Bio

DR. NJAGI LUCY WANJIRU BIOGRAPHY

Dr Lucy W. Njagi is a Senior Lecturer in the Department of Veterinary Pathology, Microbiology and Parasitology, University of Nairobi. She holds a PhD degree in Veterinary Virology, MSc in Veterinary Pathology and Microbiology and Bachelor of Veterinary Medicine degree from the University of Nairobi. She has conducted notable research in Veterinary pathology and virology and supervised several postgraduate students. Her areas of specialization are avian medicine, pathology and virology.

Publications


2014

H.W. Chege, D.C.Kemboi, L.C. Bebora, Maingi N, P.N. Nyaga, Mbuthia PG, Njagi LW.  2014.  Chicken parasites and local treatments used against them in Mbeere District, Kenya. Livestock for Research for Rural Development. 26(1)chege_et_al._2014-_chicken_parasites_and_treatment_-lrrd.pdf
Kemboi, DC, Chege HW, Bebora LC, Nyaga PN, Njagi LW, Maingi N.  2014.  Effect of parasite control on immune response to Newcastle Disease vaccination in village chicken, Mbeere sub county. Livestock Research for Rural Development . 26(2)kemboi_et_al.2014-_effect_of_parasite_on_immune26.pdf

2013

Sabuni, ZA, Mbuthia PG, Maingi N, Nyaga PN, Njagi LW, Bebora LC, Michieka JN.  2013.  Skin lesions associated with ectoparasitic infestation in indigenous chickens in Eastern province of Kenya. Research Journal of Poultry Sciences. 6(3):53-58.sabuni_et_al._2013-ectopara.lesions-research_journal_of_poultry_science.pdf
Kemboi, DC, Chege HW, Bebora LC, Maingi N, Nyaga PN, Mbuthia PG, Njagi LW, Githinji JM.  2013.  Seasonal Newcastle disease antibody titer dynamics in village chickens of Mbeere District, Eastern Province, Kenya. Livestock for Research for Rural Development. 25(10)kemboi_et_al._2013-seasonality.pdf
DC, K, HW C, C BL, Maingi N, Nyaga P N, Njagi L W.  2013.  Effect of parasite control on Newcastle disease vaccination response in free-ranged family chicken in Eastern province, Kenya, 4th April 2013. 47th Kenya Veterinary Association (KVA) annual Scientific conference. , Mombasaabstract_-_kemboi_et_al.pdf
Chege, HW, D.C.Kemboi, Bebora LC, Maingi N, Mbuthia PG, Njagi LW.  2013.  Efficacy of piperazine citrate, levamisole hydrochloride and albendazole in the treatment of chickens naturally infected with gastrointestinal helminths, 4th April 2013. 47th Kenya Veterinary Association (KVA) annual Scientific conference . , Mombasaabstract_-_chege_et_al.pdf

2012

JE, C, ME C, Nyaga P N, Gathumbi P K, Njagi L W.  2012.  Veterinary forensic medicine: an emerging and important discipline, 4th April 2012. Biennial FVM scientific conference and the 46th KVA annual scientific conference. , Safari park hotel, Nairobi, Kenya2012-veterinary_forensic_medicine.pdf
SK, M, Mbuthia PG, Waruiru RM, Njagi LW.  2012.  Prevalence and pathology of Echidnophaga gallinacean in free-range local ducks, 4th April 2012. Biennial FVM scientific conference and the 46th KVA annual scientific conference. , Safari park hotel, Nairobi, Kenya2012-prevalence_and_pathology_of_e.gallinacea_in_ducks.pdf
SK, M, Mbuthia PG, Waruiru RM, Njagi LW.  2012.  Prevalence of haemoparsites in free-range local ducks, 4th April 2012. Biennial FVM scientific conference and the 46th KVA annual scientific conference. , Safari park hotel, Nairobi, Kenya2012-_prevalence_of_haemoparasites_in_ducks.pdf
MM, K, Mbuthia PG, Maingi N, Nyaga PN, Njagi LW.  2012.  Occurrence and lesions associated with Echnostoma revolutum in free-range indigenous chickens in Kenya, 4th April 2012. Biennial FVM scientific conference and the 46th KVA annual scientific conference . , Safari park hotel, Nairobi, Kenya2012-occurrence_and_lesions_of_echinostoma_revolutum__in_chickens.pdf
DC, K, HW C, C BL, Maingi N, Nyaga P N, Njagi L W.  2012.  Seasonal Newcastle disease antibody titres in village chicken of Mbeere District, Eastern Province, Kenya, 9 September. 3rd RUFORUM Conference.. :Uganda., Uganda: RUFORUMruforum_2012.pdf
HW, C, DC K, C BL, Maingi N, Mbuthia P G, Njagi L W.  2012.  Prevalence of ecto and endo parasites in free-range chickens in Mbeere District, Eastern Province, Kenya, 9 September. 3rd RUFORUM Conference. , Ugandaabstract_-_ruforum_conference-ecto_and_endo_parasites_2012.pdf
C, BL, Maingi N, Nyaga P N, Mbuthia P G, Njagi L W.  2012.  Severe parasitism-a hindrance to effective Newcastle disease control in village chickens, 9 September. 3rd RUFORUM Conference. abstract_-ruforum_conference_-__severe_parasitism.pdf
Njagi, LW, Nyaga PN, Bebora LC.  2012.  Effect of immunosuppression on Newcastle disease virus persistence in ducks with different immune status. ISRN Veterinary Science. Abstract

