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Conference Paper
Kamwati SK;, Kakundi EM;, Mbae CK;, Kang’ethe EK;, Szonyia B;, Hussni MO. "First report of Cryptosporidium deer-like genotype in Kenyan cattle."; 2008. Abstract

The objective of the study was to identify Cryptosporidium genotypes from feces collected from urban and peri-urban dairy cattle in Nairobi, Kenya, in order to determine their zoonotic potential. DNA was extracted from 34 samples that were diagnosed positive by the modified Ziehl–Neelsen technique. Two Cryptosporidium isolates examined at the 18S rRNA locus were identified as the deer-like genotype by DNA sequencing. As public health officials are facing the difficult decision whether to allow urban livestock production because of its economic benefits and a livelihood asset to the urban communities, or to ban it for its public health risks, the finding of non-zoonotic genotypes in a smallholder dairy system has significant public health as well as economic implications that merit further investigation

Arimi SM;, Koroti E;, Kang'ethe EK;, Omore AO;, McDermott JJ;, Macharia JK;, Nduhiu JG;, Githua AM. "Risk of infection from E. coli O157: H7 through informally marketed raw milk in Kenya."; 2000. Abstract

E. coli 0157:H7 is a newly recognised bacterial zoonosis that originates from the gut of infected cattle. It causes potentially fatal haemorrhagic enteritis, haemolytic uraemic syndrome and kidney damage in humans. Epidemiological data on E. coli 0157:H7 infection and transmission in developing countries remain scarce but it is suspected that consumption of unpasteurised milk is an important vehicle for its transmission to humans, as milk can easily be contaminated with cattle faeces during milking. Given the high proportion of informal sales of unpasteurized milk in many tropical countries, E. coli 0157:H7 has been one of several zoonoses of concern. Between January 1999 and January 2000, survey data and raw milk samples were collected seasonally from households consuming unpasteurised milk in rural and urban locations in central Kenya. Respondents were randomly selected within production system (extensive and intensive) and human population density (urban, peri-urban and rural) strata. Laboratory samples were assessed for bacteriological quality by total and coliform counts. Selective media were used sequentially to screen for faecal coliforms and E. coli 0157:H7. Suspect E. coli 0157:H7 colonies were also serotyped and tested for production of verocytotoxins. E. coli was recovered from 91 out of 264 samples (34%) and E. coli 0157:H7 serotype identified in two samples (<1%). One of the two isolates produced verocytotoxins. As in many studies, the recovery rate of this serotype was low, but the finding is significant from a public health perspective. Our consumer studies have shown that over 95% of consumers of unpasteurised milk boil the milk before consumption and potential health risks from this zoonosis are therefore quite low. As informal milk markets without pasteurisation technology are likely to remain dominant for the foreseeable future, there is the need to further emphasise the importance of boiling raw milk before consumption, especially among pastoral communities where this practice is not common.

