Tuberculosis (TB) has re-emerged as a major worldwide public health hazard with increasing incidence among adults and children. Although cases among children represent a small percentage of all TB cases, they are a reservoir from which many adult cases will arise. Estimates indicate that 9 million people develop TB annually, out of which 1 million (11 percent) occur in children less than 15 years old. Childhood tuberculosis is on the increase worldwide because of persisting inability to conform the diagnosis, leading to a large number of children dying of undiagnosed tuberculosis. Diagnosis of pulmonary tuberculosis has depended on bacteriological examination of sputum. In most of the developing countries sputum smear microscopy has been used as it has been found to be cheap and relative efficient. As a result of the high TB burden, there is an urgent need for improved methods of laboratory diagnosis of TB. This is especially needed in children were diagnosis is more challenging as mycobacteria is being detected in fewer than 50 percent of the cases. Children cannot produce adequate sputum samples for examination. Their sputum samples, if produced, has a low bacterial yield and making detection of mycobacteria by using the smear microscopy difficult. Therefore, gastric lavages from children are being recommended as the best specimen for culture. In this study, gastric lavages from 408 children suspected of having tuberculosis were examined for the recovery of mycobacteria. Recovery was optimized by the use of the relatively new non-radiometric fully automated BACTEC MGIT 960. BACTEC MGIT 960 produced a positivity rate of 27.2 percent against 17.2 percent that of Lowenstein-Jensen (L-J) media, which is a conventional culture method used widely. The direct microscopy which is the cheapest traditional method used in diagnosis of tuberculosis (TB) yielded a 5.6 percent positive rate. The BACTEC MGIT 960 had also a very high isolate detection rate of 98.2 percent compared to that of L-J media of 61.9 percent, and only 20.4 percent were detected with the direct microscopy. On time taken to detection or mean time to detection (TTD) of v isolates, the BACTEC MGIT 960 technique had a shorter mean time to detection, 12.5 days as compared to 34.3 days shown by the L-J media technique. The study showed that children normally get tuberculosis from adult members of the household. A positive TB case was found in the households of 55.4 percent of the suspects. The study has found that 46.4 percent of the children below the age of 4 years developed the disease, compared to 10.5 percent the older children in the age group 10 to 14 years. The study found that tuberculosis in children is mainly caused by Mycobacterium tuberculosis. Out of the 113 isolates detected, 110 (97.3 percent) were M. tuberculosis. The remaining 2.7 percent were the non-tuberculous M. avium complex and M. kansasii. It was inconclusive whether the 2.7 percent of other species were causing tuberculosis and this need to be studied further.

Thesis (PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Tuberculosis (TB) in children is a common infectious disease in the world affecting approximately 550 000 children annually and contributing to approximately 10-15% of the TB caseload. The estimate is that 75% of the children who have TB live in the 22 countries that have the highest burden of TB disease. In these 22 countries, the technology required to make the diagnosis and manage complicated cases is limited. The epidemiological data required to estimate the proportion of children with severe disease requiring intervention at a global level are lacking. Airway involvement is commonly seen in children with primary TB, but only in a small group of children the compression is severe, needing intervention. The incidence of children with airway obstruction requiring intervention due to primary TB in the chemotherapeutic era is not known. The incidence of complicated lymph node disease in two recent reports varied from 8-38% in children younger than 15 years of age. Flexible bronchoscopy (FB) is an invasive procedure performed under general anesthetic is used to assess the airways of children. Few studies have been published on the use of FB in the diagnosis of paediatric TB and most have concentrated on the use of bronchoscopy as an intervention for obtaining samples to diagnose pulmonary TB (PTB). All previous studies only examined broncho-alveolar lavage (BAL) for Ziehl Neelsen (ZN) positive organisms and mycobacterial culture. All the published studies are from developed countries with a very low incidence of PTB in children. It has been postulated that HIV positive children with TB are more likely to have airway obstruction, but this hypothesis has not been studied. The same is true for children infected with drug-resistant strains of tuberculosis. Similarly, there have been few reports on the correlation between the findings at bronchoscopy and those found on chest computer tomography (CT). The aim of this research project was to systematically determine airways involvement in childhood pulmonary TB and assess the role paediatric bronchoscopy plays in the diagnosis, sample collection and the management of severe airway obstruction. The first part of the thesis describes the bronchoscopic assessment of airway obstruction due to pulmonary TB in children, specifically concentrating on the areas of the airway involved and the severity of the obstruction. We investigated which factors determine the severity of airway obstruction and this included age, sex, HIV status and drug sensitivities. We have shown that there was no difference in airway obstruction in HIV positive children and in children with drug resistance TB. More severe airway obstruction was seen in the younger child. The second question that was analysed is the value of flexible bronchoscopy in collecting samples for TB culture and drug sensitivity testing. It has previously been reported that BAL culture was inferior to gastric lavage in isolating the bacilli. We set out to evaluate which factors determine if a child will be culture-positive on BAL. Most childhood pulmonary TB is postulated to have a low yield of ZN positive cases. We found a higher yield from BAL as was previously reported, and the yield was increased if segmental or lobar pneumonia was present on the chest radiography. We developed novel interventions of finding the organism and increasing the yield from BAL. About 80% of children with PTB have enlarged subcarinal lymph nodes. We performed a trans-bronchial needle aspiration (TBNA) biopsy of these lymph nodes for culture. This technique enables us to differentiate the cause of enlarged mediastinal lymph nodes. This is especially important in children who are HIV positive, as they are prone to have other causes of enlarged lymph nodes. We successfully performed TBNA, even in very young infants, which resulted in a diagnostic yield of 55%. The use of Xpert has been described on other tissue, but not on BAL. We wanted to test if the use of Xpert on BAL is feasible in children, and determine if it will increase the diagnostic yield by using BAL samples. The third aspect of this research was to compare flexible bronchoscopy findings with those of chest CT scan finding. Firstly, the aim was to describe the CT scan findings of mediastinal glands and