International Scholarly Research Network
ISRN Veterinary Science
Volume 2012, Article ID 253809, 6 pages
doi:10.5402/2012/253809
Research Article
Effect of Immunosuppression on Newcastle Disease Virus Persistence in Ducks with Different Immune Status
LucyW. Njagi,1 Phillip N. Nyaga,1 Lilly C. Bebora,1 Paul G. Mbuthia,1 and UswegeM.Minga2
1Department of Veterinary Pathology, Microbiology and Parasitology, University of Nairobi, P.O. Box 29053-00625, Kangemi, Kenya
2Department of Life Sciences, FSTES, African Council for Distance Education—Technical Committee on Collaboration (ACDE-TCC),
Open University of Tanzania, P.O. Box 23409, Dar es Salaam, Tanzania
Correspondence should be addressed to LucyW. Njagi, njagiluc@uonbi.ac.ke
Received 30 November 2011; Accepted 4 January 2012
Academic Editors: A. Mankertz and I. Nsahlai
Copyright © 2012 LucyW. Njagi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

This study was carried out to verify the possibility that ducks are sources of Newcastle disease (ND) virus infection for chickens in mixed flocks. Immunosuppressed (IS) and non immunosuppressed (NIS) birds, at three different antibody levels (medium, low and absent) were used; the titres having been induced through vaccination, and Immunosuppression done using dexamethazone. Each of the 3 respective groups was further divided into 2 groups of about 12 ducks each: one challenged with velogenic NDvirus; the other not challenged. Selected ducks fromall groups had their antibody titresmonitored serially using hemagglutination inhibition test, while two birds from each of the challenged groups were killed and respective tissues processed for ND viral recovery, using chicken embryo fibroblasts. In general, antibody titres of IS and NIS challenged ducks were significantly higher
than their unchallenged counterparts (P < 0.05). Non-challenged pre-immunised ducks had a progressive decrease in antibody levels; non-immunised ducks did not seroconvert. Newcastle disease virus was isolated from livers and kidneys of the challenged ducks throughout the experimental period; indicating a possibility of viral excretion, especially when the birds are stressed. It, therefore, provides another possible model of viral circulation within mixed flocks.

2011

Kutto, EK, MW N, Njagi L W.  2011.  Bacterial contamination of kale (Brassica oleracea acephala) along the supply chains in Nairobi and its environment.. East African Medical Journal. 88:46-53. Abstract