A double antibody enzyme linked immunosorbent assay for identification of thermostable muscle antigens of autoclaved meat samples is described. The assay differentiates heterologous thermostable muscle antigens from homologous at P 0.001. In model meat mixtures, the assay detects adulterants at the level of 1% at p0.001 even in phylogenetically related species such as buffalo and cattle.
Antisera to thermosable muscle antigens (TMA) from 14 species of bovidae were raised in goats and/or sheep. To achieve species specificity the antisera were absorbed with serum from the other species. While the absorbed antisera to TMA to buffalo, impala, eland, waterbuck, wildebeest and oryx were rendered specific, the antiserum to cattle TMA cross-reacted with buffalo fresh meat antigens (FMA) and cooked meat antigens (CMA) but not with buffalo thermostable muscle antigens. Fresh and cooked muscle antigens from these two species could be differentiated by the antiserum to buffalo TMA. A similar approach was used to differentiate the FMA, CMA and TMA of kongoni, topi and wildebeest. Antiserum to cattle TMA proved useful in detecting the presence of beef meat in meat products that had undergone commercial sterilization.   Keywords: meat; meat products; thermostable muscle antitgens; immunodiffusion; antibodies; species identification
An enzyme immunoassay (EIA) suitable for use in identification of cooked and autoclaved meat samples using antisera to thermostable muscle antigens (TMA) is described. Goat antisera to TMA of various species were tested against homologous and heterologous partially purified thermostable muscle antigens (PTMA) in an indirect EIA. Goat anti-eland and anti-cattle TMA sera were the poorest in differentiating other species PTMAs. Identification of various species PTMAs could be achieved using a battery of goat anti-TMA sera, where homologous goat anti-TMA serum fails to differentiate some of the PTMAs tested.
Antisera to thermostable muscle antigens from 13 wild animals: Buffalo, Waterbuck, Bushbuck, Eland, Oryx, Kongoni, Bushpig, Warthog, Topi, Thomson’s gazelle, Grant’s gazelle, Sheep, Pig, Horse, Camel & Dog, were raised in rabbits and/or goats. Absorptions of the antisera with copolymerized pooled serum from the 20 species and the thermostable muscle antigens rendered most of the antisera mmonospecific. It was possible to identify the species of origin of saline extracts of both cooked and fresh meat samples in immunodiffusion tests. The method is promising for use in identification of the species origin of fresh and cooked animal meats.
Journal Article
Kimani VN, Mitoko G, McDermott B, Grace D, Ambia J, Kiragu MW, Njehu AN, Sinja J. "Social and gender determinants of risk of cryptosporidiosis, an emerging zoonosis, in Dagoretti, Nairobi, Kenya.". 2012. AbstractWebsite

The aim of the study was to investigate the social and gender determinants of the risk of exposure to Cryptosporidium fromurban dairying in Dagoretti, Nairobi. Focus group discussions were held in six locations to obtain qualitative information on risk of exposure. A repeated cross-sectional descriptive study included participatory assessment and household questionnaires (300 randomly selected urban dairy farming households and 100 non-dairying neighbours). One hundred dairy households randomly selected from the 300 dairy households participated in an additional economic survey along with 40 neighbouring non-dairy households. We found that exposure to Cryptosporidium was influenced by gender, age and role in the household. Farm workers and people aged 50 to 65 years had most contact with cattle, and women had greater contact with raw milk. However, children had relatively higher consumption of raw milk than other age groups. Adult women had more daily contact with cattle faeces than adult men, and older women had more contact than older men. Employees had greater contact with cattle than other groups and cattle faeces, and most (77 %) were male. Women took more care of sick people and were more at risk from exposure by this route. Poverty did not affect the level of exposure to cattle but did decrease consumption of milk. There was no significant difference between men and women as regards levels of knowledge on symptoms of cryptosporidiosis infections or other zoonotic diseases associated with dairy farming. Awareness of cryptosporidiosis and its transmission increased significantly with rising levels of education. Members of nondairy households and children under the age of 12 years had significantly higher odds of reporting diarrhoea: gender, season and contact with cattle or cattle dung were not significantly linked with diarrhoea. In conclusion, social and gender factors are important determinants of exposure to zoonotic disease in Nairobi.

Violet N K, Brigid MD, Delia G, Alfred K. L’at, Monica W K, Nancy K. "A trans-disciplinary study on the health risks of cryptosporidiosis from dairy systems in Dagoretti, Nairobi, Kenya: study background and farming system characteristics.". 2009. AbstractWebsite

Cryptosporidium was conducted with 20 farmers randomly selected from the 29 farmers in the wider survey who were considered at high risk because of farming system. We found that around 1 in 80 urban households kept dairy cattle with an average of three cattle per household. Cross-breeds of exotic and local cattle predominate. Heads of dairykeeping households were significantly less educated than the heads of non-dairy neighbours, had lived in Dagoretti for significantly longer and had significantly larger households. There was a high turnover of 10 % of the cattle population in the 3-month period of the study. Cattle were zero grazed, but productivity parameters were sub-optimal as were hygiene and husbandry practices. In conclusion, dairy keeping is a minor activity in urban Nairobi but important to households involved and their community. Ecohealth approaches are well suited to tackling the complex problem of assessing and managing emerging zoonoses in urban settings. Keywords Urban dairy . Cryptosporidiosis . Ecohealth . Kenya

