Thesis (MScMedSc (Pathology. Medical Virology))--University of Stellenbosch, 2010. / Bibliography / ENGLISH ABSTRACT: Throughout history disease entities have been described which match the description of diseases now known to be caused by hantaviruses; however these viruses were first identified as the aetiologic agent in 1976, the first species named Hantaan virus after the river near which its natural host, the rodent species Apodemus agrarius, was captured. Since then numerous species in the Hantavirus genus, family Bunyaviridae, have been found, with today more than 30 species worldwide being known. Hantaviruses are hosted by rodents from the Muridae and Cricetidae families and by shrews (insectivores) in the Soricidae family. There are two types of hantavirus disease, Haemorrhagic fever with renal syndrome (HFRS) in the Old World and Hantavirus cardiopulmonary syndrome (HCPS) in the New World. The first two African hantaviruses were identified in 2006 in Guinea, West Africa; Sangassou virus (SANGV) in a rodent, the African wood mouse (Hylomyscus simus), and Tanganya virus (TGNV) in Therese’s shrew (Crocidura theresae). In this study, rodents and shrews were trapped at localities in the Western Cape and Northern Cape provinces of South Africa, and in the southern regions of Namibia. RNA was extracted from their lungs and screened for hantavirus sequences by RTPCR, using degenerate primers designed to detect all members of the Hantavirus genus. In addition, an in-house IgG ELISA assay was set up, based on recombinant N antigen from Dobrava virus, DOB-rN, and Puumala virus, PUU-rN. The assay was used to screen patient sera collected in an anonymous convenience serological survey using residual serum samples left over from routine testing at NHLS laboratories in the Western Cape for hantavirus-specific antibodies. RNA from 576 animal specimens was screened by RT-PCR; no hantavirus genome was detected in any of the specimens. Sera from 161 patients were screened for hantavirus antibodies; 11.18% of the sera were reactive to DOB-rN, 4.97% against PUU-rN and 2.48% against both antigens. v Though no virus was detected in the animals screened, this does not necessarily mean that there are no hantaviruses present in Southern Africa. A previous seroepidemiological survey conducted in South Africa reported on the presence of hantavirus specific antibodies by IFA in two species of rodents trapped in the Western Cape and Northern Cape Aethomys namquensis and Tatera leucogaster. Our was the second known study in South Africa conducted that determined and proved the presence of hantavirus specific antibodies in humans. / AFRIKAANSE OPSOMMING: Dwarsdeur die geskiedenis was daar beskrywings van siektes wat ooreenstem met die beskrywing van hantavirus simptome, maar die eerste etiologiese oorsaak van die siekte is eers in 1976 geïdentifiseer en Hantaan virus genoem, vernoem na die rivier waar naby die gasheer, Apodemus agrarius, gevang is. Van daar af het die soektog na nuwe hantavirusse intensief gevorder en vandag is daar meer as 30 spesies wêreldwyd wat aan die Hantavirus genus, ’n lid van die Bunyaviridae familie, behoort. Knaagdiere van die Muridae en Cricetidae families, sowel as spitsmuise (insekvreters) in die Soricidae familie is gasheer vir hantavirusse. Twee tipes hantavirus siekte is bekend, hemorragische koors met nier sindroom (HFRS) in die Ou Wêreld en hantavirus kardiopulmonale sindroom in die Nuwe Wêreld. Die eerste twee Afrika hantavirusse is in 2006 in Guinee Wes-Afrika geïdentifiseer; Sangassou virus (SANGV) in ’n knaagdier, die Afrika hout muis (Hylomyscus simus) en Tanganya virus (TGNV) in Therese se spitsmuis (Crocidura theresae). In hierdie studie is knaagdiere en spitsmuise op verskeie plekke in die Wes- en Noord-Kaap provinsies, asook die Suide van Namibië, gevang. RNS is onttrek vanuit die longe en hantavirus volgordes is gesoek deur middel RT-PKR deur gebruik te maak