46 East African Medical Journal February 2011
East Africa Medical Journal Vol. 88 No. 2 February 2011
BACTERIAL CONTAMINATION OF KALE (Brassica oleracea Acephala) ALONG THE SUPPLY CHAIN IN
NAIROBI AND ITS ENVIRONMENT
E. Kutto, BSc, MSc, Department of Veterinary Pathology, Microbiology and Parasitology, M. W. Ngigi, MSc, Department of Agricultural economics, N. Karanja, BSc, MSc, PhD, Department of Land Resource Management and Agricultural Technology, E. Kange’the, Bvm, MSc, PhD, Department of Public Health, Pharmacology and Toxicology, L. C. Bebora, Bvm, MSc, PhD, Department of Veterinary Pathology, Microbiology and Parasitology, University of Nairobi P. O. Box 29052-00625, Kabete Campus, Nairobi, Kenya, C. J. Lagerkvist, BAECON, MAECON, PhD, Swedish University of Agricultural Sciences P.O. Box 7013-75007, Uppsala, Sweden, P. G. Mbuthia, Bvm, MSc, FRVCS(Dip. Path), PhD, Department of Veterinary Pathology, Microbiology and Parasitology, L. W. Njagi, Bvm, MSc, PhD, Department of Veterinary Pathology, Microbiology and Parasitology and J. J. Okello, PhD, Department of Agricultural economics, University of Nairobi, P.O. Box 29052-00625, Kabete Campus, Nairobi, Kenya Request for reprints to: K. E. Kutto, Department of Veterinary Pathology, Microbiology and Parasitology, Kabete Campus, University of Nairobi, P. O. Box 29057-00625, Nairobi, Kenya

BACTERIAL CONTAMINATION OF KALE (Brassica oleracea Acephala)
ALONG THE SUPPLY CHAIN IN NAIROBI AND ITS ENVIRONMENT
E. K. KUTTO, M. W. NGIGI, N. KARANJA, E. KANGE’THE, L. C. BEBORA, C. J. LAGERKVIST, P. G. MBUTHIA, L. W. NJAGI and J. J. OKELLO
ABSTRACT
Objective: To assess the microbiological safety of kale (Brassica oleracea Acephala)
produced from farms and those sold at the markets with special focus on coliforms,
E.coli and Salmonella.
Design: A cross sectional study.
Setting: Peri-Urban farms (in Athi River, Ngong and Wangige), wet markets (in
Kawangware, Kangemi and Githurai), supermarkets and high-end specialty store
both within Nairobi city.
Results: Mean coliform count on vegetables from farms were 2.6x105 ±5.0x105 cfu/g
while those from the wet markets were 4.6x106 ±9.1x106 cfu/g, supermarkets, 2.6x106
±2.7x106 and high-end specialty store 4.7x105 ±8.9x105. Coliform numbers obtained
on kales from the wet markets and supermarkets were significantly higher (p<0.05)
compared to those from farms, while kale samples purchased from high- end specialty
store had similar levels of coliform loads as those from the farms. E. coli prevalence
in the wet markets, supermarkets and high-end specialty store were: 40, 20 and 20%,
respectively. Salmonella was detected on 4.5 and 6.3% of samples collected from the
farms in Wangige and wet market in Kawangware, respectively. Fecal coliforms in
water used on farms (for irrigation) and in the markets (for washing the vegetables)
exceeded levels recommended by World Health Organization (WHO) of 103 organisms
per 100 milliliter while Salmonella was detected in 12.5% of washing water samples
collected from Kangemi market.
Conclusion: Poor cultivation practices and poor handling of vegetables along the
supply chain could increase the risk of pathogen contamination thus puting the health
of the public at risk, therefore good agricultural and handling practices should be
observed.

Njagi, LW, Mbuthia PG.  2011.  Viral Nucleoprotein localilzation and lesions of Newcastle disease in tissues of indigenous ducks.. Abstract

Abstract

Localization of Newcastle disease viral nucleoprotein and pathological lesions was evaluated in tissues of 55 indigenous ducks (45 experimentally infected and 10 sentinel ones). In addition, ten Newcastle disease infected chickens were used to ensure that the virus inoculum administered to the ducks produced the disease in chickens, the susceptible hosts.
Ducks were killed on day 1, 4, 8 and 14 post-infection. Post mortem examination was done with six tissues (liver, spleen, lung, caecal tonsils, kidneys and brain) being collected from
each bird. The tissues were preserved in 10% neutral formalin for 24 h. They were then transferred to 70% ethanol for histology and immunohistochemical staining. Airsacculitis,
necrotic splenic foci, congested intestines, lymphoid depleted caecal tonsils and focal infiltrations by mononuclear cells were the main pathological lesions in infected ducks. Over 28.9% of the infected ducks had Newcastle disease viral nucleoprotein in macrophage-like large mononuclear cells in the caecal tonsils and kidney tubular epithelium. The viral antigens were located in the cytoplasm and nucleolus of the cells. The other organs had no detectable viral antigens. This study shows that the kidneys and caecal tonsils are the likely predilection sites for the virus in ducks. They thus need to be considered as diagnostic indicators for the viral carriage in ducks.

