• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 34
  • 12
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 50
  • 50
  • 50
  • 43
  • 42
  • 35
  • 31
  • 26
  • 23
  • 22
  • 20
  • 20
  • 18
  • 16
  • 15
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

An exploration of emerging problems for infant feeding options : some obstacles for the rapid expansion of the HIV mother-to-child transmission prevention programme : the KwaZulu-Natal experience.

Smith, Elaine. January 2003 (has links)
No abstract available. / Thesis (M.A.)-University of Natal, Durban, 2003.
12

Antenatal mothers' practices for preventing mother-to-child HIV transmission

Chivonivoni, C. (Clara) 30 June 2006 (has links)
Health Studies / M.A. (Health Studies)
13

Problems experienced by mothers who opted for replacement infant feeding in a prevention of mother-to-child transmission programme in Makhado municipality, Limpopo Province, South Africa

Mugivhi, Modipadi Rebecca 11 1900 (has links)
The recommended infant feeding method for mothers living with HIV is either exclusive breastfeeding for six months or replacement infant feeding (RIF), while a mixed feeding method carries the greatest health risks for infants. This study focused on identifying the challenges faced by mothers who opted for RIF and the coping strategies they employ. A theoretical framework, based on gender and power, was developed. The study used a qualitative design, with semi-structured in-depth interviews. Using purposive sampling, data was collected at three clinics from 22 participants. The participants reported experiencing challenges related to RIF such as intermittent availability of formula milk at the clinics. Socio-cultural challenges include power inequalities between health care workers and mothers, pressure from family members to breastfeed, stigmatization and discrimination from community members. Coping strategies such as withdrawal from the community and trying to hide RIF from others were not sufficient to meet the challenges experienced. / Sociology / M.A. (Social Behaviour Studies in HIV/AIDS)
14

Exclusive breastfeeding in the prevention of HIV-1 transmission from mother to child : a systematic review

