Background: The purpose of this secondary data analysis was to determine the prevalence of sexually transmitted and blood-borne infections (STBBI) and to examine the role of survival sex in sexual risk among street-involved youth in Winnipeg, Manitoba. Methods: Between 1999 and 2003, 743 Winnipeg street youth were interviewed in three separate cohorts as part of a national multi-centred study by the Public Health Agency of Canada. Results: Among the 673 Winnipeg street youth who responded to questions relating to survival sex, 26.3% reported they had engaged in survival sex. Females and Aboriginal youth were at greatest risk for sex trade involvement. Youth engaged in survival sex were diagnosed with significantly higher rates of STBBI; experienced greater amounts of abuse; and were at greater risk for participating in high risk sexual behaviours compared to their non-sex trade counterparts. Conclusion: Gender specific, culturally appropriate, and youth oriented prevention and intervention strategies are urgently required to reduce the prevalence of STBBI and survival sex among this at-risk population.

Assessment of Hazard Analysis and Critical Control Points Principles in Primary School Feeding Schemes in the Western Region of Gauteng Objective: The objective of this study is to investigate the need for standard hygiene and safety practices for the National School Nutrition Program (NSNP). Food safety procedures and practices can be implemented as part of the Hazard Analysis of Critical Control Points (HACCP) program. Background: The National School Nutrition Program (NSNP) forms part of the Integrated Nutrition Program (INP) of South Africa and was implemented as a poverty alleviation strategy introduced in 1994 by government as part of the newly founded democratic Republic of South Africa. The NSNP is implemented in primary schools. Design: A questionnaire was designed to investigate, the hygiene and safety practices in primary schools in the Western Region of Gauteng. Both rural and urban schools using the NSNP were targeted. Research Project: The NSNP staff from 26 primary schools completed the research questionnaire focused on hygiene and safety practices. Results: Data collected indicated the need to implement a very basic HACCP program that include identifying the HACCP team, training for food handlers, standardized equipment and the implementation of hygiene and safety procedures. Conclusion: To implement HACCP in the NSNP, the role players from the managerial structures and food handlers at schools, the training needs of the target group and the equipment needed to comply with HACCP procedures, should to be identified. Documentation must be in place for monitoring, evaluation and verification procedures to implement the HACCP program. / Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2009.

The genomic RNA encoding the structural proteins of louping ill, a tickborne flavivirus, was cloned and sequenced. Sequence comparisons of louping ill envelope protein showed greater homology with tick-borne than mosquito-borne flaviviruses and greater homology with the western than the far eastern subtype of tick-borne encephalitis virus. Louping ill and tick-borne encephalitis viruses are probably varieties of a common tick-borne ancestral virus. The average amino acid sequence diversity between members of the tick-borne serogroup was significantly lower than that of mosquito-borne serogroups, suggesting that tick-borne flaviviruses have been subjected to different evolutionary immune selection pressure from the mosquito-borne viruses. Using the published model of tick-borne encephalitis envelope protein and the derived sequence data on louping ill virus, three discontinuous peptides (amino acids 81-88, 207-212 and 230-234) which may represent critical molecular determinants within the receptor binding site of tick-borne flaviviruses, were identified. These peptides may provide a specific genetic marker for these viruses. Recombinant baculoviruses and vaccinia viruses containing cloned DNA, encoding either the envelope protein or the structural proteins of louping ill virus, were constructed. Glycosylated envelope protein, presented both inside and on the surface of insect and mammalian cells, was expressed by all four recombinant viruses. Differences in antigenic presentation of envelope protein were observed between envelope protein and structural protein constructs as well as between insect cell and mammalian cell expression systems. Despite the expression of epitopes known to elicit neutralizing and protective antibodies when present in authentic antigen, the recombinant envelope protein expressed by either baculovirus or vaccinia virus failed to induce, under the experimental conditions employed, either neutralizing or protective antibodies in both mice and rabbits against louping ill virus. Hence, louping ill envelope protein expressed by baculoviruses and vaccinia viruses was antigenically reactive but immunogenically inert.

Ross River virus (RRV) is an Alphavirus distributed throughout Australia. It is transmitted by mosquitoes and is known to cause moderate to severe disease symptoms in humans. Along with other alphaviruses such as Sindbis virus and Chikungunya virus, RRV is known to cause arthritic symptoms, characterised by muscle and joint inflammation. Several investigations have established the role of macrophage cells and pro-inflammatory host factors in the development of RRV-induced disease. In this study, we attempted to determine differences between RRV passaged in mammalian and mosquito cells. There is strong evidence that arthropod-borne viruses are able to display enhanced infectivity when passaged into arthropod cell line. We showed that mosquito cell-derived RRV (mos-RRV) was able to replicate to higher titres than mammalian cell-derived RRV. We also showed that mos-RRV failed to induce Type I IFN-associated antiviral responses. The second aim of this study was to investigate the role of TNF-ᬠa pro-inflammatory cytokine implicated in arthritic diseases, in the development of RRV disease. We treated RRV-infected C57BL/6J mice with a commercially available TNF-ᠩnhibitor drug and monitored disease signs. We found that the TNF-ᠩnhibitor does not ameliorate RRV disease (RRVD) symptoms, and that it does not prevent muscle and joint inflammation. We analysed histological sections of muscle and joint tissue of Enbrel-treated and untreated, RRV-infected cells. We also determined and compared host cytokine expression profiles. Finally, we sought to determine the requirement for natural killer (NK) cells in RRV disease. NK cells have been detected in the synovium of RRV-infected patients since early studies, but their role in disease pathogenesis remains unclear. Using a NK-dysfunctional mouse (C57BL/6J-Lystbg), we showed that mice lacking a functional NK system are more susceptible to RRV disease than wildtype, C57BL/6J mice. We monitored disease symptoms following RRV infection and assessed muscle and joint inflammation in Lystbg and C57BL/6J mice. This thesis examines mechanisms of viral infection and immune evasion employed by RRV, as well as into the role of host cells and cytokines in RRVD pathogenesis disease mechanisms. We showed that a functional NK cell system is required for the regulation of RRV-induced muscle and joint inflammation. Our characterisation of the use of a commercial TNF-ᠩnhibitor in RRV-induced disease in mice may provide information on the role of TNF-ᠩn viral arthritis, and may help towards developing safe and effective treatment.

Thesis (M.S.)--University of Missouri--Columbia, 2004. / "May, 2004." Typescript. Includes bibliographical references (leaves 35-38). Also issued on the Internet.

Thesis (MSc (Veterinary Tropical Diseases, Veterinary Science))--University of Pretoria, 2008. / Includes bibliographical references. Also available in print format.

Thesis (M.S.)--University of Missouri--Columbia, 2004. / Typescript. Includes bibliographical references (leaves 35-38). Also issued on the Internet.

The proposed thesis contributes to the knowledge about tick-borne encephalitis and its pathogenesis. The thesis describes pathogenesis and immunopathogenesis of tick-borne encephalitis, impact of host's genotype in clinical course determination, immune response of patients with acute tick-borne encephalitis, the mechanism of tick-borne encephalitis virus migration into central nervous system and virus interaction with cells of neurovascular unit as well as potential medical interventions.

No description available.

This study was focused on the influence of hard tick from Ixodes ricinus on the replication of tick-borne encephalitis virus in vivo and the on the accompained changes in the levels of inflammatory cytokines which were determined in serum of infected mice. Futher the effect of tick cystatins, the inhibitors of cysteine proteases, on gene expression of interferon regulated factors was investigated in dendritic cells upon stimulation with Toll-like receptor ligands.