van Pan-Hanta primers wat ontwerp is om alle lede van die Hantavirus genus op te spoor. ’n Self-ontwerpde IgG ELISA, gebasseer op rekombinante N antigeen van Dobrava virus, DOB-rN en Puumala virus, PUU rN, is opgestel en gebruik om pasiënt serum, verkry in ’n anonieme serologiese opname, te toets; oorblywende serum, na toetse uitgevoer is deur NHLS laboratoriums in die Wes-Kaap, is verkry en getoets vir hantavirus spesifieke teenliggaampies. RNS van 576 dier monsters is getoets deur middel van RT-PKR en geen hantavirus is in enige van die monsters geïdentifiseer nie. Serum van 161 pasiënte is getoets vir hantavirus teenliggaampies; 11.18% van die serum was reaktief teen DOB-rN, 4.97% teen PUU-rN en 2.48% teen albei antigene. Alhoewel geen virus in die diere geïdentifiseer is nie, beteken dit nie noodwendig dat geen hantavirusse in Suidelike-Afrika voorkom nie. ‘n Vorige sero-epidemiologiese opname wat in Suid-Afrika gedoen is het die teenwoordigheid van hantavirus spesifieke teenliggaampies in twee knaagdier spesies, Aethomys namquensis en Tatera leucogaster gevang in die Wes-en Noord-Kaap, gevind. Ons studie is die tweede studie bekend in Suid-Afrika uitgevoer, wat die teenwoordigheid van hantavirus spesifieke teenliggaampies bevind en bewys het.

Thesis (MMed)--Stellenbosch University, 2012. / Includes bibliography / ENGLISH ABSTRACT: Introduction Acute respiratory tract infections cause significant morbidity and mortality worldwide, and are the main reason for the utilisation of health care services. Identifying the aetiological cause of lower respiratory tract infections (LRTIs) is difficult at the best of times, and more than 20 viruses and bacteria have been associated with LRTIs, which cannot be distinguished with clinical examination alone. Viruses can be detected in respiratory samples by a variety of methods, and without exception molecular methods have proven to be more sensitive than non-molecular-based tests. The increased sensitivity of molecular methods may assist in expanding our knowledge of the pathogenesis of severe respiratory tract infections, and could have a positive influence on patient management, infection control, vaccination strategies and public health. Aims and objectives 1. Determine the viral causes of lower respiratory tract infections requiring admission in using shell vial culture with immunofluorescent staining and two multiplex PCR assays, the Seeplex® RV15 ACE Detection system (Seeplex® RV15 ACE) and the Respiratory Multiplex Real-Time RT-PCR LightMix® Customised Kit (Resp Multiplex RT-PCR). 2. Compare the Seeplex® RV15 ACE and the Resp Multiplex RT-PCR with shell vial culture for the detection of respiratory viruses in routine diagnostic respiratory samples. 3. Examine the demographic and clinical characteristics associated with each respiratory viral pathogen. Materials and Methods One hundred and thirty-eight paediatric patients, admitted to Tygerberg Children’s Hospital from May 2010 to August 2010 with a presumptive diagnosis of an acute respiratory tract infection were included in the study. Nasopharyngeal or tracheal aspirates were collected, and all samples were tested by all three diagnostic methods. Clinical, demographic and laboratory data were collected through a systematic review of medical and laboratory records and subsequently anonymised Results Thirty-seven viruses were detected in 36 samples (26.1%) by shell vial culture with immunofluorescent staining; 169 viruses in 102 samples (73.9%) with the Seeplex® RV15 ACE; and 90 viruses in 73 samples (52.9%) with the Resp Multiplex RT-PCR. Shell vial culture had excellent specificity, but low sensitivity for all of the respiratory viruses. Conversely, the Seeplex® RV15 ACE had excellent sensitivity for all viruses, but slightly lower specificity. This was due to the detection of additional viruses, which may have been true positives due to the increased sensitivity of this assay. The