Bovine viral diarrhoea virus infection is an important viral infection affecting the cattle industry today. The prevalence of this infection in South African feedlots is unknown. Ear notch biopsies were collected from animals entering feedlots which appeared unthrifty, chronic poor doers, and animals entering the hospital pen with respiratory disease for the first time. One thousand and seventy four (1074) samples were collected from the first two categories and 616 samples from animals entering the hospital pen. Samples were processed with routine immunoperoxidase protocol. Serum samples were also collected when possible. The first aim of this study was to determine the prevalence with the use of immunoperoxidase staining on ear notch biopsies. Overall 49 animals tested positive, 43 from the 1074 group and 6 from the 616 group. The prevalence of persistently infected cattle entering the feedlots was determined as 2.9%, which is higher than the rule of thumb that 0.5% of infected animals enter feedlots. Four percent were positive in the group of 1074 animals and one percent in those entering the hospital pen for the first time. It was proposed by the author that persistently infected animals are at a greater risk to develop respiratory disease in the feedlot, but this was not supported by the data collected. There was thus no clear increase in respiratory disease in persistently infected animals. The reliability of the immunoperoxidase stain as a diagnostic method to identify persistently infected animals was also evaluated. This diagnostic method proved to be reliable, but the pathologist needs to be aware of non-specific staining. During the course of the research it became apparent that in some cases mast cells in the dermis stain positive with both DAB and NovaRED stains. Positive staining in keratinocytes and hair follicle epithelium was not present and these cases were proven as negative for persistent infection. The specific cause of positive staining of mast cell granules remains unclear. Only ten positive cases had serum samples on which ELISA tests for antigen and antibody were performed. All tests correlated well with the immunoperoxidase method except in four cases, where the animals were incorrectly diagnosed as positive due to the non-specific staining as described above. Immunoperoxidase staining on ear notch biopsies is thus a reliable diagnostic method to identify persistently infected animals with BVDV, but the pathologist must be aware of non-specific positive staining. / Bees virus diarree infeksie is ‘n belangrike virale infeksie wat die bees industrie van vandag beinvloed. Die prevalensie van die infeksie in Suid Afrikaanse voerkrale is onbekend. Oorknip biopsies is geneem van verdagte diere met aankoms by die voerkraal, chroniese swak beeste en diere wat vir die eerste keer in die hospitaal kraal weens respiratoriese siekte opgeneem is. Een duised vier en sewentig (1074) monsters is van die eerste twee kategoriee geneem en 616 monsters van diere wat in die hospitaal kraal opgeneem is. Monsters is op roetiene wyse vir immunoperoksidase kleuring geprosesseer. Serum monsters is waar moontlik ook versamel. Die eerste doel van die studie was om die prevalensie van permanente besmette draers te bepaal met behulp van immunoperoksidase kleuring op oorknip biopsies. Nege-en-veertig diere in totaal het positief getoets, 43 vanuit die eerste groep en 6 vanuit die tweede groep. Die prevalensie van permanente besmette draers wat in voerkrale opgeneem word is was 2.9% wat hoër is as die verwagte 0.5% wat deur die literatuur aangedui word. Vier persent was positief in die 1074 groep en 1% in die groep wat vir die eerste keer in die hospitaal kraal opgeneem is. Dit is deur die navorser voorgestel dat permanente besmette draers ‘n groter risiko het om met respiratoriese siektes in die hospitaal kraal opgeneem te word, maar dit is nie deur die data bevestig nie. Daar was dus geen verhoging in die teenwoordigheid van respiratoriese siektes in geaffekteerde diere nie. Die betroubaarheid van immunoperoksidase kleuring om permanente besmette diere met BVD te identifiseer is ook geevalueer. Die metode is betroubaar gevind, maar die patoloog moet bewus wees van nie-spesifieke kleuring. Gedurende die navorsing het dit aan die lig gekom dat mastselle in die dermis positief kleur met DAB en NovaRED kleuring. Positiewe kleuring was nie in die epidermis of haarfollikel epiteel teenwoordig nie en die die gevalle was negatief vir permanente besmetting. Die spesifieke rede vir positiewe kleuring in mastselle is steeds onduidelik. Slegs 10 positiewe gevalle het serum monsters gehad vir ELISA teenliggaam en antigeen toetse. Die resultate het goed gekorrelleer met die immunoperoksidase kleuring, behalwe in 4 gevalle waar gevalle verkeerd as positief gediagnoseer is as gevolg van nie-spesifieke positiewe kleuring soos beskryf. Immunoperoksidase kleuring is dus ‘n sensitiewe metode om permanente besmette draers met BVDV te identifiseer, mits die patoloog bewus is van nie-spesifieke kleuring wat mag voorkom. / Dissertation (MMedVet)--University of Pretoria, 2010. / Paraclinical Sciences / unrestricted

