Effect of operating variables on IsaMill™ performance using platinum bearing ores

Includes bibliographic references.Comminution involves crushing and grinding operations. The grinding operations use the traditional tumbling mills and stirred mills to reduce the ore to the required fineness. This thesis intends to investigate the influence of design and operating variables on the IsaMillTM specific energy and product size, when grinding UG2 platinum-bearing ore. The main objectives of this work were to study the effects of operating variables on specific energy consumption and product fineness, and to investigate IsaMillTM scale-up protocol. The experimental studies were conducted using the M4 IsaMillTM on a laboratory scale and the M10 000 IsaMillTM on an industrial scale

Use of chest radiography in patients suspected of pulmonary tuberculosis

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Malarial Infection and Curable Sexually Transmitted and Reproductive Tract Infections Among Pregnant Women in a Rural District of Zambia.

Malarial infection and curable sexually transmitted and reproductive tract infections (STIs/RTIs) are important causes of adverse birth outcomes. Reducing the burden of these infections in pregnancy requires interventions that can be easily integrated into the antenatal care (ANC) package. However, efforts to integrate the control of malarial infection and curable STIs/RTIs in pregnancy have been hampered by a lack of evidence related to their coinfection. Thus, we investigated the prevalence of coinfection among pregnant women of rural Zambia. A prospective cohort study was conducted in Nchelenge District, Zambia, involving 1,086 first ANC attendees. We screened participants for peripheral malarial infection and curable STIs/RTIs (syphilis, Chlamydia, gonorrhea, trichomoniasis, and bacterial vaginosis), and collected relevant sociodemographic data at booking. Factors associated with malarial and STI/RTI coinfection were explored using univariate and multivariate regression models. Among participants with complete results (N = 1,071), 38.7% (95% confidence interval [CI] = 35.7-41.6) were coinfected with malaria parasites and at least one STI/RTI; 18.9% (95% CI = 16.5-21.2) were infected with malaria parasites only; 26.0% (95% CI = 23.5-28.8) were infected with at least one STI/RTI but no malaria parasites, and 16.4% (95% CI = 14.1-18.6) had no infection. Human immunodeficiency virus (HIV)-infected women had a higher risk of being coinfected than HIV-uninfected women (odds ratio [OR] = 3.59 [95% CI = 1.73-7.48], P < 0.001). The prevalence of malarial and STI/RTI coinfection was high in this population. An integrated approach to control malarial infection and STIs/RTIs is needed to reduce this dual burden in pregnancy

Factors Determining the Use of Voluntary Counselling And Testing For HIV and AIDs Among Men And Women In Malawi

Voluntary Counseling and Testing (VCT) is one of the measures used in the fight of HIV and AIDS in Malawi. WHO/UNAIDS/UNICEF (2011) estimated that about 440,000 to 510,000 people living with HIV and AIDS in Malawi were not getting treatment. This could be the case because they did not know their HIV status.  Knowing the factors that lead people to seek Voluntary Counseling and Testing services in Malawi could demystify this.  This study therefore investigated the determinants of Voluntary Counseling and Testing for HIV and AIDS among men and women in Malawi. The principal research focus was on the socio-economic and socio-demographic factors that determine one’s need to demand VCT services. A logistic regression model was used due to the categorical nature of the dependent variable i.e. whether one was tested or not.  Among women, the variables age, residence, education, marital status, employment, mode of employment and lifetime number of sexual partners were found to be significant factors influencing the uptake of VCT. With the lower class as the reference variable, the ‘rich group’ was found to significantly influence the uptake of VCT but not the middle class. On the men’s side, the variables age, education, region of residence, lifetime number of sexual partners, marital status, wealth status and employment were found to have a significant influence on VCT uptake. The results also show that a man’s place of residence and mode of employment do not affect VCT uptake. In summary, the findings show that for both men and women the variables; age, education and lifetime number of sexual partners were significant. The variables; residence and mode of employment were significant only for women while the variable region of residence was only significant for men. The variable wealth status had the rich group being significant among both men and women while middle group was insignificant among both men and women. The variables marital status and employment were significant at all levels for women while for men they had at least one variable not significant. The variable religion was insignificant for both women and men except one variable – other religion affiliation, which was significant among men. Keywords: Socio-economic and socio-demographic factors, Voluntary Counselling and Testing, Logistic Regression Mode

Sulfadoxine-Pyrimethamine Exhibits Dose-Response Protection Against Adverse Birth Outcomes Related to Malaria and Sexually Transmitted and Reproductive Tract Infections

