Giardia and Cryptospovidium are both recognised as important causes of infectious diarrhoea in children worldwide, and childcare centres have been shown to be a major site of infection. The incidence of infectious diarrhoea in children attending childcare centres has been estimated at between two to five times greater than in children cared for at home. Both Giardia and Cryptospovidium have a faecal-oral route of transmission that facilitates their spread in childcare environments, but can also be interrupted through the use of efficient hygiene protocols such as handwashing. Despite their importance as causes of infectious diarrhoea, there are no data on the prevalence or transmission dynamics of these parasites in Australian childcare centres. The present study was designed to determine the prevalence and incidence of both Giardia and Ciyptosporidium in children attending childcare centres in Perth,Western Australia. Data were collected on asymptomatic infection, seasonal trends, the transmission dynamics of the parasites and risk factors for infection. The second part of the study involved the development, implementation and evaluation of a health intervention package designed to interrupt the transmission of causative organisms of infectious diarrhoea in childcare centres. This intervention was based on appropriate and effective handwashing. Over a period of 23 months, 1 172 faecal samples were collected from non-toilet-trained children (n=306) attending 14 childcare centres in Perth, Western Australia. Where possible, family and contacts of infected children were also sampled to determine the dynamics of infection in the community. Information on syrnptomology of infections and risk factors for infection was obtained by the administration of a questionnaire to parents of all the children in the study. Over all the childcare centres in the study, 7.8% of children were positive for Giardia and 10.8% were positive for Cryptosporidiunz. Of these, 37.5% of the Giardia-positive children returned positive samples on two to four occasions, but not always consecutively, suggesting either continuous or repeated infection with the parasite. Only 12% of children who were Cryptosporidiurn-positive were infected for two consecutive months. The major findings of this study included a significant seasonal peak in the prevalence of both Giardia and Cryptosporidium, with 50% of Giardia and 73% of Cryptosporidiurn infections occurring during the autumn months of March, April and May, and a high proportion of asymptomatic Giardia infections (45%), compared with only 13.5% of asymptomatic Cryptosporidiurn infections. There was evidence for the transmission of both Giardia and Cryptosporidium infections to household contacts of infected children. Of the children who were found to be positive, faecal samples were also collected from 28 family members of those children with Giardia and from 14 family members of those with Cryptosporidiunz. Of these, 17.9% family members of the children with Giardia and 28.6% of family members of the Cryptosporidiuin children returned positive faecal samples. The only significant risk factor for Giardia infection was the number of adults living in the household, with infection more likely to occur in children who had a greater number of adults in the household. Significant risk factors for Clyptosporidium infection included the age of the child: the mean age of the positive children (20.6 months) was higher than in the negative children (16.6 months), and the length of time enrolled at the centre. Children who were positive had attended for a longer time than those who were negative (1 1.2 and 7.8 months respectively). These results have important implications for the control of infection with these organisms, both within and beyond childcare centres. Since these parasites can be readily transmitted by an asymptomatic carrier, the high percentage of asymptomatic cases in this study, particularly of Giardia, strengthens the argument for health interventions which are directed at interrupting the trailsmission of the parasite. A health intervention programme was developed that focused on handwashing procedures and was targeted at the carers, the children and the parents of the children in the centres. It was designed to be a low-cost programme both financially, and in the time and effort required to implement the programme within the childcare centre, to enhance compliance with the intervention. The success of the programme in changing the knowledge, attitudes and practices of carers was evaluated through a pre- and posttest questionnaire. This showed that the programme successfully improved the knowledge of the carers in the test centres in several important areas of infection control. These included knowledge about specific organisms causing infectious diarrhoea in childcare centres, transmission of these by asymptomatic individuals and increased knowledge about effective handwashing technique. Because it has been repeatedly shown that increased knowledge does not always translate into improved practices, and that interventions are not always successful in maintaining an improvement in the desired practices, a subjective evaluation was also performed. This was designed to determine how effective the intervention was perceived to be by the carers themselves, and whether they would continue to use the intervention over time. The results showed that the majority of the carers (>88%) found the intervention appropriate and useful in teaching both the carers and the children within the centres, the importance of handwashing. Twelve months after the intervention had first been implemented, 57% of the centres in the study were still using the intervention at least once per month and a further 2996, while using it less than this, still continued to use it occasionally. This is important information, since an intervention can only be useful if it is actually being used.

Issued also as Thèse pour le doctorat en médecine - Paris. / "Bibliographie": p. 123-134.

Includes bibliographical references (leaves 117-133). / v, 133 leaves, 5 leaves of photographic plates : ill. (some col.); 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Concerned with the family of genes that encode variant-specific surface proteins in the parasitic protzoon, Giardia. Specific goals were to identify and compare closely related genes, which may form subsets within the larger VSP gene family. / Thesis (Ph.D.)--Adelaide University, Dept. of Molecular Biosciences, 2001

Thesis (Ph. D.)--University of Adelaide, Dept. of Microbiology and Immunology, 1989. / Includes bibliographical references (leaves 183-228).

Thesis (M.S.)--University of Massachusetts Amherst, 2009. / Includes bibliographical references (p. 81-93).

