The economic impact of schistosomiasis.

BACKGROUND: The economic impact of schistosomiasis and the underlying tradeoffs between water resources development and public health concerns have yet to be quantified. Schistosomiasis exerts large health, social and financial burdens on infected individuals and households. While irrigation schemes are one of the most important policy responses designed to reduce poverty, particularly in sub-Saharan Africa, they facilitate the propagation of schistosomiasis and other diseases. METHODS: We estimate the economic impact of schistosomiasis in Burkina Faso via its effect on agricultural production. We create an original dataset that combines detailed household and agricultural surveys with high-resolution geo-statistical disease maps. We develop new methods that use the densities of the intermediate host snails of schistosomiasis as instrumental variables together with panel, spatial and machine learning techniques. RESULTS: We estimate that the elimination of schistosomiasis in Burkina Faso would increase average crop yields by around 7%, rising to 32% for high infection clusters. Keeping schistosomiasis unchecked, in turn, would correspond to a loss of gross domestic product of approximately 0.8%. We identify the disease burden as a shock to the agricultural productivity of farmers. The poorest households engaged in subsistence agriculture bear a far heavier disease burden than their wealthier counterparts, experiencing an average yield loss due to schistosomiasis of between 32 and 45%. We show that the returns to water resources development are substantially reduced once its health effects are taken into account: villages in proximity of large-scale dams suffer an average yield loss of around 20%, and this burden decreases as distance between dams and villages increases. CONCLUSIONS: This study provides a rigorous estimation of how schistosomiasis affects agricultural production and how it is both a driver and a consequence of poverty. It further quantifies the tradeoff between the economics of water infrastructures and their impact on public health. Although we focus on Burkina Faso, our approach can be applied to any country in which schistosomiasis is endemic.

Comunidad de la localidad de Sumapaz: una experiencia comunitaria en la preservación del páramo como recurso de uso común en el corregimiento de San Juan de Sumapaz / Communities at locality of Sumapaz: A community experience to preserve the moorland as Common Pool Resource at the municipality of San Juan de Sumapaz / Comunidade de Sumapaz: uma experiência comunitária na preservação do Páramo como recurso de uso comum em San Juan de Sumapaz

Objetivo. Presentar las acciones comunitarias que se han implementado en la preservación del Páramo de Sumapaz y los recursos que se obtienen de él: el agua, la flora, la fauna. Se resalta la importancia de estas acciones, no solo relevantes para la Salud Pública de la comunidad que habita la zona del páramo, sino también para aquellos que se abastecen de sus recursos de una u otra forma. Materiales y métodos. Se llevó a cabo un estudio cualitativo con una muestra de tres líderes comunitarios del corregimiento de San Juán de Sumapaz. Se aplicaron entrevistas estructuradas para indagar sobre los principios de diseño característicos de instituciones de larga duración de los Recursos de Uso Común (RUC) propuesto por Elinor Ostrom. Se analiza la información y se exponen las evidencias encontradas en las entrevistas realizadas a líderes comunitarios, sobre las acciones que la comunidad y sus organizaciones han tenido en cuenta para no sobreexplotar los recursos (fauna y flora del Páramo de Sumapaz). Resultados. Se encuentran las similitudes que existen entre las estructuras organizacionales de los casos presentados por Ostrom en su libro y las estrategias que han implementado los pobladores del Páramo de Sumapaz para no hacer una sobreexplotación de los RUC. Se destaca los procesos de autoorganización realizados por las comunidades del páramo para evitar que agentes externos los utilicen de forma inadecuada; recordando la im-portancia del frágil ecosistema de páramo, el daño ambiental y consecuencias en la Salud Pública que pueden generarse al intervenir un espacio vital.

Objective: To present community actions implemented in the preservation of the moorland at Sumapaz and its resources. The importance of such actions is highlighted not only for the purposes of Public Health but also for the community inhabiting the moorland vicinity and people who procure resources from the said area Tools and Methodology: A qualitative study was conducted. The sample was comprised of three community leaders from the municipality of San Juan de Sumapaz. Structured interviews were carried out, inquiring on Elinor Ostrom ́s approach to design principles of stable local common pool resource management. Gathered information is analyzed and the evidence from the interviews regarding community actions to avoid overexploitation of the resources is presented. Results: Commonalities amongst organizational structures presented in E. Ostrom ́s work and the implemented strategies by inhabitants of the moorland at Sumapaz are drawn. Self-organized governance systems are emphasized to avoid resou-rce overexploitation

