Introduction: Integrated management of childhood illness (IMCI) is a child survival strategy that has been adopted in South Africa (SA) as the standard of care for managing sick children in the primary health care setting. IMCI includes guidelines for management of paediatric HIV. This study aimed to investigate effectiveness of IMCI as a vehicle to deliver essential child survival interventions, particularly HIV interventions, in routine practise in a high HIV prevalence setting, and to investigate barriers and enabling factors for IMCI implementation. Methods: The study was conducted in Limpopo and KwaZulu-Natal provinces, SA. In the qualitative component, focus group discussions were conducted with IMCI trained health workers and carers of children under 5 years, to explore experiences of IMCI implementation, particularly the HIV component, from the perspective of both target groups. A comparative survey was then conducted. Randomly selected IMCI trained nurses were observed for up to 20 consultations with sick children presenting consecutively to the facility, and their findings compared to those of an IMCI expert who subsequently assessed the child. Observed children were tested for HIV. Results: IMCI trained nurses found IMCI training informative and empowering, and there was agreement among nurses that their skills in managing sick children improved after training. Barriers to IMCI implementation included increased time required for IMCI consultations and lack of support from colleagues. IMCI trained nurses expressed reluctance to implement the HIV component of IMCI, believing it to be unnecessary, unacceptable to mothers and that they lacked the skills to implement HIV care. In total, 77 IMCI trained nurses were observed for a total of 1357 consultations between May 2006 and January 2007; nurses were observed for a mean of 17.7 consultations. Components of the IMCI assessment were frequently omitted; 14/77(18%) nurses asked about all main symptoms in every child. IMCI classifications were often incorrect; 52/112 (46.4%) children with a general danger sign were correctly classified. The HIV component was poorly implemented, 342/1357 (25.2%) children were correctly classified for HIV, although the HIV algorithm performed well when implemented by IMCI experts. Conclusion: IMCI implementation is fragmented and incomplete. Interventions are urgently needed to achieve and maintain high quality health worker performance in implementing IMCI. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2012.

Human immunodeficiency virus type 1 (HIV-1) isolates can be differentiated based on their ability to use particular coreceptors – R5 viruses use CCR5, X4 viruses use CXCR4 and R5X4 (dual tropic) viruses use both CCR5 and CXCR4. It is widely reported that HIV-1 subtype C (HIV-1C) has a unique viral coreceptor evolution pattern in that a complete switch from the predominant CCR5 (R5) to CXCR4 (X4) phenotype is less common for this subtype compared to other subtypes. However, dual tropic HIV-1C isolates have occasionally been described. Furthermore, it has been reported that certain highly active antiretroviral drugs (HAART) may select for X4 viral variants. Therefore, this thesis study was undertaken to better understand the functional and genotypic characteristics of dual tropic HIV-1C isolates, and to characterize drug resistance and coreceptor usage patterns in HAART-naïve versus HAART-failing HIV-1C infected patients. Thirty-five functional HIV-1 env clones derived from seven dual tropic HIV-1C strains were generated and their coreceptor usage characterized in transformed cell lines. All 35 env clones efficiently infected transformed cells expressing CXCR4. Twenty of 35 clones (57%) also utilized the CCR5 receptor. No R5-only clones were detected. Functional coreceptor usage data was correlated to env gene sequence data. The ability of the HIV-1C env clones to facilitate infection of primary lymphocytes and monocyte-derived macrophages was next investigated. The majority of clones characterized as X4 or R5X4 on cell lines used either CXCR4 alone or CXCR4 and CCR5, respectively, in primary cells. A few viruses displayed comparable CCR5 and CXCR4 usage and clones from one virus preferred CCR5 usage in macrophages. Thus in a few cases coreceptor phenotyping in transformed cell lines does not predict usage in primary cells. Genetic determinants for coreceptor usage in primary cells require further investigation. Finally the patterns of drug resistance mutations were studied and coreceptor usage among 45 HAART-naïve and 45 HAART-failing HIV-1C infected patients analyzed. Ninety-five percent of HAART-failing patients had viruses with at least one drug resistance mutation. Thymidine analog resistance mutations (TAMs) were present in 55% of patients. HAART-failing patients had significantly higher prevalence (59%) of X4/R5X4-utilizing viruses compared to HAART-naïve patients (30%) (p<0.02) using the Trofile Co-receptor Tropism Assay while 41% of HAART-failing patients used CCR5 and 70% of HAART-naïve patients used CCR5. Functional results correlated with predictive algorithm methods. This study enhances our understanding of HIV-1 pathogenesis and the results have important implications for the use of coreceptor antagonists for the clinical management of HIV-1C infection. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2011.