lungs in children with significant airway obstruction due to PTB. The second aim was to investigate how these two investigations of airway obstruction compared, with particular emphasis on their advantages and disadvantages. The areas of airway obstruction as well as the severity of the obstruction as determined by CT scan were very similar to the findings with bronchoscopy. The final part under this aspect of the study was to analyze airway shape using a computer model to asses if this could predict TB. This was done by extracting components of the airway surface mesh and branch radius and orientation features. This method showed the potential of computer-assisted detection of TB and other airway pathology by using airway shape deformation analysis. The fourth aspect investigated was to determine which children with severe airway obstruction would benefit from a surgical intervention. Surgical enucleation is done via a lateral thoracotomy in children with severe airway obstruction. We investigated which factors determine the need for surgical enucleation, the optimal timing of this intervention, and – if surgical enucleation was done as an emergency intervention – which factors would predict for this. The combination of trachea, left main bronchus and bronchus intermedius involvement was the best predictor for children requiring surgical enucleation. Involvement of the smaller airway divisions did not play a significant role. Children needing enucleation were younger and had more severe airway obstruction. The fifth aspect of this thesis was to measure the outcome following surgical enucleation. Measurements used included clinical measurements, radiological measurements and bronchoscopy. The response in children treated surgically were compared to those treated medically by estimating airway size with flexible bronchoscopy. Both groups showed significant improvement with the magnitude of improvement greater in those surgically treated. We have demonstrated in this thesis that the site and severity of severe airway obstruction can be assessed by either bronchoscopy or chest CT scan. Approximately one third of children with severe airway compression due to TB lymph nodes can be successfully treated surgically with a low morbidity and mortality. / AFRIKAANSE OPSOMMING: Tuberkulose (TB) by kinders is wêreldwyd ’n algemene siekte wat jaarliks ongeveer 550 000 kinders raak en sowat 10-15% van die algehele TB-siektelas uitmaak. Na raming kom 75% van alle kinders met TB van die 22 lande met die hoogste TB-siektelas. Hierdie 22 lande beskik oor beperkte tegnologie om die siekte te diagnoseer en ingewikkelde gevalle te bestuur. Die vereiste epidemiologiese data om te raam watter persentasie kinders wêreldwyd ernstig siek is en intervensie vereis, ontbreek ook. Lugwegaantasting word algemeen by kinders met primêre TB aangetref. Tog is die kompressie by slegs ’n klein groepie kinders so erg dat dit intervensie vereis. Die voorkoms van kinders in die chemoterapeutiese era met primêre-TB-verwante obstruksie van die lugweë wat intervensie vereis, is onbekend. In twee onlangse verslae het die voorkoms van gekompliseerde limfkliersiekte by kinders jonger as 15 jaar van 8% tot 38% gewissel. Buigbare brongoskopie is ’n indringende prosedure wat onder algemene verdowing uitgevoer word om kinders se lugweë te ondersoek. ’n Paar studies is reeds gepubliseer oor die gebruik van buigbare brongoskopie om pediatriese TB te diagnoseer. Die meeste daarvan het gekonsentreer op die gebruik van brongoskopie as intervensie vir die insameling van monsters om pulmonêre TB (PTB) te diagnoseer. Alle vorige studies het uitsluitlik ondersoek ingestel na brongo-alveolêre spoeling (BAS) vir die opsporing van Ziehl Neelsen- (ZN-)positiewe materiaal en vir kweking. Geen ander diagnostiese tegnieke is tot dusver ondersoek nie, wat die waarde daarvan vir populasies met ’n hoë siektelas beperk. Boonop is alle gepubliseerde studies in ontwikkelde lande met ’n baie lae voorkoms van PTB by kinders onderneem. Daar word aangevoer dat MIV-positiewe kinders met TB meer waarskynlik aan obstruksie van die lugweë sal ly, hoewel hierdie hipotese nog nie bestudeer is nie. Dieselfde geld vir kinders wat aan middelweerstandige vorme van TB ly. Daar is ook weinig verslae oor die verband tussen die bevindinge van brongoskopie en dié van rekenaartomografie (RT) van die borskas. Die doel van hierdie navorsing was om stelselmatig vas te stel hoe pulmonêre TB by kinders die lugweë aantas, en watter rol pediatriese brongoskopie in diagnose, monsterinsameling en die hantering van ernstige obstruksie van die lugweë speel. Die eerste deel van die tesis beskryf die brongoskopiese voorkoms van PTB-verwante obstruksie van die lugweë, met bepaalde klem op die aangetaste dele van die lugweg en die erns van die obstruksie. Daar is ondersoek ingestel na watter faktore die erns van die obstruksie bepaal, onder meer ouderdom, geslag, MIV-status en middelsensitiwiteit. Die resultate toon geen verskil in obstruksie by MIV-positiewe kinders en kinders met middelweerstandige TB nie, hoewel ernstiger obstruksie van die lugweë by die jonger kind opgemerk is. Die tweede kwessie wat ontleed is, is die waarde van buigbare brongoskopie in die verkryging van monsters vir TB-kweking en toetse vir middelsensitiwiteit. Daar is voorheen aangemeld dat BAS-kweking minder doeltreffend is as gastriese spoeling om die basille te isoleer. Hierdie studie was daarop toegespits om te beoordeel watter faktore bepaal of ’n kind kwekingspositief met BAS sal wees. Die meeste PTB by kinders toon na bewering ’n lae opbrengs van ZN-positiewe gevalle. Tog het BAS in hierdie studie ’n hoër opbrengs gehad as wat voorheen aangemeld is, welke opbrengs hoër was met die aanwesigheid van segmentale of lobêre pneumonie op die borskasradiogram. Innoverende intervensies is ontwikkel om die organisme op te spoor en die opbrengs met BAS te verhoog. Sowat 80% van kinders met PTB het vergrote subkarinale limfkliere. ’n Transbrongiale naaldaspirasie- (TBNA-)biopsie is gevolglik vir die doeleinde van kweking op hierdie kliere uitgevoer. Hierdie tegniek het die navorser in staat gestel om tussen die verskillende oorsake vir vergrote mediastinale limfkliere te onderskei. Dít is veral belangrik by MIVpositiewe kinders, wat geneig is om ander oorsake vir vergrote limfkliere te toon. Die TBNA-biopsies is selfs by baie jong babas suksesvol uitgevoer, wat tot ’n diagnostiese opbrengs van 55% gelei het. Die gebruik van Xpert op ander weefsel as BAS is al voorheen beskryf. Die navorser wou dus vasstel of die gebruik van Xpert by BAS haalbaar is by kinders, en of dit die diagnostiese opbrengs deur die gebruik van BAS-monsters sal verhoog. Die derde aspek van hierdie navorsing was om die bevindinge van buigbare brongoskopie met dié van RT-skanderings van die borskas te vergelyk. Die doel was eerstens om die bevindinge van die RT-skanderings van mediastinale kliere en longe by kinders met beduidende PTB-verwante lugweg-obstruksie te beskryf. Tweedens wou die navorser vasstel wat die verskille tussen hierdie twee ondersoeke van lugweg-obstruksie is, met bepaalde klem op die voordele en nadele daarvan. Die RT-skandering en die bevindinge van brongoskopie lewer betreklik soortgelyke resultate op wat die aangetaste gedeeltes van die lugweg sowel as die erns van sodanige obstruksie betref. Die laaste doel onder