This research report has been submitted to the Faculty of Health Sciences, University of the Witwatersrand , in partial fulfillment of the requirements for the award of the Masters of Science in Medicine (Biology and Control of African Disease Vectors)degree. May 2015 / Background: Ongoing residual malaria transmission is increasingly mediated by outdoor-biting mosquito populations, especially in communities where insecticidal interventions like indoor residual insecticides (IRS) and long-lasting insecticide treated nets (LLINs), are used. Often, the vectors are also physiologically resistant to the insecticides, making this a major against malaria elimination.

A dissertation submitted to the Faculty of Medicine, Universlty of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Medicine in the branch of Haematology. / Despite the efforts, for more than twenty years, to control malaria, the incidence of this disease still appears to be escalating globally. At the Chris Hani/Baragwanath Hospital, data analysis of malaria admissions between January 1994 to December 1996 showed an increasing trend from year to year. The main objective of the study was to try and provide some insight into this increasing rate of malaria at the ChrisHani/Baragwanath Hospital. The study was structured into two main parts: a retrospective analysis which concentrated on malaria admissions between and including January 1994 and March 1994, and a prospective analysis interviewing and examining all the malaria cases that were diagnosed between and including January 1995 and March 1995. Both aspects of the study assessed the patients socioeconomically, haematologically and immunologically. A detailed travel,medical and drug history was taken through the aid of a questionnaire. Two hundred and sixty-three patients (175 male and 88 female), of which 35% (91/263) were children (< 13 years old), were diagnosed with malaria. The clinical and laboratory presentations were consistent with other studies. The prevalence of complicated disease however was less than what has been described in the literature; cerebral malaria (as defined by Warrell, 1982) was documented in 1% of patients, hypoglycaemia (glucose < 2.2 mmol/l) and renal failure (creatinine > 265 umol/l) accounted for 5% and 3% of the cases respectively. In contrast to this 32% had features of liver dysfunction, however it appeared that haemolysis was the main contributing factor to the liver derangement. The most common infecting species was Plasmodium falciparum, alone (91.3% of the patients) or part of a mixed infection with either P. vivax or P.ovale (3.8% of patients). More than 88% of the infections were contracted in other African, mainly southern African countries, the most important of which was neighbouring Mozambique (58%). About 11% were contracted in endemic areas of South Africa i.e Northern Province, Mpumalanga and Kwazulu Natal. Twelve percent of cases (24/203) gave a history of previous malaria, The underlying immune status of these patients was analyzed using the Indirect Fluorescence Antibody Test (IFAT) and compared with the total study group. The test did not reveal any striking differences between the two groups. The previously exposed patients however did demonstrate a much lower parasitaemia, with 71% (17/24) of cases presenting with a parasite density <_;1%. These results may indicate the ability of these patients to clear their parasitaemias earlier due to previous sensitization, with the subsequent establishment of a low grade chronic infection. Seven of 88 women admitted had a documented pregnancy at the time of diagnosis. Foetal death was recorded in 517 cases which confirms the poor prognosis in pregnancy associated malaria infection, reported by other authors. Fifteen patients (13 adults and 2 children) required admission into the intensive care unit. Indications included high parasite loads, > 5% (67%) and renal failure, creatinine> 265 umol/l (33%). Standard chemotherapy was administered to all the patients with the most frequently used being quinine (94% of cases), alone or in combination with other drugs. The use of prophylactic agents for the prevention ofmalaria was restricted to twelve patients (8%), with the majority of individuals being ignorant about( malaria and therefore being unaware that any medication along with other preventative measures, were necessary prior to entering , and while staying in an endemic region. It was also apparent that the correct dosage was not adhered to as none of the patients completed their antimalarial course after returning from the malaria area. The most commonly used prophylactic drugs were chloroquine, alone or in combination with proguanil and pyrimethamine plus dapsone (Maloprim), The latter is no longer recommended routinely as a prophylactic agent. Following univariate analysis using Fisher's exact test and the student t-test, and a multivariate: nalysis (using a logistic regression model), hyperparasitaemia (p=O.0070) and renal failure (p=O.0016) were identified as significant predictors of poor outcome. Significant differences were also demonstrated in the mean WCC and the mean HB levels between the survivors versus the patients that died, indicating that a significantly elevated WCC and an anaemia at presentation, may be important risk factors towards the establishment of severe/complicated infection. The overall mortality rate was 3%. Climatic data (which was limited to the Johannesburg area), together with evidence that the malaria bearing Anopheles vector does not exist in Gauteng suggests that the conditions in the city may not be suitable for local transmission of malaria during the summer. It therefore appears that all efforts need to be channeled into the education of our travelers who visit malaria endemic regions and upon returning succumb to 'imported' malaria. Perhaps the education of the traveler alone is not sufficient, and medical personnel who diagnose the condition and who prescribe prophylactic agents need to revise their knowledge of this life threatening infection, so that their advice and drug therapies are optimal and effective. Lastly the pharmaceutical companies that manufacture these drugs might be persuaded to make their products more affordable for those individuals who are most at risk. We need to utilize our limited options to the fullest until such a time as the ultimate challenge is realised - an effective malaria vaccine. / Andrew Chakane 2018

