Integrated disease management: arboviral infections and waterborne diarrhoea.

Water-related diseases such as diarrhoeal diseases from viral, bacterial and parasitic organisms and Aedes-borne arboviral diseases are major global health problems. We believe that these two disease groups share common risk factors, namely inadequate household water management, poor sanitation and solid waste management. Where water provision is inadequate, water storage is essential. Aedes mosquitoes commonly breed in household water storage containers, which can hold water contaminated with enteric disease-causing organisms. Microbiological contamination of water between source and point-of-use is a major cause of reduced drinking-water quality. Inadequate sanitation and solid waste management increase not only risk of water contamination, but also the availability of mosquito larval habitats. In this article we discuss integrated interventions that interrupt mosquito breeding while also providing sanitary environments and clean water. Specific interventions include improving storage container design, placement and maintenance and scaling up access to piped water. Vector control can be integrated into sanitation projects that target sewers and drains to avoid accumulation of stagnant water. Better management of garbage and solid waste can reduce the availability of mosquito habitats while improving human living conditions. Our proposed integration of disease interventions is consistent with strategies promoted in several global health frameworks, such as the sustainable development goals, the global vector control response, behavioural change, and water, sanitation and hygiene initiatives. Future research should address how interventions targeting water, sanitation, hygiene and community waste disposal also benefit Aedes-borne disease control. The projected effects of climate change mean that integrated management and control strategies will become increasingly important

A cross-sectional survey of Aedes aegypti immature abundance in urban and rural household containers in central Colombia.

BACKGROUND: Aedes aegypti, the major vector of dengue, breeds in domestic water containers. The development of immature mosquitoes in such containers is influenced by various environmental, ecological and socioeconomic factors. Urban and rural disparities in water storage practices and water source supply may affect mosquito immature abundance and, potentially, dengue risk. We evaluated the effect of water and container characteristics on A. aegypti immature abundance in urban and rural areas. Data were collected in the wet season of 2011 in central Colombia from 36 urban and 35 rural containers, which were either mosquito-positive or negative. Immature mosquitoes were identified to species. Data on water and container characteristics were collected from all containers. RESULTS: A total of 1452 Aedes pupae and larvae were collected of which 81% were A. aegypti and 19% A. fluviatilis. Aedes aegypti immatures were found in both urban and rural sites. However, the mean number of A. aegypti pupae was five times higher in containers in the urban sites compared to those in the rural sites. One of the important factors associated with A. aegypti infestation was frequency of container washing. Monthly-washed or never-washed containers were both about four times more likely to be infested than those washed every week. There were no significant differences between urban and rural sites in frequency of washing containers. Aedes aegypti immature infestation was positively associated with total dissolved solids, but negatively associated with dissolved oxygen. Water temperature, total dissolved solids, ammonia, nitrate, and organic matter were significantly higher in urban than in rural containers, which might explain urban-rural differences in breeding of A. aegypti. However, many of these factors vary substantially between studies and in their degree of association with vector breeding, therefore they may not be reliable indices for vector control interventions. CONCLUSIONS: Although containers in urban areas were more likely to be infested with A. aegypti, rural containers still provide suitable habitats for A. aegypti. Containers that are washed more frequent are less likely to produce A. aegypti. These results highlight the importance of container washing as an effective vector control tool in both urban and rural areas. In addition, alternative designs of the highly productive washbasins should continue to be explored. To control diseases such as dengue, Zika and chikungunya, effective vector breeding site control must be implemented in addition to other interventions

Software reliability prediction

Two methods are proposed to find the maximum likelihood parameter estimates of a number of software reliability models. On the basis of the results from analysing 7 sets of real data, these methods are found to be both efficient and reliable. The simple approach of adapting software reliability predictions by Keiller and Littlewood (1984) can produce improved predictions, but at the same time, introduces a lot of internal noise into the adapted predictions. This is due to the fact that the adaptor is a joined-up function. An alternative adaptive procedure, which involves the parametric spline adaptor, can produce at least as good adapted predictions without the predictions being contaminated by internal noise as in the simple approach. Miller and Sofer (1986a) proposed a method for estimating the failure rate of a program non-parametrically. Here, these non-parametric rates are used to produce reliability predictions and their quality is analysed and compared with the parametric predictions

