Interactions between two digenean parasites, Diplostomum spathaceum and Schistosoma mansoni , and their respective intermediate snail hosts, Lymnaea stagnalis and Biomphalaria glabrata , were investigated. D.spathaceum infections in juvenile L.stagnalis became patent 9 to 10 weeks post-infection and inhibited initiation of host oviposition. Adult L.stagnalis resisted infection with D.spathaceum . Both juvenile and adult B.glabrata were susceptible to S.mansoni and the infections become patent 5 weeks after infection. B.glabrata infected as juveniles failed to begin egg-laying whilst those infected as adults showed a dramatic reduction of oviposition 4 weeks post-infection, i.e before the onset of patency. Infection with D.spathaceum , but not S.mansoni , resulted in the appearance of three polypeptides (68.3, 40.8 &'38 34.5 kDa) in snail serum. The additional peptides were not directly related to failure of snail reproduction and are probably of parasite origin. Reproductive failure of infected snails was linked to the later stages of cercarial development by a method developed to manipulate infections using the anthelmintic, praziquantel. D.spathaceum and S.mansoni infections were suppressed in their snail hosts following oral treatment with praziquantel. Praziquantel was selective for cercariae and inhibited cercarial shedding of both digenean species for approximately 5 to 6 weeks before recovery. In mature B.glabrata , harbouring 7 week-old infections of S.mansoni , suppression of cercarial shedding was accompanied by temporary recovery of reproduction. Snail fecundity was halted once more 2 weeks prior to resumption of cercarial shedding. Reproductive recovery depended upon the state of infection and maturity of the host at infection. Failure of D.spathaceum to infect adult L.stagnalis was attributed to the more developed and therefore more competent internal defence system of adult snails. Infection of juvenile, immunologically immature, L.stagnalis with D.spathaceum resulted in several changes in the snail immune system and infection seemed to prevent normal development of several facets of snail immunity.

A dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Nursing Johannesburg, 2015 / The purpose of the study was to explore and describe the experience of a nurse in a private sector hospital after contracting a highly pathogenic novel haemorrhagic fever from a patient and to explore the context of the environment in which she was cared for. Patients with complications from severe acute febrile diseases are admitted to intensive care units. During 2008, two patients with an unidentified disease were airlifted from Zambia and admitted to a private sector hospital in Johannesburg, South Africa. Four of five patients died in the outbreak before a diagnosis of Lujo virus was confirmed. Countries to the North and West of South Africa are known to be endemic areas of Viral Haemorrhagic Fevers (VHF). This puts South Africa at risk for imported VHF and future outbreaks. The sole survivor was able to share useful advice for future implementation from experiences during the period of her illness. Unique challenges of the management and environment of this outbreak may assist in future outbreaks. A bounded single case study design using mixed multiple qualitative approaches including phenomenology was used to underpin and guide the study of the participant’s experience. The participant’s reflection was subjected to in-depth analysis using Colaizzi’s framework. Triangulation using the reflection of the contents of the “Outbreak diary” – a journal kept by members of the managing team and clinical nursing records was undertaken. Emerging themes were grouped into four main themes: Initial contact with the source; Admission is inevitable; Moments of care and Always involved, which have been discussed in depth. The information gleaned from these themes can be applied to practice in future. The safety of patients and staff in an outbreak depends on attention to detail. History taking was identified as crucial for appropriate infection prevention methods to be put in place. Contact tracing and monitoring is key to containing an outbreak. The definition of contacts is based on the risk profile. Successful management requires coordination by a team of multi-skilled senior persons who have the authority to make decisions. As with all critically ill patients, the participant experienced many emotions. The lack of ability to control situations and care appeared to be important. Feelings of guilt still remain. A different meaning of kindness was exposed. Infection prevention and isolation is part of routine nursing practice and should be applied if there is an index of suspicion of a contagious disease. Care of patients with VHF is not routinely taught however maintaining basic principles may prevent spread and thus further cases. Support of and communication with all staff in the hospital is important for commitment. The setting in this study was a hospital in the private sector. The revelations of this case study can be used in future research to develop guidelines for use by the outbreak management team. They are intended to improve the management and emotional support of the health care workers as well as the victims and can be applied to outbreaks of any nature.