Mortality and morbidity rates associated with tuberculous meningitis (TBM) are substantial. The average duration of the untreated disease from onset to death is about 17 days. The prognosis of TBM is known to correlate with the stage of the disease at the time of diagnosis and commencement of chemotherapy. Early diagnosis improves the chances of recovery without neurological sequelae. Early diagnosis is a problem because the presenting symptoms are non-specific and the onset of the disease is typically insidious. To date no single test is available that is totally reliable and specific for TBM. I have attempted to develop a reliable and easily applicable test for the diagnosis of TBM. In fulfilling this objective, the work undertaken may be divided into three major sections:- 1. Detection of soluble Mycobacterium tuberculosis antigens in the cerebrospinal fluid (CSF) of patients with TBM and in control groups by using Mycobacterium bovis BCG antigens. The technique used was that of inhibition enzyme-linked immunosorbent assay (ELISA). The principle of this technique is illustrated in Fig. 5. 2. Detection of soluble M. tuberculosis antigens in the CSF of tuberculous and control groups of patients by using antibodies raised against M.bovis BCG. The technique used was that of the double antibody sandwich ELISA. An outline of this ELISA is given in Fig. 6. 3. Correlation of chloride levels in the blood and CSF of patients with tuberculous and other forms of meningitis. It has been established that the SERUM/CSF ratio of bromide tends towards unity in patients with TBM because the permeability of the blood-brain barrier is impaired. Since both bromide and chloride are chemically similar (both being halides), it was thought that a similar pattern may exist for BLOOD/CSF chloride ratios; and this was investigated. The method used for the INHIBITION ELISA had to be standardized before the samples could be tested. This involved investigating the acceptability of various microtitre plates; determination of the optimal working dilutions for the coating solution and conjugate; and determination of optimal conditions for the various incubation periods, both in terms of time and temperature. A total of 70 specimens was tested. These consisted of 25 normal CSF controls; 25 pleural and ascitic fluid samples; 10 TBM samples, and 10 bacterial meningitis CSF samples. It was found that a distinction existed between the absorbance values obtained from positive TBM CSF samples (Mean 0,658 + 0,043) and that from normal CSF samples (Mean 1,089 + 0,224). The mean absorbance of the culture-positive bacterial CSF's also differed significantly from the other 2 groups (Tables VII; IX). Some overlap occurred amongst the absorbance values of bacterial culture positive CSF's (Range 0,975-0,879) and normal CSF's (Range 1,486-0,934). The mean absorbance value for bacterial positive CSF samples (0,920 _+ 0,029) differed significantly (p <0,01) from those of normal CSF (1,089 + 0,224) and TBM CSF's (0,658 + 0,043). The difference between the mean values obtained with tuberculous and non-tuberculous groups of pleural and ascitic fluid was also significant (p < 0,01). The method used for the DOUBLE ANTIBODY SANDWICH ELISA was that of Sada et al. (1983). Before the samples could be tested, the method had to be standardized and similar investigations to those for the INHIBITION ELISA were performed. In addition, antibodies raised against M.bovis BCG were conjugated to alkaline phosphatase since no commercial preparation was available. Unfortunately no distinction was recorded between negative and positive test specimens, even on repetition of the entire procedure. Measurement of chloride was done by a fully automated procedure using the BECKMAN ASTRA-8. A total of 149 samples were tested. Of these 10 were tuberculous, 34 were viral, and the remainder were bacterial meningitis. No pattern was established that could differentiate TBM from viral or bacterial meningitis. The results obtained are tabulated in Table III and illustrated in Figures 9, 10, and 11. In summarizing, the use of the INHIBITION ELISA technique for the accurate diagnosis of TBM seems promising. However, its validity in the clinical situation will have to be assessed further and with greater numbers of specimens before it can be adopted as a diagnostic procedure for TBM. OBJECTIVE. To determine 1. The ability and reliability of the INHIBITION ELISA1 technique to detect mycobacterial antigens in pleural, ascitic, and cerebrospinal fluids. 2. The accuracy and reproducibility of the double antibody sandwich ELISA in the detection of mycobacterial antigens in CSF of patients with tuberculous meningitis (TBM). 3. Whether a correlation exists between blood and CSF chloride levels in patients with tuberculous and other forms of meningitis. / Thesis (M.Med.Sc.)-University of Natal, Durban, 1985.

