138 research outputs found

    Quantitative Risk Assessment of Developing Salmonellosis through Consumption of Beef in Lusaka Province, Zambia

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    Based on the Codex Alimentarious framework, this study quantitatively assessed the risk of developing salmonellosis through consumption of beef in Lusaka Province of Zambia. Data used to achieve this objective were obtained from reviews of scientific literature, Government reports, and survey results from a questionnaire that was administered to consumers to address information gaps from secondary data. The Swift Quantitative Microbiological Risk Assessment (sQMRA) model was used to analyse the data. The study was driven by a lack of empircally-based risk estimation despite a number of reported cases of salmonellosis in humans. A typology of consumers including all age groups was developed based on their beef consumption habits, distinguishing between those with low home consumption, those with medium levels of home consumption, and those with high levels through restaurant consumption. This study shows that the risk of developing salmonellosis in this population, from consuming beef, was generally low. At ID50 of 9.61 × 103 cfu/g and a retail contamination concentration of 12 cfu/g, the risk of developing salmonellosis through the consumption of beef prepared by consumers with low and medium levels of beef consumption was estimated at 0.06% and 0.08%, respectively, while the risk associated with restaurant consumption was estimated at 0.16% per year. The study concludes that the risk of developing salmonellosis among residents in Lusaka province, as a result of beef consumption, was generally low, mainly due to the methods used for food preparation. Further work is required to broaden the scope of the study and also undertake microbiological evaluation of ready-to-eat beef from both the household and restaurant risk exposure pathways

    VLBI measurements of radio source positions at the Jet Propulsion Laboratory

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    The results of approximately 1300 observations of 67 radio sources are presented. Most of the measurements were made at the stations of the Deep Space Network in California, Spain, and Australia at wavelengths of 13.1 and 3.6 cm, between 1971 and 1978. The formal errors in the derived source positions are generally in the neighborhood of 0.01 seconds of arc and the positions agree fairly well with those previously published

    Characterisation of mycobacteria isolated from slaughter cattle in pastoral regions of Uganda

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    <p>Abstract</p> <p>Background</p> <p>Bovine tuberculosis is a zoonotic problem in pastoral cattle and communities in Uganda. Tuberculin tests in pastoral cattle had shown a high herd but low animal prevalence, with a high proportion of avian reactors. No work had been done to identify the mycobacterial species involved. The objective of the study was to isolate and characterise Mycobacterial species causing tuberculous lesions in slaughtered animals. Lesioned organs compatible with bovine tuberculosis in slaughtered cattle from pastoral areas in Uganda were collected and cultured to isolate <it>mycobacteria</it>. AccuProbe culture identification kits for the <it>Mycobacterium tuberculosis </it>complex, <it>M. avium </it>complex and <it>M. avium </it>were used to identify the isolates. Spoligotyping and Insertion Sequence (IS) <it>1311 </it>and IS<it>1245 </it>Restriction Fragment Length Polymorphism analysis (RFLP) were used to further characterise the isolates.</p> <p>Results</p> <p>Of the 61 lesioned organs and tissues cultured, 19 isolates were identified as <it>M. bovis</it>, 3 as <it>M. avium </it>subsp.<it>hominissuis</it>, 1 as <it>M. intracellulare</it>, 1 as a mixed culture of <it>M. bovis </it>and <it>M. avium sp</it>. and 1 as <it>M. avium sp</it>. and unidentified <it>mycobacteria</it>. Eleven other <it>mycobacteria </it>outside the tuberculosis and avium complex groups were also isolated. Ten new spoligopatterns grouped into three clusters were identified from <it>M. bovis </it>isolates. Two of the three <it>M. avium </it>subsp.<it>hominissuis </it>isolates showed similar patterns on the IS<it>1311 </it>RFLP but all were different on the IS<it>1245 </it>RFLP.</p> <p>Conclusion</p> <p>The isolation of <it>M. bovis </it>confirms the ongoing infection with spoligotypes unique to Uganda. Isolation of environmental <it>mycobacteria </it>could explain the high avian or non specific tuberculin reactor patterns commonly observed in pastoral cattle and suggests their pathogenic or opportunistic role in the infection of cattle with disseminated bovine tuberculous lesions.</p

