3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Factors associated with pneumococcal conjugate and rotavirus vaccines update among infants: evidence from the Africa Centre Demographic Surveillance Site, South Africa, 2008-2011.(2014-03-28) Badu-Gyan, GeorginaIntroduction: Despite advances in prevention and treatment of vaccine-preventable diseases, diarrhoeal and pneumococcal diseases remain a major source of morbidity and mortality among children worldwide. The introduction of vaccines has led to dramatic reductions in the burden of infectious diseases and mortality among children. South Africa was the first country in Africa to introduce rotavirus vaccine (RV) and pneumococcal conjugate vaccine (PCV) in 2008 as part of its national immunisation programme. Performance of immunization programmes is commonly measured by the coverage and uptake of vaccines, hence ensuring that every child is immunized at the earliest or appropriate age is an important public health goal. We therefore assessed proportions and factors associated with uptake of RV and PCV among infants who were followed during the routine demographic surveillance system of the Africa Centre Demographic Surveillance Area (DSA) in a rural South Africa setting. Methods: An open cohort of children resident in the DSA aged 12 months or below was prospectively followed between January 2008 and December 2011. Trained interviewers visited households and administered a standardised questionnaire. Mothers and caregivers were asked to show the interviewers the South African Road-To-Health (RTH) card for all children aged 12-23 months at the time of the visit or through maternal recall for children whose RTH card was not available. The RTH card includes dates of all routine vaccinations a child has received. Rotavirus vaccine doses are given at 6 and 14 weeks of age and PCV doses at 6 and 14 weeks and 9 months. Complete uptake was defined as “complete” if a child received all recommended doses of either RV or PCV and incomplete if a child did not receive any dose or received one dose of RV or PCV. Logistic regression models were used to assess factors associated with uptake of RV and PCV separately. Results: A total of 6,263 children were included in the analysis, of which 3,082 (49%) were females. At birth, 3,823 (61%) children were living in rural areas and about one-sixth of the children were living in households located far from a health facility (≥5km). The overall uptake of RV and PCV vaccines among children aged 12 months or below was 50% and 37% respectively. Infants who ever migrated outside the DSA had reduced odds of complete RV and PCV vaccination compared to infants who did not out migrate (adjusted OR=0.49, 95% CI 0.41-0.57) and (adjusted OR=0.52, 95% CI 0.43-0.63) respectively. Complete uptake of RV was associated with the increase in education levels of mothers compared secondary education (adjusted OR=1.70, 95 % CI 1.02-2.34) or tertiary education (adjusted OR=1.80, 95 % CI 0.97-2.44). Infants whose mothers were employed were less likely than infants whose mothers were not employed to have complete vaccination for RV or PCV (adjusted OR=0.71, 95 % CI 0.60-0.84) and (adjusted OR=0.81, 95% CI 0.68-0.96) respectively. Similarly, infants whose mothers were resident in the DSA were more likely than infants whose mothers were not resident to have complete vaccination for RV or PCV (adjusted OR=1.97, 95 % CI 1.49-2.60) and (adjusted OR=1.55, 95% CI 1.16-2.08) respectively. Conclusion and recommendation: The uptake of complete RV and PCV were generally low among children in rural South Africa within our study period. Child outmigration, maternal employment, maternal education and maternal residency in the DSA at child birth were associated with complete uptake of RV and PCV vaccines. Programmes targeting mothers of lower socio-economic status are required. Such programmes may include vaccine awareness and immunization campaigns at the community level to improve vaccine uptake and more targeted interventions in areas with low RV and PCV uptake.Item A comparison of objective, standardised parent-administered questionnaires to that of subjective screening practices for the early detection of developmentaal delay in at-risk infants(2011-03-25) Silva, Melinda Lee EBackground The early identification of developmental disorders facilitates early intervention, improving childhood outcomes. Parent-administered questionnaires have been recommended for this purpose. The PEDS COMBINED, which includes the Parents Evaluation of Developmental Status (PEDS) and PEDS Developmental Milestones (PEDS:DM), and the Ages and Stages Questionnaire (ASQ) are parent-administered questionnaires