing prevalence rate of trypanosomosis.
 
Study design and sample size determination
 
A cross - sectional study was conducted in order to determine the prevalence of bovine trypanosomosis and associated risk factors from selected kebeles of the woreda. The size of sample was determined by the following formula (Thrusfield, 2005) with 95% confidence and an expected prevalence of 50 and at 5% absolute precision. Based on the formula the total sample size was 384.
 
Sampling procedures
 
The sampling site (marginal ear vein) of the cattle was prepared and disinfected with ethanol. Then the ear vein was punctured by lancet and the blood sample was collected by heparinized capillary tube. One end of the tube was sealed by crystal seal and finally, the blood samples were immediately transported to jinka, the town of south omo zone, regional laboratory in tightly closed ice box.
 
Sample processing and examination techniques
 
Thin blood smear
 
A small drop of blood from a micro-hematocrit capillary tube was applied to a clean slide and spread by using another clean slide at an angle of 45°. The smear was air dried and then fixed for 2 min in methyl alcohol. The thin smear was flooded with Giemsa stain (1:10 solution) for 30 min. Excess stain was drained and washed by using distilled water. Then it was allowed to dry by standing up right on the rack and examined under the microscope (x100) oil immersion objective lens (OIE, 2008).
 
Buffy coat technique
 
Heparinised micro haematocrit capillary tubes, containing blood samples were centrifuged for 5 min at 12,000 rpm. After the centrifugation, trypanosomes were usually found in or just above the buffy coat layer. The capillary tube was cut using a diamond tipped pen 1 mm below the buffy coat to include the upper most layers of the red blood cells and 3 mm above to include the plasma. The content of the capillary tube was expressed onto a glass slide, and covered with cover slip. The slide was examined under x40 objective and x10 eye piece for movement of parasite (Paris et al., 1982). Trypanosoma species were identified according to their morphological descriptions on Giemsa stained blood film as well as movement in wet film preparations provided by (Radostitis et al., 2007).
 
Data management and analysis
 
The data on individual animal and parasitological examination was entered into Microsoft Excel (MS-Excel). These data was analyzed using Statistical Package for Social Science (SPSS version 20.0) software. The descriptive statistics called Pearson Chi-Square test was used to see the association of trypanosomosis infection rates with different variables like age, sex and body condition score statistical significance for categorical data. Throughout the analysis, 95% confidence interval with 5% degrees of freedom (P < 0.05) was considered to say statistically significant difference.
 


 RESULTS

Parasitological survey
 
The result of the survey shows an overall prevalence for trypanosomosisas 26.3% and there was no significant association between the prevalence for trypanosomosis and kebeles.
 
On Peasant associations basis Lebere has the highest prevalence of 39(30.5%) followed by Shenkora34 (26.6%) and Ayipa 28(21.9%) (Table 1).
 
 
Distribution of Trypanosoma species
 
The species of Trypanosoma identified by direct smear, buffy coat technique and thin smear showed that T. congolense is the most prevalent (55.45%) followed by T. vivax (23.76%) and T. brucei (20.8%). There was a significant association between the species of Trypanosoma with age, sex and body condition (p< 0.05) and there was no significant association between the species of trypanosome with in kebelles (p>0.05) (Table 2).
 
 
Prevalence for Trypanosoma infection in both sexes
 
During the present survey, from a total of 384 cattle examined 276(71.87%) were females and 108 (28.12%) of them were male animals.
 
From the females examined, 29.3% were positive for trypanosoma infection while 18.5% of the male animals were found infected. There was significant association between sex and prevalence for Trypanosomosis (Table 3).
 
 
Prevalence for Trypanosoma infection in different age groups
 
The animals examined were categorized in different age groups as the young (1-3years) and adults (>3 years). The prevalence was 16.2% in young and 31.5%in adult animals. There was significant association between age and prevalence for trypanosomosis (p<0.05) (Table 4).
 
 
Prevalence for Trypanosoma infection in different body condition
 
The prevalence of trypanosomosis on two body condition groups was seen and the result showed that 42.8% in poor and 16.3% in good body condition. Relatively it was seen that higher proportion of poor body condition cattle were positive than good body condition animals. There was significant association between body conditions and prevalence for trypanosomiasis (p value<0.05) (Table 5).
 
 


 DISCUSSION

The overall result of prevalence of the present study (26.3%) was higher than the result of the previous work (12.79%) by Wondwosen et al. (2012). The present finding was lower than that registered by Shimelise et al. (2005) in the Ghibe valley 40.3% in late rainy and higher than in similar area (19.01%) in dry season by Wondoson (1986) in Bunno and Abiy (2002) in Goro district (19.01%). This may be due to the difference in agro ecology of the study area, prophylactic measure and difference in season. The positivity of trypanosomosis was not significantly different within kebelles of the woreda whereas the positivity of trypanosomosis was significantly variable with age, sex and body condition score of cattle.
 
