The aim of this thesis is to analyse and examine the debate on prenatal testing in Western countries, with a special focus on my own country, Sweden. In the near future it might be possible for a pregnant woman to profile the DNA of her foetus with a simple blood test early in pregnancy. This method of prenatal testing – Non Invasive Prenatal Diagnosis (NIPD) – could potentially detect the genetic causes of almost every disease. I will argue that prenatal testing should be offered by society to all pregnant women, not only to those at highest risk of giving birth to children with severe conditions. I will do that from a perspective of reproductive freedom. Furthermore, I will argue that offering prenatal testing for some conditions (such as Downs’s syndrome) and not for others, is conflicting with the autonomous choice of the pregnant woman.

Citrus greening or Huanglongbing is a severe disease affecting all citrus cultivars and rootstocks and is responsible for causing severe economic losses in many citrus producing countries. It is caused by various fastidious phloem-restricted, Gram negative bacteria belonging to the “Candidatus Liberibacter” genus. Currently only three species that affects citrus have been identified, “Candidatus Liberibacter africanus” (Laf) found in Africa, Mascarene Islands and the Middle East,“Candidatus Liberibacter asiaticus” (Las) present in Asia, and only recently emerged in Florida USA, São Paulo Brazil and Cuba and a new species “Candidatus Liberibacter americanus” (Lam) found only in São Paulo Brazil. Due to the continuing spread of this serious and destructive disease into areas of South Africa previously regarded as disease-free and disease-managed, the role of alternative hosts in the transmission of the disease is questioned. The aim of this study was to identify possible alternate hosts of Laf amongst plants of Rutaceae indigenous to South Africa. Identification of these alternate hosts forms a critical part of the integrated management and control strategies of the disease. Leaf material from symptomatic and asymptomatic indigenous rutaceous and non-rutaceous plants were collected from various sites in South Africa, from different environments which included vegetation adjacent to citrus orchards, in areas with high incidence of the citrus greening disease, from natural habitats, botanical gardens and private properties. A multiplex polymerase chain reaction (PCR) was developed for the simultaneous detection of Laf DNA and ubiquitous ribulose bisphosphate carboxylase oxygenase (Rubisco) gene which served as an internal control for the presence and quality of extracted DNA and potential amplification inhibition by compounds of the DNA extract. The multiplex PCR oligonucleotide primers were used to amplify fragments of 669bp from the β ribosomal operon of Laf and 179bp of Rubisco gene. Petioles and/or leaf midrib tissues were tested for the presence of Laf using the newly developed multiplex PCR and β operon specific primers of a published conventional PCR method. In this study seventeen Calodendrum capense Thunb. (Cape chestnut) plants from various geographic areas of South Africa were identified to be naturally infected with Liberibacter DNA. Sequence analysis revealed the DNA to be that of “Candidatus Liberibacter africanus subspecies capensis” (LafC). Although this subspecies of Liberibacter has previously been detected on C. capense in the Stellenbosch area of the Western Cape Province, this is the first report indicating the natural occurrence of LafC in C. capense in Gauteng, Limpopo and Mpumalanga Provinces of South Africa. The geographic distribution of the LafC bacterium associated with Cape chestnut appears to be more widespread than initially expected. No Laf DNA was detected from C.capense or any other indigenous plants surveyed. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Microbiology and Plant Pathology / unrestricted

Introduction: Epidemiological studies have indicated that 5-38% of influenza like illnesses (ILI) develop into severe disease due to, among others, factors such as; underlying chronic diseases, age, pregnancy, and viral mutations. There are suggestions that dual or multiple virus infections may affect disease severity. This study investigated the association between co-infection between influenza A viruses and other respiratory viruses and disease severity. Methodology: Datum for samples from North West England tested between January 2007 and June 2012 was analysed for patterns of co-infection between influenza A viruses and ten respiratory viruses. Risk of hospitalization to a general ward ICU or death in single versus mixed infections was assessed using multiple logistic regression models. Results: One or more viruses were identified in 37.8% (11,715/30,975) of samples, of which 10.4% (1,214) were mixed infections and 89.6% (10,501) were single infections. Among patients with influenza A(H1N1)pdm09, co-infections occurred in 4.7% (137⁄2,879) vs. 6.5% (59⁄902) in those with seasonal influenza A virus infection. In general, patients with mixed respiratory virus infections had a higher risk of admission to a general ward (OR: 1.43, 95% CI: 1.2 – 1.7, p = <0.0001) than those with a single infection. Co-infection between seasonal influenza A viruses and influenza B virus was associated with a significant increase in the risk of admission to ICU/ death (OR: 22.0, 95% CI: 2.21 – 219.8 p = 0.008). RSV/seasonal influenza A viruses co-infection also associated with increased risk but this was not statistically significant. For the pandemic influenza A(H1N1)pdm09 virus, RSV and AdV co-infection increased risk of hospitalization to a general ward, whereas Flu B increased risk of admission to ICU/ death, but none of these were statistically significant. Considering only single infections, RSV and hPIV1-3 increased risk of admission to a general ward (OR: 1.49, 95% CI: 1.28 – 1.73, p = <0.0001 and OR: 1.34, 95% CI: 1.003 – 1.8, p = 0.05) and admission to ICU/ death (OR: 1.5, 95% CI: 1.20 – 2.0, p = <0.0001 and OR: 1.60, 95% CI: 1.02 – 2.40, p = 0.04). Conclusion: Co-infection is a significant predictor of disease outcome; there is insufficient public health data on this subject as not all samples sent for investigation of respiratory virus infection are tested for all respiratory viruses. Integration of testing for respiratory viruses’ co-infections into routine clinical practice and R&D on integrated drugs and vaccines for influenza A&B, RSV, and AdV, and development of multi-target diagnostic tests is encouraged.