MSc (Chemistry) / Department of Chemistry

MPH / Department of Public Health / Background: Malaria is a public health issue killing more than 435 000 people in Sub Saharan Africa. In South Africa, malaria is endemic in 3 provinces namely: Limpopo, Mpumalanga and Kwazulu Natal. Limpopo Province contributes more cases than the other provinces in the country. Purpose: The purpose of the study was to assess community knowledge and prevention practices of malaria at Masisi village, in Mutale Municipality, Vhembe District. The study was conducted at Mutale municipality, Vhembe District. Methodology: A quantitative cross-sectional descriptive approach was used. Data was collected using a questionnaire with open and close ended questions. The targeted population was made up of males and females between the ages of 18 to 75. Validity and reliability have been ensured in the study and the results for reliability were 0.85. Pretesting was done in 5 household at Sanari village which is near Masisi village as they share the same characteristics. A sample of 152 participants was selected from the target population by means of systematic sampling and then select them randomly. Questionnaires were used to collect data. There after Data were analyzed using SPSS version 24.0. The analyzed data were presented in tables, graphs, and in percentages. Results: The findings revealed that majority of the participants 103(67.8%) have secondary education, and most of them, 103(67.8%) are unemployed. The study revealed that about 77% have knowledge regarding malaria transmission. About 130(85.5%) indicated that malaria is caused by a mosquito bite. About 57(38.51%) indicated that they use mosquito coils and nets in their household. Conclusion: Malaria still poses a threat to the lives of people living in malaria endemic areas. Community members at Masisi village have better insight regarding malaria transmission, causes and signs and symptoms. Although the community shows a better understanding of the prevention method they still has to put this into practice in order to eliminate malaria in the area. Health workers are doing a great job in educating the community regarding malaria related issues. / NRF

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Malaria is endemic in Uganda. The study attempted to determine how Ugandan caregivers managed home-based care of fever. Structured interviews were conducted with sixty caregivers of children under five. In 15 (25.0%) out of the 60 interviewed households, at least one child had reportedly died from malaria. Caregivers’ decisions were influenced by health education, family members, community leaders and other caregivers. Most caregivers knew about malaria, but lacked knowledge about its danger signs, and about the services of village drug distributors. Most caregivers initiated treatment for fever at home before taking the children to health units. Mosquito nets, indoor residual spraying and other malaria preventive measures were rarely used due to lack of funds. The recommendations include that anti-malaria drugs should always be available and accessible, the services of village drug distributors should be improved, health education should be enhanced, malaria preventive measures should be implemented and sustained. / Health Studies / M.A. (Public Health)

Early diagnosis and prompt treatment is one of the malaria control strategies used to minimize malaria morbidity and mortality. One of the mechanisms to implement early diagnosis and prompt treatment is community access to diagnostic services and effective antimalarial drugs. However, in Ethiopia the health system is underdeveloped and much of the rural population has limited access to modern health services. Therefore, the Ethiopian government introduced the Health Extension Programme(HEP) which is a community-based health care delivery system aimed at accessing essential health services through its health extension workers (HEWs). Involvement of the HEWs in prescribing and dispensing antimalarial drugs is shown to have improved community access to antimalarial drugs. However, there is insufficient knowledge of HEWs compliance to malaria treatment guidelines and patient adherence of patients treated by HEWs. The objectives of this study has been to describe the HEWs practice in malaria treatment, to evaluate adherence of patients to antimalarial drugs, to explore the factors influencing the HEWs malaria treatment practice and patient adherence, and to develop the guidelines to support the HEWs in malaria treatment practice. A qualitative study design was used to study the HEWs practice in malaria treatment along with patient adherence. Data were collected using in-depth face-to-face interviews, focus group discussion and patient medical record review and were analysed according to Tesch’s steps. The study revealed that the HEWs adequately comply with malaria treatment guidelines during diagnosis of malaria, as well as during the prescribing and dispensing of antimalarial drugs. However, there are some factors influencing the performance of HEWs. These are: shortage of diagnostic kit/RDT, shortage of antimalarial drugs, patient pressure to obtain coartem, work load, and community beliefs with regard to antimalarial drugs effectiveness. This study also revealed that the HEWs follow up after treatment of patients and good community support systems improved patient adherence to antimalarial drug use. Factors negatively influencing patient adherence were identified to include: forgetfulness, fear of shortage of drugs, adverse drug effects, duration of treatment, rapid relief of malaria symptoms and inadequate awareness of the consequence of incomplete dosage. Guidelines were developed to support the HEWs in malaria treatment practice with the aim to improve patient adherence to antimalarial drugs / Health Studies / D. Litt. et Phil. (Health Studies)