Thesis (Ph.D.)--University of the Witwatersrand, Faculty of Health Sciences, 2012. / The development of an effective HIV-1 vaccine is critical in mitigating the global HIV epidemic. Understanding the interplay between host immune functions, such as cellular memory differentiation, activation, inflammatory cytokine production and the virus, may provide key insight into anti-HIV immunity that can inform vaccine development. This PhD aims at understanding and identifying T cell memory, functional profiles and the effect of immune activation on in vivo HIV-1 control during primary/early infection. Furthermore, this study aims to examine and understand the potential mechanisms related to immune activation during primary HIV-1 infection. Use was made of a unique cohort of individuals recruited during primary HIV-1 infection and using a battery of assays to characterize and identify properties and mechanisms of T cell reactivity and activation. Multiparameter flow cytometry was used to measure memory differentiation (CD27 and CD45RO), activation (CD38, HLA-DR), proliferation (Ki67), and multiple cellular functions (CD107, IFNγ, IL-2, MIP-1β and TNFα) of total and antigen-specific CD4+ and CD8+ T cells from 15 HIV-1 and CMV-coinfected individuals followed over 15 months of HIV-1 infection. Plasma samples were used to measure markers associated with intestinal permeability (LBP, sCD14, I-FABP and IgM EndoCAb) and inflammation (IL-1β, IL-6, IL-7, IL-10, IL-12p70, TNFα and MCP-1). The differentiation profile of HIV-Gag specific memory CD4+ and CD8+ T cells was found to be mainly characterized by an early differentiated (ED) memory phenotype relative to CMV- specific CD4+ and CD8+ T cells. Moreover, the proportion of HIV-specific ED-memory CD4+ T cells inversely associated with viraemia, suggesting that HIV-1 antigen burden could be shaping the differentiation of HIV-specific memory CD4+ T cells during primary infection. Primary HIV-1 infection was also characterized by significantly elevated levels of activated and proliferating total and HIV-specific memory CD4+ and CD8+ T cells, which positively correlated with viraemia. Furthermore, upon sorting of total activated memory CD4+ T cells, these cells harboured more gag provirus DNA than non-activated memory cells, suggesting that activated memory CD4+ T cells support ongoing HIV-1 replication. When examining the relationship between memory differentiation and activation markers, the level of T cell activation was equally expanded across the different memory CD4+ T cell subpopulations, suggesting that memory differentiation of CD4+ T cells was unlikely driven per se by the level of T cell activation. In addition, when teasing out events that may result in T cell activation during primary HIV-1 infection using statistical models, plasma markers of microbial translocation and inflammation were found to correlate with immune activation. The lack of these associations in HIV-uninfected controls suggests that microbial translocation and inflammation were unlikely causative. Analysis of the polyfunctional profile of memory T cells during primary HIV-1 infection showed that HIV-specific CD4+ and CD8+ T cell responses are less polyfunctional relative to CMV-specific memory CD4+ and CD8+ T cell responses. Furthermore, the polyfunctional status of HIV-specific CD4+ T cells significantly correlated with viraemia at 3 months post-infection, indicating that the polyfunctionality of memory CD4+ T cells is likely driven by HIV-1 antigenemia. Overall, these observations suggest that HIV-1 antigenic burden appears to be a central driver of memory differentiation, activation/inflammation and polyfunctionality of T cells. Given the impact of HIV-1 viraemia on immune activation and memory T cell dysfunction (as measured by limited polyfunctional HIV-specific responses), preventing high levels of viral replication, with a vaccine or other early interventions may serve as an important strategy for delaying HIV-1 disease progression.

