No description available.

No description available.

No description available.

No description available.

No description available.

The number of female veterans is increasing daily. Previous research conducted on veterans has focused primarily on males or with small samples of females. Depression and suicidality are becoming increasingly evident in returning veterans. Toxoplasma gondii is an intracellular parasite that is common in the Middle East and has been reported to cause changes in personality and behavior. The purpose of the current study was to examine relationships between T. gondii antibody titer and socioeconomic variables, dysphoric moods, and risk-taking behaviors in a sample of 70 female veterans. Blood samples were collected and analyzed for T. gondii antibody titer and participants completed a battery of questionnaires, including the Center for Epidemiologic Studies Depression (CES-D) scale, Profile of Mood States (POMS), PTSD Checklist- Military version (PCL-M), Alcohol Use Disorder Identification Test (AUDIT), and a sexual harassment and assault questionnaire. Results of chi-squares showed a relationship between T. gondii titer, ethnicity, marital status, and level of education. Pearson's correlations and t-tests showed relationships between T. gondii titer and POMS depression, confusion, and anger subscales, and total mood disturbance scores.

Global growth in aquaculture, referred to as the blue revolution, is seen by many to be the solution to future food scarcity. However, this growth has been accompanied by disease emergence. Disease emergence is inevitable when host populations are concentrated and densities exceed the threshold value for occurrence of outbreaks. Abalone farming is a relatively recent development and diseases of abalone are not well characterised. There have been relatively few systematic surveys of abalone diseases in the world. Much of the available information resulted from investigations of specific disease outbreaks, such as withering syndrome in California. The outstanding example of a formal survey of abalone health was conducted in Australia. A methodical survey of abalone health, encompassing all farms and including wild abalone, has never been done in South Africa. However, South Africa has for many years had a herd health program for abalone producers and this has generated the largest body of data on abalone disease occurrence in the world. Although these data have some shortcomings, it was felt that analysis could provide insights into the epidemiology of parasites in farmed Haliotis midae, as well as informing better surveillance techniques for the future. Data for abalone submitted from nine farms as part of the herd health management program during the period 1 January 2000 to 31 December 2004 were analysed. No wild abalone were included in these data and the only abalone species considered was the South African abalone or perlemoen, Haliotis midae. Data on the age of the abalone and their diet were obtained from the farms. The abalone originated from either flow through or recirculation systems. Each animal was weighed and measured at the laboratory. A standard set of tissue sections was fixed and processed for histology. Presence of parasites was recorded, as well as the sex and degree of gonad development. Once data had been captured in Excel, a series of tables was constructed from counts of infected and non infected abalone for all host and environmental factors contained in the data set. Charts of the tables were drawn. Where host and environmental factors appeared to interact, these data were also tabulated and charted. Statistical analyses of the data in Excel followed. All analyses were performed for sessile ciliates, renal coccidia, gut protozoa, digestive gland PAGE 2 OF 137 protozoa and rickettsia like prokaryotes. The rarity of trematode infections made meaningful analyses difficult. The chi square test, effect sizes and odds ratios were used to seek significant associations. When confounding and interaction were suspected, stratum specific odds ratios were calculated. The summary odds ratio used in this study was the Mantel Haenszel summary odds ratio. The Breslow Day test for interaction was performed when necessary. Confidence intervals were determined using the method of Woolf. The overall prevalence of the various parasites was very variable. Sessile ciliates were the most common, with a prevalence of 68.3%. Rickettsia like prokaryotes were found in 13.1% of animals. The other gut associated parasites were more scarce, with prevalences under five percent. Renal coccidia affected less than two percent of animals. Trematode infections were extremely rare, at a prevalence of 0.05%. The results of the chi square test showed a significant association between age and parasite prevalence for all parasites tested. Odds ratios were calculated comparing animals of 24 months and younger to those older than 24 months. In all cases, except trematode and left kidney coccidian infections, risk of parasite infection tended to increase with increasing age. For left kidney coccidian infections, risk of infection decreased with increasing age. Trends for body mass were similar to those for age, which is expected, as animals generally become larger with increasing age. A significant association between growth rate and parasite prevalence existed for some parasites. The chi square test showed a significant association between condition index and parasite prevalence for all parasites tested. A significant association between sex and parasite prevalence was found for all parasites tested. A significant association also existed between parasite prevalence and gonad development for sessile ciliates, renal coccidia and gut protozoa. There were significant differences in parasite prevalences between farms for all parasites tested. The South and West coasts were next compared using the chi square test. There were significant differences in parasite prevalences between coasts for only three of the parasites tested, namely renal coccidia, gut protozoa and rickettsia. Crude odds ratios showed that, with the exception of left kidney coccidia and trematodes, there was a greater risk of parasite infection on the West than the South coast. For left kidney coccidia, the risk was greater on the PAGE 3 OF 137 South coast. A chi square test was performed to examine the relationship between parasite prevalence in Hermanus and other areas. A significant difference was found for renal coccidia and gut associated parasites. The crude odds ratios for parasite prevalence in other areas compared to Hermanus were calculated. With the exception of sessile ciliates and trematodes, there was a greater risk of parasite infection in areas other than Hermanus. In the case of sessile ciliates, there was a greater risk within Hermanus than in other areas. Unfortunately, it was almost impossible to determine whether a seasonal effect exists for parasite prevalence from the available data. This was shown to be partly due to the effect of prevalence on individual farms. Significant differences in parasite prevalences between diets for all parasites tested were shown using the chi square test. To further test the strength of the association, odds ratios were calculated comparing only kelp and artificial feed. For right kidney coccidia and gut associated parasites, the odds ratios indicated a significantly increased risk of infection in animals receiving kelp compared to those on artificial feed. There was no difference in risk for sessile ciliates and left kidney coccidia. The majority of animals originated in flow through systems. The chi square test showed significant differences in parasite prevalences between systems for sessile ciliates, renal coccidia and rickettsia like prokaryotes. Odds ratios showed a significantly greater risk of sessile ciliate infections, but a smaller risk of left kidney coccidia, in animals in flow through systems when comparing only kelp fed animals. Age is likely to lead to increased prevalences if the risk of infection is constant over time and also if infections are retained. Physiological changes in the animals may also affect their risk of infection. A further important aspect of age in abalone relates to changes in husbandry. Increasing age may be the underlying reason for some of the prevalence patterns seen with mass and sex. The origin of the sample population was considered in terms of farm of origin as well as geographic area. Abalone production in the study area was highly concentrated, with approximately two thirds coming from six farms situated within ten kilometres of each another on the South coast and almost forty percent from Hermanus alone. The present study found no PAGE 4 OF 137 evidence of increased parasite prevalence in areas where abalone farming is concentrated. It was felt that this study could not generate much insight into seasonal occurrence, due to uneven distribution of variables between months. The relationship between diet and parasite prevalence was perhaps the most interesting aspect of this study and possible reasons for the association are explored. Lastly, the results indicated that parasite buildup in recirculation systems was not as problematical as may be expected. It is possible that the increased prevalence of left kidney coccidia in recirculation systems is linked to the resistance of the host population rather than to the dynamics of the actual system. The very low prevalence of sessile ciliates in recirculation systems could not be explained by examination of any other variable considered in this study. Overall, the prevalences of soft tissue parasites in Haliotis midae compared favourably with those found for parasites of other abalone species abroad. Measures which would tend to reduce parasite prevalence include separation of age groups and maintaining a relatively young population on the farm. Culling of underperforming animals is recommended. Kelp should not be used in animals of two years or younger. In older animals, there was still a greater risk associated with kelp than with artificial feed, but it was not as marked. Recirculation systems proved to be less associated with increased parasite prevalence than one may expect. The other major findings of this study did not lend themselves to practical application. / Dissertation (MSc)--University of Pretoria, 2010. / Production Animal Studies / unrestricted

