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Background Among the 6.7 million people living in areas of the Philippines where infection with Schistosoma japonicum is considered endemic, even within small geographical areas levels of infection vary considerably. In general, the ecological drivers of this variability are not well described. Unlike other schistosomes, S. japonicum is known to infect several mammalian hosts. However, the relative contribution of different hosts to the transmission cycle is not well understood. Here, we characterize the transmission dynamics of S. japonicum using data from an extensive field study and a mathematical transmission model. Methods and Findings In this study, stool samples were obtained from 5,623 humans and 5,899 potential nonhuman mammalian hosts in 50 villages in the Province of Samar, the Philippines. These data, with variable numbers of samples per individual, were adjusted for known specificities and sensitivities of the measurement techniques before being used to estimate the parameters of a mathematical transmission model, under the assumption that the dynamic transmission processes of infection and recovery were in a steady state in each village. The model was structured to allow variable rates of transmission from different mammals (humans, dogs, cats, pigs, domesticated water buffalo, and rats) to snails and from snails to mammals. First, we held transmission parameters constant for all villages and found that no combination of mammalian population size and prevalence of infectivity could explain the observed variability in prevalence of infection between villages. We then allowed either the underlying rate of transmission (a) from snails to mammals or (b) from mammals to snails to vary by village. Our data provided substantially more support for model structure (a) than for model structure (b). Fitted values for the village-level transmission intensity from snails to mammals appeared to be strongly spatially correlated, which is consistent with results from descriptive hierarchical analyses. Conclusions Our results suggest that the process of acquiring mammalian S. japonicum infection is more important in explaining differences in prevalence of infection between villages than the process of snails becoming infected. Also, the contribution from water buffaloes to human S. japonicum infection in the Philippines is less important than has been recently observed for bovines in China. These findings have implications for the prioritization of mitigating interventions against S. japonicum transmission. The Editors' Summary of this article follows the references., Introduction Modern, inexpensive pharmaceuticals are dramatically reducing the burden of disease caused by schistosomes and other waterborne macroparasites in resource-poor settings [1,2]. Many of the national programs delivering these anthelmintics [...]

Objective To estimate the association between the intensity of animal infection with Schistosoma japonicum and human infection in Western Samar province, the Philippines. Methods We conducted an observational cross-sectional study of 1425 households in 50 villages. Stool samples were collected on each of 1-3 days from 5623 humans, 1275 cats, 1189 dogs, 1899 pigs, 663 rats and 873 water buffalo. Intensity of infection with S. japonicum was measured by the number of eggs per gram (EPG). Egg counts were done using the Kato-Katz method. We used a Bayesian hierarchical cumulative Iogit model, with adjustments for age, sex, occupation and measurement error. Findings The adjusted proportions of humans lightly infected (classified as 1-100 EPG) was 17.7% (95% Bayesian credible interval = 15.3-20.2%); the proportion classified as at least moderately infected (>100 EPG) was 3.2% (2.2-4.6%).The crude parasitological results for animals indicated that 37 cats (2.9%), 228 dogs (19.2%), 39 pigs (2.1%), 199 rats (30.0%) and 28 water buffalo (3.2%) were infected. In univariate analyses the odds ratios corresponding to a unit increase in the mean number of EPG at the village-level in dogs was 1.05 (1.01-1.09), in cats 1.35 (1.02-1.78), in pigs 1.16 (0.24- 5.18) and in rats 1.00 (1.00-1.01). Mean EPG values in cats, dogs, pigs and rats were correlated with one another. This confounding made interpreting the odds ratios difficult, but the odds ratios for dogs and cats were more consistent. Conclusion S. japonicum is endemic in areas of the Philippines despite implementation of control programmes. This may be due to the association of infections in dogs and cats with human infections. Infection control in dogs and cats is challenging, and there is a need to develop new methods to control transmission across all species. Resume Associations transversales entre l'intensite des infestations animale et humaine