hierdie studieaspek was om die vorm van die lugweg met behulp van ’n rekenaarmodel te ontleed om te bepaal of dit TB kan voorspel. Dít is gedoen deur komponente van die die erns van die obstruksie. Daar is ondersoek ingestel na watter faktore die erns van die obstruksie bepaal, onder meer ouderdom, geslag, MIV-status en middelsensitiwiteit. Die resultate toon geen verskil in obstruksie by MIV-positiewe kinders en kinders met middelweerstandige TB nie, hoewel ernstiger obstruksie van die lugweë by die jonger kind opgemerk is. Die tweede kwessie wat ontleed is, is die waarde van buigbare brongoskopie in die verkryging van monsters vir TB-kweking en toetse vir middelsensitiwiteit. Daar is voorheen aangemeld dat BAS-kweking minder doeltreffend is as gastriese spoeling om die basille te isoleer. Hierdie studie was daarop toegespits om te beoordeel watter faktore bepaal of ’n kind kwekingspositief met BAS sal wees. Die meeste PTB by kinders toon na bewering ’n lae opbrengs van ZN-positiewe gevalle. Tog het BAS in hierdie studie ’n hoër opbrengs gehad as wat voorheen aangemeld is, welke opbrengs hoër was met die aanwesigheid van segmentale of lobêre pneumonie op die borskasradiogram. Innoverende intervensies is ontwikkel om die organisme op te spoor en die opbrengs met BAS te verhoog. Sowat 80% van kinders met PTB het vergrote subkarinale limfkliere. ’n Transbrongiale naaldaspirasie- (TBNA-)biopsie is gevolglik vir die doeleinde van kweking op hierdie kliere uitgevoer. Hierdie tegniek het die navorser in staat gestel om tussen die verskillende oorsake vir vergrote mediastinale limfkliere te onderskei. Dít is veral belangrik by MIVpositiewe kinders, wat geneig is om ander oorsake vir vergrote limfkliere te toon. Die TBNA-biopsies is selfs by baie jong babas suksesvol uitgevoer, wat tot ’n diagnostiese opbrengs van 55% gelei het. Die gebruik van Xpert op ander weefsel as BAS is al voorheen beskryf. Die navorser wou dus vasstel of die gebruik van Xpert by BAS haalbaar is by kinders, en of dit die diagnostiese opbrengs deur die gebruik van BAS-monsters sal verhoog. Die derde aspek van hierdie navorsing was om die bevindinge van buigbare brongoskopie met dié van RT-skanderings van die borskas te vergelyk. Die doel was eerstens om die bevindinge van die RT-skanderings van mediastinale kliere en longe by kinders met beduidende PTB-verwante lugweg-obstruksie te beskryf. Tweedens wou die navorser vasstel wat die verskille tussen hierdie twee ondersoeke van lugweg-obstruksie is, met bepaalde klem op die voordele en nadele daarvan. Die RT-skandering en die bevindinge van brongoskopie lewer betreklik soortgelyke resultate op wat die aangetaste gedeeltes van die lugweg sowel as die erns van sodanige obstruksie betref. Die laaste doel onder hierdie studieaspek was om die vorm van die lugweg met behulp van ’n rekenaarmodel te ontleed om te bepaal of dit TB kan voorspel. Dít is gedoen deur komponente van die lugwegoppervlaknetwerk en vertakkingsradius- en oriëntasiekenmerke te onttrek. Hierdie metode het daarop gedui dat rekenaargesteunde opsporing van TB en ander lugwegpatologie deur middel van ’n ontleding van lugwegvervorming wél potensiaal toon. Die vierde aspek was om te bepaal watter kinders met ernstige obstruksie van die lugweë by intervensie sal baat vind. By sulke kinders word chirurgiese enukleëring deur ’n laterale torakotomie uitgevoer. Die studie het ondersoek ingestel na watter faktore die behoefte aan chirurgiese enukleëring bepaal, wat die optimale tyd vir sodanige intervensie sou wees, en – indien chirurgiese enukleëring as noodintervensie uitgevoer word – watter faktore so ’n noodintervensie sou vereis. Die kombinasie van aantasting van die tragea, linkerhoofbrongus en brongus intermedius was die beste voorspeller van kinders wat chirurgiese enukleëring benodig. Aantasting van die kleiner lugwegverdelings het nie ’n beduidende rol gespeel nie. Kinders wat enukleëring vereis, was jonger en het aan ernstiger obstruksie van die lugweë gely. Die vyfde aspek van hierdie tesis was om die uitkoms na afloop van chirurgiese enukleëring te meet. Kliniese metings, radiologiese metings en brongoskopie is hiervoor gebruik. Die reaksie by kinders wat chirurgies behandel is, is vergelyk met diegene wat medies behandel is deur lugweggrootte met behulp van buigbare brongoskopie te raam. Albei groepe het beduidende verbetering getoon. In die studie het ons getoon dat die ligging en die erns van ernstige lugwegobstruksie kan geassesseer word deur óf brongoskopie of rekenaartomografie van die borskas. Ongeveer een derde van kinders met 'n ernstige lugweg-obstruksie weens TB limfkliersiekte kan suksesvol chirurgies met 'n lae morbiditeit en mortaliteit behandel word.

Dissertation (PhD)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Children contribute little to disease transmission and the maintenance of the tuberculosis epidemic, but they constitute a significant proportion of the total tuberculosis (TB) caseload and experience considerable morbidity and mortality in endemic areas, despite the availability of cheap and effective treatment. The difficulty of diagnosing childhood tuberculosis is one of the major obstacles that hinder the provision of antituberculosis treatment to children in endemic areas. The diagnosis of childhood tuberculosis is complicated by the lack of a practical gold standard, as bacteriologic specimens are difficult to collect and the yield is low. In non-endemic countries the diagnosis of childhood tuberculosis is based on the triad of: 1) exposure to an adult index case, 2) a positive tuberculin skin test, and 3) suggestive radiographic signs. However, the triad has limited value in endemic areas where exposure to and/or infection with Mycobacterium tuberculosis is common, and chest radiography is rarely available. The objective of this dissertation was to address the diagnostic dilemma faced by health professionals in endemic areas with limited resources, where children currently have poor access to chemoprophylaxis and antituberculosis treatment. We first clarified basic disease concepts, through a critical review of the pre-chemotherapy literature that documented the natural history of childhood tuberculosis. Three central concepts were identified; 1) the importance of accurate case definition, 2) the relevance of risk stratification, and 3) the diverse spectrum of disease, which necessitates accurate disease classification. The importance of accurate case definition is illustrated by the fact that isolated hilar adenopathy, considered the principal radiographic sign of primary tuberculosis, becomes transiently visible in the majority of children following recent primary infection. Our analysis of the natural history of childhood tuberculosis allowed accurate quantification of the risk to progress to disease following primary infection with M.tuberculosis. This demonstrated that the risk depends mainly on the age and/or immune-status of the child, the time since primary infection occurred and the presence or absence of symptoms. After analysing these historic studies, we proceeded to document the burden of childhood tuberculosis in an endemic area. We first conducted a retrospective study to describe current diagnostic practices and demonstrated almost exclusive reliance on chest radiography. We then calculated the burden of childhood tuberculosis in a