University of Nairobi

1. University of Nairobi SEVERE PARASITISM – A HINDRANCE TO EFFECTIVE NEWCASTLE DISEASE CONTROL IN VILLAGE CHICKENS? L.C. Bebora1, N. Maingi1, P.N. Nyaga1, P.G. Mbuthia1, L.W. Njagi1, M. Githinji2, D.C. Kemboi1 and H.W. Chege1 1 University of Nairobi, P.O. Box 29053 – 00625, Nairobi, Kenya 2 Ministry of Livestock, Central Vet. Laboratories, Private Bag -00625, Kabete, Kenya PRESENTED AT THE 3RD RUFORUM BIENNIAL CONFERENCE ON 24TH TO 28TH SEPTEMBER 2012 IN ENTEBBE, UGANDA

2. University of Nairobi Format of presentation 1.Indigenous chickens 2.Newcastle disease 3.Chicken parasites 4.Objective; Hypothesis 5. Study design 6. Results 7. Conclusion

3. University of Nairobi Indigenous cocks

4. University of Nairobi Indigenous hens

5. Naked-necked cock and hen University of Nairobi

6. University of Nairobi Indigenous chickens They are of different colors, sizes and design They are of dual purpose – meat and eggs They are preferred due to their taste The yellow color of their egg yolk is appetizing They are also believed to be organic

7. University of Nairobi Indigenous chickens (cont.) Thus, their eggs sell more expensively than those of commercial breeds

8. University of Nairobi Indigenous chickens (c0nt.) Normally, indigenous chickens are kept by resource-poor persons They contribute immensely towards the socio-economic aspect of these people They serve as:- Source of protein Source of income (as bank for quick money when needed) Ceremonial items (slaughtered for special guests; gifts; for religious ceremonies, etc)

9. University of Nairobi Indigenous chickens (cont.) An average household keeps a flock of between 10 to 30 birds Thus, in total, these birds constitute over 70% of the estimated 36 million birds in Kenya (kept by almost every village household) This type of chicken industry is taken as one of the biggest untapped economic potential in the country

10. University of Nairobi Indigenous chickens (cont.) Because the owners could make money if they kept larger flocks When the people’s income is increased the cumulative income for the country increases One of the reasons why they don’t maintain large flocks is death due to Newcastle disease

11. University of Nairobi Newcastle disease ND causes high mortality, up to 100% Being a viral disease, ND can be effectively controlled only by vaccination Effectiveness of the ND vaccination is reduced when birds are immune-suppressed

12. University of Nairobi Newcastle disease (cont) ND is diagnosed mainly by: -high mortality exhibited by the affected birds -greenish diarrhoea -on post-mortem examination, hemorrhages in various organs, especially the proventriculus and trachea

13. University of Nairobi Hemorrhagic lesions in pro-ventriculus

14. University of Nairobi Hemorrhages in the trachea

15. University of Nairobi Newcastle disease (cont) The overall aim of this study was to see if deaths of these birds can be reduced by introducing ND vaccination This will: - increase the number of chickens per household -improve productivity of the birds, in terms of numbers, egg and meat production

16. University of Nairobi Newcastle disease (cont) -empower the people economically -contribute towards poverty alleviation From a previous study, these birds were shown to carry heavy loads of parasites

17. University of Nairobi Chicken parasites Some of parasitic diseases, like coccidiosis, can cause high mortalities Most other parasites lead to emaciation, reduced production and stress, through: Blood sucking Causing irritation to the birds Nutrient consumption

18. University of Nairobi Chicken parasites (cont) Stress is associated with immune-suppression Therefore, parasitism is expected to cause immune-suppression in the chickens Effective control of parasites is, therefore, expected to improve effectiveness of ND vaccination Through production of high immunity/titers in the chickens which will protect the chickens in the event of disease challenge

19. University of Nairobi Chicken parasites (cont) Different types of parasites that affect chickens from Mbeere District will be given in the Results section

20. University of Nairobi Previous observations on Mbeere chickens Njagi et al (2008 )established that ND is endemic in Mbeere District (thus need for vaccination) Sabuni (2009) demonstrated that these chickens from Mbeere are heavily infected with ecto – and hemo-parasites

21. University of Nairobi Underlying questions to this Will the severe state of parasitism lower the chickens’ immune response (through continued stress), so as to be a hindrance to effective ND control in the chickens? If so, to what level does it lower the immune response? A positive answer to this will emphasize the need for parasite control as we encourage the farmers to vaccinate their chickens