In the present study T. congolense was predominant species in the study area which may be due to the development of better  immune  response  to  T. vivax  by the infected animal (Leak et al., 1999). The dominancy of T. congolense (55.45%) in the present study is  comparable with the previous result of Getachew and Jobre (1996) for tsetse infested areas of Ethiopia (66.1%), Afework (2001) at Pawe North west Ethiopia(60.9%), Terzu (2004) in selected sites of southern region (63.4%) and Wodwosen et al. (2012) worked in selected villages of Arbaminch, Ethiopia.
 
The result of Tewelde et al. (2004) at Kone (75%) and village-1 (93%) settlement area of Ethiopia, Woldyes and Woldeyes and Aboset (1997) at Arbaminch zuria districs (85.2%) and Rowland et al. (2001) in Ghibe valley, South West of Ethiopia (84%) had shown higher prevalence of  T. congolense than the present finding. These high ratios of T. congolense suggest that the major cyclical vector or Glossina species are more efficient transmitters of T. congolense than T. vivax in East Africa (Langridge, 1976).
 
The distribution of Trypanosoma species was not significantly different within kebelles of the woreda whereas the distributions of species were significantly variable with age, sex and body condition score of cattle. The prevalence in adults was higher than the young ones. In the calf group the prevalence was lower which the result of low exposure to the vector was. Conversely in the adult and older age groups of animals the prevalence of Trypanosoma infection was higher due to the constant contact existing with the tsetse fly in the field.
 
The higher prevalence of poor body condition cattle than good body condition animals in the study was also comparable with the result of Wodwosen et al. (2012) in Arbaminch area and Abraham and Tesfaheyw et al. (2012).


 CONFLICT OF INTERESTS

The authors have not declared any conflict of interests.



 REFERENCES

Abiy M (2002). Prevalence Of bovine trypanosomosisinGoroWoreda, southwest Ethiopia, DVM Thesis.Abstract, DebreZeit. pp. 342-344.
 

Abraham Z, Tesfaheywet Z (2012). Prevalence of Bovine Trypanosomosisin Selected District of Arba Minch, Snnpr, Southern Ethiopia. Glob. Vet. 8(2):168-173.
 

Afework Y (2001).Field investigation on theappearance of drug resistant population of trypanosomes in Metekel District, North-West Ethiopia.Msc thesis, Addis Ababa University and Freiuniverstat Berlin, Faculty of veterinary medicine, Ethiopia. pp. 32-36.
 

Aulakh GS, Singla LD, Singh J (2005) Bovine trypanosomosis due to Trypanosoma evansi: Clinical, haemato biochemical and therapeutic studies. In: New Horizons in Animal Sciences, Sobti RC and Sharma VL(Eds), Vishal Publishing and Co., Jalandhar. pp. 137-144.
 

Black J, Seed R (2002). The African Trypanosomes.KluwerAcademi Publishers Institute), Nairobi, Kenya. pp. 146-148.
 

Central Statistical Agency (CSA) (2013). Federal democratic republic of Ethiopia Central Statistical Agency, Agricultural Sample Survey 2013/14 Volume II, Report on livestock and livestock characteristics (private peasant holdings), Addis Ababa. Stat. bull. 573:13-14.
 

DACA (2006). standard veterinary Treatment Guidelines for veterinary practice 1Sted.Drug Administration and Control Authority of Ethiopia.
 

Getachew A, Jobre Y (1996).Trypanosomiasis.A threat to cattle production in Ethiopia.Revue de Médecine Vétérinaire 147:897-902.
 

Jahnke E, Tacher G, Keil P, Rojat D (1988).Livestock production in tropical Africa, with special reference to the tsetse-affected zone. In Livestock production in tsetse affected areas of Africa. International Livestock Centre for Africa/International Laboratory for Research on Animal Diseases, Nairobi, Kenya. pp. 430-432.
 

Juyal PD, Singla LD, Kaur P (2005). Management of surra due to Trypanosoma evansi in India: an overview. Infectious diseases of domestic animals and zoonosis in India. 75:109-120.
 

Kumar H, Gupta MP, Sidhu PK, Mahajan V, Bal MS, Kaur K, Ashuma, Verma S, Singla LD (2012) An outbreak of acute Trypanosomaevansi infection in crossbred cattle in Punjab, India. J. Appl. Anim. Res. 40(03):256-259.
Crossref
 

Langridge P (1976). A tsetse and trypanosomiasis survey of Ethiopia. UK Ministry of Overseas Development, London, 118-119.
 