prospective descriptive study. The corrected tuberculosis incidence rate in children was 407/100 000/year and children with severe forms of disease, such as disseminated (miliary) tuberculosis and/or tuberculous meningitis, were rarely recorded in the TB treatment register used for routine community-based surveillance. An additional obstacle to progress in the field of childhood tuberculosis has been the lack of standard descriptive terminology. Following a careful review of the literature, we proposed a radiological classification of childhood intra-thoracic tuberculosis and explored the different pathologic mechanisms that underlie these diverse disease manifestations. We then conducted a prospective descriptive study to document the disease spectrum in children treated for tuberculosis in an endemic area. The disease patterns observed were consistent with those described in the pre-chemotherapy literature. In addition, we demonstrated that bacteriologic confirmation may be achieved in the majority of children with intra-thoracic tuberculosis, in highly endemic settings. Finally we developed a novel symptom-based approach to diagnose pulmonary tuberculosis in children from endemic areas with limited resources. We followed a step-wise approach by first conducting a community-based survey to document the prevalence of symptoms traditionally associated with tuberculosis in a random selection of children from an endemic area. The survey demonstrated that poorly defined symptoms offer poor diagnostic value. The second step was to evaluate the diagnostic value of well-defined (persistent, non-remitting) symptoms in a small prospective study. Well-defined symptoms demonstrated good diagnostic value, but these promising results required further validation. As a final step, we validated the diagnostic value of a novel symptom-based approach in a large prospective, community-based study. In this study, a simple symptom-based approach diagnosed childhood pulmonary tuberculosis with a remarkable degree of accuracy, particularly in HIV-uninfected children older than 3 years of age. This novel diagnostic approach offers the exciting prospect of extending antituberculosis treatment to children in endemic areas with limited resources, where current treatment access is poor. / AFRIKAANSE OPSOMMING: Tuberkulose beheer programme plaas feitlik geen klem op die behandeling van kinders nie, omdat kindertuberkulose selde aansteeklik is en die persepsie bestaan dat kinders slegs in raar gevalle ernstig siek word. Tuberkulose lewer egter ‘n betekenisvole bydrae tot kindermorbiditeit en mortaliteit in endemiese areas, terwyl dit ‘n maklik behandelbare siekte is. Kindertuberkulose is moeilik om te diagnoseer en dit is ‘n belangrike faktor wat daartoe bydra dat kinders dikwels nie antituberkulose behandeling ontvang wanneer hulle dit benodig nie. Die diagnose van kindertuberkulose is moeilik, omdat die organisme selde aangetoon kan word. In nie endemiese areas word kindertuberkulose dikwels gediagnoseer na aanleiding van: 1) blootstelling aan ‘n volwasse indeks geval, 2) ‘n positiewe tuberkulien veltoets, en 3) die teenwoordigheid van radiologiese tekens suggestief van tuberkulose. Hierdie benadering het defnitiewe tekortkominge in endemiese areas, waar blootstelling aan en infeksie met Mycobacterium tuberculosis algemeen is. Gevolglik berus die diagnose van kindertuberkulose hoofsaaklik op die subjektiewe interpretasie van die borskasplaat, wat welbekende tekortkominge het en verder is radiologiese toetse dikwels nie beskikbaar in hierdie areas nie. Die doel van die navorsingsprojek was om die dilemma rondom die diagnose van kindertuberkulose in endemiese areas aan te spreek. Eerstens is basiese siektekonsepte uitsorteer deur ‘n kritiese oorsig van studies uit die pre-chemoterapie era. Hierdie kosbare studies het die natuurlike verloop van tuberkulose in kinders beskryf, nog voordat antituberkulose middels beskikbaar was. Drie sentrale konsepte is geidentifiseer; 1) die belang van akkurate siekte definisie, 2) die relevansie van risiko stratifikasie en 3) die diverse spektrum van patologie wat akkurate siekte klassifikasie noodsaak. Die belang van akkurate siekte definisie word geïllustreer deur die feit dat geïsoleerde hilêre adenopatie ‘n verbygaande verskynsel is in die meerderheid van kinders kort na primêre infeksie. Ons analise het daarop gefokus om die risiko om siekte te ontwikkel nadat primêre infeksie met M.tuberculosis plaasgevind het, te kwantifiseer. Die hoof risiko faktore was; 1) die ouderdom en/of immuunstatus van die kind, 2) die tydsverloop sedert infeksie, en 3) die teenwoordigheid van simptome al dan nie. Hierna het ons die siektelas wat tuberkulose vandag op kinders in endemiese areas plaas gedokumenteer. Ons het eers die huidige diagnostiese praktyke geëvaluaeer in ‘n retrospektiewe studie en toe ‘n prospektiewe beskrywende studie gedoen om die siektelas so akkuraat as moontlik te meet. Die insidensie van kindertuberkulose was hoog (>400/100 000/jaar), selfs na korreksie vir kinders wat ontoepaslik behandeling ontvang het. Verder is gevind dat die meerderheid van kinders met ernstige siekte toestande soos miliêre tuberkulose en/of meningitis, nie in roetine moniterings data reflekteer word nie. ‘n Bykomende struikelblok in kindertuberkulose is die gebrek aan standaard beskrywende terminologie. Om dit te bevorder ontwikkel ons ‘n nuwe radiologiese klassifikasie van intra-torakale kindertuberkulose en beskryf ons die verskillende patologiese meganismes onderliggend tot hierdie uiteenlopende siektebeelde. Daarna dokumenteer ons die volledige spektum van kindertuberkulose in ‘n endemiese area en demonstreer dat die siektepatrone wat ons vandag observeer soortgelyk is aan die wat in die pre-chemoterapie literatuur beskryf is. Ons toon ook dat bakteriologiese bevestiging moontlik blyk te wees in die meerderheid van kinders wat vir intra-torakale tuberkulose behandel word in endemiese areas. Nadat ons duidelikheid verkry het oor die basiese siektekonsepte, siekte klassifikasie en die siektelading in ons omgewing, kon ons op die ontwikkeling van ‘n simptoom-gebaseerde benadering tot die diagnose van kindertuberkulose fokus. Ons het ‘n stapsgewyse benadering gevolg. Die eerste stap was om die voorkoms van simptome wat gebruiklik met tuberkulose vereenselwig word te dokumenteer in ‘n ewekansige groep kinders. Die gemeenskapsopname het getoon dat swak gedefiniëerde simptome swak diagnostiese waarde bied. Die tweede stap was om vas te stel of verbeterde simptoom definisie die diagnostiese waarde kan verbeter. ‘n Klein prospektiewe studie het getoon dat goed gedefiniëerde simptome (persisterende simptome van onlangse aankoms) goeie diagnostiese waarde bied. Die finale stap was om hierdie belowende benadering formeel te toets in ‘n groot prospektiewe, gemeenskapsgebaseerde studie. Hierdie studie het getoon dat ‘n eenvoudige simptoom-gebaseerde benadering pulmonale tuberkulose met goeie akkuraatheid kan diagnoseer, veral in HIV-ongeïnfekteerde kinders wat ouer is as 3 jaar. Hierdie nuwe diagnostiese benadering bied die moontlikheid om antituberkulose behandeling te voorsien aan kinders in endemiese areas wat tans feitlik geen behandeling ontvang nie.

Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: Please see fulltext for abstract. / AFRIKAANSE OPSOMMING: Sien asb volteks vir opsomming.

