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


2021

Otiang, E, Thumbi SM, Campbell ZA, Njagi LW, Nyaga PN, Palmer GH.  2021.  Impact of routine Newcastle disease vaccination on chicken flock size in smallholder farms in western Kenya. PLoS. 16(3)

2020

2019

Mutinda, WU, Mbuthia PG, Njagi LW, Bebora LC, Nyaga PN.  2019.  Pathogenicity of Kenyan Infectious Bursal Disease Virus Isolates in Indigenous Chickens. International Journal of Poultry Science. 18(11):523-529.

2018

Wahome, MW, Njagi LW, Nyaga PN, Mbuthia PG, Bebora LC, Bwana MO.  2018.  Knowledge, attitudes and practices of indigenous chicken value chain actors in relation to infectious bursal disease transmission in Kenya. Ruforum working Document Series . 17(2):511-518.
Waruiru, RM, Mavuti SK, Mbuthia PG, Njagi LW.  2018.  Prevalence and intensity of gastrointestinal helminth infestations of free range domestic ducks in Kenya.. Livestock Research for Rural Development . 30(4)
Mulei, IR, Nyaga P, Mbuthia PG, Waruiru RM, Njagi LW.  2018.  Infectious Pancreatic Necrosis virus isolated from farmed Rainbow Trout and Tilapia in Kenya is identical to European Isolates. Journal of Fish Diseases.. DOI:10.1111
Karoki, WH, Karanja DN, Bebora LC, Njagi LW.  2018.  Isolation, Characterization, and Quantification of Bacteria from African Sausages Sold in Nairobi County, Kenya.. Hindawi International Journal of Food Science . 2018
Igizeneza, A, Bebora LC, Nyaga PN, Njagi LW.  2018.  Antibiotic resistance in bacteria isolated from indigenous slaughter chicken in Nairobi, Kenya. East African Medical Journal . 95(10)

2017

Maina, KW, Murugami JW, Waruiru RM, Mbuthia PG, Thaiyah AG, Njagi LW, Ngowi HA, Nzalawahe J, Mdegela RH.  2017.  Prevalence and risk factors associated with parasitic infections of farmed fish in central Kenya, 26-28 April 2017. Proc. of the Joint KVA, CVA & UoN-FVM International Scientific Conference . , Safari Park Hotel, Nairobi, Kenya
Waruiru, RM, Mavuti SK, Mbuthia PG, Njagi LW, Mutune MN, Otieno RO.  2017.  Prevalence of ecto-and haemo-parasites of free-range local ducks in Kenya. Livestock Research for Rural Development . 29(7)
KW, M, Mbuthia P G, RM W, J N, JW M, Njagi L W, RH M, RH M, SK M.  2017.  Risk factors associated with parasites of farmed fish in Kiambu County, Kenya.. International Journal of Fisheries and Aquatic Studies. 5(4):217-223.
Chege, HW, Kemboi DC, Bebora LC, Maingi N, Mbuthia PG, Nyaga PN, Njagi LW.  2017.  Efficacy of Piperazine citrate, Levamisole hydrochloride and Albendazole in the treatment of chicken naturally infected with gastrointestinal helminths.. Livestock Research for Rural Development . 29(5)
Bwana, MO, Njagi LW, Nyaga PN, Mbuthia PG, Bebora LC, Wahome MW, Mutinda WU, Kitala PM.  2017.  Effects of different infectious Bursal disease vaccination regimes on biochemical and haematological parameters of indigenous chicken in Kenya. . Livestock Research for Rural Development . 29(5)
Wahome, MW, Njagi LW, Mbuthia PG, Nyaga PN, Bebora LC, Bwana MO.  2017.  Occurrence of Antibodies to Infectious Bursal Disease Virus in NonVaccinated Indigenous Chicken, Ducks and Turkeys in Kenya. Vet Sci. 6(3):159-162..
Bwana, M, Njagi L, Nyaga P, Mbuthia P, Bebora L, Wahome M, Mutinda W, Kitala P.  2017.  Stinging Nettle and Neem enhance antibody response to local killed and imported live Infectious Bursal Disease Vaccines in Indigenous Chicken in Kenya.. Poultry Science journal. 97:447–454.
Njagi, LW, Miheso KO, Mbuthia PG, Gathumbi PK, Shah DN, Wanjohi CW, Murithi MR.  2017.  Seroprevalence of Avian Leucosis in chicken in Nairobi and surrounding Counties.. Livestock Research for Rural Development. . 29

2016

Maina, KW, Murugami JW, Waruiru RM, Mbuthia PG, Thaiyah AG, Njagi LW, Ngowi HA, Nzalawahe J, Mdegela RH.  2016.  Management Practices and Constraints of Fish Farming in Kiambu and Counties, Kenya, 23 November. the 1st Eastern Africa Aquaculture Symposium and Exhibition (EAASE) . , African Institute for Capacity Development (AICAD), Kiambu, Kenya
Bwana, MO, Njagi LW, Nyaga PN, Mbuthia PG, Bebora LC, Wahome MW, Mutinda WU, Kitala PM.  2016.  Growth promotive effects of neem and stinging nettle in indigenous chickens in Kenya. Ruforum working Document Series (ISSN 1607-9345). 14(1):833-838.

2015

Mutinda, WU, Njagi LW, Nyaga PN, Bebora LC, Mbuthia PG, Kemboi, D.C., Githinji, Muriuki A.  2015.  Isolation of Infectious Bursal Disease Virus Using Indigenous Chicken Embryos in Kenya. International Scholarly Research Notices. . International Scholarly Research Notices.. 2015

2014

Chege, HW, Kemboi DC, Bebora LC, Maingi N, Mbuthia PG, Nyaga PN, Njagi LW, Githinji J.  2014.  Seasonality of ecto-and –endoparasites in indigenous chicken of Mbeere Sub-county, Kenya, 3 September. 9thBiennial Scientific Conference,. , FVM Upper Kabete Campus.
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.

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