Keywords Ducks . Immunohistochemical . Newcastle disease viral nucleoprotein

Sabuni, A, Maingi N, Njagi LW.  2011.  Prevalence of ectoparasites infestation in indigenous free-ranging chickens in different agro-ecological zones in Kenya. Livestock Research for Rural Development. 22(11):1-11. Abstract

Abstract
Ectoparasitism is an important factor associated with poor production of village indigenous chickens. A cross-sectional study was carried out to determine the prevalence of ectoparasites in free ranging indigenous chicken from two different agro-ecological zones: Lower highland 1 (LH1) in Embu District and Lower midland 5 (LM5) in Mbeere District, Kenya. A total of 144 chickens of matched age (chicks, growers and adults) and sex groups were examined for the presence of ectoparasites. Of these, 138 (95.8%) had one or more types of ectoparasites, namely; lice, mites, fleas and soft ticks.

One thirty one birds had lice, 107 mites, 42 sticktight fleas and 8 had soft ticks. Of the 138 infested birds, 25 had single while 113 had mixed infestations. Lice were the most prevalent parasites. The study documents Epidermoptes species, Laminosioptes cysticola and Megninia species for the first time in Africa as well as Lipeurus caponis and Goniodes gigas in Kenya. All adult birds were infected with ectoparasites followed by 97.7% grower and 89.6% chicks. Both male and female birds had same prevalence (95.8%) of ectoparasites. Lower midland 5 had a slightly higher prevalence of ectoparasites (98.6%) compared to LH1 (93.1%) though not statistically significant. Parasite intensity was significantly different among age groups of chicken and between agro-ecological zones (p<0.05), but not between sexes of birds (p>0.05).

Because of the high prevalence of ectoparasites revealed by this study, it is imperative that integrated control strategies need to be put in place to improve chicken productivity and enhance smallholder livelihood in these areas.

Key words: Ages, fleas, intensity, lice, mites, sexes, ticks

A, S, Mbuthia PG, Njagi LW.  2011.  Prevalence of haemoparasites infection in indigenous chicken in Eastern Province of Kenya. Livestock Research for Rural Development. Abstract

Livestock Research for Rural Development 23 (11) 2011

Prevalence of haemoparasites infection in indigenous chicken in Eastern Province of Kenya
Z A Sabuni, P G Mbuthia*, N Maingi*, P N Nyaga*, L W Njagi*, L C Bebora* and J N Michieka
Ministry of Livestock Development, Kabete,
P.O Box Private Bag, Kangemi, Kenya
alexsabuni@yahoo.com
* Department of Veterinary Pathology, Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Nairobi
P.O Box 29053-00625 Nairobi Kenya

Abstract
Indigenous chickens constitute over 81% of poultry in Kenya and produce 71% of eggs and poultry meat. Ecto- and haemoparasites limit production of these birds in the rural areas. However, there exists scanty information on these parasites infection in indigenous chicken. This study was conducted to determine and document the type and prevalence of haemoparasites affecting different ages and sex groups of free range indigenous chicken from two agro ecological zones: Lower highland 1 (LH1) in Embu District and Lower Midland 5 (LM5) in Mbeere District in Eastern Province, Kenya.