22. University of Nairobi ND vaccination and parasitism Hypothesis: . The parasite burden causes significant suppression of immunity so as to lower ND vaccination response in the village chickens. Current presentation: Is on baseline data collection – to establish the current findings on chickens from Mbeere, with respect to parasite carriage and endemicity of ND in the area

23. University of Nairobi Aim of this particular study To establish the current status of parasite carriage and endemicity of ND (indicated by presence of antibodies) in Mbeere chickens In addition to the ecto- and hemo- parasites, this study covered intestinal parasites So as to decide whether or not there is still need to advocate for ND vaccination

24. University of Nairobi Information on the study area Mbeere District, Eastern Province, Kenya It lies between latitude 0020’ and 0050’ South and longitude 37016’ and 37056’ East Altitude 500 to 1200 metres above sea level Long rains: March to June Short rains: October to December Daily temperature ranges between 20 and 30 oC

25. University of Nairobi Study design Study was cross-sectional, done during wet season. Twenty four (24) chickens of various ages (chicks, growers, adults) were used. For parasitological study, post-mortem examination of the birds was done according to Charlton et al. (2006),

26. University of Nairobi Study design (cont) Harvesting and identification of endo- and ecto-parasites were done according to MAFF (1986) and Sabuni et al. (2009). For the serological study, hemagglutination inhibition test was used to determine the respective antibody titres (OIE, 2000).

27. University of Nairobi Study design (cont) The laboratory procedures were carried out at the Department of Veterinary Pathology, Microbiology and Parasitology; College of Agriculture and Veterinary Sciences (CAVS), Kabete; University of Nairobi.

28. University of Nairobi Results: Parasites All the 24 chickens had lice infestation; some of the counts being as high as 222 per bird 17 (70.8%) of the chickens had mites on their body surface or their legs; the most prevalent was Dermanyssus gallinae (82.3%) 15 chickens (62.5%) had the stick-tight flea, Echinophaga gallinacean 6 chickens (25%) had the soft tick, Argus persicus

29. University of Nairobi Results: Parasites (cont) Fleas Leg mites Soft ticks

30. University of Nairobi Results: Parasites (cont.) This showed that the chickens were multiply infested with ectoparasites All the birds also showed multiple infections with gastrointestinal parasites Nematodes (96%), cestodes (87.5%) and coccidia (25%)

31. University of Nairobi Results: Parasites (cont) Ascarids Tetrameres Tape worms

32. University of Nairobi Results: Parasites (cont) Coccidial hemorrhages - cecum Coccidial oocysts

33. University of Nairobi Results: Parasites (cont) 19 chickens (79.2%) had hemoparasites,including Plasmodium, Leucocytozoon and Aegyptinella species Plasmodium was the most prevalent (79%; 19/24)

34. University of Nairobi Plasmodium parasites

35. University of Nairobi Results: Parasites (cont) The results thus showed that the chickens from Mbeere still carried heavy loads of various types of parasites The ecto- and hemo-parasites were similar to those found by Sabuni in 2009

36. University of Nairobi Serological results Serum samples from the 24 chickens studied were found to be positive for presence of ND antibodies, with 100% specificity Titres ranged from 16 to 256, with a geometric mean titre of 65.85 All the age groups had ND antibodies; those of chicks were considered to be maternal

37. University of Nairobi HI titres for the 24 birds studied Chicks <2 months, Growers – 2-8 months, Adults >8 months, GMT – Geometric mean

38. University of Nairobi Serological results (cont) Results indicated that ND was still endemic in Mbeere and the village chickens; confirming the findings of Njagi (2008)

39. University of Nairobi Conclusion The study demonstrated continued endemicity of ND in chickens of Mbeere District This observation emphasises the need to vaccinate the birds, so as to maintain high titres for protection against the disease

40. University of Nairobi Conclusion (cont) The study also demonstrated high carriage of various types of parasites by these chickens This intense parasitism may be responsible for continuous stress and immune-suppression to the chickens Total parasite control would, therefore, be one of the necessary measures to be taken in order to implement effective vaccination against ND

41. University of Nairobi Continuing study Another study is currently going-on to determine the extent at which parasite burden depresses the immune response to ND This will provide more information and help in formulation of parasite treatment and vaccination regimes

42. University of Nairobi Acknowledgement RUFORUM for providing funds for the study Government of Kenya and University of Nairobi for providing physical space and technical help Farmers and extension officers in the area for their participation The present audience for listening to me

43. University of Nairobi THANK YOU