Thesis (Ph.D.(Virology))--University of the Witwatersrand, Faculty of Health Sciences, 2012 / Morphological similarity between malaria vectors and non-vectors occurring in sympatry has serious consequences if the killer diseases have to be controlled. Malaria in Malawi is transmitted by Anopheles gambiae, An. arabiensis and An. funestus. This vector diversity is further complicated by the recently discovered An. funestus-like species which is morphologically similar to An. funestus, and found in association with humans. Currently there is no single assay available that differentiates An. funestus-like from the other African members in the An. funestus group. The objective of this study was to investigate the biology and behavior of the newly discovered An. funestus-like species and its possible role in malaria transmission. This information will assist in the implementation of vector control programs. In addition to this, the study investigated the development of a DNA based assay to differentiate between the members of the An. funestus group and to morphologically described An. funestus-like species. Anopheles mosquitoes were collected resting indoors and outdoors from Karonga in Malawi. Specimens were identified morphologically and molecularly using chain reaction PCR. Identified samples were analyzed by ELISA for blood meal source and Plasmodium sporozoite infection. Anopheles funestus-like was morphologically compared with An. funestus. Real time based PCR was developed and compared to the current multiplex or allele-specific PCR (AS-PCR) assay for sensitivity and performance. The IGS region of the rDNA gene was investigated for development of AS-PCR. Phylogenetic relationship of mosquitoes was constructed from ITS2 and D3 sequences. Adult An. funestus mosquitoes (n = 391) were collected during April and September, 2010. Karonga contributed 63.9% and Likoma Island 36.1%. Of the identified specimens (n = 347) An. funestus-like comprised 10.4%, An. rivulorum 31.7%, An. funestus 57.3% and An. parensis 0.6%. Most of the An. funestus-like species were collected resting indoors 91.7% (33/36) compared to outdoors 8.3% (3/36). The species was predominant during the dry season 63.9% (23/36) compared to the wet season. A total of 19 An. funestus-like females were analyzed for blood meal source. Mixed blood meal from goat and bovine was found in 7 specimens and a single blood meal from goat in 3 specimens.. The rest of the An. funestus-like was negative for blood meal. An overall dry season infection rate of An. funestus-like species by Plasmodium vivax was 5% (1/20) in this study and 3.1% (2/64) from samples collected in 2009 was found. However, the possibility of false positivity could not be excluded and further study is urgently needed to investigate this. Real-time PCR for the identification of members of the An. funestus group was found to be more sensitive (0.02ng/μl) than AS-PCR (0.04ng/μl) and had performance comparable to AS-PCR. AS-PCR developed from the intergenic spacer region of rDNA discriminates An. funestus, An. rivulorum, An. vaneedeni and An. parensis. Of all assays developed in this study, the hydrolysis probe assay is the most reliable assay for identifying members in the An. funestus group. This study confirmed the existence of An. funestus-like species in sympatry with An. funestus group members. An. funestus-like was predominantly found resting indoors (endophilic) but preferring animal over human blood (zoophilic). No consistent morphological characters were found to discriminate between An. funestus and An. funestus-like based on morphological data, An. funestus-like is very similar and closely related to An. funestus which is supported by phylogenetic analysis. However, Restriction Fragment Length Polymorphism separates the two species.