Resp Multiplex RTPCR had excellent sensitivity and specificity. At least one respiratory pathogen could be identified in 80% of the patients. At least one virus was detected in 57% of patients, bacterial micro-organisms in 6%, and both viral and bacterial pathogens in 17%. Viral-bacterial co-infections were associated with increased severity compared to other infections, as these children were more likely to receive steroids and a blood transfusion (p = 0.002), and more likely to require mechanical ventilation (p < 0.001) and admission to the intensive care unit (p = 0.04). Conclusions We confirmed that molecular techniques are significantly more sensitive than shell vial culture for the detection of respiratory viruses in children. Due to their highly specific nature and the genetic variability observed in viruses, an excellent, continuous quality control programme is essential to ensure the continued superiority of these assays. Viral-bacterial co-infection is associated with increased severity of LRTIs in children. Further research is needed to elucidate the precise pathogenic and immunologic mechanism of this interaction. / AFRIKAANSE OPSOMMING: Inleiding Akute lugweg infeksies is verantwoordelik vir beduidende morbiditeit en mortaliteit wêreldwyd en is die hoofrede vir die benutting van gesondheidsdienste. Identifisering van die oorsaak van laer lugweg infeksies is baie moeilik en meer as 20 virusse en bakterieë word hiermee geassosieer. Ongelukkig kan kliniese ondersoek alleen nie onderskei tussen die verskillende organismes nie. Respiratoriese virusse kan deur ‘n wye verskeidenheid van toets metodes aangetoon word. Molekulêre metodes is sonder uitsondering meer sensitief as nie-molekulêre metodes. Hul verhoogde sensitiwiteit mag help om ons kennis oor die patogenese van erge lugweg infeksies te verbreed en kan ’n positiewe invloed op pasiëntbehandeling, infeksiebeheer, immunisasie strategieë en publieke gesondheidsorg hê. Doel van die Ondersoek 1. Bevestig die virale oorsake van laer lugweg infeksies deur gebruik te maak van “shell vial” kultuur met immunofluoressensie en twee veelvoudige molekulêre toetse, die Seeplex® RV15 ACE en die Resp Multiplex RT-PCR. 2. Vergelyk die Seeplex® RV15 ACE en die Resp Multiplex RT-PCR met “shell vial” kultuur vir die aantoning van respiratoriese virusse in roetine diagnostiese monsters. 3. Ondersoek die demografiese en kliniese eienskappe wat met elke respiratoriese patogeen geassosieer word. Metodiek en Materiaal Een honderd agt-en-dertig kinders wat toegelaat is tot Tygerberg Kinderhopitaal vanaf Mei 2010 tot Augustus 2010 met ’n voorlopige diagnose van ’n akute lugweg infeksie is in die studie ingesluit. Nasofaringeale of trageale aspirate is van elke pasiënt gekollekteer en met al drie diagnostiese metodes ondersoek. Kliniese, demografiese en laboratorium data is gekollekteer deur ’n sistematiese ondersoek van mediese en laboratorium rekords en daarna anoniem gemaak. Resultate Sewe-en-dertig virusse is in 36 monsters (26.1%) aangetoon deur “shell vial” kultuur met immunofluoressensie; 169 virusse in 102 monsters (73.9%) deur die Seeplex® RV15 ACE; en 90 virusse in 73 monsters (52.9%) deur die Resp Multiplex RT-PCR. “Shell vial” kultuur het uitstekende spesifisiteit gehad, maar sensitiwiteit was laag vir al die virusse. Teenoorgesteld hiermee het die Seeplex® RV15 ACE hoë sensitiwiteit vir al die viruses gehad, maar effe laer spesifisiteit. Dit was as gevolg van die aantoning van addisionele virusse, wat moontlik ware positiewe resultate kon wees as gevolg van die verhoogde sensitiwiteit van hierdie toets metode. Die Resp Multiplex RT-PCR het uitstekende sensitiwiteit en spesifisiteit gehad. Ten minste een respiratoriese patogeen is in 80% van die pasiënte geidentifiseer. Een of meer virusse was in 57% van die pasiënte aangetoon, bakterieë in 6% en beide virale en bateriële patogene in 17%. Virale-bakteriële ko-infeksies, in vergelyking