<i>Trypanosoma evansi</i>: Genetic variability detected using amplified restriction fragment length polymorphism (AFLP) and random amplified polymorphic DNA (RAPD) analysis of Kenyan isolates

We compared two methods to generate polymorphic markers to investigate the population genetics of Trypanosoma evansi; random amplified polymorphic DNA (RAPD) and amplified restriction fragment length polymorphism (AFLP) analyses. AFLP accessed many more polymorphisms than RAPD. Cluster analysis of the AFLP data showed that 12 T.evansi isolates were very similar (‘type A’) whereas 2 isolates differed substantially (‘type B’). Type A isolates have been generally regarded as genetically identical but AFLP analysis was able to identify multiple differences between them and split the type A T. evansi isolates into two distinct clades

Identification of Glossina morsitans morsitans odorant binding proteins genes in Glossina fuscipes fuscipes: a preliminary study

Tsetse flies are vectors of trypanosome parasites, causative agents of Trypanosomiasis in humans and animals. Odorant Binding Proteins (OBPs) are critical in insect olfaction as they bind volatile odours from the environment and transport them to receptors within olfactory receptor neurons for processing providing critical information for host identification. Glossina morsitans morsitans primers designed for conventional PCR were used to screen OBP genes in Glossina fuscipes fuscipes in female head, thorax, abdomen and leg tissues. A total of 31.8% of OBPs were identified in G. f. fuscipes head while 18.2% were detected in the thorax. The abdomen had 22.7% OBPs identified and the legs revealed 18.2% OBPs. OBP5 and OBP6 were the most predominant since they were detected in the head, thorax and abdomen of G. fuscipes fuscipes which may provide the need to identify their functions in both G. morsitans morsitans and G. fuscipes fuscipes. This study confirms genetic differences between OBPs from riverine (G. f. fuscipes) and savanna (G. m morsitans) species which may be key in understanding the role of olfaction in enhancing vector competence of G. m. morsitans and G. f. fuscipes. Such information will be critical in designing better vector control strategies based on olfactory mediated behavior.Key words: Trypanosomiasis, olfaction, tsetse flies, odorant binding protein

Seroprevalence of HAV, HBV, HCV, and HEV among acute hepatitis patients at Kenyatta National Hospital in Nairobi, Kenya

Background: Acute viral hepatitis is most frequently caused by the hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and hepatitis E virus (HEV).Objectives: To determine seroprevalence of HAV, HBV, HCV and HEV among patients with acute hepatitis in Nairobi, Kenya, elucidate various risk factors for hepatitis viral infection and determine the co-infection rates with these viruses in the acute hepatitis patients.Design: Across sectional descriptive study.Setting: Kenyatta National Hospital, from November 2007 to April 2008.Subjects: One hundred patients were recruited by purposive sampling method and comprised of 57 males and 43 females.Results: Among the enrolled patients, twenty three tested positive for one or more markers of acute viral hepatitis, that is, HAV, HBV, HCV and HEV. No markers were detected in 77 patients, 2% tested positive for IgM anti-HAV; 11% for IgM anti-HBc; 3% for HBsAg; 5% for HCV RNA and 7% for IgM anti-HEV.Various risk factors associated with acute viral hepatitis were identified; poor sanitation, source of water, occupation, place of residence, level of education,household size, drug abuse and sexual behaviours. Co-infection rate with hepatitis Viruses was at 4%, IgM anti-HAV and IgM anti-HEV 1 % (n=1); IgM anti-HBc and IgM anti-HEV 1% (n=1); IgM anti-HBc and anti-HCV 2% (n=2).Three patients were positive for HBsAg; among this two were negative for IgM anti-HBc and this accounted for HBV carriage (2 %).Conclusion: Hepatitis viruses’ infections are common cause of hepatitis among patients with acute hepatitis at Kenyatta National Hospital. Co-infection with these viruses was also identified among these patients

Identification, Characterization and Purification of MSC_0265, a Potential Immunogenic Antigen Homologue of Mycoplasma mycoides subsp. mycoides in Mycoplasma capricolum subsp. capripneumoniae

In silico identification and characterization of vaccine antigens has opened up new frontiers in the field of reverse vaccinology to mitigate the effects of livestock diseases by development of new subunit vaccines. This study aims to characterize, express and purify MSC_0265 for eventual use in immunoassays and inoculation in goats. Mycoplasma mycoides subs. mycoides (Mmm) and Mycoplasma capricolum capripneumoniae (Mccp) are similar pathogens on the genomic level and are the causative agents of Contagious Bovine Pleuropneumonia (CBPP) in cattle and Contagious Caprine Pleuropneumonia (CCPP) in goats respectively. In this study, BLAST was used to identify the homology of MSC_0265 in Mycoplasma capricolum capripneumoniae genome and the protein it is similar to. Characterization of MSC_0265 was also done using I-TASSER to predict secondary structure, solvent accessibility, normalised B-factor, 3D models and function. With cut off points of 0.0 for E-value, 100% for Query coverage and 90% for Identity, MSC_0265 a pyruvate dehydrogenase enzyme gave a high homology score on tBLASTn and BLASTp. It had earlier been cloned in pGS21a vector before proceeding with expression and purification of the His-tagged protein by Ni-NTA affinity chromatography. This study identified the homologue of MSC_0265 as protein WP_029333261.1 in the Mycoplasma capricolum capripneumoniae genome (Accession NZ_LN515398.1) using tBLASTn and BLASTp. Additionally, MSC_0265 was characterized and its optimal expression profile and estimated molecular weight verified