Phuti, Angel 15 March 2012 (has links)
Thesis (MCurr)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: HIV infection poses a major obstacle in breastfeeding as it represents the most common way by which children acquire HIV. Exclusive breastfeeding has been discovered as the most effective intervention in preventing mother-to-child transmission of HIV, mortality and promotion of HIV free survival. The main objective was to evaluate the evidence on the effectiveness of exclusive breastfeeding versus formula feeding and/ or mixed feeding in the prevention of HIV-1 transmission from mother to child. To identify the studies, an electronic search was conducted using PUBMED/MEDLINE, CINAHL, CENTRAL and EMBASE databases. Electronic journals, which include the Southern African Journal of HIV medicine (SAJHIV), HIV Medicine Journal and American Journal of Public Health, were also accessed. Manual searches were carried out. In addition, relevant experts were contacted in order to locate more data. There were no limitations with regards to date and language. The review considered studies on infants who were vertically HIV-1 exposed (mother HIV positive during pregnancy, birth and breastfeeding). These infants were exclusively breastfed for six months with administration of antiretroviral prophylaxis and were compared to infants exclusively formula fed. The outcomes measured were vertically acquired HIV infection; mortality and HIV free survival up to 24 months of age. Two reviewers independently selected articles which met the inclusion criteria. They independently extracted the data using a data extraction tool. Disagreements were solved by discussion. Data was then meta-analysed using Rev Man 5.1.0. Methodological quality of each trial was assessed by the reviewers using the Cochrane assessment tool for risk of bias. Two randomised clinical trials and one intervention cohort study (n=2112 infants) comparing exclusive breastfeeding with exclusive formula feeding were included. HIV infection was associated with exclusive breastfeeding as compared with exclusive formula feeding (Risk ratio 1.67, 95% CI 1.26 to 2.23, p=0.0005). Exclusive formula feeding was associated with high mortality from infections (Risk ratio of 0.67 95% CI 0.43 to 0.83, p=0.002 Chi²= 1.30, p=0.52, I²=0%). There were no statistically significant differences in HIV free survival between exclusive breastfeeding and exclusive formula feeding as measured by trialists at 9, 18 and 24 months (Risk ratio 1.19, 95% CI, 0.92 to 1.54, p=0.19, Chi²= 3.15, p=0.21, I²=36 % 3 studies, 1012 infants). None of the studies included reported on mixed feeding. Complete avoidance of breastfeeding is effective in preventing mother-to-child transmission of HIV. HIV infection during breastfeeding might be an indicator of mixed feeding and poor adherence. Formula feeding is only applicable in settings where formula milk is accessible, feasible, acceptable, safe and sustainable (AFASS) because formula feeding carries a high risk of mortality from causes other than HIV. If the AFASS criteria cannot be met, mothers should be encouraged to exclusively breastfeed and ensure that their infants completely adhere to the antiretroviral prophylaxis because they decrease the rate of vertical HIV-1 transmission. / AFRIKAANSE OPSOMMING: MIV besmetting veroorsaak ‘n groot struikelblok vir borsvoeding, omdat dit die mees algemene manier is waarop babas met MIV besmet word. Eklusiewe borsvoeding is as die mees effektiewe intervensie ontdek in die voorkoming van moeder na kind oordrag van MIV, morbiditeit en die bevordering van MIV vrye oorlewing. Die hoofdoelwit is om die effektiwiteit van eksklusiewe borsvoeding teenoor formule-voeding en of gemengde voeding in die voorkoming van MIV oordrag van moeder na kind te evalueer. Elektroniese navorsing is gedoen deur gebruik te maak van PUBMED/MEDLINE, CINAHL, CENTRAL en EMBASE databasisse. Elektroniese joernale wat die Southern African Journal of HIV medicine (SAJHIV), HIV Medicine Journal and American Journal of Public Health insluit, is ook gebruik. Handnavorsing is ook gedoen, asook relevante data van kenners op die gebied, is verkry. Geen beperking is geplaas op taal of tyd nie. Studies op babas wat blootgestel is aan die MIV-1 (moeder MIV positief gedurende swangerskap en borsvoeding) is in die oorsig oorweeg. Hierdie babas is eksklusief vir 6 maande gerborsvoed, met of sonder anti-retrovirale behandeling, en is vergelyk met eksklusiewe formule-voeding. Die resultaat was dat almal tot op 24 maande gemeet is aan MIV besmetting, mortaliteit en MIV vrye oorlewing. Twee resensente het onafhanklik artikels geselekteer wat aan die ingeslote kriteria voldoen het. Hulle het onafhanklik data geselekteer deur van ’n selekteringsinstrument gebruik te maak. Misverstande is deur besprekings opgelos. Data was daarna gemeet en gemetaanaliseer deur Rev Man 5.1.0. Die metadologiese kwaliteit van elk proeflopie is geassesseer deur die resensente wat gebruik gemaak het van die Cochrane evalueringsinstrument om die risiko van onewewigtigheid uit te skakel. Twee ewekansige kliniese proewe en een intervensie kohort studie (n = 2112 babas) wat eksklusiewe borsvoeding vergelyk met 'n eksklusiewe formule-voeding is ingesluit. MIVinfeksie wat verband hou met 'n eksklusiewe borsvoeding is vergelyk met eksklusiewe formule-voeding (risiko verhouding van 1.67, 95% CI 1.26 tot 2,23, p=0.0005). Eksklusiewe formule-voeding hou verband met 'n hoë mortaliteit van infeksies met ’n risiko verhouding van 0.67, 95% CI 0.43 tot 0.83, p = 0.52, Chi ² = 1.30, p = 0.52, I ² = 0%. Daar is geen statisties beduidende verskille in MIV-vrye oorlewing tussen eksklusiewe borsvoeding en eksklusiewe formule-voeding nie wat deur die proefnemers gemeet is op 9, 18 en 24 maande (risiko verhouding 1.19, 95% CI, 0.92 tot 1.54, p = 0,19, Chi ² = 3,15, p = 0.21, I ² = 36% 3 studies, 1012 babas). Nie een van die ingeslote studies het verslag gedoen oor gemengde voeding nie. Algehele vermyding van borsvoeding is effektief in die voorkoming van Moeder na Kind oordrag van MIV. MIV-infeksie gedurende borsvoeding mag ’n aanduiding van gemengde voeding en swak nakoming wees. Formule voeding is alleenlik van toepassing in situasies waar formule-melk toeganklik, uitvoerbaar, veilig en volhoubaar is, want formule-voeding dra ’n hoë risiko van mortaliteit weens ander oorsake buiten MIV. Indien daar nie aan hierdie kriteria voldoen kan word nie, behoort moeders aangemoedig te word om eksklusief te borsvoed en seker te maak dat hulle babas die antiretrovirale profilaksie getrou neem, want dit verlaag die koers van vertikale MIV-1 oordrag.
15

