Thesis (MComm (Statistics and Actuarial Science))--University of Stellenbosch, 2009. / Incidence can be defined as the rate of occurence of new infections of a disease like HIV and is an useful estimate of trends in the epidemic. Annualised incidence can be expressed as a proportion, namely the number of recent infections per year divided by the number of people at risk of infection. This number of recent infections is dependent on the window period, which is basically the period of time from seroconversion to being classified as a long-term infection for the first time. The BED capture enzyme immunoassay was developed to provide a way to distinguish between recent and long-term infections. An optical density (OD) measurement is obtained from this assay. Window period is defined as the number of days since seroconversion, with a baseline OD value of 0, 0476 to the number of days to reach an optical density of 0, 8.The aim of this study is to describe different techniques to estimate the window period which may subsequently lead to alternative estimates of annualised incidence of HIV infection. These various techniques are applied to different subsets of the Zimbabwe Vitamin A for Mothers and Babies (ZVITAMBO) dataset. Three different approaches are described to analyse window periods: a non-parametric survival analysis approach, the fitting of a general linear mixed model in a longitudinal data setting and a Bayesian approach of assigning probability distributions to the parameters of interest. These techniques are applied to different subsets and transformations of the data and the estimated mean and median window periods are obtained and utilised in the calculation of incidence.

Em todo serviço de hemoterapia, a questão da segurança transfusional gera grande preocupação, visto que não existe transfusão isenta de risco de contaminação. Este trabalho tem como objetivo sugerir ao Centro de Hematologia e Hemoterapia do estado de Santa Catarina (HEMOSC), uma proposta de programa de uso de plasma de quarentena visando a segurança transfusional. O plasma de quarentena é aquele originado de um doador de repetição, que apresentou todos os testes sorológicos para doenças hemotransmissíveis não reagentes em doação anterior, até que o doador realize uma nova doação, este hemocomponente é mantido em quarentena, evitando o uso do mesmo em período de janela imunológica. Se todos os testes laboratoriais exigidos pela legislação vigente mantiverem-se não reativos após a nova doação, a unidade de plasma é liberada para uso. Sugere-se adequações no sistema de informática, referentes a triagem clínica e processamento do sangue, especificações para armazenamento e congelamento de plasma. Após análise da produção de plasma da hemorrede catarinense nos anos de 2012 e 2013, foi possível constatar que a instituição apresenta grande potencial para implantação da proposta, sendo necessário adequações na área física dos setores de processamento da hemorrede / Throughout the hemotherapy service, the question of transfusion safety generates great concern, whereas there is no free risk transfusion of contamination. This work aims to suggest to the Center of Hematology of the state of Santa Catarina (Hemosc) a proposal for use of quarantine plasma program to transfusion safety. The quarantine plasma that is originated from a donor replay, which showed all the non-reactive serologic tests for diseases transmissible by blood previous donation until the donor make a new donation, the blood component is kept in quarantine, avoiding the use of it in window periods. If all laboratory tests required by law are kept non-reactive after the new donation, the plasma unit is released for use. To implement the program for this product, adjustments in the computer system, related to recruitment, clinical screening, processing of blood, and specifications for storage and freezing of plasma is needed. After analysis of plasma production in Santa Catarina in 2012 and 2013, we acknowledge that the institution has a great potential for deployment of the proposal, being necessary adjustments in the physical area of the sectors of processing of the HEMOSC