par Schistosoma japonicum dans la province du Samar occidental, aux Philippines Objectif Evaluer l'association entre l'intensite de l'infestation des animaux par Schistosoma japonicum et l'infestation des etres humains par cette espece dans la province du Samar occidental, aux Philippines. Methodes Une etude transversale d'observation a ete menee aupres de 1425 menages, dans 50 villages. Des echantillons de selles ont ete recueillis quotidiennement sur une periode de 3 jours, aupres de 5623 etres humains, 1275 chats, 1189 chiens, 1899 porcs, 663 rats et 873 buffles d'eau. L'intensite de l'infestation par S. japonicum a ete mesuree par le nombre d'oeufs par gramme (EPG). Le comptage des oeufs a ete effectue par la methode de Kato-Katz. Un modele logit hierarchise cumulatif de type bayesien, avec des ajustements pour tenir compte de l'age, du sexe, de la profession et de l'erreur de mesure, a ete utilise. Resultats La proportion ajustee d'etres humains legerement infestes (categorie correspondant a 1-100 EPG) etait de 17,7 % (intervalle de credibilite bayesien a 95 % = 15,3- 20,2 %) et celle d'humains moderement infestes (> 100 EPG) de 3,2 % (2,2 a 4,6 %). Les resultats parasitologiques bruts pour les animaux ont indique que 37 chats (2,9 %), 228 chiens (49,2 %), 39 porcs (2,1 %), 199 rats (30,0 %) et 28 buffles d'eau (3,2 %) etaient infestes. Dans les analyses monovariees, les odds-ratios correspondant a l'augmentation d'une unite du nombre moyen d'EPG au niveau du village chez les chiens etait de 1,05 (1,01-1,09), chez les chats de 1,35 (1,02-1,78), chez les porcs de 1,16 (0,24-5,18) et chez les rats de 1,00 (1,00-1,01). Les valeurs moyennes de l'EPG chez les chats, les chiens, les porcs et les rats etaient correlees entre elles. Ce facteur de confusion a rendu difficile l'interpretation des odds-ratios, mais on a constate une plus grande stabilite entre les odds-ratios pour les chiens et les chats. Conclusion S. japonicum est endemique dans certaines zones des Philippines en depit de la mise en oeuvre de programmes de lutte. Cette situation peut etre due a l'association d'infestations canines et felines a des infestations humaines. La lutte contre l'infestation des chiens et des chats represente un vrai defi et il est necessaire de mettre au point de nouvelles methodes pour endiguer la transmission entre les especes. Resumen Asociacion transversal entre la intensidad de los casos de infeccion pot Schistosoma japonicum en los animales y en el hombre en la provincia de Samar occidental, Filipinas Objetivo Estimar la relacion entre la intensidad de las infecciones animales por Schistosoma japonicum y la de la infeccion humana correspondiente en la provincia de Samar occidental de Filipinas. Metodos Realizamos un estudio transversal observacional de 1425 hogares en 50 aldeas. Se recogieron muestras de heces de forma diaria durante 1-3 dias en 5623 personas, 1275 gatos, 1189 perros, 1899 cerdos, 663 ratas y 873 bufalos de agua. La intensidad de la infeccion por S. japonicum se midio en funcion del numero de huevos por gramo (HPG). Los recuentos de huevos se hicieron mediante el metodo de Kato-Katz, y utilizamos un modelo logit acumulativo jerarquico de tipo bayesiano, con ajustes para la edad, el sexo, la ocupacion y el error de medicion. Resultados La proporcion ajustada de personas con infeccion ligera (1-100 HPG) fue del 17,7% (intervalo creible bayesiano del 95% = 15,3%-20,2%), y la proporcion clasificada como afectada moderadamente (HPG > 100) fue del 3,2% (2,2%-4,6%). Los resultados parasitologicos brutos para los animales mostraron que estaban infectados 37 gatos (2,9%), 228 perros (19,2%), 39 cerdos (2,1%), 199 ratas (30,0%) y 28 bufalos de agua (3,2%). En los analisis con una variable las razones de posibilidades (OR) correspondientes a un aumento de una unidad del numero medio de HPG a nivel de aldea fueron de 1,05 (1,01-1,09) en los perros, 1,35 (1,02-1,78) en las gatos, 1,16 (0,24-5,18) en los cerdos, y 1,00 (1,00-1,01) en las ratas. Los valores medios de HPG en los gatos, perros, cerdos y ratas estaban correlacionados entre si. Este factor de confusion dificulto la interpretacion de las OR, pero las OR de perros y gatos fueron mas coherentes. Conclusion S. japonicum es endemico en algunas zonas de Filipinas pese a la puesta en practica de los programas de control. Ello puede deberse a la asociacion de la infeccion en perros y gatos a las infecciones humanas. El control de la infeccion en esas dos especies no resulta facil, de ahi la necesidad de desarrollar nuevos metodos para controlar la transmision a traves de todas las especies., [TEXT NOT REPRODUCIBLE IN ASCII] Introduction Schistosomiasis affects 200 million people in 74 countries worldwide; 120 million of these are symptomatic and 20 million have severe disease. (1) Unlike the [...]

