Background Vitamin D deficiency is prevalent in many places across the world. Breastfeeding has been suggested to be a significant predictor of vitamin D deficiency during infancy, which is preventable through proper supplementation. However, whether Hong Kong should adopt the international recommendation for supplementation of exclusive breastfed infants is still not yet answered. Objective: To review the available evidence regarding the association between breastfeeding and vitamin D deficiency during infancy, as well as the effectiveness of vitamin D supplementation of breastfed infants as an intervention measure. Methods A total of 5112 potentially relevant articles were searched and identified from MEDLINE (OVID, Pubmed), Science Citation Index Expanded (ISI Web of Science), Cochrane Central Register of Controlled Trials, EMBASE, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Chinese database (CNKI) without restriction from inception to July-06-2012. 5065 articles were excluded after the initial scanning of title and abstracts. 36 were subsequently excluded due to methodological issues. A total of 11 studies were included and reviewed by two independent reviewers. Results This review pooled together a total of 1126 exclusively breast-fed infants for less than one year old from 11 studies. The pooled average prevalence of vitamin D deficiency was 54.2%. The association between breastfeeding and vitamin D deficiency during infancy has been reported consistently, and it was found to be one of the strongest predictors of vitamin D deficiency for infants less than one year old. Sunlight exposure, season, and skin pigmentation were also found to be important affecting factors. Supplementation to breastfed infants with the dosages as recommended by American Academy of Pediatrics (AAP) seem to be effective in lifting up the vitamin D levels. Conclusions The Hong Kong Government and relevant health sectors should conduct local epidemiological study to investigate the problem of concern among our breast-fed infants, and seriously consider or evaluate the AAP recommendation of supplementation. / published_or_final_version / Public Health / Master / Master of Public Health

A systematic review and meta-analysis was conducted to evaluate the efficacy of different infant antiretroviral (ARV) prophylaxis regimens for prevention of mother to child transmission (MTCT) of human immunodeficiency virus (HIV) infection in breastfeeding infants who were born to HIV positive mothers but were HIV uninfected at birth. The systematic review of the literature published during January 2000 to April 2012 resulted in ten randomized and controlled clinical studies which met the study inclusion criteria. Two datasets were identified from the ten selected clinical trials. One dataset contains six studies evaluating short-course ARV prophylaxis regimens, and the second dataset contains four studies evaluating short-course versus extended ARV prophylaxis regimens. The odds ratio was used as the effect size to measure the efficacy between two comparative infant ARV prophylaxis regimens. Meta-analyses were conducted to assess the overall (pooled) treatment effect of the two comparative infant ARV prophylaxis regimens of the two datasets. The pooled ARV treatment effect was calculated as a weighted average of the effect estimated in the individual studies. If no heterogeneity was identified, a fixed-effect meta-analysis by the Mantel-Haenszel method was used. The random-effects method was used when there was heterogeneity in the meta-analysis. The inverse-variance method was used in the random-effects method of meta-analysis. Heterogeneity in the meta-analysis was accessed by the Chi-squared (χ2) test and I2 test. The combined sample size of all ten clinical trials was a total of 10,316 breastfeeding infants, and the overall postnatal HIV transmission rate regardless of ARV regimens and the timing of HIV infection status was approximately 8.7%. The overall HIV transmission rates of the short-course ARV prophylaxis regimen groups were 10.3% at 4-8 weeks and 9.0% at 6-9 months, respectively. The overall late postnatal HIV transmission rate (at 6-9 months after birth) was 5.5% in the extended ARV prophylaxis regimen group. The first dataset contains six randomized and controlled studies to evaluate the efficacy outcome (defined as the unadjusted HIV infection status at 4-8 weeks after birth) of two short-course infant ARV prophylaxis regimens, the nevirapine (NVP) regimen and the zidovudine (ZDV) with or without combination of lamivudine (3TC) or NVP regimen. Due to the existence of substantial heterogeneity, a random-effects method was used to test for the overall treatment effect. The results show that there was no significant difference between the two short-course infant ARV prophylaxis regimens (odds ratio:1.07; 95% CI: 0.69-1.66; Z=0.31, p=0.76). The results of the meta-analysis of five comparative short-course versus extended infant ARV prophylaxis regimens from four randomized and controlled clinical trials, demonstrate a favorable efficacy outcome (defined as the unadjusted HIV infection status at 6-9 months after birth), of the extended ARV regimens. There was no heterogeneity found in this dataset. There was a highly significant difference in the overall effect between the two ARV prophylaxis regimens by a fixed-effect model (odds ratio: 1.72; 95% CI:1.45-2.04; Z=0.68, p<0.00001). In summary, there was no significant difference in the overall treatment effect in reducing the early postnatal MTCT of HIV infection by infant short-course regimens of ARV prophylaxis, which include NVP, ZDV and their combination regimens. In comparison with the short-course ARV regimens, the extended ARV prophylaxis further reduced the risk of the late postnatal MTCT of HIV infection in breastfeeding infants. / published_or_final_version / Public Health / Master / Master of Public Health

