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  • 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.
1

Pregnancy and acquisition of sexually transmitted infections: risk behaviors and incidence

Teasdale, Chloe Anna January 2015 (has links)
This dissertation had three primary aims. The first aim was to systematically review evidence documenting incidence of sexually transmitted infections (STI) during pregnancy. Eighteen papers were included in the final review which reported incidence of five STIs: chlamydia, gonorrhea, human papillomavirus (HPV), herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus (HIV). The review found that there are very limited data on incidence of STIs during pregnancy and even fewer data comparing risk between pregnant and non-pregnant women. Although data are limited, studies suggest that women continue to acquire STIs during pregnancy, with incidence varying by type of infection, population of interest and geographic setting. Highest incidence was found for HPV and chlamydia although some studies of chlamydia showed low proportions of pregnant women infected. Studies in which partners were known to be infected with HSV-2 and HIV showed higher rates of acquisition in pregnant women compared to studies where partner status was not known. The second aim of this dissertation was to describe the impact of pregnancy on behavioral risk factors and vaginal practices that are associated with increased risk of STI acquisition. Data for this and the following aim came from the Methods for Improving Reproductive Health in Africa (MIRA) study, a randomized clinical trial conducted in South Africa and Zimbabwe 2003-2006. The analysis for the second aim included women in the MIRA trial who had a pregnancy during follow-up. Pregnancy was found to decrease sexual activity, particularly in the third trimester, but women were more likely to report sex without condoms while pregnant. There were lower reports by women during pregnancy of other risk factors for STI acquisition, including anal sex, concurrent sexual relationships and new sex partners. Vaginal wiping and insertion of material into the vagina, potentially important mechanisms for STI acquisition, were also less common during pregnancy. The data from this aim present a complicated picture of risk for STIs during pregnancy as a result of increased unprotected sex but decreased frequency of other known behavioral risk factors. The third and final aim of the dissertation was to measure incidence of four STIs in pregnant and non-pregnant women and to evaluate whether women are at greater risk during pregnancy for acquiring four STIs: chlamydia, gonorrhea, trichomoniasis and HIV. This analysis included 4,549 women 18-50 years of age, 17% (N=766) of whom had a pregnancy during follow-up. In general, women continued to be sexually active but reported less overall sex than non-pregnant women. Report of condom use was lower during pregnancy as were other types of high risk sexual behaviors, such as multiple sexual partners, sex in exchange for drugs or money and anal sex, as well vaginal practices. STI incidence was measured during pregnancy and it was found that women continued to acquire STIs when pregnant. In addition, during periods when women became pregnant, they appeared to be a high risk for acquiring chlamydia, trichomoniasis and HIV. Finally, in examining the association between pregnancy status and STI risk, we found that in multivariable models adjusted for demographic and time-varying self-reported behavioral risk factors and vaginal practices, pregnancy was not associated with increased STI risk. However in visit intervals when women became pregnant, they appeared to be at higher risk for contracting chlamydia compared to non-pregnant periods.
2

The interaction between human leucocyte antigen-G and natural killer cells at the placental interface in HIV-1 infected pregnant women and the significance, if any, to in utero transmission.