BACKGROUND Sub-Saharan Africa has the highest number of HIV-infected individuals and limited treatment programs. The use of Highly Active Antiretroviral Therapy (HAART) has resulted in a considerable decrease in morbidity and mortality among HIV-infected individuals. Long-term use of HAART has several limitations relating to cost, drug toxicity and adherence. Structured Treatment Interruption (STI) has been proposed as a therapeutic approach which limits the exposure to continuous HAART, but retains the benefits thereof. The role of HIV-specific Tcell responses in the control of viraemia has not been well studied in children and it is not clear when these responses become detectable or whether they are associated with improved viral control. Furthermore, antiretroviral drug resistance is well documented in adults infected with HIV-1 clade B virus but comparable information is lacking for chronic paediatric clade C virus infection. This pilot study focused on a chronic HIV-infected paediatric cohort from Durban, South Africa, to assess the immunologic and virologic responses in perinatal HIVinfected children undergoing STI. METHODS Thirty chronic HIV-infected treatment naïve children were enrolled and randomised into either the treatment interruption or continuous treatment group. Longitudinal measurements of viral loads and CD4 percentages were done at scheduled intervals. Peripheral blood mononuclear cells (PBMCs) were screened for cytotoxic T-lymphocyte (CTL) gamma interferon (IFN-?) enzyme-linked immunospot (ELISpot) assay responses using 410 peptides which spanned the entire HIV-1 clade C proteome. Intracellular cytokine staining (ICS) was done to distinguish between IFN-? Gag-specific T-helper and cytotoxic T cell responses. Pre-HAART drug resistance mutations testing and HLA typing were done for all children. RESULTS There was a significant increase in the median CD4 percentage after HAART was introduced. Six children randomized to the STI arm did not undergo treatment interruption because their viral loads remained detectable at the time of scheduled interruption. Most HIV proteins were targeted in this paediatric cohort. Gag was the most frequently targeted HIV-1 protein (93.1%). In both treatment groups, there were broadening of T-cell responses, however, the magnitude of T-cell responses decreased over time on HAART. Drug-resistant mutations were detectable in 4/29 children before initiation of HAART. CONCLUSION In this pilot study, the HIV-1-specific CD8+ and CD4+ T-cell responses were detected before and during HAART. Although the treatment interruption period was short, there were no adverse outcomes in either the continuous or treatment interruption groups in terms of death or other clinical outcomes. This study suggests that it is important to continue to explore alternative treatment strategies in order to reduce cost and toxicity as well as to enhance adherence. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Durban, 2010.