Control de diarrea y dengue en escuelas primarias rurales de Colombia: protocolo de estudio para un ensayo aleatorio y controlado por conglomerados

Antecedentes.Las enfermedades diarreicas y el dengue son graves problemas de salud pública a nivel global. Cuando el suministro de agua potable es inadecuado, el almacenamiento de agua es crucial. La contaminación fecal del agua almacenada es una fuente común de las enfermedades diarreicas y, al mismo tiempo, el agua almacenada proporciona criaderos para los mosquitos vectores del dengue. Un manejo deficiente del agua doméstica y del saneamiento son, por lo tanto, determinantes potenciales de ambas enfermedades. Poco se sabe de la importancia del agua almacenada para el riesgo combinado de la diarrea y el dengue, sin embargo, una intervención compartida podría ser importante para el desarrollo de esfuerzos en gestión y control integrado. Aun menos conocidos son los efectos de un control integrado de estas enfermedades en los entornos escolares.El objetivo de este estudio fue investigar si las intervenciones contra la diarrea y el dengue reducían significativamente las enfermedades diarreicas y los factores de riesgo entomológico de dengue, en las escuelas primarias rurales de dos municipios de Cundinamarca.Metodología y diseño. Se trata de un ensayo por conglomerados, factorial de 2 x 2, controlado y de asignación aleatoria. Las instituciones elegibles fueron las escuelas rurales de los municipios de La Mesa y Anapoima en el departamento de Cundinamarca. Los estudiantes elegibles fueron los niños de las escuelas de los grados 0 a 5. Las escuelas fueron asignadas aleatoriamente a uno de los cuatro grupos del estudio: intervenciones de diarrea, intervenciones de dengue, las dos intervenciones, diarrea y dengue, y control. Las escuelas fueron estratificadas por municipio y asignadas mediante un acto público al inicio del ensayo. La variable de respuesta primaria para la diarrea fue la tasa de incidencia de diarrea en los niños de las escuelas, y para dengue, la densidad de adultos hembra de Aedes aegypti por escuela. Aproximadamente, 800 estudiantes de 34 escuelas se inscribieron en el ensayo con ocho escuelas en el grupo de diarrea, nueve en el de dengue, ocho en el de diarrea y dengue, y nueve en el grupo control. El ensayo fue financiado por el Consejo de Investigaciones de Noruega, la Universidad El Bosque y la Fundación Lazos de CalandaimaDiscusión. Este es el primer ensayo en que se investiga el efecto de un conjunto de intervenciones integradas para controlar las dos enfermedades, dengue y diarrea. Es también el primer ensayo para estudiar la combinación de intervenciones para el control de dichas enfermedades en entornos escolares.El artículo original fue publicado en inglés como: Diarrhea and dengue control in rural primary schools in Colombia – study protocol for a randomized controlled. Trial. 2012; 13:182. BioMed Central es el editor original del artículo. La información para la traducción de la publicación en español fue actualizada..© 2012 Overgaard HJ, et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cite

Improving knowledge, attitudes, and practices on dengue and diarrhea in rural primary school students, their parents, and teachers in Colombia: A cluster-randomized controlled trial