    X/Ka Celestial Frame Improvements: Vision to Reality

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    In order to extend the International Celestial Reference Frame from its S/X-band (2.3/8.4 GHz) basis to a complementary frame at X/Ka-band (8.4/32 GHz), we began in mid-2005 an ongoing series of X/Ka observations using NASA s Deep Space Network (DSN) radio telescopes. Over the course of 47 sessions, we have detected 351 extra-galactic radio sources covering the full 24 hours of right ascension and declinations down to -45 degrees. Angular source position accuracy is at the part-per-billion level. We developed an error budget which shows that the main errors arise from limited sensitivity, mismodeling of the troposphere, uncalibrated instrumental effects, and the lack of a southern baseline. Recent work has improved sensitivity by improving pointing calibrations and by increasing the data rate four-fold. Troposphere calibration has been demonstrated at the mm-level. Construction of instrumental phase calibrators and new digital baseband filtering electronics began in recent months. We will discuss the expected effect of these improvements on the X/Ka frame

    Factors associated with pastoral community knowledge and occurrence of mycobacterial infections in human-animal interface areas of Nakasongola and Mubende districts, Uganda

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    <p>Abstract</p> <p>Background</p> <p>Nontuberculous mycobacteria (NTM) are emerging opportunistic pathogens whose role in human and animal disease is increasingly being recognized. Major concerns are their role as opportunistic pathogens in HIV/AIDS infections. The role of open natural water sources as source and livestock/wildlife as reservoirs of infections to man are well documented. This presents a health challenge to the pastoral systems in Africa that rely mostly on open natural water sources to meet livestock and human needs. Recent study in the pastoral areas of Uganda showed infections with same genotypes of NTM in pastoralists and their livestock. The aim of this study was to determine the environmental, animal husbandry and socio-demographic factors associated with occurrence and the pastoral community knowledge of mycobacterial infections at the human-environment-livestock/wildlife interface (HELI) areas in pastoral ecosystems of Uganda.</p> <p>Methods</p> <p>Two hundred and fifty three (253) individuals were subjected to a questionnaire survey across the study districts of Nakasongola and Mubende. Data were analyzed using descriptive statistics and multivariable logistic regression analysis.</p> <p>Results</p> <p>Humans sharing of the water sources with wild animals from the forest compared to savannah ecosystem (OR = 3.3), the tribe of herding pastoral community (OR = 7.9), number of rooms present in household (3-5 vs. 1-2 rooms) (OR = 3.3) were the socio-demographic factors that influenced the level of knowledge on mycobacterial infections among the pastoral communities. Tribe (OR = 6.4), use of spring vs. stream water for domestic use (OR = 4.5), presence of sediments in household water receptacle (OR = 2.32), non separation of water containers for drinking and domestic use (OR = 2.46), sharing of drinking water sources with wild animals (OR = 2.1), duration of involvement of >5 yrs in cattle keeping (OR = 3.7) and distance of household to animal night shelters (>20 meters) (OR = 3.8) were significant socio-demographic factors associated with the risk of occurrence of mycobacterioses among the pastoral communities in Uganda.</p> <p>Conclusion</p> <p>The socio-demographic, environmental and household related factors influence the risk of occurrence as well as pastoralists' knowledge of mycobacterial infections in the pastoral households at the human-environment-livestock/wildlife pastoral interface areas of Uganda.</p

    Incidence trend and risk factors for campylobacter infections in humans in Norway

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    BACKGROUND: The objectives of the study were to evaluate whether the increase in incidence of campylobacteriosis observed in humans in Norway from 1995 to 2001 was statistically significant and whether different biologically plausible risk factors were associated with the incidence of campylobacteriosis in the different counties in Norway. METHODS: To model the incidence of domestically acquired campylobacteriosis from 1995 to 2001, a population average random effect poisson model was applied (the trend model). To case data and assumed risk-factor/protective data such as sale of chicken, receiving treated drinking water, density of dogs and grazing animals, occupation of people in the municipalities and climatic factors from 2000 and 2001, an equivalent model accounting for geographical clustering was applied (the ecological model). RESULTS: The increase in incidence of campylobacteriosis in humans in Norway from 1995 to 2001 was statistically significant from 1998. Treated water was a protective factor against Campylobacter infections in humans with an IRR of 0.78 per percentage increase in people supplied. The two-level modelling technique showed no evidence of clustering of campylobacteriosis in any particular county. Aggregation of data on municipality level makes interpretation of the results at the individual level difficult. CONCLUSION: The increase in incidence of Campylobacter infections in humans from 1995 to 2001 was statistically significant from 1998. Treated water was a protective factor against Campylobacter infections in humans with an IRR of 0.78 per percentage increase in people supplied. Campylobacter infections did not appear to be clustered in any particular county in Norway
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