Thesis (MD)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Resistance to antituberculosis agents became evident soon after antituberculosis treatment was introduced for the first time. Combined drug therapy seemed to resolve this problem. Animal experimental studies, which showed that isoniazid (INH)-resistant strains of Mycobacterium tuberculosis were less infectious and pathogenic than drugsusceptible strains, gave further reassurance that drug resistance was not a major issue. Transmission of INH- and multiple-drug-resistant strains did, however, occur. Studies in children, who develop mainly primary drug resistant tuberculosis (TB), showed that drug resistance in adults was followed by a similar rise in drug-resistant (TB) in children, and that tuberculous infection rates in childhood contacts of INHresistant and drug-susceptible adult TB cases were the same. It was however, only after the significant rise in the incidence of TB and large outbreaks of multidrug-resistant (MDR) TB cases in developed countries (mainly because of the human immunodeficiency virus epidemic) in the early nineties that sufficient attention was again focussed on the problem of drug-resistant TB. Drugresistant tuberculosis, and more in particular MDR TB, posed a serious threat to global TB control programmes. Despite this renewed interest, childhood drug-resistant TB remained neglected. The incidence of drug-resistant TB among children, which could give a good indication of currently circulating strains in a community, is hardly known. The management of childhood contacts of adults with infectious MDR TB or children with MDR TB has also not been studied prospectively. All confirmed childhood TB cases from a specific geographic drainage area over a 3.5-year period were prospectively included in a drug resistance surveillance study. The incidence of drug resistance in children was comparable to the incidence of initial (primary plus undisclosed previous treatment) drug resistance documented in adults in the same area. The findings show that the incidence of drug-resistant TB in children in the Western Cape province is low, and probably reflects the level of primary drug resistance amongst organisms currently circulating in this community. The short- and long-term outcome of children <5 years of age in contact with infectious adult MDR TB cases was determined by prospective follow-up for 30 months. The initial evaluation showed an infection rate significantly higher in MDR TB contacts compared with contacts of drug susceptible cases, but the disease rate was lower. On follow-up, many more children became infected or developed disease. The finding that 90% of those who developed disease did so within the first 12 months, indicates that follow-up beyond 12 months is probably not cost-effective in resource poor countries. The results demonstrate that MDR TB is not less infectious than drug susceptible TB. Despite the fact that some children received chemoprophylaxis, 24% of the children eventually developed disease. This is not different from the expected prevalence of disease in childhood contacts <5 years of age of infectious drug-susceptible adult pulmonary TB cases. Restriction fragment length polymorphism analysis confirmed transmission from an adult source case to a child contact in 5 of 6 adult-child pairs in whom both isolates were available. If therefore an isolate of M tuberculosis for susceptibility testing cannot be obtained from a child in close contact with an infectious MDR TB case, the child should therefore be treated according to the drug susceptibility pattern of the source case's strain. Treatment of children with confirmed and probable MDR TB included 2 or 3 drugs to which the adult source case's isolate was susceptible in addition to pyrazinamide and high-dose INH. Duration of treatment ranged from 6 to 12 months depending on the severity of the disease. INH was included in the treatment regimen because low-level resistance to INH was present in about half the cases of primary INH resistance. The pharmacokinetics of INH in children confirmed that an adequate concentration and exposure time could be achieved for this purpose. Ethionamide often caused gastrointestinal adverse events, but these could be overcome in most cases by temporary dose adjustments. The fluoroquinolones, which are not generally recommended for use in children, possibly caused arthralgia in 1 of the17 children treated for ~6 months. This is in accordance with previous reports of the safety of these drugs in children for short- and medium-term treatment. TB disease occurred significantly less often in children who received appropriate chemoprophylaxis (according to the drug susceptibility pattern of the adult source case's isolate). Although this was not a randomised controlled trial, the group that received chemoprophylaxis was at higher risk for developing disease. This implies that prevention of TB in MDR contacts is possible. A prospective, randomised controlled study is necessary to evaluate the best drug combinations and the optimal duration of such chemoprophylactic regimens. / AFRIKAANSE OPSOMMING: Middelweerstandigheid het na vore gekom kort nadat antituberkulose behandeling vir die eerste keer in gebruik geneem is. Die gekombineerde gebruik van middels het klaarblyklik die probleem oorkom. Diere eksperimente wat getoon het dat isoniasied (INH)-weerstandige stamme van Mycobacterium tuberculosis minder infektief en patogenies IS as vatbare stamme, het verdere gerustelling gegee dat middelweerstandigheid nie 'n groot probleem is nie. Die oordrag van INH- en multi-middelweerstandige stamme het egter wel plaasgevind. Studies in kinders, wat hoofsaaklik primêre middelweerstandige tuberkulose (TB) ontwikkel, het getoon dat middelweerstandigheid in volwassenes gevolg is deur 'n soortgelyke toename in middelweerstandige TB in kinders en dat die voorkoms van tuberkuleuse infeksie in kinderkontakte van INH-weerstandige en middelvatbare volwasse TB gevalle dieselfde is. Dis egter eers toe daar 'n beduidende toename in die insidensie van TB en groot uitbrake van multimiddelweerstandige (MDR) TB gevalle in die ontwikkelde lande (hoofsaaklik as gevolg van die menslike immuungebrek virus epidemie) in die vroeë negentigerjare was dat daar opnuut aandag aan die probleem van weerstandige TB geskenk is. Middelweerstandige TB, en in besonder MDR TB, hou 'n ernstige bedreiging vir globale TB beheerprogramme in. Tenspyte van die nuwe belangstelling in middelweerstandige TB is die probleem in kinders steeds afgeskeep. Die insidensie van weerstandige TB in kinders is onbekend alhoewel dit 'n goeie weergawe van die huidig sirkuIerende stamme in 'n gemeenskap sou gee. Die hantering van kinderkontakte van volwassenes met infektiewe MDR TB of kinders met MDR TB is ook nog nie prospektiefbestudeer nie. Alle bevestigde kinder-TB gevalle van 'n spesifieke geografiese gebied is oor 'n 3.5 jaar tydperk prospektief in 'n middelweerstandige waarnemingstudie ingesluit. Die insidensie van middelweerstandigheid in kinders was vergelykbaar met die insidensie van inisiële (primêre weerstandigheid plus onbekende vonge behandeling) middelweerstandigheid in volwassenes van dieselfde gebied. Die bevindinge toon dat die insidensie van middelweerstandige TB in kinders in die Weskaap provinsie laag is. Dit weerspieël waarskynlik die vlak van primêre middelweerstandigheid in organismes wat tans in hierdie gemeenskap sirkuleer. Die kort- en langtermyn uitkoms van kinders <5 jaar oud wat in kontak met infektiewe volwasse MDR TB gevalle was, is prospektief tydens 'n 30-maande opvolg bepaal. Die aanvanklike evaluasie het 'n beduidend hoër infeksiekoers in die MDR TB kontakte in vergelyking met kontakte van middelvatbare gevalle getoon, maar die siektekoers was laer. Tydens die opvolgperiode het baie meer kinders infeksie of siekte ontwikkel. Aangesien 90% van dié wat siekte ontwikkel het, dit gekry het binne die eerste 12 maande, is opvolg ná 12 maande waarskynlik nie koste-effektief in hulpbronbeperkte lande nie. Die bevindinge toon dat MDR TB nie minder infektief is as middelvatbare TB nie. Tenspyte daarvan dat sommige kinders chemoprofilakse ontvang het, het 24% van die kinders uiteindelik siekte ontwikkel. Dit verskil nie van die verwagte siekte-insidensie van kinderkontakte <5 jaar oud wat in kontak met infektiewe volwasse middelvatbare pulmonale TB was nie. Restriksie fragment lengte polimorfisme analise het oordrag van volwasse brongeval na