Browsing by Author "Njoroge, Ernest M."

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Application of ultrasonography in prevalence studies of hydatid cysts in goats in north-western Turkana, Kenya and Toposaland, southern Sudan
(Elsevier, 2000) Njoroge, Ernest M.; Mbithi, P.M.F.; Gathumat, J.M.; Wachira, M; Magambo, J.K.; Zeyhle, E.
Application of ultrasonography in prevalence studies of hydatid cysts in goats in north-western Turkana, Kenya and Toposaland, southern Sudan. Onderstepoort Journal of Veterinary Research, 67:251-255 A study was done to determine the prevalence of hydatid cysts in goats using ultrasonography. A total of 1 390 goats were examined, 43,6 % (606/1390) of them from north-weste_rn Tu_rkana, Keny:, and 56,4% (784/1390) from Toposaland, southern Sudan. Hydatid cysts were VISualized 1n 1,82 Yo (~ 1 I 606) of the goats from north-western Turkana and 4,34% (34/784) of those from Topo~aland. Unlike abattoir surveys, the prevalence data obtained in this study were unb1ased because ent1re flocks were examined. The lower prevalence rate of the disease in goats from Turkana was attnbuted to the hydatid disease control programme in that area, which is absent in Toposaland .
Canine echinococcosis in northwest Libya: assessment of coproantigen elisa, and a survey of infection with analysis of risk-factors
(2005) Buishi, I.; Njoroge, Ernest M.; Bouamra, O.; Craig, P.
In order to determine the prevalence and risk factors for canine echinococcosis in different endemic localities in the Tripoli area of northwest Libya, stray dogs were examined post-mortem, and owned dogs screened for Echinococcus granulosus infection using a standardised genus specific coproantigen ELISA. The prevalence of E. granulosus infection at necropsy in stray-dogs was 25.8% (15/58, 95% CI 15.3-39.0%), and 21.6% (72/334, 95% CI 17.3-26.4%) of owned dogs tested were positive by coproantigen ELISA. Sheepdogs appeared to have a significantly higher copro-positive prevalence (19/19 positive, p = 0.003), compared to 23.6% of other dog classes (e.g. 52/220 guard dogs and household pets). Worm burdens in necropsied dogs ranged from 29 to 2900 (mean 1064) and were positively correlated to coproantigen ELISA OD values (rs = 0.87, p < 0.001), but negatively correlated with dog age (rs = -0.69, p = 0.001). Dog age was a significant factor in copro-prevalence as there was an increasing coproantigen-positive tendency in younger dogs (≤5 years, p = 0.04). A total of 45/132 (34%, 95% CI 25.9-42.1%) of farms/homestead had at least one dog that was coproantigen positive. Overall copro-prevalence in dogs by locality varied, with Alkhums (Leptis-Magna) district having the highest copro-prevalence at 38.7% (24/62, 95% CI 26.6-50.8%) (p = 0.001). Coproantigen testing of a cohort of owned dogs before and approximately 15 months after praziquantel treatment showed a significant decrease in the coproantigen positive rate from 21.6% (72/334) to 9% (21/233) post-treatment. The overall E. granulosus coproantigen positive rate ('re-infection rate') within the same cohort of dogs was 22 % (10/45) by 15 months post-treatment. Significant risk factors for a copro-positive owned dog were associated with non-restraint of dogs, and owners that did not de-worm their dogs. Home slaughtering of livestock and lack of knowledge about E. granulosus transmission were also significant risk factors for a canine coproantigen positive result. © 2005 Elsevier B.V. All rights reserved.
Canine echinococcosis in Turkana (north–western Kenya): a coproantigen survey in the previous hydatid-control area and an analysis of risk factors
(2013-07-18) Buishi, E.; Njoroge, Ernest M.; Zeyhle, E.; Rogan, M.T.; Craig, P. S.