Background: Maternal sensitivity, or high quality maternal caregiving, in which the mother leads and structures the infant’s early experiences in a responsive way, is associated with improved child development outcomes and health, both in the immediate and long term, and thus an important area of public health research. Although previous research has established that exposure to high maternal sensitivity advances the outcome of infant cognitive development, factors such as breastfeeding, which is hypothesized to confound the association, or depression, which is negatively associated with sensitivity, have not yet been examined together in a single study. Maternal alcohol use, associated with both breastfeeding and depression, has not been examined in any study investigating the sensitivity-cognitive development association. The majority of infant studies examining the maternal sensitivity-infant cognition association include either normal birth weight infants or LBW infant samples. Using the LBW category may result in potential misclassification since this group combines at least two different phenomena and includes infants who have had either compromised gestational time as in the case of small for gestational age (SGA), or insufficient gestational time, as in the case of premature birth, or both. In studies using comparison groups, normal birth weight infants are sometimes compared to LBW infants or infants born prematurely. However, none of these studies examine the association between sensitivity and cognitive outcome in infants exclusively premature or SGA. Aim: This study investigates the association of several factors: (1) maternal depressive symptomology, (2) breastfeeding, (3) concurrent maternal alcohol intake and (4) infant biological vulnerability upon outcomes of (1) Maternal Sensitivity and (2) Infant Cognitive Development, as well as their effect on the association between senstivity and cognitive development. Methods: Using data from the Early Childhood Longitudinal Study-Birth (ECLS-B) Cohort, a nationally representative sample of U.S. born children, depressive symptomology was evaluated as an effect-modifier, and breastfeeding was evaluated as a confounder of the sensitivity-cognitive development association. Maternal alcohol use and biological vulnerability were also hypothesized to be confounders of the sensitivity-cognitive association. Univariate and multi-variable regression analyses were used to examine whether the four maternal factors were associated with Maternal Sensitivity, measured by the Nursing Child Assessment Teaching Scale (NCATS), and with Cognitive Development, measured by the Bayley Scale of Infant Development, Research Edition (BSF-R). Results: In univariate analyses, breastfeeding, depressive symptomology and alcohol use were associated with maternal sensitivity but only breastfeeding and depressive symptomology were associated with Cognitive Development In a final model examining the effect of sensitivity, depressive symptomology and breastfeeding upon the outcome of Cognitive Development, sensitivity (β =.375, p<.001) remained significantly associated with cognitive development after adjusting for breastfeeding (β =1.592, p<.001), depressive symptomology (β =-.061), p<.05), demographic factors and birthweight (R2=.053, p<.001). Depressive symptomology was not an effect modifier of the sensitivity-cognitive developmental association. Univariate regression analyses showed that of the measures of biological vulnerability, premature birth had the greatest association with both sensitivity and cognitive development in comparison to the LBW or SGA. In a multivariate regression model in which maternal sensitivity as an outcome, premature birth (β= -.524***) was associated with maternal sensitivity (R2=.100, p<.001), after adjusting for maternal depression and breastfeeding. In a multivariate regression model analysing the effect premature birth and maternal factors, including sensitivity in which cognitive development was the outcome, maternal sensitivity (β=.369, p<.001) and breastfeeding (β=1.567, p<.001) were positively associated with infant cognitive development, while premature birth (β= -2.949, p<.001) was negatively associated (R2=.049, p<.001). Conclusion: This research demonstrates that an independent association between maternal sensitivity and infant cognitive development remains even after adjusting for breastfeeding, and that breastfeeding is a separate means to advancing infant cognitive development. Premature birth, rather than SGA drove the negative association between low birth weight and cognitive development. Future research should look at the effects of premature birth separately from SGA when examining developmental outcomes. Keywords: Maternal Sensitivity, Parenting, Cognitive Development, Breastfeeding, Maternal Depression, Premature Birth, Small for Gestational Age, Low Birth Weight