kinderkontak in 5 uit 6 volwasse-kind pare, van wie beide isolate beskikbaar was, bevestig. Indien daar dus nie 'n isolaat van M. tuberculosis vir vatbaarheidstoetse van 'n kind met nabye kontak met 'n infektiewe MDR TB geval beskikbaar is nie, behoort die kind volgens die middelvatbaarheidspatroon van die brongeval se stam behandel te word. Behandeling van kinders met bevestigde of waarskynlike MDR TB het 2 tot 3 middels waarvoor die volwasse brongeval se isolaat vatbaar was, ingesluit, tesame met pirasinamied en hoë-dosis INH. Die duur van behandeling het gewissel van 6 tot 12 maande op grond van die omvang van die siekte. INH is in die behandeling ingesluit omdat dit getoon is dat ongeveer die helfte van die gevalle met primêre INHweerstandigheid lae-vlak weerstandigheid het. Die farmakokinetika van INH in kinders het bevestig dat genoegsame vlakke en blootstellingstyd aan INH vir hierdie doel bereik kan word. Etionamied het dikwels gastrointestinale newe-effekte veroorsaak, maar dit kon in die meeste gevalle oorkom word. Die fluorokwinolone, wat nie oor die algemeen in kinders aanbeveel word nie, het moontlik artralgie veroorsaak in 1 uit 17 kinders wat vir ~6 maande behandel is, wat vorige verslae oor die veiligheid van hierdie middels in kort- en medium-termyn behandeling bevestig. TB-siekte het beduidend minder dikwels voorgekom in kinders wat toepaslike chemoprofilakse (volgens die middelvatbaarheidspatroon van die volwasse brongeval se isolaat) ontvang het. Alhoewel dit nie 'n ewekansig gekontroleerde studie was nie, het die groep wat chemoprofilakse ontvang het die hoogste risiko vir die ontwikkeling van siekte gehad. Dit dui daarop dat voorkoming van TB in MDR TB kontakte moonlik is. 'n Prospektiewe, ewekansig gekontrolleerde studie is nodig om die beste middel kombinasies en die optimale duur van so 'n chemoprofilaktiese behandeling te bepaal.

Thesis (MNutr)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Problem definition: Malnutrition increases the incidence and exacerbates the clinical manifestations of TB. Hepatotoxicity is one of the most serious and most frequent side-effects of anti-tuberculosis drugs and may be three times higher in malnourished patients. Objective: The influence of nutritional and retroviral status on the bio-availability and toxicity of anti-tuberculosis agents was studied and a possible relationship between abdominal lymph node enlargement and the occurrence of malnutrition investigated. Subjects and setting: The study subjects were 53 children, 19 HIV-infected and 34 HIV-uninfected, aged 3 months to 13 years with probable or confirmed tuberculosis admitted to the paediatric ward of Brooklyn Hospital for Chest Diseases in Cape Town, South Africa. The nutritional status of the children was assessed over the first four months of tuberculosis treatment by nutrient intake, anthropometric status and biochemical parameters. The relationship between abdominal lymph node enlargement and the occurrence of malnutrition was also evaluated. Pharmacokinetic studies were performed to evaluate the bio-availability of anti-tuberculosis agents and drug hepato-toxicity was evaluated by liver function. Results: Stunting (46.27%) and underweight (34.51%) were the most common types of malnutrition in the children studied. HIV-infection did not have a significant effect on stunting or wasting, but had a significant effect (p=0.003) on underweight for age with 31.5% HIV-infected compared to 2.9% HIV-uninfected at enrolment, but the effect was not statistically significant at month 4. There was no change in the number of stunted, wasted or underweight children from enrolment after 1 month of treatment to month 4 of treatment. HIV-infection did not have a significant effect on abdominal TB involvement (p=0.43354), and nutritional status was not significantly affected by abdominal lymph-node involvement. At enrolment weight for age had a significant effect on AST and ALT with p-values of 0.02166 and 0.02765 respectively and wasting had a significant effect on GGT at enrolment (p=0.03014). However on enrolment only two HIV-infected and two HIV-uninfected children had ALT values increased >X2 normal. Similarly AST values >X3 normal were found in only one HIV-infected child and two HIV-uninfected children. Stunting did not significantly affect liver enzymes. Anthopometric status did not have a significant effect on liver enzymes at month 4. None of the parameters used to determine nutritional status had a statistically significant effect on INH-levels or RMP-levels. HIV-infection had a significant negatve effect on selenium (p=0.030 and 0.012) and ferritin (p=0.026 and 0.002) at enrolment and month 4 and on IBC (p=0.025) at enrolment. At month 4 HIV-infection had a significant negative effect on the mean vitamin C-levels (p=0.005). Conclusions: HIV co-infection did not affect the extent or distribution of body composition changes in this study. Stunting was the most prevalent form of malnutrition in the study group, indicating longstanding undernutrition, which may be due to factors other than the present TB infection. Appropriate treatment of tuberculosis did not appear to affect the nutritional status over the four month period of the study. / AFRIKAANSE OPSOMMING: Probleemstelling: Wanvoeding verhoog die insidensie en vererger die kliniese beeld van TB. Hepatotoksisiteit is een van die ernstigste en algemeenste newe-effekte van anti-tuberkulose middels en mag tot drie keer hoër wees in wangevoede pasiënte. Doelwit: Die invloed van die kinders se voedings- en retrovirale status op die bio-beskikbaarheid en toksisiteit van anti-tuberkulose middels was ondersoek en 'n moontlike verband tussen vergrote abdominale limfnodes en die voorkoms van wanvoeding was ondersoek. Deelnemers en omgewing: Die deelnemers aan die studie was 53 kinders, 19 HIV-positief en 34 HIV-negatief, tussen die ouderdomme van 3 maande en 13 jaar met moontlike of bevestigde tuberkulose toegelaat tot die pediatriese saal van Brooklyn Hospitaal vir Borskwale in Kaapstad, Suid Afrika. Die voedingstatus van die kinders was bepaal oor die eerste vier maande van tuberkulose behandeling ten opsigte van nutriëntinname, antropometriese status en biochemiese parameters. Die verhouding tussen vergrootte abdominale limfnodes en die voorkoms van wanvoeding was ook geëvalueer. Farmakokinetiese studies was uitgevoer om die bio-beskikbaarheid van anti-tuberkulose middels te evalueer en hepatotoksisiteit was deur lewerfunksie geëvalueer. Resultate: Dwerggroei (46.27%) en ondergewig (34.51%) was die algemeenste tipes wanvoeding teenwoordig by die kinders bestudeer. HIV-infeksie het nie 'n noemenswaardige effek op dwerggroei of uittering gehad nie, maar het wel 'n noemenswaardige effek (p=0.003) getoon op ondergewig vir ouderdom met 31.5% HIV-positief vergeleke met 2.9% HIV-negatief by inskrywing, wat nie statisties noemenswaardig was teen maand 4 nie. Daar was geen verandering in die hoeveelheid kinders met dwerggroei, uittering of ondergewig vanaf inskrywing na 1 maand van behandeling tot maand 4 van behandeling nie. HIV-infeksie het nie 'n noemenswaardige effek op abdominale TB gehad nie (p=0.43354), en vergrootte abdominale limfnodes het nie 'n noemenswaardige effek op voedingstatus gehad nie. By inskrywing het gewig vir ouderdom 'n noemenswaardige effek op AST en ALT gehad met p-waardes van 0.02166 en 0.02765 onderskeidelik en uittering het 'n noemenswaardige effek op GGT by inskrywing gehad (p=0.03014). Dwerggroei het nie die lewerensieme noemenswaardig beïnvloed nie. Antropometriese status het nie 'n noemenswaardige effek op lewerensieme teen maand 4 gehad nie. Geen van die parameters wat gebruik is om voedingstatus te bepaal het 'n noemenswaardige statistiese effek op INH-vlakke of RMP-vlakke gehad nie. HIV-infeksie het 'n noemenswaardige effek op selenium (p=0.030 en 0.012) en ferritien (p=0.026 en 0.002) by inskrywing en maand 4 gehad en op IBC (p=0.025) by inskrywing. HIV-infeksie het 'n statisties noemenswaardige effek op die gemiddelde vitamien C-vlakke (p=0.005). Gevolgtrekking: HIV ko-infeksie het nie die verspreiding of mate van liggaamsamestelling veranderinge in hierdie studie geaffekteer nie. Dwerggroei was die algemeenste vorm van wanvoeding in die studiegroep, wat langstaande wanvoeding aandui en toegeskryf mag word aan faktore buiten die huidige TB infeksie. Toepaslike tuberkulose behandeling het nie 'n wesenlike effek op voedingstatus gehad tydens die vier maande periode van die studie nie.