Inhibition of nitric oxide (NO) signalling may contribute to the pathogenesis of severe malaria. This thesis examines the impact of Plasmodium infection on three key determinants of nitric oxide synthase (NOS) biochemistry: substrate availability, substrate/inhibitor homeostasis and cofactor availability. Arginine, the NOS substrate, is depleted in human patients with severe Plasmodium falciparum malaria and mice infected with P. berghei ANKA. Using heavy isotope tracer infusions to quantify arginine metabolism in infected mice, we found no evidence of increased catabolism by the enzyme arginase, widely assumed to be responsible for arginine depletion. Genetic knock-out of parasite arginase had no effect on arginine depletion in mice. Instead, our findings link arginine depletion to decreased rates of arginine and citrulline appearance in the plasma of infected mice. Asymmetric dimethylarginine (ADMA) competes with arginine for binding to the NOS catalytic site. We observed elevation of the ADMA/arginine ratio in Gambian children with severe malaria, favouring NOS inhibition. In mice infected with P. berghei ANKA, we found evidence of degradation of dimethylarginine dimethylaminohydrolase 1 (DDAH1), the enzyme primarily responsible for ADMA metabolism. We also observed reduced DDAH activity and accumulation of intracellular ADMA in hepatic tissue of infected mice, suggesting that DDAH dysfunction could contribute to disruption of ADMA/arginine homeostasis. Tetrahydrobiopterin (BH4) is an essential NOS cofactor. In P. berghei ANKA-infected mice, BH4 concentrations were decreased in plasma, erythrocytes and brain tissue, which could inhibit NO synthesis and promote NOS-dependent superoxide production. To reverse deficiencies of NOS substrate and cofactor availability, we infused P. berghei ANKA-infected mice with citrulline, an arginine precursor, and sepiapterin, a BH4 precursor. Restoration of systemic arginine and BH4 availability in infected mice improved whole blood nitrite concentrations, a biomarker of NO synthesis, but did not prevent onset of disease symptoms. These studies have identified biochemical disturbances that may contribute to severe malaria pathogenesis by inhibiting NO synthesis.

Antikörper gegen Circumsporozoite protein (CSP), ein Oberflächenantigen von Plasmodium falciparum (Pf), können sterile Immunität hervorrufen und dadurch die Entwicklung von Malaria im Tierversuch verhindern. Im Menschen werden protektive B-Zell Gedächtnisantworten gegen CSP durch natürliche Malariaerkrankung bzw. Vakzinierung jedoch nur unzureichend erzeugt. - Für die Entwicklung von Gedächtnis-B-Zellen stellt die Affinitätsreifung, welche durch somatische Immungobulin Hypermutation sowie der nachfolgenden Selektion von B-Zellen mit verbesserter Antigenaffinität charakterisiert ist, eine Schlüsselfunktion in der Generierung von protektiven Immunantworten dar. Wie Affinitätsreifung gegen CSP im Menschen stattfindet ist jedoch nicht bekannt. In dieser Arbeit wird die Affinitätsreifung von CSP Gedächtnis B-Zellen auf Einzelzellebene im Menschen über drei kontrollierte Infektionen mit Pf Sporozoiten unter Chemoprophylaxe untersucht. Durch Hochdurchsatz-Einzelzell-Sequenzierung der Immunoglobulin (Ig) gene loci und der Produktion von rekombinanten monoklonalen Antikörpern gewährt diese Arbeit Einsicht in die Selektion und Affinitätsreifung von humanen Gedächtnis-B-Zell Antworten gegen komplexe Proteinantigene und identifiziert Keimbahn kodierte Immunglobulin Charakteristika, die mit hoher CSP-Affinität und Pf-Inhibition einhergehen. Überraschenderweise zeigen die Daten, dass initiale klonale Selektion von hochaffinen B Zellen eine weitaus wichtigere Rolle als Affinitätsreifung in dieser Infektion spielt. Diese Arbeit zeigt fundamentale Eigenschaften von humanen Gedächtnisantworten in einer komplexen Parasiteninfektion und liefert die Grundlage für ein mögliches Design von neuartigen Immunogenen um hoch-affine B-Zellen gegen CSP effizienter zu induzieren. / Antibodies against the major Plasmodium falciparum (Pf) sporozoite surface protein, circumsporozoite protein (CSP), can mediate sterile immunity thereby preventing malaria disease symptoms as shown by passive transfer in animal models. However, protective anti- CSP memory antibody responses are not efficiently induced by natural Pf exposure or vaccination. Affinity maturation, i.e. the diversification of antigen-activated naïve precursor B cells by a somatic immunoglobulin (Ig) gene mutation process and the subsequent selection of B cells expressing antigen receptors with improved antigen affinity in germinal center reactions is considered key to the formation of protective memory B cell responses. However, how the anti-PfCSP memory B cell response matures in humans is not known. To address this question, the clonal evolution of the human anti-Pf CSP memory B cell response over three successive controlled Pf infections under chemoprophylaxis was assessed at single cell level by high throughput paired full-length Ig gene sequencing and recombinant monoclonal antibody production. The work provides basic insights in the longitudinal development of human memory B cell responses and identified germline-encoded Ig gene features that were associated with high anti-CSP affinity and Pf inhibitory antibody activity. The clonal selection of germline B cells expressing such antibodies, rather than affinity maturation, was associated with high quality anti-PfCSP memory B cell responses. The data provide insights into the evolution of antibody response to a complex protein antigen during infection and a strong rational for the design of novel CSP immunogens to target naïve B cell precursors expressing potent anti-CSP antibodies for the induction of protective memory B cell responses by vaccination.