January 2007 (has links)
This study was undertaken to investigate the relationship between Natural Killer cells and HLA-G at the placental barrier in HIV-I infected pregnant women and to establish the significance, if any, to in utero infection. Fifty-five HIV -I infected pregnant women were recruited into the study after consent was obtained. Blood samples were collected from both mothers and babies for viral loads and CD4+ cell counts. Placental samples were obtained from pregnancies at delivery and examined by immunoperoxidase immunohistochemistry methods using monoclonal antibodies to p24 antigens and Natural Killer (CD56+) cells. HLA-G expression was quantified using real-time polymerase chain reaction. Analysis of viral loads and CD4+ cell counts were undertaken in categories. No significant association was observed between the viral load of mothers and their CD4+ cell counts. Eighteen percent of the women in this study population had 5 log viral loads with a transmission rate of 0.27(95% Cl, 0.15 - O. 39). Maternal viraemia was significantly associated with transmission of infection to babies (p = 0.047). The odds ratio indicated that for every 1 log increase in maternal viral load the babies were 3.1 times more likely to acquire the infection (Exp (B) = 3.137 (95%CI, 1.015-9.696). Furthermore, the study found that a higher number of female babies were infected than males. Although not statistically significant the odds ratio indicated that female babies were 3.1 times more likely to become infected than males (Exp (B) = 3.110 (95%CI, 0.819-11.808). We report here the results of immunohistochemistry for p24 antigens and NK (CD56+) cells and compare them to the immunological responses of both mothers and babies at birth. HIV-1 antigens were detected in 94.5% of all placentas by immunohistochemistry. Infiltration of CD56+ was found in 98% of placental tissue. The analysis revealed that the presence of p24 antigens in placental tissue was not influenced by maternal viral load or CD4+ cell counts. Lower median NK cell values were observed in placentas of mothers with infected babies as compared with the uninfected cluster. Although not statistically significant, the risk of vertical transmission was increased 3.4 times more in placentas which had lower NK cell values. According to the odds ratio, babies CD4+ counts were affected by every 1 log increase in mother's viral load. Overall, maternal viral load emerged as a strong predictor for risk of infection from infected mothers to their infants. Our analysis indicated that female babies were 3.7 times more likely to acquire the infection than males. Using data obtained from real-time PCR we investigated the relationship between maternal viral load and the quantity of HLA-G expression (p = 0.045; 95%CI 1.029- 11.499). Logistic regression models revealed that mother's viral load was the strongest risk factor for vertical transmission. No statistically significant correlation was noted with HLA-G and viral transmission. However, the odds ratio indicated that the risk of infection increased by 1.3 with every 1 fold increase in HLA-G expression. An analysis of mother-to-child transmission rates by gender revealed that the odds ratio for transmission was 3.4 times more in female babies than in males. We then investigated the relationship between maternal viraemia and HLA-G expression. A positive correlation between maternal viral load and placental HLA-G was observed (p = 0.038). When gender susceptibility to HLA-G expression was explored a statistically significant association was observed in placental tissue of mothers with infected and uninfected male babies and HLA-G expression (p = 0.013). To conclude, the analysis found that HLA-G was up regulated 3.95 times more in placental tissue of mothers with infected babies than in mothers with uninfected babies. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2007.
3

The impact of pneumonia in human immunodeficiency virus (HIV-1) infected pregnant women on perinatal and early infant mortality.

January 2007 (has links)
Background: Although the prevalence of pneumonia in pregnancy is reported to be less than 1%, the pregnant state and risk factors associated with the development of pneumonia adversely influence the outcome of pregnancy. KwaZulu-Natal is at the epicenter of the dual epidemics of tuberculosis and HIV-1 and the impact of these diseases occurring concurrently in pregnant women at King Edward VIII hospital (KEH), South Africa have been described previously. The impact of antenatal pneumonia in HIV-1 infected and uninfected women however has not been described in the study population and was investigated. Methods: Pregnant women with clinical and radiological evidence of pneumonia were recruited from the antenatal clinic and labour ward at KEH. The study was conducted prospectively between January and December 2000. The clinical profile of these women and the causative organisms were determined. In addition the impact of HIV-1 infection, maternal immunosuppression and maternal pneumonia on obstetric and perinatal outcomes were evaluated. Mothers diagnosed with tuberculosis and multi drug resistant tuberculosis were hospitalised at King George V hospital until delivery. Results: Twenty nine women were diagnosed with antenatal pneumonia (study arm) with Mycobacterium tuberculosis the only causative organism isolated. A control arm of 112 pregnant women was also studied. Maternal and perinatal mortality was restricted to the study arm with a maternal mortality ratio of 99 per 100 000 live births and a perinatal mortality rate of 240 per 1000 births. Pneumonia was significantly associated with a negative overall obstetric outcome in the presence of HIV- l infection, antenatal care, anaemia and second trimester booking status. In addition, the presence of pneumonia was significantly associated with maternal mortality. There was a highly significant association between exposure to pneumonia and poor neonatal outcome. Maternal pneumonia, maternal HIV infection and the presence of medical and obstetric conditions were significantly associated with low birth weight and neonatal pneumonia. Further, maternal pneumonia (p <0.001) and concurrent HIV infection (p=0.002) was significantly associated with neonatal death. Conclusion: The presence of pneumonia in the antenatal period impacts negatively on maternal and neonatal morbidity and mortality. Health care providers must maintain a high degree of suspicion when managing a pregnant woman with unresolving upper respiratory tract symptoms and refer timeously for further investigation. Pneumonia and in particular pulmonary tuberculosis associated with HIV co- infection in pregnancy is a threat to mother and baby. Therefore in areas endemic for TB and HIV infection, it may be prudent to screen HIV positive pregnant women for symptoms suggestive of pneumonia and thereby identify women requiring further investigations such as sputummicroscopy and cultures, and a screening chest radiograph. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Durban, 2007.
4