Of the 144 birds examined, 79.2% were infected with haemoparasites, with 62.3% single and 37.7% mixed haemoparasitic infections. Plasmodium gallinaceum was the most prevalent haemoparasite (53.5%) followed by Leucocytozoon schoutedeni (52.1%) and Hemoproteus spp., (3.5%). Grower birds had a prevalence of 83.3% for haemoparasites compared to 81.3% of adults, and 72.9% of chicks (p> 0.05). Male birds had 83.3% prevalence, while female birds had 75.0% (p> 0.05). LH1 was found to have a slightly high prevalence of 81.9% compared to LM5, 76.4% (p> 0.05). Hemoproteus spp were isolated in chickens from LH1 but not from LM5. This study has documented a high prevalence of haemoparasites, hence further studies to determine the impact of infection on the health and productivity of these birds, and evaluation of cost benefit of various control strategies need to be undertaken.
Key words: Age, agro-ecological zones, free range, sex

Mbuthia, PG, Njagi LW, Nyaga PN, Bebora LC.  2011.  Time course investigation of infection with a low virulent Pasteurella multocida strain in normal and immune-suppressed 12 week-old free range chickens. 10 Abstract

Time course investigation of infection with a low virulent Pasteurella multocida strain in normal and immune-suppressed 12 week-old free range chickens

P. G. Mbuthiaa, L. W. Njagia, P. N. Nyagaa, L. C. Beboraa, U. Mingab, Jens Peter Christensenc & J. E. Olsenc*

Date of publication: DOI:10.1080/03079457.2011.623298; Available online: 15 Sep 2011
Avian Pathology
Abstract
Twelve week old indigenous chickens, either immune-suppressed using dexamethasone (IS) or non-immune-suppressed (NIS), were challenged with a low virulent strain, Pasteurella multocida strain NCTC 10322T and developed clinical signs and pathological lesions typical of chronic fowl cholera. NIS birds demonstrated much more severe signs of fowl cholera than IS birds. With few exceptions, signs recorded in IS and NIS birds were of the same types, but significantly milder in the IS birds, indicating that immune-suppression does not change the course of infection, but rather the severity of signs in fowl cholera.
P. multocida signals by fluorescent in situ hybridization (FISH) were observed between 1 hr and 14 days in lungs, trachea, air sacs, liver, spleen, bursa of Fabricius and caecal tonsils, while signals from other organs mostly were observed after 24 hours. More organs had FISH signals in NIS than in IS-birds and at higher frequency per organ. Many organs were positive by FISH even 14 days post infection, and it is suggested that these organs may be likely places for long term carriage of P. multocida following infection.
This study has demonstrated the spread of P. multocida in different tissues in chickens and distribution of lesions associated with chronic fowl cholera, and pointed to a decrease of pathology in immune-suppressed birds. Since dexamethasone mostly affects heterophils, the study suggests that these cells play a role in the development of lesions associated with chronic fowl cholera in chickens.

2010

PW, K, Mbuthia P G, RM W, Njagi L W.  2010.  Some pathological changes in Nile Tilapia and Nile Perch from Lake Victoria, 4 April 2010. Biennial FVM scientific conference. , College of Agriculture and Vet. Sciences, University of Nairobi2010-some_pathological_changes_in_nile_tilapia.pdf
PW, K, Mbuthia P G, RM W, Njagi L W.  2010.  Trypanosoma infection in carrier fish of Lake Victoria, Kenya, 4 April 2010. Biennial FVM scientific conference. , College of Agriculture and Vet. Sciences, University of Nairobi2010-trypanosoma_infection_in_fish.pdf
Njagi L W, Nyaga P N, UM M.  2010.  A retrospective study of factors associated with Newcastle disease outbreaks in village indigenous chickens. Abstract

Bull. Anim. Hlth. Prod. Afr., (2010), 58, 22-33.

A RETROSPECTIVE STUDY OF FACTORS ASSOCIATED WITH NEWCASTLE
DISEASE OUTBREAKS IN VILLAGE INDIGENOUS CHICKENS

L.W. Njagi1*, P.N. Nyaga1, P.G. Mbuthia1, L.C. Bebora1, J.N. Michieka1, and U.M. Minga2