Certain HLA-B-restricted CD8+ T cell responses are associated with control of viremia whereas HLA-Cw* restricted responses, including Gag epitopes are associated with high viremia. To better understand the role of HLA-Cw* restricted epitopes in viral control, HLA-Cw* restricted epitopes were optimally defined. Seventy eight study subjects from a cohort of 451 chronically infected participants had HLA-Cw* restricted CD8+ T cells responses as quantified by intracellular cytokine staining assessing IFN-γ secretion. Fine mapping and HLA restriction of the optimally defined HLA-Cw* restricted epitopes were performed using ELISPOT assay. Functional avidity of responses was assessed by peptide dilution in an ELISPOT assay. Two novel HLA-Cw* restricted epitopes Cw*04- TF10 (in reverse transcriptase) and Cw*08-RM9 (in gp120) were optimally defined. A previously described epitope, Cw*07- KY11 (Nef) was the most frequently targeted epitope in this cohort (30/78) and has high functional avidity compared to other HLA-Cw restricted CD8+ T cell responses. The polyfunctionality of HLA-B*57/5801-restricted Gag-specific HIV-1 CD8+ T cell responses and HLA-Cw*07-KY11 restricted CD8+ T cell responses within the same study subject was determined. Polyfunctionality of CD8+ T cell responses to HLAB* 57/5801 and HLA-Cw*07 restricted epitopes were determined in nine study subjects assessing IFN-γ, TNF-α, IL-2, MIP-1β, and CD107a by multicolour flow cytometry. Additionally gag and nef genes were sequenced from plasma. HLA-B*57/5801-restricted IFN-γ-producing CD8+ T cell responses were of lower magnitude than HLA-Cw*07 responses (p=0.0012) for the nine subjects. The majority of responses were monofunctional (75%), irrespective of HLA restriction. HLA-B*57/5801 and HLACw* 07 restricted CD8+ T cells did not differ significantly in polyfunctionality (p=0.84). Possession of ≥3 functions correlated positively with CD4+ T cell counts (r=0.85; p=0.006). The percentages of monofunctional CD8+ T cells inversely correlated with CD4+ T cell counts (r=-0.79; p=0.05). There was no correlation between polyfunctionality and viral load and sequence variation within targeted epitopes did not impact polyfunctionality. These results suggest that polyfunctionality of HIV-1-specific CD8+ T cells is associated with disease progression independent of restricting HLA alleles, and that loss of these polyfunctional cells correlates with increased in the frequency of monofunctional virus-specific CD8+ T cells. In addition, sequence variation does not appear to significantly impact CD8+ T cell polyfunctionality in chronic HIV infection. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2010.

No abstract available.

Background: in 1987, the first child with HIV-1 infection was identified in the paediatric wards at King Edward VIII Hospital in Durban. This made paediatricians aware that the epidemic had spread to the children of KwaZulu/Natal. Although information on transmission and natural history was becoming available from developed countries, little was known about the disease in developing countries. It was important to determine transmission rates and disease patterns in the local population, in order to appropriately counsel women, and for management of infected infants. In addition, with resources for laboratory diagnoses being limited in developing countries, much emphasis had to be placed on clinical findings for identification of infected children. In 1989, a retrospective analysis was made of the HIV-infected children seen over a 2-year period, between 1987 and 1989. Nine such children were identified and their clinical and biochemical features were described. It was concluded that HIV infected children presented with an identifiable pattern of signs, fairly similar to that described for children in industrialised countries. With these findings, a prospective study was undertaken, to determine the vertical transmission rate, the factors affecting this rate, and natural history of vertically transmitted I-IIV-1 infection. ix KwaZulu/Natal, being at the epicentre of the epidemic in South Africa, was a natural site for the study. Patients and Methods: a trained research worker was placed in the antenatal clinic at King Edward VIII Hospital for the specific purpose of educating, counselling, and testing of all women attending the clinic. Women attending the clinic for the first time in the index pregnancy were offered HIV testing if informed consent was obtained. Blood for HIV serology was drawn at the same time as sampling for the obligatory syphilis serology. The acceptance rate for sampling was > 95%. The majority of the women attending the clinic were black, and first attendance was generally late, into the third trimester. The same research worker was responsible for post-test counselling which was offered to all the women, not only those who tested positive. This research worker was also responsible for obtaining maternal consent for entering the newborn infant into the study. All newborn infants were seen within 48 hours of birth. At this time they were examined, growth parameters were recorded, and initial blood samples taken. These infants were then followed-up at 1 month, 2 months, 3 months, then at 3-month intervals up to 18 months, then at 6-month intervals. At each visit, a thorough clinical examination was performed, growth measurements taken, and development assessed. Record was made of any