1. Untangling the respiratory disease complex in small ruminants in Ethiopia
Biruk Alemu, Hiwot Desta, Fasil Aklilu, Matios Lakew, Demeke Sibhatu and Barbara Wieland
15th International Symposium of Veterinary Epidemiology and Economics Chiang Mai, Thailand, November 2018
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2. Introduction
Small ruminants serve multiple livelihood roles: food and nutrition security, income, and providing raw material for industries
Diseases are an important constraint for production
Different production systems in different agro-ecologies: pastoralist vs. mixed crop-livestock systems

3. RDC as priority
Participatory epidemiological studies showed livestock keepers prioritized respiratory diseases across production systems
RDC in Ethiopia: CCPP, PPR, pasteurellosis, lung worm, Maedi Visna, PI-3, etc….. (unknown)
Past surveys on pasteurellosis have shown high seroprevalence with cross-reaction observed between different serotypes

4. Objective The study aimed at:
Investigating the role of different pathogens involved in the respiratory disease complex in small ruminant in Ethiopia

5. Methodology Household and sero-survey
Laboratory analysis of biological samples
Multivariable logistic regression analysis for risk factors

6. Household and sero-survey
432 households in 4 regions
Data on vaccination history, clinical signs observed, husbandry, health management, and production data
2’110 serum samples (1’547 Sheep, 563 goats) were collected (5-6 per farm)
Tissue samples were collected from clinically suspicious animals
Testing of samples for PPR (Ab and Ag serology), CCPP (serology), and Pasteurella (culture of samples of suspicious animals)

7. Results Frequency percentage of clinical signs
Men
Women

8. Sero-prevalence of PPR
Region
Vaccinated
Unvaccinated
Pos (%)
95% CI
P-Value
Amhara
90.9
85.58 – 94.68
30.9
26.83 – 35.35
0.000
Tigray
58.9
54.39 – 63.22 -
Oromia
85.5
79.84 – 90.07
17.4
13.79 – 21.59
SNNP
11.3
8.34 – 15.16
Overall
71.4
20.8
The Ab sero-prevalence level in Tigray vaccinated animals indicate low herd immunity level
The relatively high sero-prevalence in unvaccinated animals may be due to some animals actually having been vaccinated in the past, but reported as non-vaccinated in this survey

9. Sero-prevalence levels of CCPP
Region
Vaccinated
Unvaccinated
Pos (%)
95% CI
P-Value
Amhara -
2.2
1.23 – 3.68
Tigray
0.8
0.26 – 2.2
Oromia
52.9
35.1 – 59.5
0.97 – 3.6
0.000
SNNP
1.1
Overall
1.3
Generally low sero-prevalence level of CCPP observed in unvaccinated population in all regions
The Ab sero-prevalence level in vaccinated population indicates low herd immunity level compared to previous studies

10. Results for animals with clinical signs
Ag detection for PPRV – negative result from 29 clinical samples
3/55 positive result for pasteurella culture (M. hemolytica and B. trehalosi)

11. Risk factors for PPR Term Odds Ratio CI 95% S.E. P-Value
Age (Adult/Young)
1.89
1.2069
2.9595
0.2288
0.0054
Species (Ovine/Caprine)
0.32
0.2101
0.4861
0.2140
0.0000
Sex (Male/Female)
0.64
0.4333
0.9525
0.2009
0.0276
Agroecology (Highland/Midland)
0.25
0.1479
0.4390
0.2775
Flocksize (Medium/Small)
3.22
2.1867
4.7388
0.1973
Flocksize (Large/Small)
5.21
0.8455
0.9280
0.0752
Region (Oromia/Amhara)
0.21
0.1195
0.3531
0.2763
Region (SNNPR/Amhara)
0.23
0.1376
0.3694
0.2519
CONSTANT *
0.3685
0.0285

12. Risk factors for CCPP
Term
Odds Ratio
95%
C.I.
S.E.
P-Value
Agroecology (Mid land/Lowland)
0.16
0.0195
1.2621
1.0637
0.0817
Agroecology (Highland/Lowland)
0.73
0.3112
1.7057
0.4341
0.4655
GrazingHus (Mixed with other LS/ Sheep and goat separately)
1.37
0.4608
4.0956
0.5573
0.5688
GrazingHus (Sheep and goat together/Sheep and goat separately)
3.22
1.3108
7.9233
0.4590
0.0108
CONSTANT *
0.4748
0.0000
Mixed (sheep and goats) raising was identified as a risk factor for CCPP sero-positivity

13. Discussion
Our results provide evidence of ongoing PPR circulation in lowlands and highlands, but the participatory research indicated that livestock keepers struggle to identify the disease
The PPR sero-prevalence in vaccinated animals was above 80% in some of the study area, indicating sufficient herd immunity after vaccination
Targeting agroecology in vaccination may play a key role in limiting the transmission of PPR infection
Much less vaccination had been done for CCPP
In lowland areas that had vaccination, sero-prevalence was low (low vaccination coverage)

14. Limitations Pasteurella serology unreliable with tests available
Lungworm testing not done in this study
Other pathogens not investigated yet

15. Outlook
To further understand the relative importance of different pathogens and the role of co-infection, a longitudinal survey is being conducted
Follow selected farms over 12 months
Record morbidity and mortality and other productivity parameters
Sample collection and testing for: Pasteurellosis, Maedi-Visna, caprine arthritis encephalitis virus, parainfluenza, and bluetongue

16. Acknowledgements This work is financed by
IFAD SmaRT Project, Africa RISING Project, CGIAR Research Program Livestock
It is implemented in a partnership with
ICARDA, Regional Research Centers

17. better lives through livestock
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