The antimicrobial susceptibility and gene-based resistance of Streptococcus Agalactiae (group B Streptococcus) in pregnant women in Windhoek (Khomas region), Namibia

Engelbrecht, Fredrika January 2015 (has links)
Thesis (MTech (Biomedical Sciences))--Cape Peninsula University of Technology, 2015. / BACKGROUND AND OBJECTIVES: Group B Streptococci (GBS) can asymptomatically colonise the vagina and rectum of women. Studies have shown that this bacterium is the leading cause of septicemia, meningitis and pneumonia in neonates. In Namibia no known studies have investigated GBS colonisation and the antibiotic resistance profile of GBS isolates in pregnant women. This study accessed the GBS colonisation rate amongst the pregnant women who attended the Windhoek Central Hospital Antenatal Clinic (Khomas region), in Namibia for a period of 13 months. Furthermore, using the VITEK 2 system, the GBS isolates were tested against the following antimicrobial substances; benzylpenicillin, ampicillin, clindamycin, erythromycin, tetracycline, vancomycin, cefotaxime, ceftriaxone, linezolid and trimethoprim/sulfamethoxazole. Penicillin G is the drug of choice in the majority of studies, and seems to be the most effective drug for intrapartum antibiotic prophylaxis (IAP). All the GBS isolates found in this study were also analysed for the presence of selected genes known to be associated with resistance to key antibiotics using specific primers within a polymerase chain reaction (PCR).
5

Incidence and mechanism of antibiotic resistance of Streptococcus Agalactiae isolates from pregnant women and their babies at Dr George Mukhari Academic Hospital, Pretoria

Bolukaoto, Yenga John 10 1900 (has links)
BACKGROUND AND OBJECTIVES: Streptococcus agalactiae (Group B Streptococcus, GBS) is the leading cause of neonatal infections and deaths in human. It can also cause infections in pregnant women and non-pregnant adults. Penicillin and ampicillin are antibiotics of choice for the treatment of GBS infections. Erythromycin and clindamycin are used as alternative therapy in penicillin allergic patients, however resistance to these agents has been increasingly observed. This present study was undertaken to determine the colonization rate of GBS, susceptibility profile and the mechanism of antibiotic resistance in pregnant women and their babies at Dr. George Mukhari Academic Hospital in Pretoria. METHODS: Rectal and vaginal swabs were collected from pregnant women; ear and umbilical swabs from newborns over an 11 month period. Samples were cultured on selective media (CNA agar and Todd-Hewitt broth) and GBS positively identified using morphological and biochemical tests including Gram staining, hemolytic activity, catalase test, bile esculin, CAMP test and Latex agglutination test. The susceptibility testing was done using the Kirby-Bauer and E-test methods. The D-test method was used to determine the inducible clindamycin resistance. Multiplex PCR with were used to detect different genes coding for resistance. RESULTS: Out of the 413 patients evaluated, 128 (30.9%) were positive with GBS. All isolates were sensitive to penicillin and ampicillin. Erythromycin and clindamycin resistance was 21.1% and 17.2% respectively; of which 69% harbouring constitutive MLBB, 17.4% inducible MLSB. The alteration of ribosomal target encoded by ermB genes was the commonest mechanism of resistance observed in 55% of isolates, 38% of isolates had both ermB and linB genes and efflux pump mediated by mefA genes was detected in one of isolates. Conclusion: This study reaffirms the appropriateness of penicillin as the antibiotic of choice for treating GBS infection. However it raises the challenges of resistance to the macrolides and lincosamides. More GBS treatment options for penicillin allergic patients need to be researched. / Health Studies / M.Sc. (Life Sciences (Microbiology))
6

Incidence and mechanism of antibiotic resistance of Streptococcus Agalactiae isolates from pregnant women and their babies at Dr George Mukhari Academic Hospital, Pretoria