Evaluation of a quality improvement cycle intervention in the provision of PMTCT at a regional hospital

Van Niekerk, Elizabeth C 12 1900 (has links)
Thesis (MMed)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: The vast majority of new Human Immunodeficiency Virus (HIV) infections in infants and young children occur through mother-to-child-transmission (MTCT), either during pregnancy, labour or delivery or by breastfeeding. Without access to perinatal MTCT (PMTCT) programmes approximately 30% of all babies born annually will be infected with HIV. OBJECTIVES The aim was to implement and audit a quality improvement cycle at the Worcester Obstetric Unit, which comprises of Worcester Hospital, a regional hospital in the Western Cape Province and its level one midwife obstetric Unit (MOU), in order to improve the quality of the PMTCT programme. The intervention included the implementation of easy changes and tools in the Antenatal Clinic, Infectious Diseases Clinic and Labour ward. METHODS The files and antenatal records of all HIV positive patients and patients with an unknown HIV status, who delivered at the Worcester Obstetric Unit during January, February and March of 2010 and 2011, were reviewed. All HIV negative patients and patients that had stillbirths and miscarriages were excluded. The pre-interventional findings of 2010 were compared with the post-interventional findings of 2011. RESULTS At the Worcester Obstetric Unit, for the study time period, there were 907 deliveries in 2010, of which 102 (11.2%) patients were HIV positive and 4 (0.4%) had an unknown HIV status compared to 2011, with 865 deliveries of which 108(12.5%) patients were HIV positive and no patients had an unknown HIV status. Significantly more patients were diagnosed with HIV before they fell pregnant than during pregnancy in the 2011 group, when compared with the 2010 group. A CD4 count was done on 94% of patients who were newly diagnosed with HIV and those with an unknown CD4 count result in the 2010 group, compared to 92% in 2011. There was a significant improvement after the intervention in the time it took from when blood was drawn for a CD4 count until the result was followed up, the median time decreased from 34 to 8 days (p=0.000001). Significantly more patients qualified for highly active antiretroviral therapy (HAART) after the guidelines were changed and the CD4 cut off was increased to 350 cells/l (p=0.001). Prior the intervention 18 patients did not receive the correct management before delivery due to preventable reasons, compared to one at the MOU. After the intervention this decreased significantly to only one patient at Worcester Hospital and none at the MOU (p=0.000001). Before the intervention adherence to the PMTCT protocol at the MOU was significantly better than at the hospital (p=0.0005) and after the intervention there was no significant difference (p=1.0). CONCLUSION Although the audit and quality improvement cycle was performed at a single hospital, with specific changes geared towards their needs, the basic principles can be applied to any Unit in the country providing a PMTCT service. Educating staff, creating awareness and reminding staff of the basic principles of PMTCT, implementing small changes and streamlining processes and setting specific goals or timelines, can lead to significant improvements in care, which ultimately will lead to a decrease in PMTCT of HIV and HIV related maternal and infant