Veterinary Medicine

Permanent URI for this collection

http://41.63.25.24:4000/handle/123456789/86

Browse

Recent Submissions

Now showing 1 - 5 of 115
  • Thumbnail Image
    Item
    Investigation of the presence and health risk assessment of lead in vegetables grown in the vicinity of a lead-zinc mine Kabwe, Zambia.
    (The University of Zambia, 2019) Kagoli, Victor Kwaambwa
    Mining is one of the main sources of heavy metals that present great harm to human health even in low concentrations. Lead (Pb) contamination of food and especially of frequently consumed vegetables is a growing public health concern worldwide. Although levels of exposure in developed countries have declined over the past decades, the same cannot be said of the developing countries. Health risk assessment has increasingly been employed to determine the potential hazards of heavy metal exposure to humans. In this current study, the aim was to investigate the presence and health risk of Pb in vegetables commonly grown in the vicinity of the lead-zinc mine in Kabwe, with the objectives of assessing the Pb levels in garden soils used for growing vegetables and also analyzing Pb levels in the vegetables commonly grown on household backyard garden. Therefore Pb was measured in edible portions of vegetables (giant rape (brassica napus) and onion (allium cepa)) and soils around the residential areas (Chowa, Kasanda and Mutwewansofu) in the vicinity of the lead-zinc mine plant in Kabwe, Zambia. The results of Pb levels in the backyard soil, where the vegetables samples were randomly picked ranged from 865.7 to 58600mg/kg, all above the maximum permissible limit recommended by WHO/FAO. The potential health risk of Pb contamination to the local population via vegetable consumption was evaluated. The concentrations in edible portions of vegetables were 2.14 (0 to 9.657 mg/kg) onion (allium cepa) and 2.35 (0 to 9.8 mg/kg) giant rape (brassica napus) respectively. Approximately 71% of the Pb in the vegetables samples exceeded the maximum allowable concentrations by WHO/FAO of 2015. The calculated estimated daily intake or the estimated daily dose of Pb from both onion and giant rape were also higher than the permissible tolerable daily intake PTDI- 0.0035 mg/kg/day of Pb in both adult and children. Target hazard quotient THQ value >1 were also estimated in both children and adults, therefore indicating that, there is a health risk from consumption of these vegetables in these sampled residential areas in the vicinity of the Pb-Zn mine in Kabwe.
  • Thumbnail Image
    Item
    Quantitative exposure assessment to vibrio cholerae through consumption of fresh fish in Lusaka province, Zambia.
    (The University of Zambia, 2019) Malata, Mulenga
    Fresh fish is one of the cheapest sources of proteins in the Zambian diet and widely consumed nationwide. Fresh fish harbours a number of spoilage bacteria and pathogens including V. cholerae which cause cholera in humans. Consumption of contaminated fresh fish has been linked to zoonotic transmission of diseases in humans. The aim of the study was to carry out a quantitative exposure assessment to Vibrio cholerae through consumption of fresh fish in Lusaka Province of Zambia. The data used to achieve this objective were obtained from reviews of scientific literature, government reports, questionnaire survey and expert opinions. The swift Quantitative Microbial Risk Assessment (sQMRA) model was used to model the risk of exposure. The study was driven by the lack of research-based information in this area despite the increase in the number of reported cases of cholera in Lusaka Province. Results showed that the average serving portion for fresh fish in Lusaka District was 200g for fresh fish consumers in the restaurants and high socio-economic status households, while 100g were for the consumers in low socio-economic status households, respectively. The probability of exposure to Vibrio cholerae through consumption of fresh fish was estimated to be low. At serving portions of 100g and 200g in the low and high socio economic status households with a concentration of 50 cfu/g, infectious dose 50 (ID50) of 106 cells, one person would get ill, representing a probability of 0.000044%. At an average serving portion of 200g at restaurants level, 50cfu/g and ID50 of 106 cells, 47 people would get ill, translating into a probability of 0.0021% per year The study concludes that the risk of exposure to Vibrio cholerae among residents in Lusaka Province, as a result of fresh fish consumption, would be generally low, attributed to preparation methods. The study also revealed that cross-contamination during preparation and consumption could be a source of exposure to the Vibrio cholerae. Improvement in food hygiene practices and processing are needed to minimize the occurrence of foodborne illnesses. Further, work is required to broaden the scope of the study and also undertake a microbiological evaluation of fresh fish from both household and restaurant risk exposure pathways.
  • Thumbnail Image
    Item
    Quantitative exposure assessment to listeria species through consumption of polony imported from South Africa in Lusaka, Zambia.
    (The University of Zambia, 2019) Siamate Sakala James