1University of Nairobi,
Department of Veterinary Pathology, Microbiology and Parasitology,
Faculty of Veterinary Medicine,
P.O. Box 29053 – 00625, Kangemi, Kenya.
2Open, University of Tanzania, P.O. Box 23409, Dar es salaam, Tanzania
ÉTUDE RÉTROSPECTIVE DES FACTEURS ASSOCIÉS À LA DÉCLARATION DE
LA MALADIE DE NEWCASTLE CHEZ LA POULE DE RACE LOCALE
Résumé
Bien que l'épidémiologie de la maladie de Newcastle soit bien documentée dans les systèmes
aviaires commerciaux, les informations relatives à l’écologie de la maladie chez la poule de race locale, en particulier sous les tropiques, sont par contre peu disponible. L'objectif de cette étude était de déterminer les facteurs de risque associés à la maladie de Newcastle chez la poule de race locale. L'étude a été menée dans cinq zones agro-écologiques et a concernées
soixante quinze ménages élevant des poules de race locale. Les éleveurs ont été sélectionnés de manière aléatoire et évalués sur leurs connaissances de la maladie, et les signes cliniques
manifestés par les oiseaux infectés. Les données sur les pratiques de gestion, l’incidence des
maladies et les facteurs de risque associés à la déclaration de la maladie de Newcastle ont été
recueillies à l'aide d'un questionnaire et analysées à l'aide d’un logiciel de statistiques. Le taux de fréquence de la maladie de Newcastle était élevé (93,8%) dans la zone sèche et faible (50%) dans la zone fraîche et humide (dans les régions basses de montagnes). Les déclaration de la maladie de Newcastle étaient significativement associées aux différents facteurs suivant cloisonnement des oiseaux dans toutes les zones écologiques, sauf celle située dans le Bas-
Midland où pour la plus part des cas signalés, les oiseaux n’étaient pas enfermés; le mode
d’évacuation des oiseaux infectés ; les carcasses des volailles et les matières fécales; les saisons sèches dans les zones sèches juste avant les pluies ; les conditions de ventilation ; les changements irréguliers de température et l’approvisionnement en volaille sur les marchés (P <0,05). Par contre, la poussière n'était pas significative (P> 0,05) associée aux déclarations de la maladie de Newcastle. Les réponses variaient selon les saisons et entre les zones agro - écologiques. En guise de conclusion, l'étude a montré que plusieurs facteurs à savoir: cloisonner les oiseaux, les températures froides ou très chaudes, la ventilation, l'achat d’oiseaux sur les marchés, l'élimination de la matière fécale et les oiseaux infectés sont des facteurs majeurs de risque pour la survenue de la maladie de Newcastle chez les poules de race locale. Il est recommandé que les éleveurs de volaille soient informés sur la transmission de la maladie de Newcastle et sa prévention.

Mots clés: facteurs de risque, zones agro-écologiques, cloisonnement, saisons chaudes et
fraîches.

Summary
Although the epidemiology of Newcastle disease in commercial poultry systems is well
documented, its ecology in indigenous birds, especially in tropics, is not adequately reported.
The objective of this study, therefore, was to determine the risk factors associated with occurrence of Newcastle disease in village indigenous chickens. The study was carried out in
five agro –ecological zones and seventy five households keeping indigenous chickens. Farmers were randomly selected and assessed on whether they understood Newcastle disease including knowing its local name and clinical signs manifested by the affected birds. Those who did not fit into the above category were excluded from further interviews. Data on management practices, incidence of diseases and risk factors associated with Newcastle disease outbreaks were collected using a questionnaire and analysed using statistical package. The prevalence rate of Newcastle disease was highest (93.8%) in the dry zone (Low midland 5) and lowest (50%) in cool wet zone (Lower Highland 1). Newcastle disease outbreaks were significantly associated with the following factors namely: confinement of birds in all ecological zones except in lower midland 5 where most cases were reported without confinement; mode of disposal of infected birds, carcasses and poultry faecal matter; dry seasons in the dry zones just before the rains; wind conditions; short intermittent temperature changes and the restocking of farms with chickens from the markets (P<0.05). Dust storm was not significantly (P>0.05) associated with Newcastle disease outbreaks. The responses varied across the seasons and between the agro – ecological zones.
In conclusion, the study has shown that several factors namely: confinement; cold or very hot
temperatures; winds; introduction of market birds and disposal of manure and sick birds are
major risk factors to occurrence of Newcastle disease in indigenous chickens. It is recommended that flock owners be educated on Newcastle disease transmission and prevention.

Key – words: risk factors, agro–ecological zones, confinement, hot and cold seasons.

