A semi-quantitative human exposure assessment to taenia saginata infection through beef consumption in Windhoek, Namibia.
Date
2021
Authors
Benhard, Vistorina
Journal Title
Journal ISSN
Volume Title
Publisher
The University of Zambia
Abstract
Human taeniasis is an internal parasitic disease associated with the handling, preparing, and consuming
infected beef or pork with viable cysts. However, the association between exposures to infections and
causal factors varies from person to person. Numerous factors are responsible for exposure which may
be linked to the socio-economic status of the society, the geographical location of the country or
environment, the level of awareness of the society and the health system of a country to combat such
diseases. Economic and cultural conditions may contribute to perpetuating exposure to the disease. The
risk of exposure and infection may be reduced by routine meat inspection. This study aimed to assess
the risk of human exposure to Taenia saginata through beef consumption.
To achieve this objective, a three-tier study was conducted to estimate the prevalence of T. saginata in
slaughtered cattle, describe the beef consumption pattern among residents in Windhoek, and quantify
the risk of human exposure through beef consumption. The first study was a retrospective review of
meat inspection records at a selected abattoir to estimate prevalence. The second part was a crosssectional
survey to gather beef consumption data from the study population. The final part of the study
used primary data inputs and the consumption survey to estimate the risk of exposure to Cysticercus
bovis and possible risk factors contributing to the risk of exposure using Monte Carlo simulation-based
in the @Risk software embedded in Microsoft Excel. Research ethics was considered and applied in all
aspects.
The prevalence of bovine cysticercosis was 0.70% among the inspected beef carcasses. Beef consumers
were estimated to be 99.5% of the population. The majority consumed 40-50g pieces in a serving, with
the largest portion being 300g per serving. The number of cysts that could be found in a 300g portion of
beef was 5 (95% CI 1-11). The probability of human exposure to T. saginata was 0.0076%. Although
the risk of exposure increased with the absence of home freezing of beef and Post Mortem Inspection
(PMI) by 0.0094% and 0.109%, respectively, improving home freezing and routine PMI may reduce the
risk of exposure to 0.0038% and 0.0040%, respectively. Hence PMI and home freezing were both
protective and contributing factors to the risk of exposure
The probability of C. bovis viability after home freezing of beef and C. bovis viability in infected beef
after cooking were the most influencing risk factors. Therefore, improving home freezing, efficient PMI
and thorough cooking of beef coupled with one health approach are recommended to reduce the risk.
Description
Thesis
Keywords
Food--Biotechnology. , Taeniasis. , Internal parasitic disease. , Parasitic diseases.