interim illness and visits to health centres, and of hospital admissions. Method of feeding was note& and details on immunisation obtained from the child's immunisation card. The children received all the x routine childhood immunisations according to the national regimen, based on WHO recommendations. Mothers were asked to bring the child to the follow up clinic for any problem, so that episodes of illness would not be missed. The women were reimbursed for transport costs to encourage follow up visits. Calculation of transmission rate and classification of infection status were made according to the recommendations of the Ghent workshop. Children were regarded as infected if they were antibody positive at 18 months or had an HIV related death. They were classified as uninfectd if the antibody test was negative at 9 months of age. Those infants who were lost to follow up before the age of nine months whilst still antibody positive and those whose cause of death could not be determined, were classified as indeterminate. The diagnosis of AIDS was based on the WHO criteria. Blood samples were taken at birth, at age one and three months, then at three month intervals to 18 months; thereafter at six month intervals. Sera were tested for HIV1 antibodies by a commercial enzyme-linked immunosorbent assay,ELISA. Samples that tested positive were confirmed by two tests, a Roche Elisa and by an immunoflourescent assay (IFA). A sample was regarded as being positive if both the second ELISA as well as the IFA or the Western Blot tested positive. xi Results: between October 1990 and March 1993, 234 infants and their 229 mothers were entered into the study. Those who did not attend a single follow up after birth were excluded from the study. The final cohort comprised 181 infants, of whom 48 were classified as infected ( including 17 deaths); 93 not infected, and 40 as indeterminate ( including 8 deaths). Maternal Data: about 60% of the mothers were under 30 years of age and were multiparous; 18% tested positive for syphilis serology; 22.9% were anaemic during pregnancy, and 37% were delivered by caesarean section. Most women lived in urban areas, and 16% chose to bottle-feed exclusively. Vertical Transmission Rate and Factors affecting this Rate: the median vertical transmission rate was 34%, (95% confidence intervals, CI 26%-42%). This figure is similar to that found in most parts of Africa, but much higher than those for Europe and USA. The maternal factors found to be associated with an increased risk of transmission were vaginal deliveries and a low haemoglobin level during pregnancy. Breastfeeding, Transmission, and Outcome: breastfeeding was found to have an increased risk of transmission, by 15 % (CI 1.8-31.8). On assessing growth and morbidity, it was noted that breastfed infants were not protected against such common childhood infections as pneumonia and diarrhoea, and that failure to thrive occurred with equal frequency in both those breastfed as well as those receiving artificial feeds. Newborn Data: when comparing newborn data between those infants who were subsequently found to be infected with those who were uninfected, it was found that there were no major differences between these groups with regard to growth parameters and neonatal complications. However, those infants with rapidly progressive disease (those who died within 24 months), were noted to have lower mean birth weights and lengths, a higher frequency of low birth weights, and tended to have more neonatal problems. Clinical Manifestations: the first differences between the infected and the uninfected infants generally manifested from about 3 months of age. HIV infected children were identifiable by higher frequencies of thrush, lymphadenopathy, skin rash, and hepatosplenomegaly in the early stages, and later on with a higher tendency to neurological and developmental abnormalities, as well as of diarrhoea. Pneumonia was found with equal frequencies in both the infected and uninfected children. The HIV infected child could be distinguished fairly early in life by the combination of the manifestations described above. Progression to AIDS: AIDS was diagnosed in 44% of all the infected children during the study period. Ninety five percent of these children were identified by 12 months of life, showing a rapid progression of the disease Longitudinal Growth: when longitudinal growth parameters were analysed in this cohort, it was found that HIV infected children were stunted from as early as 3 months of age, and remained below the international standards into early childhood. Infected children were also found to be malnourished (i.e. weight for age below international means), from an early age, and this persisted throughout early childhood. Of note, the uninfected childrens' weights, although comparable to international means initially, dropped after the first year of life. However, both groups did not have significant wasting, when compared to international means. Mortality: there were 25 known deaths during the study period. Of these, 17 were classified as HIV-related, and 8 as indeterminate. The mean age at death was 10.1 months, with 83% of all the HIV-related deaths occurring within the first year of life. The commonest diagnoses at the ti me of death were diarrhoea, pneumonia, and failure to thrive; also, thrush was common, as were neurological abnormalities. / Thesis (MD)-University of Natal, Durban, 1999.