M.Med. (Diagnostic Radiology), Faculty of Health Sciences, University of the Witwatersrand, 2011 / Pneumocystis jirovecci pneumonia (PJP) in HIV/AIDS is a significant opportunistic infection. As CD4 counts decrease, so does specificity of chest X-ray (CXR). AIM: To determine the proportion of bronchoscopically proven PJP in HIV infected adults, CD4 counts, CXR signs and compare PJP to TB. METHODS: The proportion of bronchoscopically proven PJP and co-infection was determined. Sensitivity and specificity of CXR for the diagnosis of PJP and TB, and frequency of CXR signs were determined. RESULTS: PJP was present in 26.6% and co-infection 19%. Median CD4 (13 cell/mm3) was significantly lower for PJP patients (p = 0.0089). CXR sensitivity for PJP was 33% and specificity was 100%. Bilateral, multilobar and diffuse disease, bronchopneumonia, nodules and cavitation overlapped for PJP and TB. Unilateral and unilobar disease indicated TB over PJP. Effusions and lymphadenpopathy were not seen with PJP. CONCLUSION: PJP makes up a quarter of indeterminate diagnoses in HIV infected adults. Sensitivity of diagnosis on CXR is low. The CXR diagnosis of TB is made more confidently, but is overcalled. In patients with low CD4 levels, a diagnosis of PJP should be considered as important as TB.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Medicine in the branch of Radiology Johannesburg, 2011 / Management guidelines for urinary tract infections (UTI) invariably include renal ultrasound (RUS). Adequacy of RUS requests and reports is important for clinical practice. Aim To assess the adequacy of paediatric RUS requests and reports, the effects of the former on the latter, the effect of reporter`s rank, determine the yield and correlate adequacy with regard to the frequency of pathology. Materials and Methods Retrospective review of RUS reports of children was performed. A “Request Adequacy Score” (total 3) and a “Report Adequacy Score” (total 21) based on the RSNA reporting template was developed. A UTI subgroup was created. Results Mean “Report Adequacy Score” was 6.67. Residents performed better than consultants. There was no significant factor correlating with report adequacy. Hydronephrosis was the commonest pathology. Conclusion RUS requests and reports are inadequate. To improve reporting a renal ultrasound reporting template was developed.

MMed (Otorhinolaryngology), Faculty of Health Sciences, University of the Witwatersrand / HIV/AIDS continues to be an important public health challenge in sub Saharan Africa. It is estimated that approximately 68% of people living with HIV in the world are from this region [1]. South Africa has the largest infected population in the world, the adult (15-49 years) HIV prevalence is estimated at 17.64% [2]. It has been estimated that 40 - 70% of such HIV positive individuals present with head and neck manifestations, which include infection, inflammation and tumours, and are often the only and initial presenting sign [3,4]. Peritonsillar abscess is the most common deep infection of the head and neck in young adults and can occur in all age groups, but the highest incidence is in adults 20 to 40 years of age [5]. The aim of this study was to assess the relationship between peritonsillar abscess and the HIV status of patients. Method: An analytical cross sectional study utilising retrospective clinical data from ward registers, patient records, treatment registers and National Health Laboratory System (NHLS) databases. This study was conducted in the adult ENT ward at the Chris Hani Baragwanath Hospital and sample consisted of patient records over a 4 year period from January 2005 to December 2008. All patients admitted to the ENT ward with the discharge diagnosis of peritonsillar abscess that have been tested for HIV were included in this study. In this study period 450 patient files were reviewed of which 291 fulfilled the inclusion criteria. The demographic details, clinical presentation which included head and neck manifestations of HIV, the HIV status, management and complications of peritonsillar abscess were recorded. This data was analysed using STATA-10 software. Results: The age ranged from 15 to 63 years with a mean (SD) 29.3 years (9.58). From the 291 patients, 86 (29.55%) were HIV positive. This is significantly higher than the adult (15-49years) HIV prevalence rate of 17.64% [6]. The male: female ratio of HIV positive patients 1:1.53. Forty-nine (16.84%) patients presented with cervical lymph nodes of which 65.31% were HIV positive (P< 0.001). From the 86 HIV positive patients oral candida was present in 15.12% (P<0.001), lymphoma in 6.98% (P<0.001), oral hairy leukoplakia in 2.33%, Kaposi’s sarcoma in 1.16% and complications (parapharyngeal abscess) 3.48%. There was no statistical significance in the management of HIV positive patients, however hospital stay was longer with a mean of 3.802 days (P<0.001). From this study sample the HIV prevalence of 29.55% suggests that peritonsillar abscess may be an early clinical marker of HIV infection. Due to the high incidence of head and neck manifestations in HIV positive patients identifying a clinical marker (quinsy) in the earlier stages of HIV infection would allow for better screening, earlier diagnosis and treatment of HIV infection.

