Thesis (M.S.)--Michigan State University. Dept. of Fisheries and Wildlife, 2008. / Title from PDF t.p. (viewed on July 29, 2009) Includes bibliographical references (p. 64-73). Also issued in print.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 174-184).

Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 1997. / Vita. Includes bibliographical references (leaves 116-132).

Thesis (Ph.D.)--Aberdeen University, 2008. / Title from web page (viewed on June 26, 2009). Includes bibliographical references.

Thesis (M.P.H.)--Georgia State University, 2007. / Title from file title page. Michael Eriksen, committee chair; Betty Apt, Marshall Kreuter, committee members. Electronic text (121 p. : ill. (some col.), col. maps)) : digital, PDF file. Description based on contents viewed Oct. 25, 2007. Includes bibliographical references (p. 109-115).

Thesis (M. Med. Sc.)--University of Hong Kong, 2006.

Approximately 2-4 billion cases of infectious diarrhoea occur every year, with the highest numbers recorded in sub-Saharan Africa. It remains the most common public health issue among children in developing nations. The purpose of this research was to unfold the prevalence of diarrhoeagenic E. coli and Campylobacter pathotypes as well as elucidate their antibiogram characteristics in diarrhoeal stool samples collected in some medical facilities in Eastern Cape Province, South Africa. Two hundred stool samples were collected from both inpatients and outpatients from male and females of all age groups attending selected medical facilities in the study area. Isolation and characterization of both organisms were done using culture based and molecular methods. Antibiotic susceptibility patterns of identified isolates were determined against a panel of 12 antimicrobial agents. One hundred and twenty presumptive E. coli isolates and 42 presumptive isolates of Campylobacter spp. Were isolated. Eighty-two percent (82 percent) of the presumptive E. coli isolates were confirmed as E. coli while 46.3 percent belonged to Campylobacter spp. Pathotyping of the diarrhoeagenic E. coli isolates by Polymerase chain reaction (PCR) showed the following prevalences: DAEC 43 (32 percent), EHEC 18 (17 percent), EIEC 11 (10 percent) and EPEC 18 (17 percent). EAEC and ETEC were not detected, while for Campylobacter spp. 37 (88 percent) were C. jejuni, and C. coli was not detected. A total of 12 (32.4 percent) of the confirmed Campylobacter jejuni isolates were found to possess the fliM gene, 9 (24.3 percent) possessed the flhA gene and only 6 (16.2 percent) harboured the gene flgE2. None were positive for the flaA, flab and flhB genes.The antibiotic resistance patterns observed among the E. coli isolates were high against ampicillin (98.1 percent), chloramphenicol (94.3 percent) and tetracycline (90.6 percent). For Campylobacter spp., resistance observed were: chloramphenicol (91.6 percent), tetracycline (25.2 percent), erythromycin (49.6 percent) and gentamycin (56.4 percent). A lesser resistance against imipenem (35.9 percent) and quinolone (ciprofloxacin) (45.5 percent) were exhibited by the E.coli isolates. 10.8 percent and 20.3 percent of the Campylobacter isolates were resistant to imipenem and ciprofloxacin respectively. The presence of chloramphenicol (CatA1) and tetracycline (tetA) resistance genes were detected in 94 percent and 89 percent of E. coli isolates respectively while 98 percent of Campylobacter spp. Harboured the catA1 resistance gene. It could be deduced from this study that E. coli and Campylobacter spp. are predomiant enteric pathogens as the etiologic agents of diarrhoea in the study community, and that their antimicrobial resistance is high in the study location. The need to develop strategies to prevent infection and control resistant organisms is evident.

>Magister Scientiae - MSc / Campylobacter species are the most common bacteria associated with acute diarrhoea and is responsible for 400 to 500 million reported cases globally. It is not uncommon for 35% to 85% of chicken flocks to be infected with campylobacters and it is because of this high prevalence that chicken is considered to be the primary source of Campylobacter contamination in the domestic setting. Therefore, a very high risk of acquiring campylobacteriosis is associated with the mishandling and consumption of contaminated chicken. The present study had isolated a total number of 156 Campylobacter isolates, of which 102 isolates were C. jejuni and 51 were C. coli. The speciation of 3 Campylobacter isolates could not be determined. It had shown that there is a high prevalence of Campylobacter in South African chicken. Retail chicken (n = 84) has a lower prevalence of 27% whereas chicken sampled directly from the abattoir (n = 182), but also intended for human consumption, had an average prevalence of 73%. It also showed that free range chicken (n = 118) has a higher prevalence (average of 79%) of Campylobacter than commercial chicken (n = 64) (average of 56%). It is for this reason that free range chicken is not always the safer option considering that the purchasing of free range chicken is becoming more popular for health reasons. There is no standardized universal isolation protocol for Campylobacter species and the current isolation techniques creates a bias for the optimal growth of C. jejuni and C. coli, the two thermotolerant species most commonly associated with human illnesses. Recently, the non-selective Cape Town Protocol was designed for efficient isolation of campylobacters from clinical samples and proved to be superior to the former techniques in the isolation of the thermotolerant campylobacters as well as emerging campylobacters. However, the protocol is not suited to the isolation of Campylobacter from food samples. This study successfully optimized the Cape Town protocol by incorporating the use of the selective Bolton broth for the recovery and enrichment of injured cells from raw chicken samples. The technique proved to be equal in isolation efficiency to the ISO 1272-1:2006 method but loses its ability to recover all campylobacters that may be present in the food sample. It is for this reason that a non selective enrichment broth should be sought but the technique boasts superiority over the ISO 10272-1:2006 method in that it reduces the time in obtaining the results at least by 48 h and is more cost effective. / National Research Foundation (NRF)