In many infections some patients recover while others die or are permanently disabled. These extremes in clinical outcome may be determined as much by the capacity of the host to eliminate the infecting agent as by the antigenic load on the individual. Children with measles who do not recover may succumb to acute complications (mainly respiratory) or chronic disease (respiratory and neurological) may develop. Analysis of immunological function antedating any of these final events would assist in understanding their pathogenesis and possibly aid in management. In order to achieve t h i s , immunological responsiveness was at f i r st studied in 24 children with acute measles and compared with that in 20 children with established chronic post measles chest disease investigated 6 - 1 6 weeks after appearance of the rash. The immunosuppressive effects of acute measles were extensive. Total white cells were reduced and this reduction was accounted for entirely by lymphopenia which was equally expressed among the major lymphocyte sub-populations studied; the function of T cells, assessed by radioisotope incorporation into phytohaemaggiutinin-transformed lymphocytes and by delayed skin hypersensitivity to dinitrochlorobenzene, was depressed. Serum IgA was reduced in acute measles patients. In contrast there was a relative sparing of the measured indices of immunity in patients with chronic post measles chest disease, with the major defect being an impaired delayed hypersensitivity reaction to dinitrochlorobenzene. There were minor alterations in complement components in both groups of patients with the evidence suggesting minimal utilisation of the alternative pathway in acute measles and classical pathway in chronic patients. High levels of heterophile antibodies to sheep red blood cells were detected in patients with chronic chest disease. (11) The results suggested that the conditions for chronicity of pulmonary disease in measles were unlikely to be determined by persistent abnormalities in the immunopathological factors enumerated, most of which were normal in chronic patients. It was not possible to interpret the findings of defective delayed hypersensitivity and complement components in patients with chronic chest disease as being either the cause or the effect of chronicity. The latter findings would have to be compared with results in children who had recovered from measles studied six weeks after onset of rash. An attempt was made to resolve this problem. Twenty-two children with measles were studied in the acute stage of the rash and six weeks later and results compared with matched controls. The above findings in acute measles were confirmed: the total lymphocyte count and major lymphocyte sub-populations were significantly below control values. At six weeks the B cell and Null cell counts were s t i ll significantly diminished. The function of T cells assessed by radioisotope uptake by phytohaemagglutinin-stimulated lymphocytes and by delayed skin hypersensitivity reaction to dinitrochlorobenzene was impaired during the acute stage and this persisted for six weeks. No important abnormalities were detected in serum immunoglobulins and complement components. Partial reversal of immunological suppression caused by measles was therefore demonstrated at 6 weeks after the appearance of rash. Demonstration of a persistently defective delayed hypersensitivity in those who recovered made i t unlikely that this anergy was important in the development of chronicity. Complement abnormalities were similarly unrelated to progression to chronic lung damage. ( Children who recovered, when studied at six weeks, appeared to be worse o f f immunologically than those with established chronic chest disease following measles. Children with chronic chest disease were studied 6 - 1 6 weeks after onset of rash, by which time the partial reversal of immune deficiency, noted at 6 weeks, would be complete. Among the