Agrobiodiversity endangered by sugarcane farming in Mumias and Nzoia Sugarbelts of Western Kenya

Commercial sugarcane farming has been practised in western Kenya for nearly forty years. This monocultural land use is associated with loss of natural vegetation and cropland, thus undermining food security status of a place. Further, sugarcane farming is a major contributor to loss of biodiversity in western Kenya. This study was therefore aimed at determining the long-term effects of sugarcane farming on indigenous food crops and vegetables in Mumias and Nzoia sugarbelts of western Kenya. Up to 188 respondents in three divisions of Mumias and 178 respondents of three divisions in Nzoia were purposively selected. These included small-scale and large-scale farmers. Data were collected using questionnaires, Participatory Rural Appraisal tool, interviews and field observations. Secondary data were obtained from documented materials. Land under indigenous food crops and vegetable has been declining since the introduction of sugarcane. Indigenous food crops and vegetable cultivation by farmers in the sugarbelts has been declining. Furthermore, some farmers have abandoned the growing of these crops altogether. Our results imply that sugarcane farming is a major contributor to agrobiodiversity erosion, but that there are also other important reasons such as change of consumer preference, land fragmentation, climate variability among others. In order to curb further loss of biodiversity, efforts should particularly focus on food crops and livelihood diversification and adoption of farming technologies such as agroforestry.Key words: Biodiversity, farming, indigenous crops, monoculture, Western Kenya

A Study of Diplostomum Parasites Affecting Oreochromis niloticus in Chepkoilel Fish Farm and Two Dams in Eldoret-Kenya

The Diplostomum parasite completes its life-cycle in fish eating birds, but spends considerable time in the eye vitreous humor of many fresh water fishes. Its infection in fish causes severe ocular pathology, and leads to increased susceptibility to predation. A study on Diplostomum parasites was conducted at Chepkoilel University with an objective of assessing its parasitic indices and effects on O. niloticus. A total of 40 fish were collected from the fish farm and 155 from the dams between November 2010 and January, 2011. Fish were weighed and length measured to ascertain their condition factor. The fish were observed for the Diplostomum parasite to ascertain parasitic indices in the different habitats. The parasite abundance was related to fish size and condition factor to determine parasite’s effect on O. niloticus. Fish were found to have a parasitic prevalence (%) of 100, 84 and 66 in Kerita dam, Kesses dam and Chepkoilel fish farm. Parasite mean intensity was 12, 9 and 14 respectively.The wellbeing of the fish was not compromised by the parasites, as was seen in the correlation between condition factor and parasite abundance. There was a Pearson correlation of P = 0.357, 0.516 and 0.565 in Kerita dam, Kesses dam and Chepkoilel fish farm respectively. The dams and the fish farm did not pose significant difference in the parasitic indices, probably due to their proximity. There was seen equal abundance in both fish sexes, implying no sex preference in infection. Keywords: Diplostomum, Oreochromis niloticus, prevalence, Abundance, Mean intensity, Condition factor

Animal-level risk factors for Trypanosoma evansi infection in camels in eastern and central parts of Kenya

Point prevalences and animal-level risk factors for Trypanosoma evansi infection were investigated in a cross-sectional study that involved 2227 camels from eastern and central parts of Kenya. The screening tests used were haematocrit centrifugation technique (HCT), mouse inoculation and latex agglutination (Suratex®). All camels were screened with HCT, while 396 and 961 of them were, in addition, screened with mouse inoculation and Suratex® tests, respectively. Parasitological and Suratex® test results were used in parallel to determine the number of camels exposed to T. evansi infections. Statistical analyses were conducted using Statistical Analysis Systems. Parasitological and Suratex® test results in parallel were dependent variables in multivariable logistic regression models that determined risk factors for T. evansi infection. Herd-level clustering was corrected with general estimation equations. The prevalences were 2.3% and 19.6%, using parasitological and Suratex® tests, respectively, and 21.7% when both tests were used in parallel. There was a positive association between the screening tests (McNemar's test=104.8, P=0.001) although the strength of association was low (Kappa=0.2; 95% CI: 0.1-0.3). Before accounting for herd-level clustering, dry season (OR=1.5; 95% CI: 1.0, 2.1) and nomadic pastoralism (OR=1.8; 95% CI: 1.1, 3.2) were associated with increased odds of a camel being exposed to T. evansi infection compared to wet season and ranching, respectively. Following this correction, only nomadic pastoralism was significantly associated (OR=3.1; 95% CI=1.0, 14.4) with T. evansi infection compared to ranching. It is concluded that camels managed under nomadic pastoralism had higher risk of being exposed to T. evansi infections than camels from ranching systems of management.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.DFID's Animal health Programme.mn201