Despite the burgeoning literature documenting the effects of breast-feeding on cognition and educational attainment over the past several decades, there remains important gaps in our knowledge regarding whether this relationship is dictated by sociodemographic factors. The current investigations, which examined the literature on the effects of breast-feeding on cognition and educational attainment in children, adolescents, and older adults addressed these gaps. Chapter 2 was an up-to-date global systematic review of population studies in individuals ≤ 25 years and ≥ 25 years of age. Results indicate that the majority of published studies conducted by researchers demonstrated a positive relationship between the effect of breast-feeding on cognitive outcomes and educational attainment. Additionally, findings highlighted the importance of possible confounders and how adjusting for them can change the relationship between breast-feeding and cognition and educational attainment. Chapter 3 investigated the breast-feeding-cognition/educational attainment relationship across race, as well as whether mother-child stimulation might mediate this relationship. The National Longitudinal Study of Adolescent to Adult Health (Add Health) was used to examine the effect of being breast-fed or not, and duration on cognitive outcomes and grade point average (GPA). Results indicate that individuals who were breast-fed had slightly higher GPAs and performance on both a vocabulary test and a number recall test compared to adolescents who were not breast-fed. There was an effect for race, but no interaction between race and breast-feeding. Mother-child stimulation had a limited effect on the relationship between breast-feeding and cognitive outcomes and GPA. Chapter 4 explored whether the effect observed in adolescence persists into older adulthood. The Reasons for Geographic and Racial Differences in Stroke (REGARDS) Cohort was used to examine this relationship in adults age ≥ 45 years. The covariates included sex of adolescent, race (Black or White), maternal education, paternal education, maternal smoking history, number of other children mother has, resident location (urban/not-urban), and a financial adversity index. This was a composite score consisting of yes or no responses to (1) do you have health insurance, (2) have you been employed within the past 12 months, (3) are you on public assistance, and (4) do you have enough money to pay your bills? Results show that self-report history of being breast-fed did not current predict performance on cognitive tests. Additionally, neither race nor sex moderated this relationship between breast-feeding and cognition. Overall, evidence from the review and two studies highlight the important of assessing the effect of breast-feeding on cognition and educational attainment in populations with varying confounding factors, however, while some of the results are inconsistent with our hypothesis, replication is clearly essential to further explore the possible underlying mechanism.

The prevalence of sub-clinical vitamin A deficiency (VAD) and anemia of lactating women (n = 113) and their breastfed infants aged 1--6 months was measured among a peri-urbanite South African sample. Mother's mean hemoglobin (Hb) was 12.4 +/- 1.3 g/dL with 32% anemia (Hb < 12g/dL). Retinol in serum was 49.8 +/- 13.2 mug/dL and 66.0 mug/dL (median) in breast milk; no evidence of sub-clinical VAD. Infants, 62% &le; 3 months, had mean Hb of 10.9 +/- 1.1 g/dL (with anemia present (<11g/dL), in 50%). Mean infant serum retinol was 26.9 +/- 7.2 mug/dL (10% prevalence of marginal VAD). No infants were exclusively breastfed. Weaning foods and breast milk substitutes were introduced early and infant intake of traditional medicines was common (52%). Our data suggest that anemia was present in both mothers and infants while VAD was evident only in infants. This early occurrence of micronutrient deficiencies may be attributed to less than optimal breastfeeding practices.

No description available.

published_or_final_version / Community Medicine / Doctoral / Doctor of Philosophy