morbidity and mortality. / AFRIKAANSE OPSOMMING: Die oorgrote meerderheid (>90%) van nuwe Menslike Immuniteitsgebreksvirus (MIV) infeksies in babas en jong kinders vind plaas deur middel van moeder-na-kind-oordrag, hetsy gedurende swangerskap, die kraamproses of borsvoeding. Sonder toegang tot perinatale voorkomingsprogramme (PMTCT) sal ongeveer 30% van alle babas jaarliks met MIV geïnfekteer word. DOELWITTE Die doel van die studie was om ‘n gehalteverbeteringsiklus by die Worcester Verloskunde Eenheid, wat bestaan uit Worcester Hospitaal, 'n streekshospitaal in die Wes-Kaapprovinsie en sy vlak een vroedvrou verlossingseenheid (VVE), te implementer en daarna te oudit, om sodoende die gehalte van die PMTCT-program te verbeter. Die intervensie het bestaan uit die implementering van eenvoudige veranderinge en prosesse in die voorgeboortekliniek, infeksiesiekte-kliniek en kraamsaal. METODES Die lêers en voorgeboorte rekords van alle MIV-positiewe pasiënte en pasiënte met 'n onbekende MIV-status, wat gedurende Januarie, Februarie en Maart van 2010 en 2011 verlos het by die Worcester Verloskunde Eenheid, is nagegaan. Alle MIV-negatiewe pasiënte en pasiënte met doodgebore babas en miskrame is uitgesluit. Die pre-intervensie bevindings van 2010 is vergelyk met die post-intervensie bevindings van 2011. RESULTATE By die Worcester Verloskunde Eenheid was daar 907 geboortes gedurende die studietydperk in 2010, waarvan 102 (11,2%) pasiënte MIV-positief was en 4 (0,4%) met ‘n onbekende MIV-status. In 2011 was daar 865 geboortes waarvan 108 (12,5%) pasiënte MIV-positief was en geen met 'n onbekende MIV-status. In die 2011-groep is beduidend meer pasiënte gediagnoseer met MIV voor as tydens swangerskap. In die 2010-groep is daar 'n CD4-telling gedoen vir 94% van nuut gediagnoseerde pasiënte en diegene met 'n onbekende CD4-telling, in vergelyking met 92% in 2011. Daar was 'n beduidende verbetering na die intervensie in die tyd wat dit geneem het vandat bloed getrek is vir 'n CD4-telling totdat die resultaat opgevolg is. Die mediane tyd het verminder vanaf 34 na 8 dae (p = 0.000001). Nadat die riglyne vir kwalifisering vir hoogs aktiewe antiretrovirale terapie (HAART) verander is na ‘n CD4 telling 350 selle/l het daar beduidend meer pasiënte gekwalifiseer vir HAART. By Worcester Hospitaal het 18 pasiënte voor die intervensie nie die korrekte behandeling intrapartum ontvang nie weens voorkombare redes, in vergelyking met slegs een pasiënt by die VVE. Na die intervensie was daar ‘n beduidende afname na slegs een pasiënt by Worcester Hospitaal en geen by die MOU (p = 0.000001). Voor die intervensie was die korrekte uitvoering van die PMTCT-protokol by die MOU beduidend beter as by die hospitaal (p = 0,0005) en na die intervensie was daar geen beduidende verskil (p = 1.0). GEVOLGTREKKING Alhoewel die oudit en gehalteverbeteringsiklus uitgevoer is by 'n enkele hospitaal, met spesifieke veranderinge gerig tot hul behoeftes, kan die basiese beginsels toegepas word in enige eenheid in die land wat ‘n PMTCT diens verskaf. Opvoeding van personeel en bewusmaking rakende die basiese beginsels van PMTCT, klein veranderinge en die vaartbelyning van prosesse by die voorgeboorte klinieke en die stel van spesifieke doelwitte of tydlyne, kan lei tot aansienlike verbeteringe in pasiënte sorg. Dit sal uiteindelik lei tot 'n afname in die MIV oordrag van moeder na kind, asook MIV-verwante morbiditeit en mortaliteit in moeders en kinders.
16