ENGLISH : The purpose of this study was to determine the role of fear for HIV/AIDs in adolescents’ sexual choices. Theories which informed the study included developmental theory, decisionmaking theory, as well as emotion theory. In this survey study a mixed-method questionnaire was designed, piloted and then implemented with 252 purposefully selected Grade 11, Afrikaans learners (127 boys and 125 girls), aged 16 to 17 years in one high school in Gauteng. Data was analysed quantitatively and qualitatively. It was found that adolescents link several emotions with HIV&AIDS: fear, concern and caution. Another finding was that adolescents reportedly made safe sexual choices. Therefore, it was concluded that adolescents fear for HIV&AIDS positively impacted on their safe sexual choices. AFRIKAANS : Die doel van hierdie studie was om te bepaal welke rol vrees vir MIV&VIGS speel in adolessente se seksuele keuses. Teorieë wat die studie ingelig het was ontwikkelingsteorie, besluitnemingsteorie en emosie-begronde teorieë. Die navorsingsontwerp van hierdie studie was ‘n opname studie. ‘n Gemengde metode vraelys is ontwerp, geloods, aangepas en geïmplementeer met. 252 graad 11, Afrikaanse leerders (127 seuns en 125 dogters), tussen die ouderdom van 16 en 17 jaar, wat doelgerig geselekteer is vanuit een hoërskool in Gauteng. Vraelysdata is kwantitatiewe en kwalitatiewe geanaliseer. Daar is bevind dat adolessente MIV/VIGS verbind met die emosies: vrees, bekommernis en versigtigheid. Verder blyk dit dat adolessente veilige seksuele keuses maak. Die gevolgtrekking is gemaak dat adolessente se vrees vir MIV&VIGS positief korreleer met hul veilige seksuele keuses. / Dissertation (MEd)--University of Pretoria, 2009. / Educational Psychology / unrestricted

The effects of HIV/AIDS and subsequent opportunistic infections and/or associated conditions on the development of infected children are substantial. Considerable delays and/or disorders in communication development have been noted in the HIV/AIDS infected child, as well as the need for Early Communication Intervention (ECI) services for this population. A dearth of locally relevant data regarding the speech, language and hearing development of HIV/AIDS infected children within the South African context currently exists. The objective of this study was to describe the characteristics of a group of HIV/AIDS infected children being managed at an outreach clinic of regional hospital in Gauteng. A cross-sectional, retrospective, non-experimental, descriptive, quantitative research design was used in this study. The main objective was achieved by analysing the clinic records of 203 children infected with HIV/AIDS between the ages of 0 – 5 years 11months through the use of a pre-designed checklist. A questionnaire completed by four medical doctors practicing at the HIV/AIDS clinic within the hospital was also used. This allowed for the perceptions and practices of the medical doctors to be described. Results revealed that the majority HIV/AIDS infected children being managed at the outreach clinic were significantly immunocompromised and diagnosed with Stage III or Stage IV HIV/AIDS infection. Furthermore, results indicated the presence of several opportunistic infections and HIV/AIDS associated conditions (such as Tuberculosis, Candidiasis and Encephalopathy). A positive finding was that 76% of the HIV/AIDS infected children (n=153) were receiving Highly Active Antiretroviral Therapy (HAART) at the time of data collection. The most outstanding finding was that very few of the children with HIV/AIDS being managed at the outreach clinic were recorded as having speech, language and/or hearing delays and/or disorders. Similarly, referrals to other professionals as recorded in the children’s hospital records seemed to be limited to Social Workers and Dietitians, with only one child recorded as being referred to a Speech-Language Therapist and Audiologist for further management. It was unclear whether more children were in fact referred for additional intervention by other professionals and this was simply not recorded in the children’s records, or whether these referrals were in fact not made. Results from the questionnaires completed by the medical doctors working with the pediatric HIV/AIDS population within the outreach clinic were significant. Findings indicated that the majority of the respondents believed that HIV/AIDS infected infants were more at risk for developmental and communicative delays and/or disorders than the general population, and that this population would likely