Bolukaoto, Yenga John 10 1900 (has links)
BACKGROUND AND OBJECTIVES: Streptococcus agalactiae (Group B Streptococcus, GBS) is the leading cause of neonatal infections and deaths in human. It can also cause infections in pregnant women and non-pregnant adults. Penicillin and ampicillin are antibiotics of choice for the treatment of GBS infections. Erythromycin and clindamycin are used as alternative therapy in penicillin allergic patients, however resistance to these agents has been increasingly observed. This present study was undertaken to determine the colonization rate of GBS, susceptibility profile and the mechanism of antibiotic resistance in pregnant women and their babies at Dr. George Mukhari Academic Hospital in Pretoria. METHODS: Rectal and vaginal swabs were collected from pregnant women; ear and umbilical swabs from newborns over an 11 month period. Samples were cultured on selective media (CNA agar and Todd-Hewitt broth) and GBS positively identified using morphological and biochemical tests including Gram staining, hemolytic activity, catalase test, bile esculin, CAMP test and Latex agglutination test. The susceptibility testing was done using the Kirby-Bauer and E-test methods. The D-test method was used to determine the inducible clindamycin resistance. Multiplex PCR with were used to detect different genes coding for resistance. RESULTS: Out of the 413 patients evaluated, 128 (30.9%) were positive with GBS. All isolates were sensitive to penicillin and ampicillin. Erythromycin and clindamycin resistance was 21.1% and 17.2% respectively; of which 69% harbouring constitutive MLBB, 17.4% inducible MLSB. The alteration of ribosomal target encoded by ermB genes was the commonest mechanism of resistance observed in 55% of isolates, 38% of isolates had both ermB and linB genes and efflux pump mediated by mefA genes was detected in one of isolates. Conclusion: This study reaffirms the appropriateness of penicillin as the antibiotic of choice for treating GBS infection. However it raises the challenges of resistance to the macrolides and lincosamides. More GBS treatment options for penicillin allergic patients need to be researched. / Health Studies / M. Sc. (Life Sciences (Microbiology))
7

The experience of midwives delivering the babies of HIV positive women

Thopola, Magdeline Kefilwe 12 September 2012 (has links)
M.Cur. / Statistics prove that the monster called HIV/AIDS invades our country. More women are said to be HIV positive in comparison to men. The midwives are the frontline health workers who have to care for these pregnant HIV positive women and therefore are at occupational risk of HIV infection because of their caring role. The experience of midwives regarding the delivery of the babies of HIV positive women was not well addressed before as limited studies have been undertaken about the experiences of midwives, therefore inspiring the researcher to undertake this study. The purpose of this study was to: • Explore and describe how midwives experienced the delivery of the babies of HIV positive women. • Describe the guidelines for health professionals to support midwives in order for them to render good midwifery care. The paradigmatic perspective of this study was guided by the Theory for Health Promotion in Nursing (Rand Afrikaans University, Department of Nursing Science, 1992:2-15), which reflects the focus on the whole person.
8

Epidemiology and multilocus sequence typing of group B streptococcus colonising pregnant women and their neonates at Dr George Mukhari Academic Hospital, Pretoria.

Monyama, Maropeng Charles 11 1900 (has links)
Background: Group B streptococcus (GBS) is regarded as one of the most important causes of maternal and neonatal morbidity and mortality in many parts of the world. GBS recto-vaginal colonization is important in the health of a mother and her neonate, especially in developing countries. Maternal vaginal colonization with GBS at the time of delivery can cause vertical transmission to the neonate. Multilocus sequence typing (MLST) is a technique used to characterize microbial isolates by means of sequencing internal fragments of housekeeping genes and has the advantage of reproducibility and has been shown to correlate with the other typing techniques and thus has emerged as the standard for delineating the clonal population of GBS. The study aimed to investigate the epidemiology of GBS colonization among pregnant women and their neonates, and to characterize the isolates by multilocus sequence typing technique at Dr George Mukhari Academic Hospital, Pretoria. Methodology: A total of 413 pregnant women who visited the antenatal clinic were recruited and screened. Participants were interviewed using a questionnaire to gather demographic and other relevant information such as history of current pregnancy, previous miscarriages and still births. Samples from maternal rectum and vagina as well as neonate ear and umbilical cord were taken for culture using colistin and nalidixic acid (CNA) blood agar and incubated for 24-48 hours. If negative after 48 hours, Todd-Hewitt broth was subcultured after 18-48 hours onto sheep blood agar. Multilocus sequence typing (MLST) was used to characterize seven group B streptococcus isolates collected at Dr George Mukhari academic hospital. Fragments of seven housekeeping genes were amplified by polymerase chain reaction (PCR) for each strain and sequenced. CLC bio software (Inqaba biotech, South Africa; Pretoria) was used to analyse sequenced loci and UPGMA dendrogram was constructed. Results: The colonization rate for GBS in pregnant women and their neonates was 30.9% and 0%, respectively. A higher proportion of GBS were isolated from the rectum (37.9%) as compared to the vagina (20.6%). Most socio-economic, demographic and obstetric factors analysed were not significantly associated with.GBS colonization. On 128 positive samples, the results of Todd-Hewitt enrichment broth and direct plating method using CNA were compared. A total of 45.3% of colonised were positive on direct selective agar (CNA); an additional 54.7% samples were recovered from Todd-Hewitt broth. Three genes (adhP, glnA and tkt) were sequenced successfully for six samples (1, 2. 4,6,12 and 65). The UPGMA tree with 1000 bootstrap showing the relationship between six samples was drawn.Conclusion: This study revealed that pregnant women of all ages are at risk of group B streptococcus colonization. Group B streptococcus was common among pregnant women at Dr George Mukhari Academic Hospital. No socio-economic risk factor was associated with group B streptococcus colonization. Results confirm that the combination of Todd-Hewitt broth and CNA agar plate is a time saving and sensitive method. The allelic profile, characteristics such as G+C (guanine+cytosine) content and dN/dS ratio were not analysed because of the smaller sample size used in this study, which shows that the MLST method was unsuccessful in this study. The UPGMA tree based on differences in consensus of the isolates showed that all group B streptococcus isolates are clustered and descend from a single node. / Life & Consumer Sciences / Life Sciences / M.Sc. (Life Sciences)
9