met ander infeksies, was geassosieer met meer ernstige lugweg infeksies aangesien hierdie kinders meer geneig was om steroïede en ’n bloedtransfusie te ontvang (p = 0.002). Hulle het ook meer waarskynlik meganiese ventilasie (p < 0.001) en toegang tot die intensiewe sorg eenheid benodig (p = 0.04). Gevolgtrekkings Ons het bevesitg dat molekulêre tegnieke aansienlik meer sensitief is as “shell vial” kultuur vir die aantoning van respiratoriese virusse in kinders. As gevolg van hul hoogs spesifieke aard en die genetiese variasie waargeneem in virusse, is ’n uitstekende deurlopende kwaliteitsbeheer program noodsaaklik vir die voortgesette uitneemendheid van hierdie metodes. Virale-bakteriële ko-infeksies word geassosieer met meer ernstige laer lugweg infeksies in kinders. Verdere navorsing is nodig om die presiese patogenetiese en immunologiese meganisme van hierdie interaksie toe te lig.

Thesis (MScMedSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Background: In South Africa alone, 30% of women of child-bearing age are infected with HIV. With the increasing focus and success of prevention of mother-to-child transmission (PMTCT) programmes, an estimated 300 000 infants are born exposed to HIV every year. The underlying impact of in utero HIV exposure on infant immune health has not been extensively characterised. Clinical follow-up of these HIV-exposed uninfected (HEU) infants reveals increased infectious morbidity and mortality compared to their unexposed (UE) counterparts. Objectives: (i) To evaluate and characterise adaptive immune properties by measuring vaccine-specific antibody levels in children from 2 weeks to 2 years of age in the presence and absence of maternal HIV infection. (ii) To investigate specific cellular markers of immune activation, immune regulation, apoptosis and B cell memory on T and B cell populations in HEU and UE children measured at 18 and 24 months of age. Methods: This sub-investigation formed part of a collaborative pilot study between the universities of British Columbia (Vancouver, Canada) and Stellenbosch. A total of 95 HIV-positive and HIV-negative mothers were recruited after delivery at Tygerberg Hospital, and signed informed consent for their infants to be included in the study. Of these infants, only 27 HEU and 30 UE infants were eventually enrolled and followed up at various time points, starting at two weeks of age. Four of these infants were confirmed to be HIV-positive at 2 weeks and clinically followed up according to the protocol, but were excluded from statistical data analyses. Blood was collected at 2, 6 and 12 weeks and again at 6, 12, 18 and 24 months of age. Quantitative IgG-specific antibodies to Haemophilus influenzae B (Hib), Bordetella pertussis, tetanus and pneumococcus were measured at each time point, using commercially available ELISA (Enzyme-Linked ImmunoSorbent) kits. Cellular markers of immune activation, immune regulation, apoptosis and memory were measured in various populations of T and B cells at 18 and 24 months only, by using four-colour flow cytometry and validated whole-blood staining methods. In addition, a functional assay was developed to evaluate cell susceptibility to apoptosis (spontaneously) by measuring the expression of Annexin V on both CD4+ T and CD20+ B cells after 16 and 24-hour incubation periods. The statistical analysis of the antibody data was conducted by repeated-measures ANOVA (i.e. analysis of variance), using a mixed-model approach. Differences in the expression of the two groups’ cellular markers were compared by employing one-way ANOVA. An F test p value (which assumes normality) was reported, while the non-parametric Mann-Whitney U test served as confirmatory tool. Repeated-measures ANOVA was used for the evaluation of the functional spontaneous apoptosis assay at three time points (ex vivo, 16 and 24 hours) on the 18-month samples, while one-way ANOVA was used for the 24-month