benefit from Speech-Language Therapy and/or Audiology intervention services. Respondents indicated that medical doctors working with the pediatric HIV/AIDS population were often not adequately informed regarding the effects of HIV/AIDS on communication development and that they would benefit from further training in this regard. The need for further research regarding the characteristics of the pediatric HIV/AIDS population, particularly on a larger sample, was described. This would assist in the development of a guideline for ECI service delivery for children infected with HIV/AIDS. The need for further training of other professionals regarding the effects that HIV/AIDS has on the communication development of the infected child, to assist with necessary referrals and teamwork, was also highlighted. AFRIKAANS : Suid-Afrika is een van die lande ter wêreld, wat die hoogste voorkoms van Menslike Immuniteitsgebrekvirus/ Verworwe Immuniteitsgebreksindroom (MIV/VIGS), toon - met die pediatriese populasie op die voorfront van hierdie epidemie. Die effek wat MIV/VIGS en opeenvolgende opportunistiese infeksies en/of ander geassosieerde toestande op die ontwikkeling van kinders het, is verreikend. Internasionale literatuur beskryf agterstande en/of akwykings in die kommunikasie ontwikkeling van kinders wat met MIV/VIGS geinfekteer is. Die behoefte vir Vroeë Kommunikasie Intervensie (VKI) vir hierdie populasie word ook gemeld. Daar bestaan egter slegs ‘n beperkte hoeveelheid relevante, plaaslike literatuur met betrekking tot die spraak-, taal- en gehoorontwikkeling van kinders met MIV/VIGS binne die Suid-Afrikaanse konteks. Die doelwit van hierdie studie was om die kenmerke van ‘n groep kinders, wat met MIV/VIGS besmet is en by ‘n streekshospitaal in Gauteng behandel word, te beskryf. ‘n Kwantitatiewe, nie-eksperimentele, terugwerkende, dwarsdeurige, beskrywende navorsingsontwerp is gebruik. Die hoofdoelwit was bereik deur die kliniekrekords van kinders wat met MIV/VIGS besmet is, te analiseer deur van ‘n vooraf-ontwerpte merklys gebruik te maak. Data is ook ingesamel deur middel van vraelyste wat deur mediese dokters, wat by MIV/VIGS klinieke binne die hospitale werk, voltooi is. Dit het toegelaat dat die persepsies en praktyke van die mediese dokters ook beskryf kon word. Resultate het getoon dat die meerderheid kinders met MIV/VIGS, wat by klinieke behandel word, se immuunsisteme ernstig onderdruk was en dat hulle met stadium III of stadium IV van MIV/VIGS gediagnoseer was. Die resultate het verder ook die voorkoms van verskeie opportunistiese infeksies en MIV/VIGS geassosieerde toestande aangedui. ‘n Positiewe bevinding was dat 76% van die kinders (n=153), wat met MIV/VIGS geinfekteer was, tydens die proses van data-insameling reeds Hoogsaktiewe Antiretrovirale Terapie (HAART) ontvang het. Die mees uitstaande bevinding was dat slegs ‘n geringe hoeveelheid kinders met MIV/VIGS by die kliniek, as met ‘n agterstand en/of afwyking in spraak, taal en/of gehoor, aangeteken is. Beperkte verwysings na ander professionele persone is ook in die kliniekrekords opgemerk. Verwysings was beperk tot Maatskaplike Werkers en Dieëtkundiges. Daar was slegs een aantekening van ‘n kind wat vir behandeling na ‘n Spraak- en Taalterapeut en Oudioloog verwys is. Dit is egter onduidelik of daar werklik meer verwysings na ander professionele persone gemaak is, maar net nie in die kinders se kliniekrekords aangedui is nie, of dat daar werklik min verwysings na ander professionele dissiplines gemaak is. Bykomend, was die resultate van voltooide vraelyste deur mediese dokters, wat met die pediatriese MIV/VIGS populasie in die kliniek werk, insiggewend. Bevindings dui aan dat die meerderheid proefpersone, wat aan die studie deelgeneem het, van mening is dat kinders wat met MIV/VIGS besmet is wel ‘n hoër risiko toon vir ontwikkelings- en kommunikasie agterstande en/of afwykings in vergeleke met die algemene populasie. Die proefpersone is verder ook van mening dat hierdie populasie wel van spraak- en taalterapie en/of oudiologiese intervensie sal baatvind. Proefpersone het verder aangedui dat mediese dokters, wat met die pediatriese MIV/VIGS populasie werk, nie ten volle ingelig is omtrent die effek van MIV/VIGS op kommunikasie ontwikkeling en dat hulle van verdere opleiding sal baatvind. Die behoefte vir verdere navorsing in die veld van pediatriese MIV/VIGS en kommunikasie ontwikkeling, binne die Suid-Afrikaanse konteks, word in hierdie studie beskryf. Dit sal as riglyn vir VKI dienslewering aan hierdie populasie dien. Daar is ook ‘n groot behoefte vir verdere opleiding van ander mediese professionele persone met betrekking tot pediatriese MIV/VIGS en die effek wat die op die kind se kommunikasie ontwikkeling het. / Dissertation (MCommunication Pathology)--University of Pretoria, 2010. / Speech-Language Pathology and Audiology / unrestricted