Factors influencing adoption of New Castle Disease Vaccine in Kakamega County in Kenya

Kenya has approximately 28 million poultry of which 22 million (76%) are indigenous chicken kept on free-range system by small-scale farmers in rural and peri-urban areas. Poultry production requires low initial capital and maintenance costs; however, predation and disease hinders this potential from full exploitation by 50-74% and 36-50% respectively. New castle disease (NCD) is the major cause of mortality in indigenous chicken flock. In Western Kenya, vaccination using heat labile live vaccines has been in use for its control. Due to high costs incurred in handling the vaccines, only large-scale commercial farms have the capacity to meet the demand. This leaves out the small-scale indigenous chicken farmers who produce over 70% of meat and 50% of eggs consumed in Kenya. This study was undertaken in January 2011 with the main objective being to determine mortality due to NCD and the factors influencing the adoption of its vaccine. Descriptive survey using questionnaire was used and forty respondents were involved the study. Only 35% of the respondent in the study area had adopted the vaccination and out of all the chicks hutched, only 45% survived to maturity. The loss due to predation and diseases were 45% and 55% respectively. The factors that influenced adoption were effectiveness, ease of availability, lack of any other option and affordability of vaccine at 34.6%, 26.9%, 23.1% and 15.4% respectively

Zoonotic pathogens of dromedary camels in Kenya:a systematised review

Kenya is home to Africa’s third largest population of dromedary camels, and production at commercial and local levels are increasingly important. In pastoral and nomadic communities in the arid and semi-arid lands (ASALs), camels play a vital role in food security, while commercial milk production and formalized export markets are rapidly emerging as camel populations expand into non-traditional areas. Until recently, little focus was placed on camels as hosts of zoonotic disease, but the emergence of Middle Eastern respiratory coronavirus (MERS-CoV) in 2012, and the discovery of exposure to the virus in Kenyan camels, highlighted the need for further understanding of this area. This systematised review utilised a robust search strategy to assess the occurrence of camel-associated zoonoses in Kenya and to evaluate the quality of the published literature. Seventy-four studies were identified, covering sixteen pathogens, with an increasing number of good quality studies in recent years. Despite this, the area remains under-researched and there is a lack of robust, high-quality research. Trypanosome spp., Echinococcus granulosus and Brucella spp. appeared most frequently in the literature. Pathogens with the highest reported prevalence were MERS-CoV (0–100%), Echinococcus granulosa (7–60%) and Rift Valley fever virus (7–57%). Exposure to Brucella spp., Coxiella burnetii and Crimean-Congo haemorrhagic fever virus showed higher levels in camel or camel-associated vectors than other livestock species, although brucellosis was the only disease for which there was robust evidence linking camel and human exposure. Zoonotic agents with less severe human health outcomes, such as Dermatophilosus congolensis and contagious ecthyma, were also represented in the literature. This review provides an important summary of the scope and quality of current knowledge. It demonstrates that further research, and improved adherence to robust study design and reporting are essential if the zoonotic risk from camels in Kenya, and elsewhere, is to be better understood

Multiple evolutionary origins of Trypanosoma evansi in Kenya

Trypanosoma evansi is the parasite causing surra, a form of trypanosomiasis in camels and other livestock, and a serious economic burden in Kenya and many other parts of the world. Trypanosoma evansi transmission can be sustained mechanically by tabanid and Stomoxys biting flies, whereas the closely related African trypanosomes T. brucei brucei and T. b. rhodesiense require cyclical development in tsetse flies (genus Glossina) for transmission. In this study, we investigated the evolutionary origins of T. evansi. We used 15 polymorphic microsatellites to quantify levels and patterns of genetic diversity among 41 T. evansi isolates and 66 isolates of T. b. brucei (n = 51) and T. b. rhodesiense (n = 15), including many from Kenya, a region where T. evansi may have evolved from T. brucei. We found that T. evansi strains belong to at least two distinct T. brucei genetic units and contain genetic diversity that is similar to that in T. brucei strains. Results indicated that the 41 T. evansi isolates originated from multiple T. brucei strains from different genetic backgrounds, implying independent origins of T. evansi from T. brucei strains. This surprising finding further suggested that the acquisition of the ability of T. evansi to be transmitted mechanically, and thus the ability to escape the obligate link with the African tsetse fly vector, has occurred repeatedly. These findings, if confirmed, have epidemiological implications, as T. brucei strains from different genetic backgrounds can become either causative agents of a dangerous, cosmopolitan livestock disease or of a lethal human disease, like for T. b. rhodesiense