samples. Results: The HEU group (n = 23) displayed significantly lower levels of antibodies to pertussis (20.80 vs 28.01 Food and Drug Administration [FDA] U/ml; p = 0.0237), tetanus (0.08 vs 0.53 IU/ml; p < 0.001) and pneumococcus (31.67 vs 80.77 mg/l; p = 0.003) than the UE group (n = 23) at 2 weeks of age. No statistical differences were noted for Hib antibody levels between the two groups at this time point. At 6 weeks of age, HEU infants displayed lower mean levels of all antibodies measured; however, these differences did not reach statistical significance. Following vaccination, compared to UE controls, the HEU group presented with statistically significantly higher antibody levels to pertussis at 6 months (155.49 vs 63.729 FDA U/ml; p = 0.0013), 12 months (26.54 vs 8.50 FDA U/ml; p < 0.001) and 18 months of age (1658.94 vs 793.03 FDA U/ml; p = 0.0362). A significant difference in tetanus antibody levels between the two groups was only evident at 24 months, with the HEU group displaying higher levels (3.28 vs 1.70 IU/ml; p = 0.018) than the UE group. No differences were observed between the two groups following vaccination for Hib. At 18 and 24 months, the HEU group showed increased expression of cellular markers of immune activation (CD69 and CD40L) on CD4+ T cells compared to UE controls. The two groups showed similar expression of the cellular marker of activation CD38 on CD8+ T cells. The HEU group displayed significantly higher levels of CD127, the interleukin (IL) 7 receptor, on CD4+ T cells compared to UE controls at 18 months of age. The HEU group also showed increased expression of cellular markers of apoptosis on both CD4+ T and CD8+ T cells. No statistical significance was noted for the expression of Fas on CD4+ T cells at 18 and 24 months of age. However, at 24 months, the HEU group showed significantly increased expression of FasL on both CD4+ T and CD8+ T cells. During cell culture experiments, the HEU group displayed increased susceptibility to spontaneous apoptosis shown by increased Annexin V expression on CD4+ T cells after a 16-hour incubation period at both 18 and 24 months. At 18 and 24 months, no difference was noted in the two groups’ immune regulation as measured by the expression of CTLA-4. The HEU group displayed increased levels of the cellular markers of immune activation CD80 on CD20+ B cells at 18 and 24 months of age. The HEU group also showed significantly increased levels of CD69 on CD19+ B cells at 24 months. No statistical significance was reached for the expression of CD62L and CD10 at either 18 or 24 months. Although the HEU group displayed increased levels of apoptosis (Fas) on CD20+ B cells, no statistical significance was reached at 18 or 24 months of age. In addition, the HEU group showed no difference in the expression of programmed death 1 (PD-1) at 18 and 24 months. HEU and UE groups showed similar expression of Annexin V after 16 hours of incubation in the 18 and 24-month samples. The expression of the biomarker of B cell memory CD27 on CD20+ B and CD19+ B cells was comparable between the two groups at both time points. Conclusion: At 2 and 6 weeks, lower mean antibody responses in HEU infants suggest poor placental transfer due to maternal HIV infection, while increased responses to specific antibodies may reflect an exaggerated immune response to immunisation. These robust responses may be due to the lack of competition with maternal antibodies, or may be ascribed to indirect stimulation of B cells via the activation of T cells. A hyper-inflammatory state is an imminent danger, with increased expression of cellular markers of immune activation and apoptosis that may be consistent with early HIV exposure that persists following infancy. These observations may serve as contributing factors to the extensively documented increased susceptibility to infections in the HEU population. Although these findings are consistent with a primed