Epidemiology and multilocus sequence typing of group B streptococcus colonising pregnant women and their neonates at Dr George Mukhari Academic Hospital, Pretoria

Monyama, Maropeng Charles 11 1900 (has links)
Background: Group B streptococcus (GBS) is regarded as one of the most important causes of maternal and neonatal morbidity and mortality in many parts of the world. GBS recto-vaginal colonization is important in the health of a mother and her neonate, especially in developing countries. Maternal vaginal colonization with GBS at the time of delivery can cause vertical transmission to the neonate. Multilocus sequence typing (MLST) is a technique used to characterize microbial isolates by means of sequencing internal fragments of housekeeping genes and has the advantage of reproducibility and has been shown to correlate with the other typing techniques and thus has emerged as the standard for delineating the clonal population of GBS. The study aimed to investigate the epidemiology of GBS colonization among pregnant women and their neonates, and to characterize the isolates by multilocus sequence typing technique at Dr George Mukhari Academic Hospital, Pretoria. Methodology: A total of 413 pregnant women who visited the antenatal clinic were recruited and screened. Participants were interviewed using a questionnaire to gather demographic and other relevant information such as history of current pregnancy, previous miscarriages and still births. Samples from maternal rectum and vagina as well as neonate ear and umbilical cord were taken for culture using colistin and nalidixic acid (CNA) blood agar and incubated for 24-48 hours. If negative after 48 hours, Todd-Hewitt broth was subcultured after 18-48 hours onto sheep blood agar. Multilocus sequence typing (MLST) was used to characterize seven group B streptococcus isolates collected at Dr George Mukhari academic hospital. Fragments of seven housekeeping genes were amplified by polymerase chain reaction (PCR) for each strain and sequenced. CLC bio software (Inqaba biotech, South Africa; Pretoria) was used to analyse sequenced loci and UPGMA dendrogram was constructed. Results: The colonization rate for GBS in pregnant women and their neonates was 30.9% and 0%, respectively. A higher proportion of GBS were isolated from the rectum (37.9%) as compared to the vagina (20.6%). Most socio-economic, demographic and obstetric factors analysed were not significantly associated with.GBS colonization. On 128 positive samples, the results of Todd-Hewitt enrichment broth and direct plating method using CNA were compared. A total of 45.3% of colonised were positive on direct selective agar (CNA); an additional 54.7% samples were recovered from Todd-Hewitt broth. Three genes (adhP, glnA and tkt) were sequenced successfully for six samples (1, 2. 4,6,12 and 65). The UPGMA tree with 1000 bootstrap showing the relationship between six samples was drawn.Conclusion: This study revealed that pregnant women of all ages are at risk of group B streptococcus colonization. Group B streptococcus was common among pregnant women at Dr George Mukhari Academic Hospital. No socio-economic risk factor was associated with group B streptococcus colonization. Results confirm that the combination of Todd-Hewitt broth and CNA agar plate is a time saving and sensitive method. The allelic profile, characteristics such as G+C (guanine+cytosine) content and dN/dS ratio were not analysed because of the smaller sample size used in this study, which shows that the MLST method was unsuccessful in this study. The UPGMA tree based on differences in consensus of the isolates showed that all group B streptococcus isolates are clustered and descend from a single node. / Life Sciences / M.Sc. (Life Sciences)

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