Njagi L W, UM M.  2010.  Prevalence of Newcastle disease virus in village indigenous chickens in varied agro-ecological zones in Kenya. 22(5) Abstract

Abstract
It was hypothesized that the agro-ecological zone in which village indigenous chickens were farmed influenced the level of diseases occurrence. One hundred and forty four apparently healthy chickens (71 from lower highland 1, a cold zone and 73 from lower midland 5, a hot zone) were randomly sampled. Oro–pharyngeal and cloacal swabs were collected from each bird and processed for virus isolation in 10-12 day old embryonated chicken eggs. In addition, blood, without anticoagulant was obtained from each bird through wing venipuncture. Haemagglutination inhibition assay was performed for all sera samples.

Prevalence of Newcastle disease (NDV) virus was significantly higher (17.8%) in the dry hot zone (lower midland 5) compared to the cool wet zone (lower highland 1) at 9.9% showing evidence for climate as a risk factor in the occurrence of NDV in village chicken. Female birds had higher mean Newcastle disease viral titers than their male counterparts. All Newcastle disease virus isolates recovered were from healthy appearing birds and were all velogenic. Sero-prevalence was significantly highest (p<0.05) in adult birds (10%) while growers had 5.1% and chicks 2.9%. Apparently healthy-appearing birds were reported to be reservoirs of velogenic Newcastle disease virus strains that could initiate endemicity NDV cycles in the village setting.
Key words: cool and dry zones, healthy-appearing chickens, reservoirs, velogenic Newcastle disease virus

2008

JK, K, Nyaga P N, JN N, JN M, Njagi L W.  2008.  An invitro study of some factors that may influence changes of virulence for Newcastle disease virus, 4 April 2008. Biennial FVM scientific conference. , College of Agriculture and Vet. Sciences, University of Nairobi2008-invitro_study_of_virulence_of_ndv.pdf
C, BL, Njagi L W, Mbuthia P G, DI K.  2008.  Various manifestations of ovarian carcinoma and Marek’s disease / leucosis complex in chickens: Case reports , 4 April 2008. Biennial FVM scientific conference. , College of Agriculture and Vet. Sciences, University of Nairobi2008-manifestation_of_ovarian_carcinoma_and_chicken.pdf
C, BL, Njagi L W, Mbuthia P G, Nyaga P N.  2008.  Importance of environmental hygiene in reducing bacterial load exposure to night – housed indigenous chickens, 4 April 2008. Biennial FVM scientific conference. , College of Agriculture and Vet. Sciences, University of Nairobi2008-importance_of_environmental_hygiene_in_indigenous_chicken.pdf
Mbuthia P G, C BL, G M, Njagi L W.  2008.  Histomoniasis and traumatic gastritis (Hardware disease) in peacocks: Case Reports , 4 April 2008. Biennial FVM scientific conference. , College of Agriculture and Vet. Sciences, University of Nairobi2008-histomoniasis_and_hardware_disease_in_peacockc.pdf
Mbuthia P G, C BL, G M, SY S, Njagi L W.  2008.  Myopathy and parasitism in a guinea fowl: A case report, 4 April 2008. Biennial FVM scientific conference. , College of Agriculture and Vet. Sciences, University of Nairobi2008-myopathy_and_parasitism_in_a_guinea_fowl.pdf
Sabuni Z A, Mbuthia P G, Maingi N, Nyaga P N, Njagi L W.  2008.  Prevalence of hemoparasites in indigenous chickens in Eastern province, Kenya. , 4 April 2008. KVA annual scientific conference . , Golf hotel, Kakamega, Kenya
Sabuni Z A, Mbuthia P G, Maingi N, Nyaga P N, Njagi L W.  2008.  Prevalence of ectoparasites in indigenous chickens in two agro –ecological zones, Eastern province, Kenya, 4 April 2008. Annual KVA scientific conference . , Golf hotel, Kakamega, Kenya
Njagi L W, Mbuthia P G, Nyaga P N, C BL.  2008.  Localization of Newcastle disease viral nucleoprotein in the tissues of carrier ducks, 4 April 2008. Biennial FVM scientific conference. , College of Agriculture and Vet. Sciences, University of Nairobi2008-location_of_nd_viral_nucleoprotein_in_ducks.pdf
Lucy W Njagi, Nyaga PN, Mbuthia PG.  2008.  Newcastle disease virus and antibody levels in matched sera, ovules and mature eggs of indigenous village hens. Abstract