Community perceptions, attitudes and knowledge regarding mother to child transmission of HIV: a baseline evaluation before the implementation of the Prevention of Mother to Child Transmission of HIV Program using a short course of Nevirapine at Onandjokwe Hospital, Namibia.

Mtombeni, Sifelani January 2004 (has links)
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.
17

Transmission rates of HIV-1 and the mortality rate in high risk infants exposed to HIV, in the PMTCT programme, at the Neonatal Unit, of King Edward VIII Hospital , Durban, South Africa.

Nair, Nadia. January 2012 (has links)
Introduction. Previous studies have established that infants born to mothers with advanced HIV disease and co-infections are smaller, premature and have rapidly progressive HIV disease and an early death. King Edward VIIIth Hospital, in Durban, admits many sick mothers and manages a large proportion of low birth weight and ill newborns. On discharge and follow-up, the mortality and morbidity of these infants are known to be high and are related to the prematurity. How much is related to being HIV exposed is still uncertain. Aim. To determine the perinatal transmission rate of HIV-1 and mortality at 12 months in HIV exposed infants that were admitted to and discharged from the Neonatal Unit, in Durban, South Africa. Methods. In this observational study, data from the outpatient charts of HIV exposed infants that required specialised neonatal care and subsequent follow up, between the period November 2007 and December 2009, were collected. Perinatal transmission rates and mortality of these infants were compared with maternal and infant risk factors. Results. Data on 463 HIV exposed, predominantly low birth weight infants are presented. The median maternal CD4 count was 309cells/mm3 with 16.8% of mothers commenced on HAART. Maternal co-infection with TB was found in 19.2% of the cohort. Early HIV transmission occurred in 11.5% of infants and was influenced by the type of ARV exposure (None, 20%; single dose NVP, 14.3%; dual therapy, 10.6%; maternal HAART, 8.5%). The dual therapy regimen for 7 days was more protective than that for 28 days (p=0.045). HIV infection was associated with higher risk of neonatal sepsis (RR 1.6; 95% CI, 1.1-2.3; p=0.015). The mortality for the cohort at 12 months was 10%. Maternal HAART was associated with a lower mortality: 2.95% vs.10.2% (RR 3.0; 95% CI, 0.4-20.5). There was a higher mortality rate in those that were low birth weight (RR 4.2; 95% CI, 1.02-18.8; p=0.037); those that were HIV infected (RR 4.8; 95% CI, 1.9-11.6; p=0.002) and those that were breastfeeding compared to formula feeding (RR 2.7; 95% CI, 1.1-6.8; p=0.038). Discussion. Rates of HIV transmission within the PMTCT programme were similar to that reported by the Department of Health. Early maternal ARVs for PMTCT prophylaxis, prevents HIV transmission. The coverage of maternal HAART was sub-optimal. Breastfeeding was associated with a higher HIV transmission rate and was most likely associated with non-exclusive breastfeeding during neonatal admission. Recommendations. Maternal HAART or ARV prophylaxis should be commenced early in the pregnancy for the best benefits. Meticulous attention should be paid to the feeding practices of high risk HIV exposed infants admitted for specialised neonatal care. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2012.
18

Acceptability and feasibility of heat-treated expressed breastmilk following exclusive breastfeeding by HIV-1 infected South African women

Sibeko, Lindiwe Nobesuthu. January 2007 (has links)
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 + < 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.
19

Characterization of CD4+ and CD8+ T cell responses in HIV-1 C-Clade infection.

Ramduth, Dhanwanthie. January 2011 (has links)
HIV-1 specific CD4+ T cell activity in clade C infected subjects has not been studied. CD4+ T cells play a vital role in controlling infectious diseases and there is a need to augment our knowledge of HIV immunology to aid vaccine design. We therefore embarked on a study to characterize HIV-1 specific CD4+ T cell activity in both adults and infants; assess the relationship between CD4+ and CD8+ immune responses; and the relationship between CD4+ T cell activity and markers of disease progression (viral loads and CD4 counts). Our study revealed that the magnitude of CD8+ T cell responses correlated significantly with CD4+ T cell responses, but that the percentage of CD8+ T cells directed against HIV-1 was always greater than that of CD4+ T cells. Gag was the frequently targeted HIV-1 protein by CD4+ T cells and had the highest density of epitopes targeted by CD4+ T cells. Patients with either a dominant CD4 or CD8 T cell response against Gag had significantly lower viral loads than patients in whom non-Gag proteins were the main target (p< 0.0001 for CD4 activity and p= 0.007 for CD8 responses). Single IFN- producing CD4+ T cells were present in significantly higher numbers than cells producing both IFN- and IL-2 simultaneously (p=0.009). Gag also dominated the CD4+ T cell response in acutely infected infants with IFN- production detected more frequently than IL-2 or TNF- . Longitudinal analysis of infants receiving early ARV treatment and then ceasing after 12 months revealed that early treatment conferred no protection against increasing viremia and disease progression. CD4+ T cell responses were detected sporadically in untreated infants indicating a dysfunctional immune response in the face of constant exposure to high levels of viremia. Taken together, the data reveal that a vaccine inducing Gag specific CD4+ T cell responses has the potential to confer some degree of protection, but other immunological parameters need to be investigated especially in infants. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2011.
20

Community perceptions, attitudes and knowledge regarding mother to child transmission of HIV: a baseline evaluation before the implementation of the Prevention of Mother to Child Transmission of HIV Program using a short course of Nevirapine at Onandjokwe Hospital, Namibia.

Mtombeni, Sifelani January 2004 (has links)
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.

Page generated in 0.07 seconds