group of children studied during the acute rash of measles there were five who subsequently died and one who progressed to chronic chest disease. Results in these six children were compared with those in six age-matched children who recovered from measles within a week. In the children who subsequently died or developed chronic pneumonia, immunosuppression was more pronounced during the acute rash ( i . e ., 3 - 2 0 days before death) than in the children who recovered. The absolute total lymphocyte count (T and B cells) was s i g n i f i c a n t ly lower in those who died or developed chronicity. Mean serum C, was also lower in this group. There were no significant differences between the two groups for total white c e l l s , neutrophils, Null c e l l s, cells with both T and B cell markers, other complement factors, serum immunoglobulins and phytohaemagglutinin stimulation of lymphocytes. The total lymphocyte count in a further nineteen patients with measles who had died, studied retrospectively, was s i g n i f i c a n t l y lower than that in twenty-seven patients with measles who recovered. Children whose outcome was poor generally had absolute lymphocyte 3 counts below 2000 cells/mm whereas those who recovered had values above this level. (iv) Therefore children who w i l l die or develop chronic chest disease can be often distinguished, within two days of the appearance of the rash, from those who w i l l recover. In order to test the v a l i d i t y of this conclusion based on results obtained from a small sample the study was extended so as to increase the number of patients with measles who had severe lymphopenia (< 2000 cells/mm3). Seventy seven per cent of 30 children who had severe lymphopenia within 2 days of appearance of rash f a i l e d to recover: 30% died from pulmonary complications within a few days to two months of the onset of the exanthem while 47% developed chronic lung damage. This was s i g n i f i c a n t ly worse than the outcome in 30 children with lymphocyte counts above 2000 3 cells/mm , of whom 67% recovered, 33% developed chronic chest disease and none died. Persistence of severe lymphopenia (which was due to reduction 3 in both T and B cells) in those with i n i t i a l counts below 2000 cells/mm , for at least fifteen days after onset of rash, remained a good predictive index of morbidity and mortality. Reversal of immunoparesis in those with i n i t i a l severe lymphopenia was slower and less complete 42 days from the appearance of the rash in children who subsequently died or progressed to chronicity than in those who recovered. All patients who died f a i l ed to produce an adequate or sustained antibody response to measles. The results of these studies suggest that long term pulmonary and possibly neurological sequelae of measles are probably due to a transient widespread immunoparesis during early measles with persistent defects in specific immunity to measles and probably other viruses, whereas recovery is due to less severe effects of shorter duration. (v) In order to answer the question why some children do badly and others well after measles, studies on the HLA frequencies and measles antigen load have been undertaken in children with severe lymphopenia. Results of viral load are inconclusive and those of HLA suggest a trend towards histocompatibility linked genetic susceptibility to the development of severe lymphopenia in measles associated with HLA AW32. The therapeutic implication of these studies is that children with measles who are at risk for death and chronic disease can be identified early in the disease and intervention at this stage may reverse the severe immunosuppression which leads to rapid demise or modify the immunopathological changes progressing relentlessly in some cases to permanent lung and brain damage and occasionally to death. / Thesis (MD)-University of Natal, Durban, 1977.

Thesis (MD)-University of Natal, Durban, 1967.

