Diarrhoea is one of the killer diseases resulting from the dehydration and loss of electrolytes through profuse and excessive excretion of loose stool. The pathoaetiologies include infections, intestinal inflammation, imbalanced intestinal oxidative homeostasis and altered motility. Treatment with oral rehydration therapy (ORT) is a key intervention especially in secretory diarrhoea as supportive therapy. Symptomatic and non-symptomatic therapies directed at treating the intestinal tissues are available. However, these conventional treatments are still not sufficient in curing diarrhoea due to their associated hazards such as the development and spread of drugresistant pathogens, changes in normal intestinal bacteria flora and potential chronic toxicity. Therapies targeted at intestinal tissue include antimotility and antisecretory agents have adverse effects such as addictiveness, constipation and fatal ischaemic colitis. Many ethnopharmacological and ethnobotanical therapies for treating diarrhoea exist among different cultures. The aims of this study were to evaluate the biological activities of plant extracts against some diarrhoeal pathophysiologies. A literature search in English of published articles and books that discussed ethnobotanical uses of medicinal plants in southern Africa was conducted. A list of 230 medicinal plants used in South African traditional medicines for treating diarrhoea and associated complications was created. The list included family, genus, species, biological activities and bioactive isolates as well as the remedies for diarrhoea. Twenty seven species were selected to evaluate for antimicrobial, antioxidant and anti-inflammatory activities. Safety of the plants was determined by determining the cytotoxicity of the crude extracts against Vero African green monkey kidney cell lines using a standard method. Motility effects of Bauhinia galpinii (BGE) and Combretum vendae (CVE) were determined by modulation of the contractility process of the isolated rat ileum induced by spasmogens. Phenolic compositions of the crude extract were determined using various standard methods and finally bioactivity guided isolation of antimicrobial and antioxidant compounds from BGE and CVE were carried out using open column chromatography. Identification and characterization of the isolated compounds was achieved by NMR, EI-MS and UV spectroscopy. The non-polar fractions had good antimicrobial activities with MIC ranged between 19 – 1250 μg/ml while the polar fraction had moderate antimicrobial activities with MIC ranged between 39 - >2500 μg/ml. In general the non-polar fractions had a higher antimicrobial activity. The crude extracts contained wide range phenolic compounds with a total phenolic (74.91±1.26 to 467.04±15.82 mg GAE/g plant material), and total flavonoids (11.27±3.37 to 176±5.96 mg EQ/g plant material). The antioxidant activities were concentrated and potentiated in the polar fractions. The non-polar fractions had poor antioxidant activities with EC50 values ranging from 0.21±0.03 to 303.65±3.84 μg/ml for DPPH radical scavenging and 0.43±0.03 to 1709±91.44 μg/ml for ABTS radical scavenging. The crude extracts had selective COX-1 inhibitory activities ranging between 41.70 to 84.61% and had no COX-2 inhibitory activity. All the extracts tested had 15-LOX inhibitory capacity with LC50 values ranging between 0.86±0.27 and 111.44±37.28 μg/ml. The cytotoxicity results indicated a wide variation in toxic potential of the crude extracts with LC50 values ranging from 3.51 to 741.90μg/ml. The BGE extracts had dual activities as spasmolytic by stimulating the spontaneous contractility and also agonised contractions induced by spasmogens but it inhibited K+ induced contraction. CVE had spasmodic activities through a multiple mechanisms inhibiting contractions induced by spasmogens and K+ in a dosedependent manner. Several bioactive xompoundswere isolated from the Combretum vendee leaves, There were triterpenoids (ursol-12-en-28-oic acid, mixtures of corosolic acid and maslinic acid, and asiatic acid and arjunolic acid) as well as bibenzyls combretastatin B5-O-2’-β-D-glucopyranoside, combretastatin B1-O-2’-β-D glucopyranoside and a flavonoid (apigenin). From Bauhinia galpinii the following bioactive compounds were isolated and characterized: P-3 ethoxy sitosterol, one new flavone (5, 7, 4’ 5’ tetrahydroxy-2’-methoxyflavone (isoetin 2’-methyl ether) or 5, 7, 2’ 5’ tetrahydroxy-4’-methoxyflavone (isoetin 4’-methyl ether)), 3, 5, 7, 3’, 4’-pentahydroxyflavone and 3, 5, 7, 3’, 4’, 5’- hexahydroxyflavone, quercetin-3-O-β-galactopyranoside and myricetin-3-O-β-galactopyranoside. The extraction protocol used in this work potentiated the antimicrobial activities in the non-polar fractions while antioxidant activities were potentiated in the polar fractions. This indicated that using polar solvents as extractant for treating infectious diarrhoea may not be quite effective unless some other antidiarrhoeal mechanisms are involved. Therefore, mixture of organic solvent (ethanol) and water can be recommended for broad-based activity. Bauhinia galpinii extracts had a dual- mechanism of action (prokinetic and relaxant) on gastro-intestinal motility, depending on the prevalent patho-physiological condition and Combretum vendee mediated spasmolytic effects on isolated rat ileum through multiple inhibitions of a wide range of contractile stimuli. Hence, the presence of multiple acting spasmolytic activities in the plant extract might be contributing towards its effectiveness in treating diarrhoea and abdominal spasm. The uses of these plants in traditional medicine need to be monitored closely because of the selective inhibition of COX-1 and its associated GIT injury, and the high toxicity potential of some of the extracts. Further work evaluating the antidiarrhoea mechanisms, identification and isolation of bioactive compounds, sub-acute and acute toxicity of the plant extracts is recommended. / Thesis (PhD)--University of Pretoria, 2012. / Paraclinical Sciences / unrestricted