Building supply chain coordination frameworks is a popular practice in the private sector in many developed countries. Despite this fact, in developing countries such as Uganda, the public health sector has hardly adopted this practice. Although the existing frameworks offer a good platform for measuring and improving the understanding of concepts underlying coordination dimensions at the micro-environment, they have limited capacity to analyse coordination interactions within the health sector, especially in developing countries like Uganda. Using the business management environment framework, this study explored the critical supply chain coordination dimensions, logistics activities dimensions and the management environment (market and macro) dimensions affecting the availability of Artemisinin-based Combination Therapies for malaria (ACTs). The overall main research goal of this thesis was to develop a supply chain coordination framework for malaria treatment therapies (ACTs) in general hospitals in Uganda. To understand the coordination dimensions of ACTs, the study adopted an exploratory sequential mixed research design, which involved a mixture of qualitative and quantitative approaches. For the qualitative phase, four focus group discussions were held. From the results, an instrument was developed and later validated using the quantitative approach. Specifically, Exploratory Factor Analysis (EFA) with a maximum likelihood extraction method followed by Confirmatory Factor Analysis (CFA) were used to analyse quantitative data. Considering the volume of the dimensions, Analytical Process Hierarchy (AHP) was carried out to rank the dimensions in order of priority. Analysis of the factor correlation matrix shows no common variance among the components; therefore, the principal components were distinct from one another and there was no discriminant validity. The CFA results showed that the standardised parameter estimates of the initial measurement models were all significant (p<.05). CFA and APH outputs were somehow different simply because each technique has its own purpose and principles. It was indicated that the correlation between critical supply chain coordination dimensions and level of ACTs availability is moderately higher, followed by logistics, macro and market environments. By better understanding the supply coordination dimensions effects on ACTs in Uganda, the research provides important direction to African governments and international donor agencies in their efforts to make malaria treatment therapies available, especially to the rural poor and avert death. The findings serve as a platform to argue for revisiting coordination dimensions in view of conditions that include a resurgent market and macro-environment in developing countries. The insight raises implications for extending coordination frameworks that are geographically focused, and specific to ACTs. It may influence policy direction in this regard and thus contribute to the body of knowledge. / Business Management / D. Phil. (Management Studies)