Objective To examine the association between smoking and cutaneous involvement in systemic lupus erythematosus (SLE). Methods We analyzed data from a multicenter Canadian SLE cohort. Mucocutaneous involvement was recorded at the most recent visit using the Systemic Lupus Erythematosus Disease Activity Index 2000 Update (rash, alopecia, and oral ulcers), Systemic Lupus International Collaborating Clinics/American College of Rheumatology (ACR) Damage Index (alopecia, extensive scarring, and skin ulceration), and the ACR revised criteria for SLE (malar rash, discoid rash, photosensitivity, and mucosal involvement). Multivariate logistic regression models were used to estimate the independent association between mucocutaneous involvement and cigarette smoking, age, sex, ethnicity, lupus duration, medications, and laboratory data. Results In our cohort of 1,346 patients (91.0% women), the mean ± SD age was 47.1 ± 14.3 years and the mean ± SD disease duration was 13.2 ± 10.0 years. In total, 41.2% of patients were ever smokers, 14.0% current smokers, and 27.1% past smokers. Active mucocutaneous manifestations occurred in 28.4% of patients; cutaneous damage occurred in 15.4%. Regarding the ACR criteria, malar rash was noted in 59.5%, discoid rash in 16.9%, and photosensitivity in 55.7% of patients. In the multivariate analysis, current smoking was associated with active SLE rash (odds ratio [OR] 1.63 [95% confidence interval (95% CI) 1.07, 2.48]). Having ever smoked was associated with ACR discoid rash (OR 2.36 [95% CI 1.69, 3.29]) and photosensitivity (OR 1.47 [95% CI 1.11, 1.95]), and with the ACR total cutaneous score (OR 1.50 [95% CI 1.22, 1.85]). We did not detect any associations between previous smoking and active cutaneous manifestations. No association was found between smoking and cutaneous damage or mucosal ulcers. No interaction was seen between smoking and antimalarials. Conclusion Current smoking is associated with active SLE rash, and ever smoking with the ACR total cutaneous score. This provides additional motivation for smoking cessation in SLE. [ABSTRACT FROM AUTHOR]

Objective To estimate the population-based prevalence of systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) in Alberta, Canada, stratified by First Nations status. Methods Physician billing claims and hospitalization data for the province of Alberta (1994-2007) were used to ascertain cases of SLE and SSc using 3 case definitions. A latent class Bayesian hierarchical regression model was employed to account for the imperfect sensitivity and specificity of billing and hospitalization data in case ascertainment. We accounted for demographic factors, estimating prevalence rates for the First Nations and non-First Nations populations by sex, age group, and location of residence (urban/rural). Results Our model estimated the prevalence of SLE in Alberta to be 27.3 cases per 10,000 females (95% credible interval [95% CrI] 25.9-28.8) and 3.2 cases per 10,000 males (95% CrI 2.6-3.8). The overall prevalence of SSc in Alberta was 5.8 cases per 10,000 females (95% CrI 5.1-6.5) and 1.0 case per 10,000 males (95% CrI 0.7-1.4). First Nations females over 45 years of age had twice the prevalence of either SLE or SSc relative to non-First Nations females. There was also a trend toward higher overall SLE prevalence in urban dwellers, and higher overall SSc prevalence in rural residents. Conclusion First Nations females older than 45 years of age have an increased prevalence of either SLE or SSc. This may reflect a true predominance of autoimmune rheumatic diseases in this demographic, or may indicate systematic differences in health care delivery. [ABSTRACT FROM AUTHOR]