Randolph TF, M'Ibui GM, Kang'ethe EK, Lang'at AK. "Prevalence of aflatoxin M1 and B1 in milk and animal feeds from urban smallholder dairy production in Dagoretti Division, Nairobi, Kenya.". 2007. Abstract

To estimate the prevalence of Aflatoxin M1 and Total Aflatoxin B1 in milk and animal feeds. Cross sectional household study. Urban and peri-urban area of Dagoretti Division, Nairobi, Kenya. Two hundred fifty seven dairy farming households and 134 non-dairy neighbouring households. The prevalence of AFM1 in milk was found to be 45.5% (178/391). The farmer prevalence was 43.5% (112/257), while that of non-farmer was 49.2% (66/ 134). There was however no statistical significant difference between the two categories. Of the 178 positive milk samples, 49% had aflatoxin levels exceeding 0.05 microg Kg(-1). The prevalence of AFB1 in the feed was found to be 98.6% (69/70) with 83% of the samples having aflatoxin B1 levels exceeding 10 microg Kg(-1). Only one feed sample had no traces of AFB1. This study points to an underlying problem that requires the action by policy makers, considering the number of samples with aflatoxin M1 [49%] and aflatoxin B1 [83%] exceeding the WHO/FAO tolerance limits for milk and feeds destined for dairy animals.

Kang'ethe EK, Arimi SM, MacDermott JJ, Omore AO. "Analysis of Public Health Risks From Consumption of Informally Marketed Milk in Kenya.". 2004. Abstract

Despite an unfavorable policy environment against informal milk markets, these market account for most milk sales in Kenya. Convenient delivery and lower prices are the principal benefits for poor consumers. Current milk handling and safety regulations in Kenya are derived from models in industrialized countries. These may not be appropriate for local market conditions. An important step in targeting policies better is to collect quantitative and qualitative information about milk-borne health risk under different market situations. Preliminary results of assessments of milk quality and handling practices of informal milk market agents and consumers in central Kenya show very low apparent prevalence of zoonotic health hazards in milk from smallholder herds o[that contribute most marketed milk. Higher bacterial counts were associated with longer market chains and distance to urban areas. Most (up to 80%) of samples did not meet national bacterial quality standards. Over 96% of consumes boiled milk before consumption mainly to lengthen shelf life but also for health reasons. The most important health risks were judged to be from antimicrobial residues found in up to 16% of milk samples tested.

Githua A, Macharia JK, Nduhiu JG, McDermott JJ;, Omore AO, Arimi SM, Kang'ethe EK. "Testing for Antibodies to Brucella abortus in Milk From Consumers and Market Agents in Kenya Using Milk Ring Test and Enzyme Immunoassay.". 2004. Abstract

Over 85% of all milk sales on Kenya pass through informal channels. The extent of the risk posed by the sale of this raw milk to human health in respect to brucellosis is unknown. This paper presents the results of a study on the occurrence of antibodies to Brucella abortus in milk from households consuming raw unpasteurized milk and market agent selling the same. Four hundred thirty four (434) raw milk samples from consumer households and 508 from informal market agents were collected between January 1999 and January 2000 from Nakuru /Narok and Nairobi/Kiambu. Milk agents sampled included co-operative societies, milk collecting centers and self-help groups, milk bars, shops and kiosks and mobile traders on foot, bicycle or motorized transport. In addition, 147 samples from the formal market chain (pasteurized) were collected. All the samples from the samples were screened for antibodies to Brucella abortus using ELISA and Milk Ring Test (MRT), except for the formal milk that was tested using ELISA only. Five percent of the consumer household samples and 4% of the samples form informal milk market agents tested positive on ELISA. There was poor agreement between the two antibody surrogate tests (Kappa =0.40, 95% confidence interval =0.19-0.60). ELISA detected 3.2% more samples from consumer households and 0.4% from informal market agents than MRT. Of the formal market samples, 16.4% were positive. Ways of reducing the risk of contracting brucellosis from drinking raw milk are proposed.