Thesis (MScMedSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: BACKGROUND: The emergence of mycobacterium tuberculosis resistance to first line drugs has renewed interest in second-line anti-tuberculosis drugs. Generally, Paraaminosalicylic acid (PAS) is less potent and frequently more toxic than the first line drugs. Furthermore, the pharmacokinetics of PAS in children has not been well characterized. AIMS: The aims of the present study were (1) to determine the pharmacokinetics of PAS in pediatric patients, (2) to describe the discrepancy between children and adult pharmacokinetics and the appropriate dosing regimen of PAS and (3) to investigate the potential of the second-line anti-tuberculosis drugs PAS, terizidone and ethionamide (often used as first-line drug in children) to inhibit the catalytic activities of CYP450 1A2 and 2C9. PATIENTS: Twenty two patients with drug resistant tuberculosis were included in the study. Ten patients were children with mean age of 4.2 years (range: 1 to 12 years). Twelve patients were adults with mean age of 31.3 years (range: 18 to 53). 4 children (40%) and 4 adults (33.3%) were HIV positive and were on ART. METHODS: Children received 75 mg/kg twice daily on the first visit and after two weeks they received 150 mg/kg once. Adults received a standard 4 g twice daily. Blood samples were taken at different time points after the dose. In the additional study, the inhibitory effects of PAS, ethionamide and terizidone on phenacetin O-deethylation, a marker substrate of CYP1A2 and diclofenac 4’-hydroxylation, a marker substrate of CYP2C9, were studied using human liver microsomes. RESULTS: For the 75 mg/kg dose, the mean AUC was 233.3 =g•h/ml and the mean CL was 10.4 l/h/kg. The mean of the observed Cmax of the drug was 45.4 =g/ml and the mean Tmax was 4.8 hrs. For the 150 mg/kg dose, the mean AUC of PAS was 277.9 =g•h/ml and the mean CL was 47.1 l/h/kg. The mean of the observed Cmax of the drug was 56.5 =g/ml and the mean Tmax was 4.8 hrs. On the first visit the mean AUC was 368 =g•h/ml and the mean CL was 13.2 l/h/kg. The mean of the observed Cmax of PAS was 51.3 =g/ml and the mean Tmax was 5.2 hrs. On the second visit the mean AUC was 230 =g•h/ml and the mean CL was 23.9 l/h/kg. The mean of the observed Cmax of PAS was 37.6 =g/ml and the mean Tmax was 5.2 hrs. The comparisons between pharmacokinetics profile of PAS and patients characteristics e.g. age, indicated no statistically significant differences between children (both treatment regimens) and adult patients as well as HIV positive and negative patients. In the in vitro study, all drugs demonstrated no inhibition potency towards the investigated CYP450 enzymes. CONCLUSIONS:The dose of 75 mg/kg twice daily in children appears to be appropriate to achieve serum concentration above the PAS minimum inhibitory concentration of approximately 1 =g/ml. PAS, ethionamide and terizidone are unlikely to affect the metabolism of concomitantly administered medications that are metabolized by either CYP450 1A2 and/or 2C9 isoenzymes. / AFRIKAANSE OPSOMMING: AGTERGROND: Die opkoming van eersteliniemiddel-weerstandige mycobacterium tuberculosis het opnuut belangstelling in tweedelinie-antituberkulosemiddels aangewakker. Oor die algemeen is para-aminosalisielsuur (PAS) minder kragtig en dikwels ook meer toksies. Verder is die farmakokinetika van PAS in kinders nog nie goed vasgestel nie. DOELSTELLINGS: Die doelstellings van hierdie studie was (1) om die farmakokinetika van PAS in pediatriese pasiënte vas te stel, (2) om die diskrepansie tussen kinder- en volwasse-farmakokinetika, sowel as die toepaslike doseringskedule, van PAS te beskryf en (3) om die potensiaal van die tweedeline-antituberkulosemiddels PAS, terisidoon en etioonamied (gereeld gebruik as eerste linie middels in kinders) te ondersoek wat betref hul vermoë om die katalitiese werking van CYP450 1A2 en 2C9 te inhibeer. PASIËNTE: Twee-en-twintig pasiënte met middelweerstandige tuberkulose is in hierdie studie ingesluit. Tien pasiënte was kinders met ‘n gemiddelde ouderdom van 4.2 jaar (reeks: 1 tot 12 jaar). Twaalf pasiënte was volwassenes met ‘n gemiddelde ouderdom van 31.3 jaar (reeks: 18 tot 53 jaar). 4 kinders (40%) en 4 volwassenes (33.3%) was MIV positief en was op TRM’s. METODES: Kinders het 75 mg/kg twee maal daaliks gedurende die eerste besoek ontvang en 150 mg/kg een maal ná twee weke ontvang. Volwassenes het ‘n standaarddosis van 4 g twee maal daagliks ontvang. Bloedmonsters is op verskillende tye ná die dosering geneem. In die addisionele studie is in die inhiberende effekte van PAS, etioonamied en terisidoon op fenasetien-O-deëtilering, ‘n merkersubstraat van CYP1A2 en diklofenak-4’-hidroksilasie, ‘n merkersubstraat van CYP2C9, ondersoek deur gebruik te maak van menslike lewermikrosome. RESULTATE: Vir die 75 mg/kg dosis was die gemiddelde area-onder-die-kurwe (AOK) 233.3 =g•h/ml en die gemiddelde middelopruiming (CL) 10.4 l/h/kg. Die gemiddelde geobserveerde Cmaks van die middel was 45.4 =g/ml en die gemiddelde Tmaks was 4.8 h. Vir die 150 mg/kg dosering was die gemiddelde AOK van PAS 277.9 =g•h/ml en die gemiddelde CL 47.1 l/h/kg. Die gemiddelde geobserveerde Cmaks van die middel was 56.5 =g/ml en die gemiddelde Tmaks was 4.8 h. Gedurende die eerste besoek was die AOK 368 =g•h/ml en die gemiddelde CL was 13.2 l/h/kg. Die gemiddelde geobserveerde Cmaks van PAS was 51.3 =g/ml en die gemiddelde Tmaks was 5.2 h. Gedurende die tweede besoek was die gemiddelde AOK 230 =g•h/ml en die gemiddelde CL 23.9 l/h/kg. Die gemiddelde geobserveerde Cmaks van PAS was 37.6 =g/ml en die gemiddelde Tmaks was 5.2 h. Die vergelyking van PAS-farmakokinetika en eienskappe van die pasiënte het geen statisties beduidende verskille in die gemiddelde AOK tussen kinders (op albei doserings) en volwassenes getoon nie. Met die in vitrostudie het geen van die middels inhibisie-werking teenoor die CYP450-ensieme wat ondersoek is, getoon nie. GEVOLGTREKKINGS: Die gevolgtrekking kan gemaak word dat die dosering van 75 mg/kg twee maal daagliks voldoende is om serumkonsentrasies wat bo PAS se minimum inhiberende konsentrasie van 1 =g/ml te bereik. Dit is onwaarskynlik dat PAS, etioonamied en terisidoon die metabolisme van gelyktydig-toegediende medikasies, wat op hul beurt deur die CYP240-isoënsieme 1A2 en/of 2C9 gemetaboliseer word, sal affekteer. / Division of Pharmacology, Stellenbosch University / National Research Foundation (NRF) grant generously offered by Professor Donald Grant