Bakgrund: Malaria är en av de allvarligaste infektionssjukdomarna i världen. De allvarligaste malariafallen orsakas främst av Plasmodium falciparum som sprids av Anopheles-myggor. Ett vaccin med långvarigt och potent skydd skulle kunna minska dödligheten, men också minska behovet av kontrollåtgärder och problemet med läkemedelsresistens. Subenhetsvaccin är den vaccintyp som kommit längst i kliniska studier men dessa uppvisar begränsad effekt. Helparasitvaccin ger en bredare immunitet vilket kan ge ett mer fullständigt skydd. Syfte: Syftet med denna litteraturstudie var att jämföra effekt och varaktighet i skydd mot P. falciparum hos de två P. falciparum sporozoit (PfSPZ)-helparasitvaccinkandidaterna: RAS (Radiation-attenuated sporozoites) och CPS (Chemoprophylaxis and sporozoites), samt att undersöka betydelsen av vaccindos och administreringssätt. Metod: Arbetet är en litteraturstudie baserat på 14 vetenskapliga studier vilka har erhållits via sökning i PubMed. De aspekter som avhandlas är: vaccineffekt och dess varaktighet, immunsvar och dess korrelation till vaccineffekt, betydelsen av dos och administreringssätt samt vaccinens säkerhetsprofil. Resultat: Litteraturstudien visade att RAS-vaccin och CPS-vaccin kan ge ett potent samt säkert kort- och långvarigt skydd mot homolog kontrollerad human malaria-infektion (CHMI) vid immunisering via myggor eller venös inokulation. Dosen har stor betydelse för vaccineffekten och CPS-vaccin kan uppnå potent skydd vid mycket lägre doser än RAS-vaccin. En del immunmekanismer har visat sig korrelera med skydd men CD8+ T-celler i levern verkar ha störst betydelse för långvarigt sterilt skydd. Det långvariga skyddet mot heterolog kontra homolog CHMI är bristfälligt för både RAS-vaccin och CPS-vaccin. Slutsats: En potent vaccineffekt uppnås med PfSPZ-vaccin mot homolog CHMI vid tillräckligt hög dos, men inte ett långvarigt skydd mot heterolog CHMI vilket begränsar användningen i endemiska områden. / Background: Malaria is still one of the most common infectious diseases in the world and there is an overwhelming threat to the development of resistance to different control methods such as drugs and insecticides. A durable vaccine with sterile protection would reduce and maybe eradicate the disease. The most serious cases of malaria are caused by Plasmodium falciparum that is transmitted through the bites of infected Anopheles mosquitoes. The life cycle of malaria is extremely complex and different vaccine candidates have effects at different stages. Naturally acquired immunity develops gradually after many years of clinical episodes but never becomes sterile. RTS,S is the only vaccine candidate who has been in phase III clinical trials. Unfortunately this vaccine has limited efficacy, like many other subunit vaccines, due to rapidly diminishing antibody titers. Whole parasite vaccines have the ability to generate a greater quantity and breadth of antigenic exposure within both the humoral and cellular immunity. This results in stronger immune response and can provide sterile protection. The development of whole parasite vaccines has mainly focused on the pre-erythrocytic stage and the most tested vaccine candidates that are in early clinical trial are radiation-attenuated sporozoites (RAS), chemoprophylaxis and sporozoites (CPS) and genetically attenuated parasites (GAP). Aim: The purpose of this literature study is to examine and compare the vaccine efficacy and durability towards P. falciparum of the two whole parasite vaccine candidates: RAS and CPS and to examine the importance of dose and different routes of administration. Methods: Fourteen different clinical studies were selected from PubMed to be included in this literature study. Different variables were selected for study: the vaccine efficacy and it´s durability after controlled human malaria infection (CHMI) using P. falciparum parasites homologous or heterologous to the vaccine strain, the correlation between the immunogenicity and protection, the importance of the dose and different kinds of administration and vaccine safety. Results: According to the findings in the literature study, direct venous inoculation of RAS-vaccine and CPS-vaccine have the ability to give short and longlasting protection against CHMI using P. falciparum parasites homologous to the vaccine strain. The dose is of great importance to the vaccine efficacy and CPS-vaccine has the ability to give potent protection with much lower doses than RAS-vaccine. Some immune mechanisms in the blood correlate with protection but it seems to be the number of CD8+ T-cells in the liver that are of greatest importance for longlasting and steril protection. Whole parasite vaccines are safe but transient parasitemia is common when using CPS-vaccine. Unfortunately, vaccines with longlasting protection against CHMI using P. falciparum parasites heterologous to the vaccine strain has limited efficacy. Conclusion: RAS-vaccine and CPS-vaccine have the ability to give a potent vaccine efficacy against CHMI using P. falciparum parasites homologous to the vaccine strain when used in sufficiently high doses. Longterm protection against CHMI using P. falciparum parasites heterologous to the vaccine strain is limited and this in turn affects the use in endemic areas. In the future, the vaccine effect can be improved by higher doses, more infectious vaccine strains or vaccine cocktails. An alternative to RAS-vaccine and CPS-vaccine could be direct venous inoculation of late arresting GAP.