Despite the efforts, for more than twenty years, to control malaria, the incidence of this disease still appeal's to be escalating globally. At the Chris Hani/Baragwanath Hospital, data analysis of malaria admissions between January 1994 to December 1996 showed an increasing trend from year to year. The main objective of the study was to try and provide some insight into this increasing rate of malaria at the Chris Hani/Baragwanath Hospital. The study was structured into two main parts: a retrospective analysis which concentrated on malaria admissions between and including January 1994 and March 15)94, and a prospective analysis interviewing and examining all the malaria cases that were diagnosed between and including January 1995 and March 1995. Both aspects of the study assessed the patients socioeconomically, haematologicaliy and immunologicailly. A detailed travel,medicai and drug history was taken through the aid of a questionnaire. Two hundred and sixty-three patients (175 male and 88 female), of which 35% (91/263) were children (< 13 years old), were diagnosed with malaria. The clinical and laboratory presentations were consistent with other studies. The prevalence of complicated disease however was less than what has been described in the literature; cerebral malaria (as defined by Warrell, 1982) was documented in 1% of patients, hypoglycaemia (glucose < 2.2 mmol/1) and renal failure (creatinine > 265 pnol/1) accounted for 5% and 3% of the cases respectively. In contrast to this 32% had features of liver dysfunction, however it appeared that haemolysis was the main contributing factor to the liver derangement. The most common infecting species was Plasmodium falciparum, alone (91.3% of the patients) or part of a mixed infection with either P.vivax or P.ovale (3.8% of patients). More than 88% of the infections were contracted in other African, mainly southern African countries, the most important of which was neighbouring Mozambique (58%). About 11% were contracted in endemic areas of South Africa i.e Northern Province, Mpumalanga and Kwazulu Natal. Twelve percent of cases (24/203) gave a history of previous malaria. The underlying immune status of these patients was analyzed using the Indirect Fluorescence Antibody Test (IFAT) and compared with the total study group. The test did not reveal any striking differences between the two groups. The previously exposed patients however did demonstrate a much lower parasitaemia, with 71% (17/24) of cases presenting with a parasite density <1% . These results may indicate the ability of these patients to clear their parasitaemias earlier due to previous sensitization, with the subsequent establishment of a low grade chronic infection. Seven of 88 women admitted had a documented pregnancy at the time of diagnosis. Foetal death was recorded in 5/7 cases which confirms the poor prognosis in pregnancy associated malaria infection, reported b / other authors. Fifteen patients (13 adults and 2 children) required admission into the intensive care unit. Indications included high parasite loads, > 5% (67%) and renal failure, creatinine > 265 p.mol/1 (33%). Standard chemotherapy was administered to all the patients with the most frequently used being quinine (94% of cases), alone or in combination with other drugs. The use of prophylactic agents for the prevention of malaria was restricted to twelve patients (8%), with the majority of individuals being ignorant about malaria and therefore being unaware that any medication along with other preventative measures, were necessary prior to entering , and while staying in an endemic region. It was also apparent that the correct dosage was not adhered to as none of the patients completed their antimalarial course after returning from the malaria area. The most commonly used prophylactic drugs were chloroquine, alone or in combination with proguanil and pyrimethamine plus dapsone (Maloprim). The latter is no longer recommended routinely as a prophylactic agent. Following univariate analysis using Fisher’s exact test and the student t-test, and a multivariate analysis (using a logistic regression model), hyperparasitaemia (p=0.0070) and renal failure (p=0.0016) were identified as significant predictors of poor outcome. Significant differences were also demonstrated in the mean WCC and the mean HB levels between the survivors versus the patients that died, indicating that a significantly elevated WCC and an anaemia at presentation, may be important risk factors towards the establishment of severe/complicated infection. The overall mortality rate was 3%. Climatic data (which was limited to the Johannesburg area), together with evidence that the malaria bearing Anopheles vector does not exist in Gauteng suggests that the conditions in the city may not be suitable for local transmission of malaria during the summer. It therefore appears that all efforts need to be channeled into the education of our travelers who visit malaria endemic regions and upon returning succumb to ‘imported’ malaria. Perhaps the education of the traveler alone is not sufficient, and medical personnel who diagnose the condition and who prescribe prophylactic agents need to revise their knowledge o f this life threatening infection, so that their advice and drug therapies are optimal and effective. Lastly the pharmaceutical companies that manufacture these drugs might be persuaded to make their products more affordable for those individuals who are most at risk. We need to utilize our limited options to the fullest until such a time as the ultimate challenge is realised - an effective malaria vaccine.