Thesis (MTech (Biomedical Technology))--Cape Peninsula University of Technology, 2009. / Bibliography: leaves 73-78. Also available online.

Thesis (MTech (Biomedical Technology))--Cape Peninsula University of Technology, 2009. / The role of the mycobacteriology laboratory in the diagnosis of childhood tuberculosis has become increasingly important in the human-immunodeficiency virus era. Due to the paucibacillary nature of childhood mycobacterial disease, laboratory optimisation of mycobacterial cultivation is necessary for paediatric clinical management and epidemiological surveillance. Previous studies have shown that growth supplements markedly improve the recovery rate and time-to-detection in mycobacterial cultures. In this study, we hypothesised that specialised culture media and meat-based growth supplements would improve the recovery rate and time-to-detection in clinical samples from paediatric patients. Pulmonary sputa and gastric aspirates and extra pulmonary fine needle aspiration biopsies were processed from children less than 15 years of age routinely investigated for mycobacterial disease. The processed clinical samples were split into a control aliquot that was cultured in liquid and solid media without growth supplement, and an intervention aliquot cultured on supplemented media. The effect of enrichment of the culture media was then calculated by comparison to the control. These results indicated a significant reduction in the time-to-detection, 18.5 to 12.4 days, and an improved primary recovery rate of 14% in paediatric samples when cultured in liquid media enriched with a nutrient meat broth growth supplement. The findings of this study confirm the value of optimising mycobacterial cultivation with the use of growth supplements to enhance the detection of childhood mycobacterial disease.

Tuberculosis(TB) was declared to be a global emergency in 1993, with South Africa declaring it to be the country’s top health priority in 1996, but ineffective treatment strategies have led to fewer than half of all treated patients in South Africa being cured. At present,paediatric treatment remains a problem, as the antitubercular preparations of rifampicin, isoniazid and pyrazinamide, that are currently available, were not initially designed for the treatment of paediatric TB patients, providing a motivation for this project. The aim of this project is thus the development of a microemulsion dosage form for the oral delivery of RIF(Rifampicin), INH(Isoniazid) and PZA(Pyrazinamide) in combination. RIF, INH and PZA were adequately characterised with reference to the monograph standards referenced and were found to be sufficiently pure to be used in subsequent work. A chromatographic system and conditions were selected and validated as being optimal for HPLC analysis of RIF, INH and PZA in combination, with a drug partitioning method for miglyol 812 developed and validated. Ternary and pseudo-ternary phase diagrams were constructed and reported, all employing miglyol 812 as the lipid. It was undoubtedly the imwitor 308 and crillet 3 combination o/w microemulsion system that proved most successful, maintaining homogeneity on dilution. The microemulsion used in formulation comprised imwitor 308 (27.63%), crillet 3 (27.63%), miglyol 812 23.68%) and water (21.06%). The stability of RIF, INH and PZA was investigated in aqueous solution, miglyol 812, corn oil, 10%m/v cremophor RH, 5%m/v imwitor 308, 10%m/v crillet 3 and 70%m/v sorbitol solution. Trends in the stability assessments conducted on RIF, INH and PZA were noted, with slight variation depending on the formulation component being evaluated. RIF invariably demonstrated temperature and oxidation dependent degradation in all vehicles, with a definite distinction possible between samples stored at 25, 40 and 600C over a 7 day trial period. A definite advantage of storing RIF solutions under nitrogen was observed, with these solutions showing less degradation over the course of the trial, than those stored under air. INH produced a pronounced increase in the degree of degradation of RIF, whereas PZA had a negligible effect on it’s stability. INH proved to be most stable in the 70%m/v sorbitol solution with no significant oxidation or temperature dependent degradation indicated. Temperature dependent degradation was only noticable when INH was in combination with RIF, most significant in crillet 3 solution. PZA was the most stable of the three drugs, remaining relatively unaffected by temperature and the presence of air, independent of the vehicle employed, although the drug remaining did decrease slightly in the presence of RIF.Due to drug dose specifications and solubility limitations, the final formulation assessed, only contained RIF and INH, despite INH and PZA having no significant effect on the stability of each other. The solubility of PZA in the lipid and aqueous components of the microemulsion was not great enough to achieve the required 500 mg/10ml dose, while RIF and INH could achieve the respective 150mg/10ml and 100mg/10ml dose. RIF stability was improved, as anticipated, with the incorporation of RIF into the internal phase decreasing contact with INH which has been shown to affect it’s stability. RIF behaved as predicted, possessing greater stability than shown in the individual formulation components, however, INH did not, being less stable in formulation in the absence of antioxidant, than in it’s presence. A novel microemulsion formulation capable of delivering the incompatible RIF and INH in combination, with numerous microemulsion systems mapped,with the ability of being used for the delivery of other lipophilic drugs and drug combinations, was produced.The final formulation provided valuable information into possible future improvements of the microemulsion to improve drug stability.