The aim of this thesis was to analyse possible effects of prenatal arsenic exposure on foetal and infant health. The setting is Bangladesh, where two cohorts were studied, both part of a health and demographic surveillance system in Matlab. A historical cohort 1991-2000 included 29,134 pregnant women with information on drinking water sources and arsenic testing of tube well water. A prospective cohort study included pregnant women 2002 - 2003 where urinary arsenic concentrations were assessed twice during pregnancy; 2,924 women and their pregnancy outcomes were evaluated for foetal loss, perinatal and infant mortality; 1,578 mother-infant pairs were analysed for size at birth; and 1,552 were analysed for morbidity during infancy. Women exposed to arsenic levels ≥ 50 µg/L in water had an increased risk of foetal loss and infant death in comparison with women exposed to arsenic levels < 50 µg/L. These findings were confirmed in the prospective cohort study. Women with urine arsenic concentrations at the 5th quintile had 62% increased risk of spontaneous abortion (OR 1.62, 95% CI 1.04 - 2.55) in comparison with women who had arsenic concentrations at the 1st quintile level. Increased risks of perinatal morality (RR 3.01, 95% CI 1.07 - 8.45) and infant mortality (RR 5.01; 95% CI: 1.41 - 17.84) were also observed at the 5th quintile of exposure. Significant negative dose-effect associations were found between arsenic exposure and birth weight, head and chest circumferences at a relatively low level of exposure (<100 µg/L in urine). In this range of exposure birth weight decreased by 1.68 g (SE 0.62) for each 1 µg/L increase of arsenic in urine. In comparison with exposure at the 1st quintile level the risk of lower respiratory tract infection was significantly increased (RR 1.68, 95% CI 1.35-2.07) for women who had urinary arsenic concentrations at the 5th quintile level. The risk was also increased for diarrhoeal diseases. The study findings highlight the negative effects of arsenic exposures on pregnancy outcomes and infant health. Mitigation programs need to be strengthened and women of reproductive ages should be prioritized in arsenic affected regions worldwide.

Rotavirus infection causes acute gastroenteritis in children younger than five years of age, and commonly occurring human rotavirus strains include G1 - G4 and G9 associated with P[4], P[6] and P[8]. In this study, of 6050 stool samples collected from a Private Pathology Practice in Pretoria, March 2010 - August 2011, 664 tested positive using Coris test-strips. Of these samples, 752 were retested using EIA and, results showed: Coris sensitivity was 93,7% and specificity 99,8%; the winter epidemic peaked in July of both years; more males and children under 30 months of age were particularly vulnerable to infections. Rotavirus-positive samples from Trichardt, Rustenburg and Middelburg were analysed by PAGE and RT-PCR showing circulating strains as mainly G8P[4] (60%) with short electropherotypes, G12P[8] (66%) with long electropherotypes, and G1P[8] at low incidence in the 2010/2011 seasons. These results suggest additional research to monitor the impacts of recently introduced rotavirus vaccines on changing strain profiles in South African communities / Life & Consumer Sciences / M.Sc. (Life Sciences)

Rotavirus infection causes acute gastroenteritis in children younger than five years of age, and commonly occurring human rotavirus strains include G1 - G4 and G9 associated with P[4], P[6] and P[8]. In this study, of 6050 stool samples collected from a Private Pathology Practice in Pretoria, March 2010 - August 2011, 664 tested positive using Coris test-strips. Of these samples, 752 were retested using EIA and, results showed: Coris sensitivity was 93,7% and specificity 99,8%; the winter epidemic peaked in July of both years; more males and children under 30 months of age were particularly vulnerable to infections. Rotavirus-positive samples from Trichardt, Rustenburg and Middelburg were analysed by PAGE and RT-PCR showing circulating strains as mainly G8P[4] (60%) with short electropherotypes, G12P[8] (66%) with long electropherotypes, and G1P[8] at low incidence in the 2010/2011 seasons. These results suggest additional research to monitor the impacts of recently introduced rotavirus vaccines on changing strain profiles in South African communities / Life and Consumer Sciences / M.Sc. (Life Sciences)

Worldwide, around 780 million people lack access to improved drinking water sources and 2.5 billion lack improved sanitation (WHO, 2013c). The United Nations (UN) declared access to drinking water and sanitation a fundamental human right in July 2010 (UN, 2010). Each year there are approximately 1.7 billion cases of diarrhoea worldwide. It kills around 2.2 million people globally each year (4.0% of all death), of which 760,000 are children under five years old, mostly in developing countries. Diarrhoeal disease is the second leading cause of death in children under five years old (WHO, 2013c). The lack of drinking water, sanitation facilities and good hygiene practises are considered the main causes for diarrhoea (WHO, 2013d). For this dissertation, a specific health intervention (CBHFA - Community based Health and First Aid) was evaluated which had taken place during three