Abstract
In this study, one hundred and thirty three non - vaccinated village hens in lay were tested for carriage of Newcastle disease virus and presence of antibody against the virus in sera, ovules and eggs. Blood was obtained from the hens through wing venipuncture while matched ovules and mature eggs were taken from the oviducts. Cloacal and oropharyngeal swabs
were collected from each hen for virus isolation. Haemagglutination inhibition assay was performed for all sera and egg yolk samples. Protective serum antibody titres of ≥3 (log2) were recorded in 5.3% of the naturally exposed, indigenous village hens. Antibody titres to Newcastle disease virus in the yolks were higher than in their sera (230.08 ± 40.05; 1.56
± 0.74 for egg yolk and sera, respectively) (P<0.05). The mature egg yolks had significantly higher titres of antibodies as compared to the ovules (P<0.05). Sera and egg yolk antibodies were positively correlated (r = 0.50). Newcastle disease virus was isolated in 3.0% of the hens that were also sero - negative. The presence of Newcastle disease virus antibodies in egg yolks and Newcastle disease virus isolation in sero-negative hens, indicate previous natural exposure to the virus, hence viral endemicity in the area.

Key words: Newcastle disease, egg yolk, non-vaccinated, village chickens

Mbuthia P G, Njagi L W.  2008.  Pasteurella multocida in scavenging family chickens and ducks; carrier status, age susceptibility and transmission between species. 37:51-57. Abstract

Abstract
Pasteurella multocida causes fowl cholera, a highly contagious and severe disease in chickens and water fowls. The disease is not well described in less intensive production systems, including scavenging family poultry production in developing countries. P. multocida was isolated from 25.9% of healthy-looking ducks and 6.2% of chickens from free-range family poultry farms and at slaughter slabs at market. On experimental infection with 1.2 to 2.0×108 organisms of the P. multocida type strain (NCTC 10322T), 12-week-old chickens expressed fowl cholera clinical signs significantly more times (372 signs) than those of 4-week-old, 8-week-old and 16-week-old chickens (173, 272 and 187 signs) and more signs were severe. In family ducks the 8-week-old birds expressed clinical signs significantly more times (188 signs) than those of the other age groups (117, 80, and 83 signs, respectively) and severe signs were more frequent. P. multocida transmitted from seeder birds (n=12) to sentinel birds (n=30), which developed clinical signs, and in some cases lesions of fowl cholera allowed bacterial re-isolation, whether infected ducks served as seeders for chickens or chickens served as seeder for ducks. This study has documented the occurrence of P. multocida among healthy-appearing family poultry in a tropical setting, and demonstrated that age susceptibility is highest in 12-week-old family chickens and 8-week-old family ducks when challenged with a low-virulent strain of P. multocida. It has further demonstrated that cross-transmission of fowl cholera may happen between family ducks and chickens, and vice versa.

2007

C, BL, Njagi L W.  2007.  A case of Newcastle disease in parrots in Nairobi, Kenya. Bulletin of Animal Health and production in Africa. 55:292-295. Abstractabstract-_nd_in_parrots-2007.pdf

Bull.Anim.Hlth.Prod.Afr.,(2007),55,292-295

2006

Mbuthia P G, Njagi LW, Nyaga PN, Bebora LC, Mugera GM.  2006.  Preliminary study of Tetrameres species infestations in different age groups of village free – range chickens in Embu and Mbeere districts, Kenya., 4 April 2006. Biennial FVM scientific conference. , College of Agriculture and Vet. Sciences, University of Nairobi2006-preliminary_of_tetrameres_in_chicken.pdf
Njagi L W, Nyaga P N.  2006.  The risk factors associated with Newcastle disease occurrence in indigenous free – range chickens in Embu and Mbeere districts, Kenya. , 4 April 2006. Biennial FVM scientific conference. , College of Agriculture and Vet. Sciences, University of Nairobi2006-risk_factors_of_nd-copy.pdf

UoN Websites Search