Leak A (1999). Tsetse biology and ecology: The role in the epidemiology and control of trypanosomosis. CAB international. Walling fored (UK). pp. 152-210.
 

OIE (Office Internationale des Epizooties)(2008).Trypanosomiasis(tsetse-transmitted):TerrestrialManual.OfficeInternationale des.Epizooties (OIE), Paris, France.
 

Paris J, Murray M, Mcodimba F (1982). A comparative evaluation of the parasitological technique currently available for the diagnosis of African trypanosomosis in cattle. Acta Trop. 39:307-316.
 

Radostits OM, Gay CC, Hinchcliff, KW and Constable, PD (2007).Veterinary Medicine, A textbook of the disease ofcattle,sheep,goat,pigsandhorses, 10th edi. Saunders Elsevier London, New York. pp. 2047-1533.
 

Rowlands GJ, Leak SG, Peregrine AS, Nagda SM, Mulatu W, Dieteren GD (2001). The incidence of new and the prevalence and persistence of recurrent trypanosome infections in cattle in south-west Ethiopia exposed to a high challenge with drug-resistant parasites. Acta Trop. 79:149-163.
Crossref
 

Sharma A, Singla LD, Tuli A, Kaur P, Bal MS (2015). Detection and assessment of risk factors associated with natural concurrent infection of Trypanosomaevansiand Anaplasmamarginalein dairy animals by duplex PCR in eastern Punjab. Trop. Anim. Health Prod. 47:251-257.
Crossref
 

Sharma P, Juyal PD, Singla LD, Chachra D, Pawar H (2012). Comparative evaluation of real time PCR assay with conventional parasitological techniques for diagnosis of evansi in cattle and buffaloes. Vet. Parasitol. 190:375-382.
Crossref
 

Shimelis D, Aran S, Getachew A (2005). Epidemiology of tsetse transmitted Trypanosomosis in Abay (Blue Nile) basin of North West Ethiopia. Proceedings of the 28th meeting of the International Scientific Council for Trypanosomiasis.
 

Shimelis D, Aran S, Getachew A (2005). Epidemiology of tsetse transmitted Trypanosomosis in Abay (Blue Nile) basin of North West Ethiopia. Proceedings of the 28th meeting of the International Scientific Council for Trypanosomiasis. pp. 49-53.
 

Singla LD, Juyal PD, Sharma NS (2009) Immune responses to haemorrhagicsepticaemia (HS) vaccination in Trypanosomaevansi infected buffalo-calves. Trop. Anim. Health Prod. 42:589-595.
Crossref
 

SOFEDD (South Omo zone Finance and Economy Development Department) (2012). Zonal Statistical Abstracts 2012 (2004 E C), Jinka, Ethiopia.
 

Sumbria D, Singla LD, Sharma A, Bal MS, Kumar S (2015). Multiplex PCR for detection of Trypanosomaevansiand Theileriaequiin equids of Punjab, India. Vet. Parasitol. 211(3-4):293-299.
Crossref
 

Terzu D (2004).Season dynamics of TseTse and trypanosomiasis in selected sites of Southern Nations and Nationality People Region (SNNPRG).Mscthesis.AAU.Debrezeit Ethiopia.
 

Tewelde N, Abebe G, Eisler M, Mcdermott J, Greiner M, Afework Y, Kyule M, Munstermann S, ZessinH, Clausen H (2004).Application of field methods to assess isomethamidium resistance of trypanosomes in cattle in Western Ethiopia. Acta Trop. 90:163-170.
Crossref
 

Thrusfield M (2005). Veterinary Epidemiology.3rd edition. UK, Blackwell science Ltd. pp. 233-250.
 

Uilenberg G (1998). A field guide for diagnosis, treatment and prevention of African animal trypanosomosis. Adapted from the original edition by Boyt.W. P. Food and Agriculture organization of United Nations (FAO), Rome. pp. 43-135.
 

Urquhart M, Armour J, Duncan L, Dunn M and Jennings W (1996). parasitology 2nd edition. Black Well Science Ltd., London UK. pp. 212-219.
 

Woldeyes G, Aboset G (1997). Tsetse and trypanosomosis distribution, identification and assessment of socio-economic viabilities of the new vector control approaches in Arbaminch ZuriaWoreda. EVA. Proceedings of the 11th conference 143-154.
 

Wondewosen T, Dechasa T, Anteneh W (2012). Prevalence study of bovine trypanosomosis and tsetse density in selected villages of Arbaminch, Ethiopia. J. Vet. Med. Anim. Health 4(3):36-41.
 

Wondwosen A (1986). Tsetse andTrypanosomosis in Bunnoprovince. DVM Thesis.F.V.M: A.A.U. Debre Zeit.

 




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