immune system, larger studies are required to confirm these observations in relation to clinical outcomes and to assess further whether these differences persist in later years. / AFRIKAANSE OPSMOMMING: Agtergrond: In Suid-Afrika alleen het 30% van vroue van ʼn vrugbare leeftyd MIV. Met die toenemende fokus en sukses van programme vir die voorkoming van moeder-na-kind-oordrag (sogenaamde PMTCT-programme) word ongeveer 300 000 babas jaarliks aan MIV blootgestel. Die onderliggende impak van intra-uteriene MIV-blootstelling op ʼn baba se immuunstelsel is nog nie omvattend beskryf nie. Kliniese opvolgondersoeke van hierdie MIV-blootgestelde dog onbesmette babas (sogenaamde HEU’s) dui op ʼn hoër siekte- en sterftesyfer weens infeksies as hul nieblootgestelde eweknieë (sogenaamde UE’s). Doelstellings: (i) Om kinders met MIV-positiewe en MIV-negatiewe moeders se aangepaste (verworwe) immuuneienskappe te beoordeel en te beskryf deur hulle vaksienspesifieke teenliggaamvlakke vanaf die ouderdom van twee weke tot twee jaar te meet. (ii) Om ondersoek in te stel na bepaalde sellulêre merkers van immuunaktivering, immuunregulering, apoptose en B-selgeheue by die T- en B-selgroepe van sowel HEU’s as UE’s op die ouderdom van 18 en 24 maande. Metodes: Hierdie subondersoek het deel uitgemaak van ʼn samewerkende loodsondersoek tussen die universiteite van Brits-Columbië (Vancouver, Kanada) en Stellenbosch. Altesaam 95 MIV-positiewe en MIV-negatiewe moeders is gewerf nadat hulle by Tygerberghospitaal geboorte geskenk het, en het ingeligte toestemming verleen dat hul babas by die studie ingesluit kon word. Van dié babas is slegs 27 HEU’s en 30 UE’s uiteindelik in die studie opgeneem en in verskillende stadia vanaf die ouderdom van twee weke opgevolg. Vier van die babas is op twee weke as MIV-positief bevestig en volgens die protokol klinies opgevolg, maar is van die statistiese dataontleding uitgesluit. Bloedmonsters is op twee, ses en 12 weke en weer op ses, 12, 18 en 24 maande geneem. Kwantitatiewe IgG-spesifieke teenliggame teen Haemophilus influenzae B (Hib), Bordetella pertussis, tetanus en pneumokokkus is telkens met behulp van kommersieel verkrygbare ELISA- (“Enzyme-Linked ImmunoSorbent”-)stelle bepaal. Sellulêre merkers van immuunaktivering, immuunregulering, apoptose en geheue is op slegs 18 en 24 maande by verskillende populasies T- en B-selle deur middel van ʼn vierkleurvloeisitometrie en geldig verklaarde volbloedkleuringsmetodes bepaal. Voorts is ʼn funksionele toets ontwikkel om selvatbaarheid vir apoptose te bepaal deur die ekspressie van Annexin V op sowel CD4+ T- as CD20+ B-selle ná 16 en 24 uur van inkubasie te meet. Die statistiese ontleding van die teenliggaamdata is met behulp van herhaaldemetings-ANOVA (d.w.s. afwykingsontleding) volgens ʼn gemengdemodel-benadering gedoen. Verskille in die twee groepe se sellulêre merkervlakke is deur middel van eenrigting-ANOVA vergelyk. ʼn F-toets-p-waarde (wat normaliteit veronderstel) is bereken, terwyl die nieparametriese Mann-Whitney-U-toets as bevestigende instrument gedien het. Vir die 18 maande-monsters is herhaaldemetings-ANOVA gebruik om die funksionele toets vir spontane apoptose in drie stadia (ex vivo, op 16 uur en op 24 uur) te beoordeel. Vir die 24 maande-monsters is eenrigting-ANOVA gebruik. Resultate: Op die ouderdom van twee weke het die groep HEU’s (n = 23) aansienlik laer teenliggaamvlakke teen kinkhoes (20.80 vs 28.01 Food and Drug Administration [FDA] U/ml; p = 0.0237), tetanus (0.08 vs 0.53 U/ml; p < 0.001) en pneumokokkus (31.67 vs 80.77 mg/l, p = 0.003) as die UE-groep (n = 23) getoon. In dié stadium is geen statistiese verskille in Hib-teenliggaamvlakke tussen die twee groepe opgemerk nie. Op ses weke het die groep HEU’s laer gemiddelde vlakke van ál die betrokke teenliggame getoon, hoewel hierdie verskille nie statisties beduidend was nie. In vergelyking met die UE-kontrolegroep het die groep HEU’s ná inenting statisties