HN/AIDS in South Africa has grown to very serious proportions. An estimated number of 5.3million South Africans are infected with HIV and the majority of these infections are in the reproductive age group. Based on Annual Antenatal survey 2002,of the total 2.95 million were women aged 15-49, with an estimation of 91271 babies infected through mother to child transmission. Breastfeeding is said to be an ideal food for growth and development of a child. Given that HIV is transmissible through breastfeeding, the paper aims at examining patterns and attitudes towards breastfeeding in the era of HIV/AIDS. A total of 400 respondents drawn from Mafikeng district were interviewed. The majority were aged 20-39, never married, rural, unemployed with high school level of education. Areas of interest were knowledge about HIV/AIDS, patterns of breastfeeding and attitudes towards alternative methods of infant feeding for an HIV positive mother. Previous reports gave clarity to HIV transmission rates at various stages of life. Evidence has shown that rates of transmission are higher in early stages than late stages of life. Few weeks of life from 6-8 weeks may particularly be a period of high risk than ages above three months. Transmission might have occurred during pregnancy, labor or through breastfeeding, whereby data has shown that colostrums have high concentration of Human Immune Virus than mature milk. The study shows that breastfeeding is still regarded as an important infant feeding method that is ideal for child's growth and development but HIV infection is seen as a disturbing factor to successful breastfeeding. Fifty four percent of respondents did not breastfeed exclusively as promoted by UNICEF and WHO; mean duration for exclusive breastfeeding is two months, support is given by SADHS 1998, mean duration for complementary feeding is two months which gives an indication that more infants are at higher risk of contracting the virus should their mothers test positive which in turn gives rise to high infant /childhood morbidity and mortality rates. There is a need to strengthen and expand programmes such as VCT and PMTCT in all communities especially in rural setting where there is lack of pure water supply and proper sanitation. Efforts to reduce the risk of transmission should therefore be centered on promoting the understanding that mixed feeding or breastfeeding with supplementary feeding carries the highest risk of HIV transmission compared to exclusive breastfeeding or exclusive formula feeding. / Thesis (M.Soc.Sc. (Population Studies) North-West University, Mafikeng Campus, 2004

Each year approximately 600 000 infants, most of them in Sub-Saharan Africa are born with HIV infection as a result of mother to child transmission of HIV. Whereas significant progress has been made in reduction of mother to child transmission of HIV in developed countries, the situation remains desperate in developing countries. Progress has been hampered by shortage of staff, facilities, limited access to voluntary counselling and testing and lack of support for women by their partners and communities. The challenge is to increase voluntary counselling and testing uptake during antenatal care. Onandjokwe district in Northern Namibia is currently introducing the Prevention of Mother to Child Transmission Program (PMTCT). It has been found the previous PMTCT programs have failed because they adopted a top down approach where there was no community consultation. This study was conducted to explore the community perceptions, knowledge and attitudes regarding mother to child transmission of HIV through focus group discussions and in-depth interviews of key community members.

Qualitative and quantitative research methods were employed to evaluate the acceptability and feasibility of HIV-1 infected, urban South African mothers being able to feed their infants heat-treated expressed breast milk (HTEBM). Nutritional status assessment of HIV-infected breastfeeding mothers (n=84) indicated that maternal status was not compromised; mean body mass index 26.8 (4.0) kg/m2, triceps skinfold 14.8 (5.50) mm and hemoglobin 11.6 (1.49) g/dL. However, severely immunocompromised mothers (CD4 + &lt; 200 cells/mm3) were more likely to be anemic. Breastmilk viral loads were also higher in mothers with lower CD4+ cell counts. Community based inquiry on the acceptability of HTEBM was accomplished through in-depth interviews of participants (n=31), at the individual (mothers), family (partners, grandparents, mothers-in-law) and at the community level (traditional healers, daycare worker, health care counselors). Although an unfamiliar concept for all interviewed, overall, HTEBM was found to be an acceptable feeding choice regardless of respondents' gender, age, maternal status, family or community role. Further, data indicated mothers rarely received quality infant feeding counseling, consequently mixed feeding, a high risk for HIV transmission, was a common practice. In a pilot longitudinal study, using mixed-methods, the feasibility of mothers successfully implementing a modified breastfeeding intervention (6 months exclusive breastfeeding (EBF), cessation of breastfeeding, followed by use of HTEBM with complementary diet) was evaluated. The majority of mothers (36/66) practiced EBF for 6 months, 42% of whom also used HTEBM, expressing a range of approximately, 65 ml to 600 ml of breastmilk daily, for varying durations (2 weeks to 5 months). Mothers did not experience breast pathology. Home visits were highly enabling as was disclosure of HIV status to a partner. This is the first study to demonstrate that use of HTEBM is a feasible infant feeding option for HIV infected women. HTEBM may offer one solution to reduce vertical transmission of HIV and help maintain nutritional adequacy, as a component of complementary feeding.