Abstract Malaria vector control relies principally on the use of insecticides. However, the increasing incidence of insecticide resistance threatens to undermine the effectiveness of this approach, necessitating resistance management strategies. Multiple insecticide resistance is becoming common in West Africa including Ghana. In particular, a population of the major malaria vector Anopheles gambiae, from the Ahafo region of Ghana, shows resistance to all classes of insecticide currently available for use in public health. Insecticide resistance is a primary adaptive characteristic of epidemiological importance although other adaptive traits such as staggered larval time-to-hatch may also be important. Typically, An. gambiae oviposits in small, temporary, sun-lit water bodies and eggs generally hatch 2-3 days post-oviposition. However, staggered distribution of hatching has previously been shown and was also observed in a newly colonized strain (GAH) from Ahafo. The broad aims of this project were therefore to assess and characterize multiple insecticide resistance in An. gambiae from Ahafo as well as to quantify and describe staggered time-to-hatch in a laboratory colony of this population in terms of its adaptive significance and pleiotropic effects on resistance.

by Senok, Abiola Catherine. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 206-236). / ACKNOWLEDGEMENT --- p.ii / LIST OF ABSTRACTS AND PRESENTATIONS --- p.iv / ABSTRACT --- p.viii / INTRODUCTION AND OBJECTIVES --- p.1 / Chapter SECTION ONE : --- LITERATURE REVIEW --- p.8 / Chapter CHAPTER 1 : --- THE MALARIA PARASITE --- p.8 / Chapter CHAPTER 2 : --- RED CELL PHYSIOLOGY --- p.19 / Chapter CHAPTER 3 : --- THE THALASSAEMIAS --- p.27 / Chapter CHAPTER 4 : --- PROTECTION AGAINST MALARIA IN THALASSAEMIA: THE EVIDENCE --- p.32 / Chapter CHAPTER 5 : --- POSSIBLE MECHANISMS INVOLVED IN THE PROTECTION AGAINST MALARIA IN THALASSAEMIC RBC --- p.40 / Chapter SECTION TWO : --- RED CELL FRACTIONATION --- p.48 / Chapter CHAPTER 6 : --- COMPARISON OF FRACTIONATION TECHNIQUES --- p.48 / Chapter CHAPTER 7 : --- PERCOLL SEPARATION OF THALASSAEMIC RBC --- p.63 / Chapter SECTION THREE : --- INHIBITION OF P. FALCIPARUM ACTIVITY IN THALASSAEMIC RBC --- p.79 / Chapter CHAPTER 8 : --- IN VITRO CULTURE OF P. FALCIPARUM --- p.79 / Chapter CHAPTER 9 : --- PARASITE GROWTH IN THALASSAEMIC RBC --- p.92 / Chapter SECTION FOUR : --- OXIDATIVE STRESS AS A PROTECTIVE MECHANISM --- p.127 / Chapter CHAPTER 10 : --- ASSESMENT OF SENSITIVITY TO OXIDATIVE STRESS --- p.127 / Chapter CHAPTER 11 : --- EFFECT OF OXIDANT MODULATING AGENTS ON PARASITE ACTIVITY --- p.143 / Chapter SECTION FIVE : --- ULTRASTRUCTURE OF MALARIA PARASITES IN THALASSAEMIC RBC --- p.180 / Chapter CHAPTER12 --- p.180 / Chapter SECTION SIX : --- FUTURE WORK AND CONCLUSION --- p.202 / Chapter CHAPTER13 --- p.202 / REFERENCES --- p.205

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references. Also available in electronic version.

Thesis (M. Phil.)--University of Queensland, 2002. / Submitted for Master of Philosophy, University of Queensland June 2002 (rewrite). Includes bibliographical references.

No description available.

Rostock, Universiẗat, Habil.-Schr., 2007. / Text teilw. dt., teilw. engl. - Enth. 15 Sonderabdr. aus verschiedenen Zeitschr.