Staal S, McDermott JJ, Kang'ethe EK, Arimi SM. "Analysis of milk-borne public health risks in milk markets in Kenya.". 2002. Abstract

The major role played by informal milk markets in Kenya and the benefits to those associated with it are now widely acknowledged. The benefits include higher prices for farmers, income generation for the market agents and convenient delivery and lower prices for poor consumers. However, in spite of these benefits, regulations governing informal marketing of milk continue to be unfavourable and do not reflect local realities of milk marketing, having been based on models derived from industrialised countries where virtually all milk destined for the market is pasteurised and packaged. Results of risk assessment, including HACCP analysis, of milk quality and handling practices of informal milk market agents and consumers in central and southern Kenya show variable apparent prevalence of zoonotic health hazards in marketed milk, high bacterial counts especially in outlets associated with longer market chains. Notably, the ineffectiveness of current regulations was reflected in the lack of difference in the quality of milk sold by licensed and non-licensed traders. The study shows that health risks from the bacterial hazards identified are mitigated by the common consumer practice of boiling milk before consumption. The most important health risks were judged to be from two main sources: (i) anti-microbial residues found in up to 15% of milk samples tested and (ii) consumption of naturally fermented milk. Proposals for management of these health risks and the engagement of stakeholders and key players in the process to achieve more favourable policy environment policy are presented and discussed.

Ouma EA, Kang'ethe EK, Arimi SM, Staal S, McDermott JJ, Omore AO. "Analysis of public health risks from consumption of informally marketed milk in sub-Saharan African countries.". 2000. Abstract

Despite policies to discourage them, informal milk markets account for over 80% of milk sales in most sub-Saharan African (SSA) countries. Informal milk market agents include farmer dairy co-operatives, small traders using bicycles and public or private transport and small retail outlets, such as dairy kiosks, and shops. Studies conducted by the International Livestock Research Institute (ILRI) and national collaborators (e.g., in Kenya1) show that convenient delivery and lower prices (reflecting lower handling and processing costs) are the principal benefits for consumers. Current milk handling and safety regulations in most SSA countries are derived from models in industrialised countries. These may not be appropriate for local market conditions where such regulations may unnecessarily inhibit efficient milk marketing. An important step in developing targeted policies more supportive of market participation of the majority is to collect quantitative and qualitative information about milk-borne health risks under different production and marketing situations. This paper gives an over-view of on-going activities in central Kenya aimed at assessing public health risks from informally marketed milk and presents preliminary results of milk quality and handling practices of informal milk market agents and consumers

Githua A, Macharia JK, Nduhiu JG, McDermott JJ, Omore AO, Arimi SM, E K K'the. "The prevalence of antibodies to Brucella abortus in marketed milk in Kenya and its public health implications.". 2000. Abstract

The risk of infection by milk-borne brucellosis is one reason for public health regulations which discourage informal milk markets that sell unpasteurized milk. However, these regulations are not generally implemented in many developing countries. Kenya is a typical example, with over 85% of milk sales passing through informal channels. Consumer practices to reduce or eliminate potential infection by milk-borne health hazards under these circumstances have rarely been studied. Seasonal survey data were collected between January 1999 and January 2000 from informal milk market agents of various cadres and from households consuming unpasteurized milk in rural and urban locations in central Kenya. Respondents were randomly selected within production system (extensive and intensive) and human population density (urban, peri-urban and rural) strata. In addition, pasteurized and packaged milk samples from five processors were collected. Samples were screened for antibodies to Brucella abortus using the milk ring test (MRT) (unpasteurized milk) and indirect antibody ELISA (both unpasteurized and pasteurized milk). Milk samples originating from farms in the extensive production system and those containing milk from many sources were associated with higher antibody detection proportions. Five percent of all raw milk samples collected from consumer households and 4% of samples collected from various levels of bulking of market samples were positive to the ELISA. There was poor to no agreement between the two antibody detection tests. All urban consumers and 96% of rural consumers of unpasteurized milk indicated that they boil the milk (in tea or otherwise) before consumption. The implications of these results on milk marketing in Kenya are discussed.

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