A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy Johannesburg, South Africa 2016 / Introduction: Neonatal infections contribute to 25% of all neonatal deaths, which account for approximately 44% of all under-5 childhood deaths globally. Pathogens responsible for sepsis in neonates and young infants can be acquired vertically prior to or during labour, or from the environment (community or hospital). This project evaluated the burden and aetiology of sepsis in neonates and young infants (≤90 days), and explored this association to in-utero exposure to human immunodeficiency virus. The study also included a specific focus on the epidemiology of invasive Group B Streptococcal disease in young infants. Additionally, we assessed the efficacy of intrapartum chlorhexidine vaginal washes for: (i) preventing early-onset neonatal sepsis; and (ii) vertical transmission of potentially pathogenic bacteria to the newborns. Furthermore, we evaluated risk factors for poor outcomes due to neonatal sepsis. Materials and methods: (i) A bacterial surveillance system was established at Chris Hani Baragwanath Academic Hospital (CHBAH) from 2004-2008 to identify young infants with bacterial sepsis hospitalised in the neonatal and paediatric wards. Medical and microbiological records were utilised to obtain clinical and laboratory data. Maternal HIV results were obtained from antenatal testing records or admission records. (ii) A blinded, randomised, placebo-controlled trial of 0.5% chlorhexidine maternal vaginal intrapartum wipes and newborn skin wipes was conducted at CHBAH between 2004 and 2007. Consented, eligible participants were randomised during labour to receive either chlorhexidine vaginal wipes or water external genitalia wipes. Newborns received either chlorhexidine full-body wipes (intervention arm) or foot wipes (control arm). Maternal and infant participants were followed up for admissions during the first month after delivery/ birth. A subset of 5144 maternal participants had an intrapartum lower vaginal swab collected, and skin swabs were collected from their newborns to assess colonisation with potentially pathogenic bacteria (Group B streptococcus, Escherichia coli and Klebsiella pneumoniae). Results: Group B streptococcus (GBS) was the most commonly isolated bacterial pathogen, causing 35.2% of culture-confirmed sepsis in infants ≤90 days, 41.6% of early-onset disease (EOD, 0-6 days), 40.5% of late-onset neonatal disease (LOD, 7-27 days) and 18.7% of young-infant community-acquired disease (YI-CAD, 28-90 days). Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) contribute 16.2%, 12.2% and 3.4% to sepsis in young infants. Overall, incidence (per 1000 live births) of invasive GBS disease was 2.72 (95% confidence interval [95% CI]: 2.46 to 3.01), including an incidence of 1.50 and 1.22, respectively, in infants 0-6 days and 7-90 days of age. HIV-exposed infants were at greater risk of EOD (Relative risk [RR]: 1.69; 95% CI: 1.28-2.24) and LOD (RR= 3.18; 95% CI: 2.34-4.36) than HIV-unexposed infants. GBS serotypes Ia and III caused 84.0% of invasive GBS disease in young infants. Intrapartum chlorhexidine interventional wipes was not efficacious in prevention of any of: (i) vertical transmission of pathogenic bacteria (54% vs. 55%; efficacy -0.05, 95% CI: -9.5 to 7.9) to the newborns; (ii) sepsis in first 3 days of life (3% vs. 4%; p=0.65,); (iii) sepsis in the later neonatal period (both <1%; p=0.4444); or (iv) maternal puerperal sepsis(both <1%; p=0.56). Conclusion: GBS, S. aureus, E. coli and K. pneumoniae are the most commonly isolated bacterial pathogens in neonates and infants ≤90 days old. HIV-exposed infants are at greater risk of GBS sepsis. Intrapartum chlorhexidine intervention was not efficacious in reducing vertical transmission of pathogenic bacteria, neonatal or maternal sepsis. Alternative interventions to prevent sepsis in young infants, including maternal immunisation, need to be investigated in setting such as ours where there is a high prevalence of maternal HIV infection. / MT2017

This study is concerned with the economic burden of HIV/AIDS in Nepal. It focuses on the direct costs of seeking treatment, productivity costs (before and after adjustment for coping strategies), catastrophic and impoverishing impacts, the coping strategies used by households and the socio-economic impacts of stigma and discrimination. The study was cross-sectional and employed a mixed-methods approach. The survey questionnaire (quantitative study) with 415 respondents and in-depth interviews (qualitative study) with 30 participants were conducted in six treatment centres in six different districts. Total costs due to HIV/AIDS (the sum of direct costs and productivity costs before adjustment for coping strategies) were an average of Nepalese Rupees (NRs) 2,233 per month (US$ 30.2/month), 28.5% of the household income. The main determinants of direct costs were found to be cluster of differentiation 4 (CD4) level, household income, occupation, whether the people living with HIV/AIDS (PLHA) was accompanied, and district. The main determinants of productivity costs were found to be self-reported health status, ethnicity, sexual orientation, and district. The most frequently used coping strategies were the use of savings or income, taking a loan and sale of assets. Nearly 75% of households faced catastrophic impacts due to direct and productivity costs. The study concluded that HIV/AIDS has caused a significant economic burden for (PLHA) and their families in Nepal. The study has helped fill the knowledge gap about the extent, nature and determinants of this economic burden. It has also involved methodological innovation, particularly in the measurement of productivity costs. The major limitations were a concentration on respondents attending treatment centres, the lack of a control group, the possibility of recall bias and restrictions on the type of analysis conducted because of time constraints. The study has a number of policy implications for different stakeholders and sets a further research agenda.