Objetivo: Apresentar as ações comunitárias que tem sido realizadas na preservação do Páramo de Sumapaz, sua agua, flora e fauna. Estas ações são relevantes para a Saúde Pública da comunidade que mora no Páramo, mas também para a cidade capital.Materiais e Métodos: estudo qualitativo cuja amostra são três líderes comunitários de San Juan de Sumapaz. Entrevistas foram realizadas para aprofundar em aspectos das instituições de longa duração dos Recursos de Uso comum (RUC) proposto por Elinor Ostrom. Analisa-se informação e mostra-se evidencia a respeito de essas ações que a comunidade e suas organizações tem realizado para não sobre explorar os recursos do páramo. Resultados: Tem semelhanças entre as estruturas organizacionais dos casos apresentados por Ostrom no seu libro e as estratégias práticas dos moradores do Páramo do Sumapaz para proteger os recursos naturais. A auto-organização das comunidades evita que agentes externos ao território abuse dos recursos

Dynamics of freshwater snails and Schistosoma infection prevalence in schoolchildren during the construction and operation of a multipurpose dam in central Côte d'Ivoire.

BACKGROUND: The construction and operation of small multipurpose dams in Africa have a history of altering the transmission of water-based diseases, including schistosomiasis. The current study was designed to investigate the abundance and dynamics of schistosomiasis intermediate host snails and Schistosoma infections in humans during the construction and the first years of operation of a small multipurpose dam in Côte d'Ivoire. METHODS: The study was carried out in Raffierkro and four neighbouring villages in central Côte d'Ivoire between 2007 and 2012. Snails were collected by two experienced investigators using scoops and forceps for 15 min at each site. Snails were identified at genera and, whenever possible, species level, and subjected to testing for cercarial shedding. Schoolchildren aged 6-15 years were examined once every year for Schistosoma haematobium and S. mansoni infection, using urine filtration and duplication Kato-Katz thick smears, respectively. Additionally, 551 adults were examined for Schistosoma infection before (June 2007) and 359 individuals 2 years after dam construction (June 2009). RESULTS: Overall, 1 700 snails belonging to nine different genera were collected from 19 sampling sites. Bulinus (potential intermediate host snails of S. haematobium) and Pila were the most common genera, whereas Biomphalaria (potential intermediate host snail of S. mansoni), Lymnaea, Physa and Melanoides were found in two villages. During the first-year sampling period, 65 snails were collected, of which 13 (20%) were schistosomiasis intermediate hosts. In subsequent years, out of 1 635 snails collected, 1 079 (66%) were identified as potential intermediate host for schistosomiasis, but none were shedding cercariae. The prevalence of S. mansoni among adults in the study area was low (0.4% in 2007 and 0.3% in 2009), whereas the prevalence of S. haematobium declined from 13.9% to 2.9% in this two-year period. CONCLUSIONS: The low prevalence of schistosomiasis in humans and the absence of infected intermediate host snails during the construction and early phase of operation of a small multipurpose dam suggest that there was no or only very little local transmission. However, the considerable increase in the number of intermediate host snails and their dispersion in irrigation canals call for rigorous surveillance, so that adequate public health measures can be taken in case of early signs of an outbreak.

Characteristics and epidemiological profile of Buruli ulcer in the district of Tiassalé, south Côte d'Ivoire.

Buruli ulcer (BU) is a cutaneous infectious disease caused by Mycobacterium ulcerans. It is the third most common mycobacterial disease in the world in the immunocompetent patient and second in Côte d'Ivoire after tuberculosis. This study aimed to assess the characteristics and epidemiological profile of BU in the district of Tiassalé, an important focus of the disease in south Côte d'Ivoire, in order to better direct actions for prevention and control. Retrospective clinical data of BU cases in the period 2005-2010 from all 19 district health centres were collected and linked with geographical and environmental survey data. A total of 1145 cases of BU were recorded between 2005 and 2010 in the district of Tiassalé. Children under the age of 15 years were the most affected (53.0%) with a higher prevalence among males compared to females (54.7% versus 45.3%). Among individuals aged 15-49 years, females had a higher prevalence than males (54.2% versus 45.8%). The villages of Ahondo, Léléblé and Taabo, located in close proximity to the man-made Lake Taabo that was constructed in the late 1970s by damming the Bandama River, and the village of Sokrogbo located downstream of the dam, showed the highest BU rates in the sub-prefecture of Taabo. In the sub-prefecture of Tiassalé, the villages of Affikro, Morokro and N'Zianouan, located near N'Zi River, a tributary of the Bandama River, were the most affected. The distribution of BU is associated with environmental patterns (i.e. distance between village and Lake Taabo or Bandama River and its tributary N'Zi River). Awareness campaigns, coupled with early diagnosis and improved clinical management of BU, have been implemented in the district of Tiassalé and the incidence of BU has declined.