The ocular complications of vitamin A deficiency have been known for many years, however, recent studies have suggested that marginal vitamin A status enlarges the risk of common childhood infections and increases mortality. It is therefore important to assess the vitamin A status, and some of its consequences, in children who are most likely to be at risk for vitamin A deficiency as this has important implications for promoting the health of children and for formulating appropriate primary health care policies. In South Africa very little data is available on vitamin A nutrition of communities; therefore one of the objectives of this research programme was to document the vitamin A status of African children who, because of historical inequities, are most likely to be at risk for deficiency. Sound, epidemiologically based surveys of vitamin A intake and body levels were conducted in a typical established township (using dietary intake as the measuring tool) and in a typical peri-urban informal settlement (using serum retinol and conjunctival impression cytology as the measuring tools). These studies revealed that the majority (97%) of children living in the established township surveyed had an adequate intake of vitamin A, whereas 44% of the children in the informal settlement had low serum retinol levels (20 ug/dL), and 18% had insufficient vitamin A, as assessed by 2 abnormal disc specimens, using the conjunctival impression cytology test. In order to investigate the interrelationsnips between vitamin A, other micronutrients and some risk factors, an analysis was undertaken of anthropometry, parasite infestation and blood concentrations of vitamin E, calcium, magnesium, phosphorous, albumin, haemaglobin, serum iron and ferritin and percent transferrin saturation. Significant positive correlations were found between serum retinol and all the biochemical indicators of iron metabolism studied except for serum ferritin. Ninety one percent of the children sampled were infested with parasites. These results highlight the fact that in this population close interconnections exist among nutrients and suggest that attempts at correcting vitamin A deficiency in such communities should be based on comprehensive intervention programmes rather than on single nutrient replacement. The impact of infections on blood levels of vitamin A was investigated in African children with severe measles. In addition, substances related to vitamin A metabolism such as other micronutrients (zinc, vitamin E) and proteins (retinol binding protein, prealbumin, albumin) were measured in serum. In addition the changes induced in these substances by vitamin A supplementation (offered in a randomised, double blind, placebo controlled trial) were studied. Serum retinol as well as the other nutrients measured were significantly reduced early in the exanthem in measles patients as compared to healthy controls. Vitamin A and prealbumin levels on day 8 (of the intervention trial) were significantly increased in the supplemented group compared to the placebo group. vitamin A levels in serum correlated with those of retinol binding protein (RBP), prealbumin and zinc. These findings strengthen the hypothesis that hyporetinaemia during measles is the consequence of impaired mobilisation of retinol stores from the liver. The effect of reversing the temporary lowering of serum retinol concentrations during acute measles infections by supplementation with vitamin A was investigated in a hospital based, randomized, double-blind, placebo controlled trial. The two groups were comparable in known covariates of measles severity : weight/age centiles; overcrowding; rash; total 90% of the patients had blood lymphocytes; serum levels pre-albumin, RBP, vitamins A and E. of zinc, albumin, hyporetinaemia. Integrated Morbidity Scores ( IMS) derived from diarrhoea, herpes and respiratory tract infection (radiologically confirmed) were assigned on day 8, at 6 weeks and 6 months - these were reduced by 82%, 61% and 85% respectively in the supplemented group. This was mainly due to reduced respiratory tract infection. There was one death in the placebo group. At 6 weeks there was significant weight gain in the supplemented group. Despite the selected sample, attention to multiple covariates enhances the validity of the data obtained and supports the current WHO recommendations for vitamin A supplementation during measles. There are several mechanisms by which vitamin A is thought to have its effect of reducing morbidity, one of which is by improving immune responsiveness. This particular mechanism has not been adequately studied in children; most of the studies having been conducted in animals. The effect of vitamin A supplementation on selected factors of immunity in African children with complicated measles was therefore investigated during the randomized double-blind, placebo controlled, intervention trial described above. Placebo and treated groups had similar baseline characteristics. In the treated group there was a significant increase in total number of lymphocytes (day 42, P = .05) and measles IgG antibody concentrations (day 8, p = .02), both of which have consistently been shown to correlate more closely with outcome in measles than other immunological, clinical and radiological factors. Interleukin-2 (IL-2) and plasma complement (C3 ) values were unaffected by vitamin A supplement.at.Lon , These findings reinforce results from animal studies which show that the pathways of vitamin A activity in decreasing morbidity and mortality are partly founded on selective immunopotentiation. In conclusion epidemiological and biochemical methods which were used to assess the vitamin A status of African children in South Africa revealed that overt vitamin A deficiency is not a Public health issue to the extent it is in the poor rice eating nations of the world. Marginal vitamin A deficiency is however prevalent in informal settlements. Interventions to reverse this marginal vitamin A deficiency should be incorporated in comprehensive programmes to ensure food security. Infections such as measles which increase utilisation and inhibit mobilisation from body stores are damaging to vitamin A homeostasis in the individual. The morbidity associated with measles can be reversed by high dose vitamin A supplementation during the acute phase of the infection. Improving immune responsiveness is one of the likely paths of vitamin A activity in decreasing morbidity from measles. / Thesis (Ph.D.)-University of Natal, Durban, 1993.