A study of Echinococcus granulosus infection in dogs, with risk-factor analysis, was carried out in the endemic area of northern Turkana district, Kenya, using necropsy on 42 strays and a coproantigen-ELISA survey of 161 owned animals. During the post-mortem examinations, 14 (33%) of the necropsied dogs were found infected with E. granulosus, with a mean burden of 540 worms (range=two to 4080 worms). The 26 necropsied dogs that came from the north–western Lokichoggio division — an area where, from 1983 to 1997, there had been a continuous programme of hydatid control — showed a similar prevalence of infection to the other dogs (34.6%) but a significantly lower mean burden, of 53 worms (range=two to 300). Forty-two (26%) of the animals tested for Echinococcus coproantigen were found positive. Although the dogs from the Lokichoggio division were more likely to be coproantigen-positive (29%) than those from the central Kakuma division (20%) or the north–eastern division (18%), the differences were not statistically significant. In questionnaire-based interviews, the owners of the dogs tested for coproantigens were asked about possible risk factors for canine infection with E. granulosus. Women were found to have twice the level of contact with dogs as men. The results of a univariate analysis of the dog-owners' responses revealed six factors that appeared to be significantly associated with a coproantigen-positive dog: non-restraint of the dog (P<0.001); dog fed on raw offal (P<0.001); the improper disposal of slaughter offal (P<0.001); the dog-owner's lack of knowledge about the transmission of echinococcosis (P=0.001); the dog not receiving anthelmintic treatment (P=0.003); and dog age ≤5 years (P=0.01). The results of a multivariate analysis confirmed that lack of dog restraint, access to raw offal, and young age of the dog (≤5 years) each significantly increased the risk of coproantigen positivity (P, 0.005). Dogs that scavenged from cooking pots, were used to clean babies, had access to the inside of houses, and/or slept indoors appeared, however, to be at no increased risk of coproantigen positivity. The present results are discussed in relation both to older information on the epidemiology and role of human behaviour in the transmission of E. granulosus in Turkana, and the effects of the hydatid-control programme that ran continuously in the north–western division of Turkana between 1983 and 1997.
Epidemiology and control of echinococcosis in sub-saharan Africa
(Elsevier, 2000) Magamboa, Japhet; Njoroge, Ernest M.; Zeyhleb, Eberhard
Cystic echinococcosis (CE) is highly endemic among the nomadic pastoral tribes of East Africa, but is rare amongst the agriculturally based communities. Echinococcus granulosus infections are common in dogs from all countries in sub-Saharan Africa where they have been examined. Transmission of E. granulosus to humans is affected by such factors as prevalence of the parasite in domestic dogs, behaviors of humans towards dogs, and heterogenicity of the parasite and susceptibility of humans to infection. Sheep and goats appear to be the most common domestic intermediate hosts, but recent studies suggest that camels are equally important intermediate host, especially in Sudan and Turkana. At least five of ten E. granulosus genotypes are infective to humans in sub-Saharan African. Most human cases of CE are caused by the sheep strain (GI) and camel strain (G6) of E. granulosus. Other strains occurring in the area may include a lion strain, the horse strain (G4 or Echinococcus equinus) and the cattle strain (G5 or Echinococcus ortleppi).
Oxfendazole treatment for cystic hydatid disease in naturally infected animals
(American Society for Microbiology, 1997-09-09) Blanton, Ronald E.; Wachira, Timothy M.; Zeyhle, Eberhard E.; Njoroge, Ernest M.; Magambo, Japheth K.; Schantz, Peter M.
Few chemotherapeutic agents are available for the medical management of hydatid disease caused by the parasite Echinococcus granulosus. In order to test the potential of oxfendazole for the treatment of infection with this parasite, nine infected goats and four sheep were given oxfendazole twice weekly at a dose of 30 mg/kg of body weight for 4 weeks and monitored by ultrasound for an additional 4 weeks. Efficacy was finally evaluated by postmortem examination, including determination of protoscolex viability and cyst wall histology. In treated animals, protoscolices were dead or absent in 97% of cysts from oxfendazole-treated animals compared to 28% of cysts from untreated control animals. On postmortem examination, 53% of cysts from treated animals were found to be grossly degenerate. A sample of those cysts that appeared potentially viable all demonstrated evidence of severe damage to the cyst wall. By light microscopy, cysts showed severe disorganization of the adventitial layer with invasion of inflammatory cells and in some cases frank necrosis with no apparent adventitial layer. The follow-up period for assessment of the drug’s ability to cause complete degeneration and resorption of cysts was relatively short. This study, however, indicates that oxfendazole is at least as effective as and is easier to administer than albendazole for the treatment of hydatid disease.
A PCR system for detection of species and genotypes of the Echinococcus granulosus-complex, with reference to the epidemiological situation in eastern Africa
(Elsevier, 2004-04) Dinkel, Anke; Njoroge, Ernest M.; Zimmermann, Anja; Wälza, Marcus; Zeyhleb, Eberhard; Elmahdi, Ibrahim E; Mackenstedt, Ute; Romig, Thomas
We describe the development of a specific and sensitive PCR/semi-nested PCR system for the rapid diagnosis of Echinococcus granulosus genotype G1, E. granulosus genotype G6/7, and Echinococcus ortleppi (G5). Diagnosis of G1 and the group G5/6/7 is performed by a simple PCR, while discrimination between E. ortleppi (G5) and G6/7 involves a subsequent semi-nested PCR step. The target sequence for amplification is part of the mitochondrial 12S rRNA gene. Specificity of the PCRs was 100% when evaluated with isolates of 16 species of cestodes, including Echinococcus multilocularis, Echinococcus equinus, E. ortleppi and three strains of E. granulosus (G1, G6 and G7). Sensitivity threshold was 0.25 pg of DNA. This new approach was compared with published protocols of restriction fragment length polymorphism-PCR and sequencing of mitochondrial cytochrome c oxidase subunit 1 and NADH dehydrogenase 1 genes using Echinococcus isolates of human, sheep, goat, camel, cattle and pig origin from Kenya and Sudan. Additionally, two internal DNA probes were developed, one hybridising only with G1, the other with G5, G6 and G7 amplification products. Preliminary epidemiological results obtained with this PCR approach include the detection of a camel strain (G6) infection for the first time in a human patient from eastern Africa, and the first reports of E. ortleppi (G5) in livestock from Kenya and the Sudan.