MMed, Haematology, Faculty of Health Sciences, University of the Witwatersrand / Background: Mycobacterium tuberculosis (MTB) infection remains a serious public health challenge in sub-Saharan Africa. Rapid and early diagnosis is critical in the successful control of this eminently treatable infection. This study compared the diagnostic usefulness of culture, bone marrow trephine biopsy granulomata, bone marrow trephine biopsy Ziehl-Neelsen (ZN) stain and bone marrow mycobacterial polymerase chain reaction (PCR) in establishing the diagnosis of mycobacterial infection in HIV infected patients. Materials and methods: The trephine biopsies of HIV positive patients done for the investigation of suspected tuberculosis were reviewed for granulomata and stained with ZN stain. The corresponding bone marrow aspirates were subjected to DNA real-time PCR analyses using LightCyler TB Kit® (Roche Diagnostic). Culture results were used as diagnostic gold standard. Results: Of the 60 patients studied, 24 were culture negative. Of the 34 culture positive, 62% were Mycobacterium tuberculosis and 38% were Mycobacterium avium intracellulare. Using the culture method as a gold standard, the sensitivities and specificities were 97% and 23% for bone marrow trephine biopsy granulomata, 65% and 58% for bone marrow trephine biopsy ZN staining and 50% and 73% for bone marrow aspirate PCR analysis respectively. Ninety-seven percent of all trephine biopsies with positive ZN stain had granulomata. Conclusion: The presence of granulomata in bone marrow trephine biopsies of HIV infected patients appear to have a high diagnostic yield whilst mycobacterial PCR has the lowest yield but highest specificity. These results should be confirmed in a prospective case controlled study because the sample size in this study was small, and the study was a retrospective one.

Introduction Bacterial vaginosis (BV) is a highly prevalent vaginal infection which poses a significant public health burden in Sub-Saharan Africa (SSA) due to its association with HIV, other STIs and several gynaecological and obstetrical complications. The aim of this study was to explore the underlying and proximate factors associated with BV and the relationships between them. Materials and Methods This study was a cross-sectional secondary analysis of the data collected during the Microbial Development Program (MDP) 301 trial. Logistic regression and structural equation modelling were used to test for the associations between BV and the explanatory variables and to test for the direct, indirect and total effects of the variables on BV. Results A total of 2 470 women were included in the analysis and of these 2 203 were aged 40 and below. The majority of them were unemployed at 72% and 51,8% were in the lowest socio-economic level. The baseline prevalence of BV was 40.5%. In the logistic regression, high socio-economic level (AOR=1.66; 95% CI 1.04-2.64) and using a condom during their last sexual encounter (AOR 0.82; 95% CI 0.69-0.97) were associated with BV infection. The STIs significantly associated with BV infection were: Herpes Simplex Virus 2 (HSV2) (AOR=1.31; 95% CI 1.10-1.56), trichomoniasis (AOR=2.68; 95% CI 1.97-3.64) and chlamydia infection (AOR 2.02; 95% CI 1.61-2.62). In the structural equation modelling (SEM) high socio-economic status had a positive direct effect on BV infection (beta=0.12, OR=1.14).Condom use during the last sex act had a negative direct effect on BV (beta=-0.043, OR=0.96). The presence of T.vaginalis, HSV2 or chlamydia infection had significant positive effects on BV infection. Conclusions Sexual behavioural factors and the presence of STIs were significantly associated with BV. The SEM analysis showed the interaction of contraceptive use and sexual behavioural factors. No interaction between the STIs and sexual behaviour could be demonstrated in this study.