with good psychometric properties. It has not been determined if they identify the same infants at-risk for developmental delays however. It is also not know how South African paediatricians monitor childhood development. Objective To compare the ASQ, PEDS COMBINED and South African paediatricians’ subjective assessment (PSA) of neonatal intensive care graduates at 6-months corrected age. To identify trends in developmental screening practices, including the knowledge and use of parentadministered screening tools, in a diverse group of paediatricans working in Gauteng, South Africa. Methods Developmental screening and referral practices of paediatricians were ascertained by analysis of a short questionnaire sent to participating paediatricians. Concordance between the questionnaires and PSA was determined using the kappa coefficient (κ) and Test of Symmetry (κ ≤ 0.4 indicating poor agreement; κ ≥ 0.75 indicating excellent agreement). Results Concordance between the ASQ and PEDS COMBINED was 90.7% (κ = 0.82, ρ = 0.05). The PSA showed poor concordance with both PEDS COMBINED and ASQ (κ = 0.28, ρ = 0.03 and κ= 0.26, ρ = 0.01 respectively). The ASQ and PEDS COMBINED identified 40% and 42% of the cohort with developmental concerns and the PSA identified 6%. Only 13% of paediatricians used specific guidelines for developmental assessment and none used, or could name any parent-administered questionnaire. Conclusion There is excellent agreement between the ASQ and PEDS COMBINED in identifying the same children with developmental concerns. Paediatricians identified significantly fewer infants and showed statistically significant poor agreement with both questionnaires. Most paediatricians in Gauteng, South Africa are not using standardized screening tools to detect developmental delay and have poor knowledge regarding these tools.Item Factors associated with mortality from childhood malaria in Navrongo DSS Site, Ghana, 1995-2000(2008-05-15T08:14:38Z) Chalwe, Victor F.ABSTRACT: Background: Malaria is endemic throughout Ghana and continues to be a major public health concern especially among pregnant women and children under the age of five. The Ministry of Health (MoH) estimates that over the past ten years, there have been 2-3 million cases of malaria each year, representing 40 percent of outpatient cases, while severe malaria accounts for 33-36 percent of in-patients. Malaria also accounts for 25 percent of the deaths in children under the age of five (GHS, 2001). Correct identification of risk factors could focus interventions at reducing malaria mortality in children. Demographic Surveillance System (DSS) sites have been established and they generate high quality population based longitudinal health and demographic data. The DSS conduct Verbal Autopsies to determine probable causes of death. Objective: This study examines factors affecting childhood malaria mortality in Northern Ghana, using longitudinal data collected by the Navrongo DSS during the period 1995- 2000. It deals especially with the role of socioeconomic factors (mother’s education, family wealth index based on the possessions and housing characteristics and residence, and possession of bed net) and the demographic characteristics (child’s sex and age, and mother’s age). Design: Secondary data analysis of longitudinal data collected by the Navrongo Health Research Centre. Multinomial logistic regression was used to compare the relative risk in three groups of children i.e. those who died of Malaria and those who died of other causes to those who survived as base. Results: Overall, for the deaths due to malaria, older children (1-5years) had a higher risk (RRR 1.4, 95%CI 1.25-1.57 P <0.0001) of dying compared to the infants. Equally, children born of older mothers (maternal age at birth of child >30 years) had a higher risk (RRR 1.28, 95%CI 1.15-1.42 P <0.0001). However, maternal education and residence had a protective effect, with children born of mothers who had some education (RRR 0.79, 95%CI 0.67-0.93 P=0.004) and residing in urban area (RRR 0.61, 95%CI 0.46-0.82 P=0.001) having a lower risk. Similarly, those children whose families are in the highest wealth index had a lower risk (RRR 0.76, 95%CI 0.63-0.91 P=0.003). Interestingly, the same factors were associated with deaths occurring due to other causes, but with varying degree of association. Whereas sex of child was not associated with malaria deaths, being female offered a lower risk of dying from other causes (RRR 0.9, 95%CI 0.84-0.98 P=0.017). It was observed that children in the older age group (1-5 years) were at higher risk of dying (RRR 1.14, 95%CI 1.05-1.25 P=0.002) just as those born of older mothers (RRR 