Progressive atrophic rhinitis in a medium-scale pig farm in Kiambu, Kenya
(Elsevier, 2012) Wabacha, J.; Maribei, J.; Thaiya, A.; Munyua, S.; Karanja, D.; Njoroge, Ernest M.
Forty-two pigs in a herd of 117 displayed various clinical signs of progressive atrophic rhinitis. The main signs included sneezing, coughing, lachrymation, serous to muco-purulent nasal discharge, and nasal bleeding in 1 pig. Three pigs had lateral deviation of the snout, while 4 had brachygnathia superior with obvious deformation of the face. Four acutely affected weaner pigs appeared weak, while the 7 chronically-affected pigs appeared smaller than their apparently unaffected penmates of the same age. Treatment of the acutely affected pigs with long-acting oxytetracycline at 20 mg/kg body weight intra-muscularly, repeated once after 7 days, reduced the severity but did not clear the sneezing from all the pigs. Fifteen pigs were slaughtered 2 months after the clinical diagnosis was made. The carcasses of the chronically affected pigs were about 15 % lighter than those of the apparently normal pigs of the same age and from the same pen, which translated to a loss of 921.00 Kenya shillings per pig (US$13.7). Diagnosis of progressive atrophic rhinitis was confirmed by sectioning the snouts of randomly selected slaughtered pigs with obvious deformation of the snout. Sections were madeat the level of the 1st/2nd upper premolar tooth. Varying degrees of turbinate atrophy, from mild to complete, were noted. Histopathology of the turbinates revealed metaplasia of nasal epithelium and fibrosis in the lamina propria.
Streptococcal meningitis in a five-month-old male lamb
(1999) Maribei, J.M.; Wabacha, J.K.; Njoroge, Ernest M.
Streptococcus species cause a wide variety of diseases in food animals, including septicaemia, mastitis, meningitis, encephalitis and pneumonia5 . Meningitis due to Streptococcus spp. is commonly a complication of bacteraemia and septicaemia in neonates. In older animals, streptococcal meningitis is common only in pigs3 . A case of streptococcal meningitis in a 5-month-old lamb is reported. To the best of our knowledge this is the 1st report of the disease in an older lamb. A 5-month-old male lamb was brought to the University of Nairobi Large Animal Clinic with a history of being well in the early morning and then falling frequently to the left side later in the day. A clinical examination was carried out and blood taken in EDTA for haematology. In addition, cerebrospinal fluid was obtained aseptically through the atlanto-occipital joint and submitted for bacterial culture and sensitivity determination. On clinical examination, the lamb was dull, recumbent, staggered when forced to move and would fall over to the left side. Body temperature was 40.0 C and there was opisthotonus. It was hyperaesthetic, grinding its teeth, with paddling movements of the hind limbs and appeared blind. A tentative diagnosis of meningitis was made on the basis of the clinical manifestation.
A study of cystic echinococcosis in slaughter animals in three selected areas of northern Turkana, Kenya
(Elsevier, 2002-02-27) Njoroge, Ernest M.; Mbithi, P.; Gathuma, J.; Wachira, T.; Gathura, P.; Magambo, J.; Zeyhle, E.
In an attempt to establish the prevalence of cystic echinococcosis, a study was conducted in slaughter animals in three divisions of northern Turkana, Kenya. A total of 5752 goats, 588 sheep, 381 cattle and 70 camels were examined at slaughter. Echinococcus granulosus metacestodes were found in 19.4% of the cattle, 3.6% of sheep, 4.5% of goats and 61.4% of camels. The prevalence of cystic echinococcosis in cattle, sheep and goats was higher in Lokichogio than in either Kakuma or Central divisions. On the other hand, the prevalence of the disease in camels was higher in Central (84.6%) than either Lokichogio (70.6%) or Kakuma (50%). The differences in prevalence rates in different study areas are attributed to differences in environmental conditions, livestock stocking intensity and cross-border migration of livestock.
Water intoxication in cattle
(1999) Njoroge, Ernest M.; Maribeia, J.M.; Mbuguaa, P. N.; Njiru, S M.
Water intoxication is a condition that is common in cattle, and has also been reported in other domestic animals and man. A comprehensive description of the condition is lacking. For a better understanding of the condition, this paper reviews work that has been reported previously by various authors.