: We conducted a prospective cohort study in Zambia among pregnant women who received intermittent preventive treatment using sulfadoxine-pyrimethamine (IPTp-SP). : We calculated the odds ratios (ORs) of adverse birth outcomes by IPTp-SP exposure, 0-1 dose (n = 126) vs ≥2 doses (n = 590) and ≥2 doses (n = 310) vs ≥3 doses (n = 280) in 7 categories of malaria infection and sexually transmitted and reproductive tract infections (STIs/RTIs). : We found no significant differences in baseline prevalence of infection across IPTp-SP exposure groups. However, among women given 2 doses compared to 0-1 dose, the odds of any adverse birth outcome were reduced 45% (OR, 0.55; 95% confidence interval [CI], 0.36, 0.86) and 13% further with ≥3 doses (OR, 0.43; 95% CI, 0.27, 0.68). Two or more doses compared to 0-1 dose reduced preterm delivery by 58% (OR, 0.42; 95% CI, 0.27, 0.67) and 21% further with ≥3 doses (OR, 0.21; 95% CI, 0.13, 0.35). Women with malaria at enrollment who received ≥2 doses vs 0-1 had 76% lower odds of any adverse birth outcome (OR, 0.24; 95% 0.09, 0.66), and Neisseria gonorrhoeae and/or Chlamydia trachomatis had 92% lower odds of any adverse birth outcome (OR, 0.08; 95% CI, 0.01, 0.64). Women with neither a malaria infection nor STIs/RTIs who received ≥2 doses had 73% fewer adverse birth outcomes (OR, 0.27; 95% CI, 0.11, 0.68). : IPTp-SP appears to protect against malaria, STIs/RTIs, and other unspecified causes of adverse birth outcome.<br/

The epidemiology of malaria, curable sexually transmitted and reproductive tract infections and their coinfection among pregnant women in a catchment area in Nchelenge District, Zambia

Introduction: Malaria and curable sexually transmitted and reproductive tract infections (STIs/RTIs) are important causes of adverse birth outcomes (ABO) and are both prevalent in most parts of sub-Saharan Africa. From a public health perspective, control of these infections requires interventions that are part of an integrated antenatal care package. The extent to which there may be coinfection increases the importance of such an integrated approach to reduce ABO. A systematic review and meta-analysis published in 2012 showed that the prevalence of malaria and curable STIs/RTIs among antenatal attendees in sub-Saharan Africa is considerable. However, the prevalence of malaria and curable STI/RTI coinfection has not been reported in any epidemiological setting. The primary objective of this thesis is to address this knowledge gap by estimating the prevalence of malaria, curable STIs/RTIs and their coinfection and to highlight the importance of an integrated approach to control malaria and STIs/RTIs in pregnancy. Secondary objectives of the study were to: (1) determine risk factors for malaria, curable STIs/RTIs and their coinfection; (2) estimate the prevalence of ABO and identify risk factors for ABO; (3) measure the in vivo efficacy and the prophylactic effect of sulphadoxine-pyrimethamine (SP) in pregnant women, and (4) characterise the molecular markers associated with parasite resistance to SP among pregnant women. Methods: A prospective cohort study of 1,086 antenatal attendees was conducted in Nchelenge District, Zambia. Consenting women visiting two health centres for their first antenatal care (ANC) visit were screened for malaria and curable STIs/RTIs (Chlamydia, gonorrhoea, trichomoniasis, bacterial vaginosis [BV] and syphilis). Socio-demographic data and maternal characteristics were also collected at enrolment. Sulphadoxine-pyrimethamine was administrated as intermittent preventive treatment to eligible women and they were followed up at day 28 for a second 13 malaria screening to determine the therapeutic and prophylactic failure of SP. At delivery participants were screened for placental malaria and data on birth outcomes were recorded. Univariate and multivariate analyses were conducted to determine the association between the potential risk factors for infection and ABO. Results: Of the 1086 women recruited 729 were successfully followed to delivery. The prevalence of malaria infection measured by microscopy was 31.8% (95% CI, 29.1-34.6) and by PCR was 57.8% (95% CI, 54.9-60.8). The risk of malaria infection was higher among pregnant women recruited from Nchelenge health centre compared to those attending the Kashikishi health centre (adjusted odds ratio [aOR] = 1.81; 95% CI, 1.38-2.37, P < 0.001), and HIV-infected women across health centres had a greater risk of malaria infection compared to HIV-uninfected women (aOR = 1.46; 95%, 1.00-2.13, P = 0.045). Infection with at least one STI/RTI was observed in 64.8% (95% CI, 61-67.4) of the participating women. With the exclusion of BV the prevalence of infection with at least one curable STI was 34.5% (95% CI, 31.7-37.4). Infection with at least one STI was associated with BV. In comparison to uninfected women, women infected with BV were at a higher risk of being infected with at least one STI (aOR 1.44; 95% CI, 1.08-1.92, P = 0.012). HIV-infected women had a higher risk of infection with BV than HIV-uninfected women (aOR 1.87; 95% CI, 1.24-2.83, P = 0.003) and women infected with at least one STI had a higher risk of BV (aOR 1.40; 95% CI (1.07 -1.84, P = 0.01). Among participants with complete results (n=1071), 38.7% (95% CI,35.7-41.6) were coinfected with malaria parasites and at least one STI/RTI; 18.9% (95% CI, 16.5-21.2) were infected with malaria parasites only; 26.0% (95% CI, 23.5-28.8) were infected with at least one STI/RTI but no malaria parasites, and 16.4% (95% CI, 14.1-18.6) had no infection. The risk of malaria and curable STI/RTI coinfection was higher among HIV infected women than HIV-uninfected women (OR; 3.59 [95% CI, 1.73-7.48], P < 0.001). The prevalence of composite ABO was 35.1%. Women shorter than 1.5m were at a higher risk of experiencing at least one ABO (aOR 1.55; 95% CI, 1.10-2.18, P = 0.02). The risk of having ABO among para II was less than half of the risk observed in 14 primiparous women (aOR 0.41; 95% CI, 0.27-0.61, P < 0.001) and much lower among multiparous women (aOR 0.32; 95% CI, 0.22-0.48, P < 0.001). Having taken two or more doses of SP during pregnancy was protective against ABO (aOR 0.47; 95% CI, 0.31-0.72, P = 0.001). None of the infections (malaria, curable STIs/RTIs and their coinfection) diagnosed at first ANC were associated with ABO. The prevalence of highly resistant quintuple mutant was 68.8% among first ANC attendees. Despite the moderate prevalence of the quintuple mutant among pregnant women, SP cleared parasitaemia in 86% of the asymptomatic malaria cases among HIV-negative women Conclusion: The prevalence of malaria, STI/RTI and their coinfection at first ANC in this study population was considerable. However, no association was found between ABO and infection with malaria or STI/RTI or their coinfection. This lack of association is partially a result of interventions within the ANC package including treatment of some STI/RTI, intermittent preventive treatment in pregnancy with SP and iron and folic acid supplementation. Sulphadoxine-pyrimethamine retains partial efficacy against P. falciparum malaria in this area with moderate prevalence of the quintuple mutant. While continuing the policy of offering intermittent preventive treatment with SP during pregnancy, an alternative preventive therapy that is effective against both malaria and STIs/RTIs needs to be considered