1.16, 95%CI 1.07-1.26 P <0.0001). Even in this group, maternal education (RRR 0.87, 95%CI 0.76-0.98 P=0.023), a higher wealth index (RR 0.87, 95%CI 0.77-0.99 P=0.032 and RRR 0.63 95%CI 0.54-0.73 P <0.0001 for the two highest categories of wealth indices respectively), and area of residence (RRR 0.67, 95%CI 0.55-0.83 P <0.0001) offered a reduction in the risk of dying. Conclusion: The study identified the risk factors (age and sex of the child and mother’s age, maternal education, wealth and residence of the family) associated with malaria mortality and other causes of death in childhood in northern Ghana and this should help formulate cost effective interventions such as health education.Item Early diagnosis of human immunodeficiency virus infection status in vertically exposed infants in a low resource setting.(2007-02-14T11:18:48Z) Sherman, Gayle GillianSub-Saharan Africa is the eye of the HIV epidemic. This study was conducted when treatment for the majority of HIV-infected patients in low resource settings was considered unattainable and the risks of diagnosing HIV often outweighed the benefits. Coupled with the complexities of HIV diagnosis in infancy, children typically were only diagnosed once already ill or not at all. Key strategies to address the paediatric epidemic focused on preventing mother to child transmission and reducing mortality and morbidity of infected children predominantly with co-trimoxazole prophylaxis. Both strategies required early diagnosis of HIV infection in infancy for monitoring prevention programs and identifying infected children respectively. The diagnostic algorithm for resource limited settings recommended the use of inexpensive, technically simpler HIV antibody detection assays that are unsuitable for use in HIV-exposed children under 12-months of age. Paradoxically this algorithm provided a barrier to HIV diagnosis in children because of high loss to follow-up rates and death in the first year of life. The objective of this study was to establish an accurate, affordable diagnostic algorithm for early diagnosis of HIV infection that could be rapidly implemented in South Africa and benefit other resource limited settings. The HIV infection status of 300 vertically exposed infants was determined according to first world criteria in a prospective, cohort study at Coronation Hospital, Johannesburg over 21 months. This status was used to assess the accuracy of clinical examinations and HIV assays in diagnosing HIV at 6-weeks, 3-, 7- and 12-months of age. The average cost of determining an infant’s HIV infection status was measured. A single HIV DNA PCR test at 6-weeks of age proved highly accurate in determining HIV status at a marginally increased cost to government and was incorporated by the South African Department of Health into national policy. The ultrasensitive p24 antigen assay and HIV antibody detection assays on serum and oral fluid were identified as valuable candidates where PCR testing is unavailable. Dried blood spot samples from heelpricks are critical for policy to be translated into practice since skills to perform venesection in 6-week old babies are limited. The next challenge lies in operationalising these findings at a clinical and laboratory level to the benefit of the 300 000 South African children annually exposed to HIV at birth. The urgency of early diagnosis has been increased by the availability of highly effective antiretroviral therapy.Item Ethnicity and Sex Differentials in Infant and Child Mortality in Ghana(2006-11-01T07:17:36Z) Antobam, Samuel KojoSex differentials in infant and child mortality have been reported in many studies. These studies posit that generally the male child has better survival advantage over than the female child. However, none of these studies have examined the role of ethnicity in understanding these differentials. The question then is, to which extent does sex differences in child mortality exist in a society with patrilineal and matrilineal structures. Using Ghana Demographic and Health Survey of 2003 (GDHS, 2003), the study examines the intensity of these differentials by employing indirect method of estimation, and bivariate and multiple regression models, while giving detailed consideration to the differences in biological and behavioural/environmental perspectives as regards child health and nutritional care. It is found that among all the four major ethnic groups in the country, including the matrilineal societies, the male child has higher survival advantage than the female counterpart. The study therefore concludes that ethnicity, be it matrilineal or patrilineal, does not make any difference in sex differentials in child mortality.