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Publicación a texto completo no autorizada por el autor / Estima la frecuencia de infección con Giardia sp en caninos menores de tres años que concurren a los parques públicos del distrito de Santiago de Surco de Lima Metropolitana, además su asociación con las variables sexo, edad, estado físico de heces, frecuencia de concurrencia a los parques; determina la concordancia entre tres técnicas de diagnóstico. Se recolectan muestras fecales de 140 caninos aparentemente sanos, menores de tres años de edad, los cuales acuden a parques públicos del mencionado distrito y cuyos propietarios acceden participar en el estudio. Para el diagnóstico de las muestras, se utilizan las técnicas de: Inmunoensayo de Cromatografía (IEC), Técnica de Faust (TF) y la Técnica de Sedimentación espontánea (SE), encontrándose frecuencias de 25, 17.9 y 12.1% respectivamente. Al realizar el análisis de asociación entre la frecuencia de infección y las variables predictoras en un modelo de regresión logística no demuestran significancia estadística (p>0.05). Por otro lado, los índices de concordancia de Kappa entre las pruebas diagnósticas son 0.78 (IEC versus TF), 0.58 (IEC versus TSE) y 0.77 (TF verss TSE), demostrando todas significancia estadística (p<0.05). Estos resultados indican un moderado nivel de infección con Giardia sp. en caninos que concurren a parques públicos en el distrito de Santiago de Surco-Lima, evidenciando un potencial riesgo zoonótico para la población humana. Adicionalmente, tanto la IEC como TF demostraron un nivel de concordancia substancial. / Tesis

Thesis (Ph. D. -- Nutritional Sciences) - University of Arizona. / Includes bibliographical references (leaves 126-137).

El objetivo del estudio fue determinar la prevalencia de Giardia sp. en caninos y niños de comunidades campesinas de los distritos de Ajoyani, Palca y Santa Lucía en Puno. Se recolectaron 130 muestras fecales tanto de niños como de canes. Las muestras fueron conservadas en formol al 10%, siendo luego enviadas al Laboratorio de Parasitología de la FMV-Lima para su procesamiento. Para el diagnóstico de Giardia sp. cada muestra fue analizada mediante las técnicas de Sedimentación Espontánea y Sheather. Considerando como positivo el hallazgo del parásito en una de las dos técnicas usadas, se obtuvo una prevalencia global de 14.6+6.1% y 28.5+7.8% en caninos y niños respectivamente. En caninos se hallaron prevalencias de 31.8%, 18.2% y 9.3% en los distritos de Ajoyani, Palca y Santa Lucía, respectivamente; las prevalencias en machos y hembras fueron de 14.6% y 17.4% respectivamente y según los grupos de edad de 0-6 meses, >6-12 meses, >12-72 meses y >72 meses fueron de 7.7%, 21.7%, 11.4% y 16.0% respectivamente. En niños se obtuvieron prevalencias de 36.4%, 13.6% y 30.2% en Ajoyani, Palca y Santa Lucia, respectivamente; los niños presentaron prevalencias de 14.6% y las niñas 17.4%; según los grupos etarios de 0-3años, >3-7años, >7-12 años fueron de 33.3%, 29.7%, 25.9% respectivamente. Para el análisis estadístico se empleó la prueba de chi cuadrado, con un nivel de significancia de 0,05%. No se encontró asociación estadística significativa (p>0,05) entre la presencia de Giardia sp. y las variables estudiadas. Además la técnica de sedimentación espontánea demostró ser la técnica más eficaz para el diagnóstico del parásito. Las prevalencias halladas en caninos y niños sugieren infecciones independientes. Sin embargo, sólo se esclarecería con futuros estudios moleculares, para descartar posible riesgo zoonótico. Palabras clave: Giardia sp., Puno, Sedimentación espontánea, Sheather, zoonosis / --- The aim of this study was to determine the prevalence of Giardia sp. in dogs and children in rural communities of the districts Ajoyani, Palca and Santa Lucía in Puno. We collected 130 fecal samples from both children and dogs. The samples were preserved in formaldehyde at 10%, then sent to the Laboratory of Parasitology of the FMV-Lima for processing. For the diagnosis of Giardia sp. each sample was analyzed by spontaneous sedimentation techniques and Sheather. Considering as positive the parasite founding in one of two techniques used, we obtained an overall prevalence of 14.6+6.1% and 28.5+7.8% in dogs and children respectively. In dogs, were found prevalences of 31.8%, 18.2% and 9.3% in the districts of Ajoyani, Palca, and Santa Lucía, respectively; the prevalences in males and females were 14.6% and 17.4% respectively and according to age groups from 0-6 months,> 6-12 months, > 12-72 months and > 72 months were 7%, 21.7%, 11.4% and 16.0% respectively. In children, were obtained 36.4%, 13.6% and 30.2% prevalences in Ajoyani, Palca and Santa Lucía, respectively; boys had prevalences of 14.6% and girls had 17.4%, according to the age groups from 0-3years,> 3-7years, > 7-12 years were 33.3%, 29.7%, 25.9%, respectively. For statistical analysis we used the chi square test with a significance level of 0.05%. There was not significant association (p> 0.05) between the presence of Giardia sp. and the variables studied. Furthermore, the spontaneous sedimentation technique proved to be the most effective technique for the diagnosis of the parasite. The prevalence found in dogs and children suggest independent infections. However, only molecular studies would clarify in future to rule out possible zoonotic risk. Keywords: Giardia sp., Puno, spontaneous sedimentation, sheather, zoonosis

Bibliography: leaves 183-228