beduidend hoër teenliggaamvlakke teen kinkhoes getoon op ses maande (155.49 vs 63.729 FDA U/ml; p = 0.0013), 12 maande (26.54 vs 8.50 FDA U/ml; p < 0.001) én 18 maande (1658.94 vs 793.03 FDA U/ml; p = 0.0362). ʼn Beduidende verskil in die twee groepe se tetanus-teenliggaamvlakke het eers op 24 maande geblyk, met die groep HEU’s s’n hoër (3.28 vs 1.70 IE/ml; p = 0.018) as die UE’s s’n. Ná inenting teen Hib is geen verskille tussen die twee groepe waargeneem nie. Op 18 en 24 maande het die HEU’s verhoogde ekspressie van sellulêre merkers van immuunaktivering (CD69 en CD40L) op CD4+ T-selle getoon in vergelyking met die UE-kontrolegroep. Soortgelyke vlakke van die sellulêre merker van aktivering CD38 is ook op die CD8+ T-selle van die twee groepe opgemerk. Op 18 maande het die HEU-groep ʼn beduidend verhoogde ekspressie van CD127, die IL-7-reseptor, op CD4+ T-selle getoon in vergelyking met die UE-kontrolegroep. Die HEU groep het ook verhoogde ekspressie van sellulêre merkers van apoptose op sowel CD4+ T- as CD8+ T-selle getoon. FAS-ekspressie op CD4+ T-selle op 18 en 24 maande was nie statisties beduidend nie, hoewel die HEU-groep op 24 maande beduidend verhoogde ekspressie van FasL op CD4+ T- sowel as CD8+ T-selle getoon het. In selkwekingseksperimente het die HEU-groep ʼn verhoogde vatbaarheid vir apoptose getoon na aanleiding van die ekspressie van Annexin V op CD4+ T-selle ná 16 uur van inkubasie op sowel 18 as 24 maande. Op 18 en 24 maande was immuunregulering, aan die hand van die ekspressie van CTLA-4, bykans dieselfde by albei groepe. Op sowel 18 as 24 maande toon die HEU’s verhoogde ekspressie van die sellulêre merker van immuunaktivering CD80 op CD20+ B-selle. Op 24 maande het die HEU’s ook aansienlik hoër vlakke van CD69 by CD19+ B selle getoon. Op nóg 18 nóg 24 maande was die ekspressie van CD62L en CD10 statisties beduidend. Hoewel verhoogde vlakke van apoptose (Fas) by CD20+ B-selle by die HEU-groep opgemerk is, was dit nie statisties beduidend op 18 óf 24 maande nie. Daarbenewens was daar ook geen verskil in die ekspressie van geprogrammeerde seldood 1 (PD-1) op 18 en 24 maande nie. Op 18 en 24 maande het die HEU’s en UE’s ʼn soortgelyke ekspressie van Annexin V ná 16 uur van inkubasie getoon. Op sowel 18 as 24 maande was die twee groepe se ekspressie van die biomerker van B-selgeheue CD27 op CD20+ B- en CD19+ B-selle vergelykbaar. Gevolgtrekking: Op twee en ses weke dui laer gemiddelde teenliggaamreaksies by HEU’s op swak plasentale oordrag weens die moeder se MIV-infeksie, terwyl verhoogde reaksies op bepaalde teenliggame weer op oordrewe immuunreaksie op inenting dui. Hierdie robuuste reaksie kan toegeskryf word aan die gebrek aan mededinging met die moeder se teenliggame, of kan deur indirekte stimulasie van die B-selle via die aktivering van die T-selle veroorsaak word. ʼn Hiperinflammatoriese toestand is ʼn dreigende gevaar, met verhoogde ekspressie van sellulêre merkers van immuunaktivering en apoptose wat met vroeë MIV-blootstelling met ʼn latere nawerking verbind kan word. Hierdie waarnemings kan bydraende faktore wees tot HEU’s se goed gedokumenteerde verhoogde vatbaarheid vir infeksies. Hoewel hierdie bevindings met ʼn geaktiveerde immuunstelsel strook, moet groter studies dit aan die hand van kliniese uitkomste bevestig en ook bepaal of hierdie verskille in later jare voortduur. / The Harry Crossley Foundation, Poliomyelitis Research Foundation (PRF) / NHLS Research Grant Trust