No description available.

The immune system provides protection against parasites and is crucial for survival, but mounting, maintaining and controlling an immune response is expensive. Under limited resources these costs can lead to investment trade-offs between life history traits in order to maximize an individual's fitness. Understanding how these trade-offs relate to immunity can be important in understanding individual variation in fitness and the broader ecological implications that this may have in a population. In the wild there is evidence of trade-offs between life history traits and immunity, but there are relatively few studies which have measured specific aspects of the immune system under natural parasitic exposure. Using reagents developed in domestic sheep, I measured an unusually broad range of immune markers in a wild population of Soay sheep on the island of Hirta, St Kilda, Scotland. These include: T cell subsets (CD4+, CD8+, CD4+ & CD8+ naïve, gamma delta and Foxp3), anti-T.circumcincta (T. circ) antibody isotopes, (IgA, IgE, IgG), leukocyte subtypes (neutrophil:lymphocyte ratio & eosinophils), and leukocyte telomere length (LTL). I found that, in a year under high selection pressure for survival, anti-T. circ IgG positively predicted survival across all ages and for both sexes. Additionally, females had higher proportions of naïve T cells than males; a previously unreported sex difference in a wild mammal. In chapter 2, analysis of lambs in early life found higher growth rates associated with low antibody measures, while lower growth rates related to low antibody measures and high levels of inflammatory marker. I also found that male lambs with high anti-T. circ IgE and IgG were less likely to survive over-winter, contrary to the findings across all ages in chapter 1. In chapter 3, I detected an increase in LTL attrition with age in males >3 years, but this was not significant in females or in younger animals. In male lambs, high investment in horn growth was related to reduced LTL. Changes in LTL were independent of variation in leukocyte cell populations. The data in this thesis demonstrate the complexity of immune variation in the wild, and highlight the value of multiple ecologically relevant markers to understanding the evolutionary implications of resource trade-offs.

Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul / Gastrointestinal worms are the main obstacle in the production of sheep. The helminth Haemonchus contortus is the species that most parasites sheep in Brazil. It is located in the abomaso of the host and has a habit of blood feeding. Considering clinical signs, the animals present anemia and hypoproteinemia, which reduces the productivity of animals; it can lead to death and causes serious damage to the activity. Iron supplementation in parasitized sheep assists in the hematopoietic process, although further studies are needed to assess the iron metabolism in such animals. Given the above, the following study aimed to evaluate the effects of injectable iron supplementation in sheep experimentally infected with Haemonchus contortusTwenty-four lambs have been used, divided into four groups, being Group 1 - uninfected animals, Group 2 - animals infected with 10000 third stage larvae of H. contortus and treated with three doses of 20mg/kg of body weight of dextran iron intramuscularly, one dose every seven days, Group 3 - non-infected animals and treated with three doses of 20mg/kg body weight iron dextran intramuscularly, one dose every seven days, and Group 4 - animals infected with 10000 third stage larvae of H. contortus. The experiment has lasted 21 days. Blood samples were collected on days 10 (D10), 17 (D17), 24 (D24), and 31 (D31) after parasitic infection to assess the metabolism of iron (ferritin, transferrin, Serum Iron, saturation index to transferrin, Iron Connection Total Capacity, and Spinal Cord Iron stocks) and erythrocyte (red blood cell count, Hematocrit, hemoglobin, reticulocytes, mean corpuscular hemoglobin concentration). Samples of feces for measuring the number of eggs per gram of feces (EPG) have been obtained at the same experimental time. OPG values were positive in Groups 2 and 4. Regarding hematological indices, groups of animals infected and treated with iron had higher values of hematocrit and hemoglobin compared to the group of animals infected and not treated with iron. The results showed that the spinal cord iron stocks were greater in the groups supplemented with iron. Sheep infected with H. contortus presented exhaustion of iron spinal cord reserves, thus the use of injectable iron aids in maintaining the stock and makes the mineral available for erythropoiesis by improving the organic response of animals against infection. / As verminoses gastro-intestinais é o principal entrave na produção de ovinos. O helminto Haemonchus contortus é a espécie que mais parasita ovinos no Brasil. Localiza-se no abomaso do hospedeiro e possui como hábito a hematofagia. Como sinais clínicos os animais apresentam anemia e hipoproteínemia, o que diminui a produtividade dos animais, pode levar a morte e traz sérios prejuízos para a atividade. A suplementação com ferro em ovinos parasitados auxilia no processo hematopoiético, porém ainda são necessários estudos para avaliar o metabolismo do ferro nestes animais. Diante do exposto, o presente estudo teve como objetivo avaliar os efeitos da suplementação de ferro injetável em ovinos infectados experimentalmente com Haemonchus contortus. Utilizou-se 24 cordeiros divididos em quatro grupos experimentais, sendo o Grupo 1 animais não infectados, Grupo 2 animais infectados com 10000 larvas de terceiro estágio de H. contortus e tratados com três doses de 20mg /Kg de peso vivo de ferro dextrano por via intramuscular, um dose a cada sete dias, Grupo 3 animais não infectados e tratados com três doses de 20mg /Kg de peso vivo de ferro dextrano por via intramuscular, um dose a cada sete dias e Grupo 4 animais infectados com 10000 larvas de terceiro estágio de H. contortus. O período experimental foi de 21 dias. As amostras de sangue foram coletadas nos dias 10 (D10), 17 (D17), 24 (D24) e 31 (D31) pós-infecção parasitária para avaliação do metabolismo do ferro (Ferritina, Transferrina, Ferro Sérico, Índice de saturação à transferrina, Capacidade Total de Ligação do Ferro e estoques de Ferro Medular) e do eritrograma (Contagem de Hemácia, Hematócrito, Hemoglobina, Reticulócitos, Volume Corpuscular Médio e a Concentração de Hemoglobina Corpuscular Média). Amostras de fezes para quantificar o número de ovos por grama de fezes (OPG) foram obtidas nos mesmos momentos experimentais. Valores de OPG foram positivos somente nos Grupos 2 e 4. Quanto aos índices hematológicos, os grupos de animais infectado e tratados com ferro apresentaram maiores valores de hematócrito e hemoglobina em relação ao grupo dos animais infectado e não tratado com ferro. Os resultados demonstraram que as reservas de ferro medular foram maiores nos grupos suplementados com ferro. Ovinos infectados com H. contortus apresentam exaustão das reservas medulares de ferro, com isso o uso de ferro injetável auxilia na manutenção de estoque e torna o mineral mais disponível para a eritropoiese, melhorando a resposta orgânica dos animais contra à infecção.