years in 20 target communities in Bokeo Province in Lao PDR. The activities were in the field of water supply, sanitation facilities and hygiene education against diarrhoea. Objective: The objective of this survey study is to show that hygiene behaviour changes in a certain target population through the implementation of CBHFA, if a) individuals have access to improved drinking water sources; b) have access to a HH latrine and c) receive hygiene information. An improvement by 50.0% for each of the hygiene indicator: water use and treatment, hand washing, sanitation, food handling, waste disposal and cleanliness was considered a behavioural change and thus an illustration of the effectiveness of CBHFA. Methods: Hygiene behaviour was measured before and after the CBHFA intervention through above mentioned hygiene indicators. Quantitative figures were collected at two different points in time, in a pre- and post-survey, then analysed and evaluated. Interviews and observations were done through community assessment/evaluation with 20 focus groups in all target communities. 488/487 (pre-survey/post-survey) households (HHs) were interviewed and observed. Knowledge about diarrhoea (definition/signs, prevention, danger, treatment and modes of transmission) was tested. The change in hygiene behaviour as well as the water and sanitation situation was measured through a comparison of the pre- with the post-results. The Relative Risk (RR) and Odds Ratio (OR) were calculated for different variables, such as ethnicity, gender, education, age and income and their changes before and after the implementation of the health intervention project. Results: Water use and sanitation This research clearly shows that the availability of a public water system (gravity fed water system) in the target communities has increased (from 45.0% to 85.0%) as well as the availability and use of hand flush pit latrines (from 20.2% to 63.7%). 95.2% of HHs that owned a latrine used them. The water treatment through “boiling” (from 70.1% to 75.0%) in HHs has improved, but not significantly. Open defecation (OD) decreased from 78.9% to 34.7% (by 56.0%). However it is still practised by more than a third of HHs. OD is one of the highest transmission risks of diarrhoea and can only be eliminated by 100.0% sanitation within the community (WHO, 2008). Hand washing There has been a significant increase of interviewees washing their hands with water and soap (from 8.0% to 38.0%). This result was confirmed by observing the existence of soap in kitchens with 33.0% and in latrines with 20.3% of HHs. The ORs calculated for hand washing “with water and soap” and compared for each stratum of the variables gender, formal education and age group show no statistical difference, but there is a statistical difference regarding income and washing hands “with water and soap”. Relevant occasions for hand washing, such as “after defecation” and “before food preparing”, that could reduce the risk of the transmission of diarrhoeal diseases have not achieved a meaningful improvement. Waste disposal Waste disposal, such as collecting and burning has increased from 23.4% to 42.5% (by 81.6%) according to the HH responses. A matter of concern is the increased HHs (from 26.8% to 29.0%) that disposed their waste by “throwing the waste outside the village”. This waste disposal method is statistically different regarding formal education. The number of HHs with non-educated interviewees where this method was practised has increased over the intervention time in contrast to the number of HHs with educated interviewees. Knowledge about diarrhoea Knowledge was tested. The definition/signs of diarrhoea, its prevention, danger, treatment and modes of transmission were not known by more than 50.0% of the interviewees. It seems that hygiene indicators can improve without this awareness, if improved water and sanitation facilities are provided. However, further investigations are required. The results show that knowledge about diarrhoea is not statistically different regarding formal education and age, but regarding gender. Giving at least one right answer was higher in women than in men. Results and income The results of the pre-survey show that income is significantly associated with owning a latrine and using water vessels, such as pots and jars for drinking, but not associated with using soap for hand washing. However after the implementation of the health interventions, the comparison of the ORs of the HHs with low income per capita (≤200,000 LAK, exchange rate: 1 EUR=10,000 LAK) versus the HHs with high income per capita (>200,000 LAK) shows a statistical difference regarding hand washing “with water and soap”. The OR of the high income per capita group is stronger than the OR of the low income per capita group. Owning a latrine does not show a statistical difference regarding income due to the provision of subsidized latrines by the health intervention project. Occurrence of diarrhoeal diseases The pre-survey results clearly show that diarrhoeal diseases ranked at the top of all recorded cases of diseases. The post-survey results show fewer villages with diarrhoeal outbreak and reduced numbers of reported cases. Summary: An improvement by 50.0% has been reached in hand washing with water and soap, reduction of OD, safe food (by covering), waste disposal (by collecting and burning) and cleanliness but no improvement has been reached in the hygiene indicators “water use and treatment” and in crucial “occasions for hand washing (after defecation, before food preparing)”. Therefore the CBHFA intervention is considered only partially effective in the field of hygiene behaviour change.