Thesis (MMed (Pathology. Forensic Medicine))--University of Stellenbosch, 2010. / Bibliography / ENGLISH ABSTRACT: Background - The workload of the forensic pathologist and Forensic Pathology Services staff is increased by the referral of potentially unnecessary natural cases to the Forensic Pathology Services. The primary aims of the medico-legal autopsy are limited to establishing a cause of death in presumed unnatural cases, and to exclude criminality or negligence. Objective – To determine the final outcomes of forensic post-mortem examinations in “sudden and unexpected” adult deaths over a 5 year period. Methods - An observational, retrospective, descriptive study was conducted. ”Sudden and unexpected” adult deaths referred to Tygerberg Forensic Pathology Services between 1 January 2001 and 31 December 2005 were reviewed. Data was collected from the autopsy reports, contemporaneous notes and hospital records. Findings – A total of 816 adult cases of sudden and unexpected death were referred to Tygerberg Forensic Pathology Services over the 5 year period studied. Complete autopsies had been performed in 74% (601/816) of cases. The presumed manner of death was natural in 79 % of cases, and an increase in the number of natural cases autopsied per year was noted over the 5-year study period. Diseases of the cardiovascular, respiratory and central nervous systems were responsible for the majority of natural deaths. Infectious diseases were responsible for most deaths in the youngest age group studied (18-29 years). Acute alcohol poisoning was responsible for the deaths of 35 (6%) cases, with an average blood alcohol concentration of 0.38g/100mL in these cases. Eight deaths were drug-/substance related. Waiting times for blood alcohol and toxicology results increased over the 5-year study period. No cause of death was found in 10.6% of cases. Conclusions -The questionnaire and interviewing structure could possibly be improved in order to obtain better pre-autopsy information and to reduce the number of “unnecessary” medicolegal autopsies, thereby reducing the burden of cost on the Forensic Pathology Services. / AFRIKAANSE OPSOMMING: Agtergrond – Die werkslading van die forensiese patoloog en ander personeel van die Forensiese Patologie Dienste word vermeerder deur die verwysing van moontlik onnodige natuurlike gevalle na die Forensiese Patologie Dienste. Die primêre doelwitte van die medies-geregtelike nadoodse ondersoek is beperk tot die bepaling van ‘n oorsaak van dood in vermoedelik onnatuurlike gevalle, en om nalatigheid of kriminele aksies uit te skakel. Doelwit – Om die finale uitkomste van medies-geregtelike nadoodse ondersoeke in “skielike en onverwagte” volwasse sterftes oor ‘n 5-jaar tydperk te bepaal. Metodes – ‘n Observasionele, retrospektiewe, beskrywende studie is uitgevoer. “Skielike en onverwagte” volwasse sterftes wat verwys is na Tygerberg Forensiese Patologie Dienste vanaf 1 Januarie 2001 tot 31 Desember 2005 is hersien. Inligting is versamel vanaf die nadoodse ondersoekverslae, kontemporêre notas en hospitaalnotas. Bevindinge – Agthonderd en sestien volwasse gevalle van skielike en onverwagte sterftes is oor die 5-jaar periode verwys na Tygerberg Forensiese Patologie Dienste. Volledige lykskouings is uitgevoer in 74% (601/816) van die gevalle. Die vermoedelike wyse van die sterfte was natuurlik in 79.04% en ‘n toename in die aantal natuurlike gevalle wat lykskouings ondergaan het, is waargeneem oor die 5-jaar studie tydperk. Siektes van die kardiovaskulêre, respiratoriese en sentrale senuweestelsel was verantwoordelik vir die meerderheid natuurlike sterftes. Infektiewe toestande was verantwoordelik vir die meeste sterftes in die jongste ouderdomsgroep (18-29 jaar) wat bestudeer is. Akute alkoholvergiftiging was verantwoordelik vir die sterftes van 35 (6%) gevalle, met ‘n gemiddelde bloed-alkohol-konsentrasie van 0.38g/100mL in hierdie gevalle. Agt sterftes was dwelm-/middelverwant. Die wagtyd vir bloed-alkohol en toksikologie resultate het vermeerder oof die 5-jaar studie tydperk. Die oorsaak van dood was nie gevind in 10.6% van gevalle. Afleidings – Die vraelys en onderhoud-struktuur kan moontlik verbeter word om sodoende beter inligting te verkry voor die uitvoering van ‘n lykskouing, en om die aantal “onnodige” medies-geregtelike nadoodse ondersoeke te verminder, en sodoende die kostedruk te verminder op die Forensiese Patologie Dienste.