Guidelines for promoting supplementary infant feeding techniques among HIV-positive mothers

Vertical transmission of HIV is still a growing concern in South Africa. Breastfed infants are still at risk as HIV is present in breast milk, leaving HIV-positive mothers unsure of the best feeding option for their infants. However, there are various infant feeding techniques that HIV-positive mothers can use to supplement breastfeeding and flash-heat is one of them. Flash-heat is heat treating expressed breast milk to deactivate HIV for infant feeding. This study explored the possibility of HIV-positive mothers to practice flash-heating method for their infants exclusively for four months as a strategy to prevent vertical transmission of HIV. A descriptive, explorative and contextual design using a mixed method was used to obtain data from mothers in a post natal ward at Tembisa hospital. The mixed method used was useful in identifying the number of HIV-positive mothers who would adopt the flash-heat technique, the characteristics of mothers whom the technique could be promoted to, the factors that influence/affect the choice of infant feeding for these mothers, as well as their feelings associated with the feeding technique. Most (74%) mothers had a positive response to the flash-heat technique compared to 10% who were uncertain. They believed that heat treating their breast milk would result in their infants being HIV-free. In addition they believed that this method was cheaper than formula feeding and expressed positive feelings about touching their breast milk while expressing with no adverse feelings of expressing into a glass jar. Furthermore, findings of this study indicated that HIV-positive mothers in a public health facility would adopt flash-heat as an alternative infant feeding method. Thus practical guidelines to promote this feeding method were proposed. The proposed draft guidelines which promote the use of the flash-heat infant feeding method for HIV-positive mothers in public sector facilities will be communicated to relevant authorities such as the National Department of Health. These guidelines support the new policy shift to exclusive breastfeeding as a child survival strategy in South Africa.Health StudiesD. Litt. et Phil. (Health Studies

Factors influencing HIV-positive mothers to choose to use the flash-heat process of heating breast milk in South Africa

The objective of this cross-sectional study was to establish factors influencing HIV-positive mothers to choose to use the Flash-heat (FH) method to feed milk to new-born babies in South Africa. A total of 70 HIV-positive mothers were selected using purposive sampling methods. Backward stepwise binary logistic regression analysis was carried out to establish their willingness to use the FH feeding method. More than half (54.3%) the mothers were not breastfeeding their infant and among them a third (31.6%) mentioned that breastfeeding was difficult and this was given as the reason for not breastfeeding. Most of the mothers (74.3%) reported that they would use the FH method at home as a feeding method for their infants, and most (83%) of the mothers reported that they were willing to heattreat their expressed breast milk (EBM) in a pot on a Primus stove until the water boils-as required by the FH guideline. The results showed that mothers who reported that they were willing to heat EBM at home were 24 times more likely to adopt FH compared to those who were not willing to heat EBM at home (OR=24.23, p=0.001). Also, those mothers who reported that they were willing to express milk for 4 months had 22 times more chance of adopting FH than mothers who reported that they were not willing to express for 4 months (OR=21.60, p=0.016). The findings suggest that HIV-positive mothers in a public-health facility would adopt flash-heating as an alternative infant-feeding method at home.www.biomedres.infoam2017School of Health Systems and Public Health (SHSPH