Introduction Streptococcus pneumoniae (the pneumococcus) is a leading cause of death in under-five children. The HIV/AIDS epidemic in sub-Saharan Africa contributes substantially to the pneumonia burden in the region. Vaccination against pneumococcus is a core component of the pneumococcal disease control program. It is a good, practical and cost-effective option to overcome some of the difficulties in facing the factors which facilitate the occurrence of pneumococcal disease. The aim of this study was to assess the persistence of efficacy of 9-valent pneumococcal conjugate vaccine (PCV9) against radiographically-confirmed pneumonia among children over 24 months of age in comparison to children before 6 months and between 6 and 24 months of age in South Africa. Materials and methods The study was an analytic cohort study using secondary data of a randomised controlled trial (RCT) of PCV9 from the Respiratory and Meningeal Pathogens Research Unit (RMPRU), University of the Witwatersrand. STATA and Epi-info computer software programs were used in the analysis. Findings Three thousand seven hundred PCV9 trial participants, who had chest x-ray records, form the cohort of the study. Overall PCV9 efficacy against radiographically-confirmed pneumonia was 7%. PCV9 was more efficacious against radiographically-confirmed pneumonia in 6 to 24 month of age children (21%) compared to under-6 month (0%) and beyond-24 month of age children (-5%). Partial PCV9 vaccination was more efficacious against radiographically-confirmed pneumonia than full vaccination. The association between partial and complete vaccination and radiographically-confirmed pneumonia was not statistically significant, however. HIV infection profoundly affected the efficacy of PCV9 in all age groups. Other factors which were associated with radiographically-confirmed pneumonia were clinical pneumonia, more than two previous pneumonia admissions and presence of pneumonia predisposing factors. Conclusion and recommendations PCV9 vaccination had limited efficacy against radiographically-confirmed pneumonia. However, it was more effective against radiographically-confirmed pneumonia in 6 to 24 month old children. Partial vaccination was more efficacious than a full course (given at 6, 10 and 14 weeks of age). Adoption of two primary doses of PCV9 with one booster dose, in-depth studies to investigate the factors that affect PCV9 efficacy, raising awareness about the potential effect of these factors on radiographically-confirmed pneumonia and the improvement of HIV/AIDS interventions are recommended.

Leptospirosis is a zoonosis of ubiquitous distribution and causes a wide spectrum of disease. Burkholderia species are important plant and human pathogens. Little or no investigation has been performed on any clinically-relevant Burkholderia or Leptospira species in Johannesburg. Environmental samples were taken from different sites in Johannesburg along the Jukskei River. These were subjected to culturing for Burkholderia spp. and polymerase chain reaction (PCR) for Burkholderia and Leptospira spp. Human serum, animal serum and kidney samples were also subjected to PCR for both organisms. A Leptospira IgM ELISA was also performed on human serum samples. More Burkholderia spp. were isolated by culture from soil samples than water samples. The PCR yielded a significantly higher PCR positive from soil samples (p = 0.015). There was a high prevalence of pathogenic Leptospira spp. in soil samples. The ELISA yielded only 7.8% (26/332) positive samples. There were no human or animal positive PCR results for either organism. There is an environmental presence of both leptospires and Burkholderia in the area sampled. More studies are needed to establish how both organisms might affect patients with compromised immune systems, and how often both infections are incorrectly or under-diagnosed.