    This study aimed to quantitatively assess the Risk of Exposure to Listeria through consumption of ready to eat meat and meat products (RTE) imported from South Africa in Lusaka Province of Zambia. A swift quantitative microbiological risk assessment (sQMRA) simulation model was used to analyse data, which was collected through a literature review. A literature review was guided by the eleven questions, which make up the Microsoft Excel-based sQMRA model. Results showed that the average serving portion for Polony in Lusaka District was 30g per day. The probability of exposure to Listeria species through consumption of Polony was relatively low. At a serving portion of 30g, the concentration of 1000 cfu/g, infectious dose 50 (ID50) of 105 , two people in a population of 1,765,488 would get ill, representing a probability of 0.00011 percent. Similarly, at a serving portion of 30g, the concentration of 100 cfu/g, infectious dose 50 (ID50) of 105 and 107 , no person in a population of 1,765,488 would get exposed, representing a probability of zero. This study concludes that the risk of exposure to Listeria spp through consumption of RTE meat and meat products imported from South Africa in Lusaka district, was extremely low, mainly due to the nature of the product (Polony), which it is well done at factory prior to supply in supermarket and the serving size portion was very minimal. Since cross-contamination accounted for 100% high risk of exposure to Listeria spp., it is important to sanitise the slicing equipment every time they are used to slice Polony. A proper hygienic system can prevent the cross-contamination with L. monocytogenes, which is a fundamental risk factor in Polony facilities
  • Thumbnail Image
    Item
    Occurrence of extended –spectrum beta-lactamase-producing enterobacteriaceae and bacterial loads in dust from poultry farms in Lusaka-Zambia.
    (The University of Zambia, 2023) Basikolo, Linda
    Poultry houses accommodate substantial amounts of microorganisms which are carried by the dust present in these premises and the effects of this dust on humans and animal health is detrimental when inhaled. Extended Spectrum beta lactamases are a universal public health alarm which are frequently identified in humans and animals including poultry. Poultry dust is a possible source of drug resistant microorganisms including Extended spectrum beta lactamases which confer antimicrobial resistance to different classes of antimicrobials including beta lactam, cephalosporins and fruoloquinolones. The concentration of microorganisms in dust from poultry houses in Lusaka-Zambia is not known and in order to know the risks for birds, environment and people working in these houses, it is important to have information on the microbial composition of this dust, therefore, this study is conducted to determine poultry dust bacterial composition in farms in Lusaka, Zambia. A cross sectional study with quantitative data collection approach was conducted in Kafue, Lusaka and Chongwe districts of Lusaka province where 351 dust samples from intensive poultry production were collected from 29 poultry farms (10 kafue,12 Lusaka and 7 Chongwe). 4 farms were for indigenous chickens, 15 layer farms and 10 broiler farms. They were analyzed for total viable bacteria counts (cfu/g), the occurrence of extended-spectrum beta- lactamases (ESBL)-producing Enterobacteriacea, antimicrobial resistance for ESBL-E isolates. The association between the sociodemographic issues and the occurrence of the pathogens in dust from poultry houses in Lusaka- Zambia was also determined. The total viable bacterial counts was 2.599 x108 cfu/g. For Enterobacteriaceae was 2.296x108 cfu/g. 62 Positive ESBL samples occurred in 16 farms (n=29) where ESBL samples was 4.842x104cfu/g. E.Coli showed highest resistant rate amongst other isolates. All ESBL- E isolates showed 100% resistance rate to penicillin followed by 56.5% for cefotaxime and 48.4% for ciprofloxacin. There was no association between the sociodemographic issues and the occurrence of the pathogens in dust from poultry houses. The results obtained would help that ensures poultry farms comply to safety rules by providing protective clothing for their workers and also close monitoring of antibiotic usage to poultry to avoid dust transmitted antimicrobial organisms to humans, animals and the environment.
  • Thumbnail Image
    Item
    The risk of exposure to aflatoxins through consumption of nshima made from maize meal in selected areas of Lusaka district.
    (The University of Zambia, 2023) Musonda, Mumba
    Maize and its products, such as maize meal, are susceptible to aflatoxin contamination. Maize is the staple crop of Zambia and is widely consumed as thick porridge, commonly called nshima. Previous studies have reported high levels of AFs in maize produced in Zambia. However, no study has determined the risk of exposure to AFs through the consumption of maize nshima. This cross-sectional study was designed to determine the risk of exposure to aflatoxins through the consumption of maize nshima in households in the Lusaka District. A questionnaire was administered to households to investigate dietary consumption patterns and revealed that most Zambians consumed nshima twice a day, prepared from either breakfast or roller maize meal. It was also noted that males aged 18 years and above consumed more nshima per day (360 – 980g) than children and female adults. The Zambia Bureau of Standards Laboratory recorded aflatoxin concentrations ranging from 0.2 μg/kg to 150 μg/kg in breakfast (flour from polished maize grain) and roller (flour from whole maize grain) meal samples from 2019-2022. This was used as secondary data for determining the risk of exposure to aflatoxins during this study. The risk of exposure was estimated using the Model Risk Software® using the estimated daily intake of maize nshima and secondary aflatoxin data as input parameters. The maximum exposure of 80.2 to aflatoxins was highest for the males compared to other age groups. The risk was further characterized using the margin of exposure (MOE). The MOE was < 10000 for age categories, thus indicating potential adverse health effects, with the highest MOE of 0.005 recorded for the males. The high levels of AFs in maize meal and high exposures accentuate the need for preventive measures. Particular attention should be given to raising awareness of the impact of aflatoxin risk exposure and setting maximum allowable limits in maize meal considering maize product consumption patterns in Zambia