Em todo serviço de hemoterapia, a questão da segurança transfusional gera grande preocupação, visto que não existe transfusão isenta de risco de contaminação. Este trabalho tem como objetivo sugerir ao Centro de Hematologia e Hemoterapia do estado de Santa Catarina (HEMOSC), uma proposta de programa de uso de plasma de quarentena visando a segurança transfusional. O plasma de quarentena é aquele originado de um doador de repetição, que apresentou todos os testes sorológicos para doenças hemotransmissíveis não reagentes em doação anterior, até que o doador realize uma nova doação, este hemocomponente é mantido em quarentena, evitando o uso do mesmo em período de janela imunológica. Se todos os testes laboratoriais exigidos pela legislação vigente mantiverem-se não reativos após a nova doação, a unidade de plasma é liberada para uso. Sugere-se adequações no sistema de informática, referentes a triagem clínica e processamento do sangue, especificações para armazenamento e congelamento de plasma. Após análise da produção de plasma da hemorrede catarinense nos anos de 2012 e 2013, foi possível constatar que a instituição apresenta grande potencial para implantação da proposta, sendo necessário adequações na área física dos setores de processamento da hemorrede / Throughout the hemotherapy service, the question of transfusion safety generates great concern, whereas there is no free risk transfusion of contamination. This work aims to suggest to the Center of Hematology of the state of Santa Catarina (Hemosc) a proposal for use of quarantine plasma program to transfusion safety. The quarantine plasma that is originated from a donor replay, which showed all the non-reactive serologic tests for diseases transmissible by blood previous donation until the donor make a new donation, the blood component is kept in quarantine, avoiding the use of it in window periods. If all laboratory tests required by law are kept non-reactive after the new donation, the plasma unit is released for use. To implement the program for this product, adjustments in the computer system, related to recruitment, clinical screening, processing of blood, and specifications for storage and freezing of plasma is needed. After analysis of plasma production in Santa Catarina in 2012 and 2013, we acknowledge that the institution has a great potential for deployment of the proposal, being necessary adjustments in the physical area of the sectors of processing of the HEMOSC

<p>Background. Platelets (thrombocytes) are the smallest cells in the blood. Platelet fulfils functions as formation of blood clots when bleeding. Low levels leads to bleeding while high levels increase the risk of thrombosis (obstruction of the circulatory flow system). Platelet transfusions may be required for patients with systemic bleeding and for patients at higher risk of bleeding because of coagulation defects, sepsis (presence of bacteria in the bloodstream), or platelet dysfunction related to medication or disease. A pathogen-reduction system for platelet components would be a useful method since it reduces the risk of bacterial, protozoa, viral and white blood cell contamination. The Intercept Blood System method (IBS) for platelets, destroys DNA and RNA and was validated against the routine method in order to reduce pathogen transmission risk during transfusion. The validation of IBS, the trombocyte count for100 buffy coat concentrates from 2007 were compared to values for 100 buffy coat concentrates from 2006 that had been treated with gamma-radiation. Akademiska sjukhuset in Uppsala has a requirement that 75% of the platelet concentrates contain at least 300*10 9 platelets per unit. IBS fulfilled to 94% compared to 98% for the routine method.</p><p>Thus, the IBS-method was well above the required value and is now used at</p><p>Akademiska sjukhuset in Uppsala.</p>

Background. Platelets (thrombocytes) are the smallest cells in the blood. Platelet fulfils functions as formation of blood clots when bleeding. Low levels leads to bleeding while high levels increase the risk of thrombosis (obstruction of the circulatory flow system). Platelet transfusions may be required for patients with systemic bleeding and for patients at higher risk of bleeding because of coagulation defects, sepsis (presence of bacteria in the bloodstream), or platelet dysfunction related to medication or disease. A pathogen-reduction system for platelet components would be a useful method since it reduces the risk of bacterial, protozoa, viral and white blood cell contamination. The Intercept Blood System method (IBS) for platelets, destroys DNA and RNA and was validated against the routine method in order to reduce pathogen transmission risk during transfusion. The validation of IBS, the trombocyte count for100 buffy coat concentrates from 2007 were compared to values for 100 buffy coat concentrates from 2006 that had been treated with gamma-radiation. Akademiska sjukhuset in Uppsala has a requirement that 75% of the platelet concentrates contain at least 300*10 9 platelets per unit. IBS fulfilled to 94% compared to 98% for the routine method. Thus, the IBS-method was well above the required value and is now used at Akademiska sjukhuset in Uppsala.