Background: Improved education on water-related diseases in schools could help to reduce disease burden. This paper presents specific results on knowledge, attitudes and practices (KAP) of a cluster-randomized controlled trial to reduce diarrheal disease and dengue entomological risk factors in rural primary schools in Colombia. The aim was to investigate whether enhanced educational interventions on dengue and diarrheal disease in schools could improve KAP scores related to these diseases in students and teachers in rural primary schools, as well as the students’ parents. Methodology/Principal findings: A factorial cluster-randomized controlled trial was carried out in 35 rural primary schools in two municipalities in Cundinamarca, central Colombia. Schools were randomized into four arms: interventions related to diarrheal disease (DIA), dengue (DEN), both (DIADEN), or no interventions (control, CON). Both educational and physical interventions to reduce risk factors of dengue and diarrhea were implemented. Comprehensive teachers’ manuals were developed and deployed to guide the learning activities. The intervention was carried out over two school years. The knowledge scores of students receiving dengue interventions (DEN, DIADEN) increased by 1.16 point score (0.75–1.56, p<0.001) and those receiving diarrhea interventions (DIA, DIADEN) increased by 1.15 point score (0.67–1.63, p<0.001). The attitude and practice scores of students receiving the diarrhea interventions increased (Attitudes: 0.41 [0.11–0.71, p = 0.01]; Practices: 0.33 [0.01–0.65, p = 0.042]), but not for those receiving the dengue interventions (p = 0.31 and p = 0.08, respectively). Conclusions/Significance: There were increases in knowledge scores among students, their teachers and their parents for both diseases. However, the attitudes and practices components were not affected to the same extent. The hypothesis that the students would disseminate knowledge acquired from the educational interventions to their parents was confirmed for dengue, but not for diarrhea

Razones de ausentismo en escuelas primarias rurales de dos municipios colombianos

Background: School absenteeism is a considerable problem generally related to higher dropout rates, poor academic achievement and school lag. This study determined the frequency and causes of overall and illness-related absenteeism of students in rural schools from two Colombian municipalities. Methods: A prospective and descriptive study was conducted in a population of 948 school children from 34 rural schools. Absenteeism data were collected for 2013 academic year consisted of the number of students registered and absent by grade, school, day and reason for absence. Absence rates (overall and illness-related absenteeism) were recorded, based on full or partial days absence, measured both as episodes, and accumulating the number of days. Results: From the students included in the study, 55.1% were male and 71.6% were between 5 and 9 years old. The overall absence rate was 5.7 episodes per child-year (95% confidence interval 5.5 to 5.8) and 8.6 days per child-year (8.4 to 8.9). The main reasons for non-attendance were illness (24.4%), medical or dental check-up (12.9%), travel (12.3%), lack of motivation to attend school (10.0%) and bad weather (9.3%). The illness-related absence rate was 1.4 episodes per child-year (95% confidence interval 1.3 to 1.5) and 2.5 days per child-year (2.4 to 2.6). The main reasons for illness-related absence were cold (37.0%), nonspecific fever (10.9%) and stomach pain or vomiting (8.4%). Conclusions: In this study, the most common reasons for non-attendance were illness-related. The importance of respiratory and gastrointestinal infections in absenteeism was evident, showing rates similar to other urban school studies. Then, the results of this study provide knowledge on the magnitude and reasons for absenteeism in rural schoolchildren.Antecedentes. El ausentismo escolar es un problema importante relacionado con altas tasas de abandono escolar, bajo rendimiento académico y rezago escolar. Este estudio determinó la frecuencia y las causas del ausentismo general y el ausentismo relacionado con la enfermedad en estudiantes de escuelas rurales de dos municipios de Colombia. Métodos. Se realizó un estudio descriptivo en una población de 948 escolares de 34 escuelas rurales. Los datos de ausentismo recopilados para el año 2013 consistieron en el número de episodios y días de ausentismo por grado y motivo de ausencia general y por enfermedad. Se calcularon las tasas de ausentismo general y por enfermedad. Resultados. El 55,1% de la población participante eran hombres y el 71,6% tenían entre 5 y 9 años. La tasa de ausentismo general fue 5,7 episodios por niño-año, IC 95% (5,5-5,8) y 8,6 días por niño-año, IC 95% (8,4-8,9). Las principales razones del ausentismo fueron enfermedades (24,4%), chequeo médico u odontológico (12,9%), viajes (12,3%), falta de motivación para asistir a la escuela (10,0%) y mal clima (9,3%). La tasa de ausentismo por enfermedad fue 1,4 episodios por niño-año IC 95% (1,3-1,5) y 2,5 días por niño-año IC 95% (2,4-2,6). Las principales razones del ausentismo por enfermedad fueron el resfriado común (37,0%), la fiebre inespecífica (10,9%) y el dolor de estómago o vómito (8,4%). Conclusiones. Las razones más comunes para la no asistencia estuvieron relacionadas con la enfermedad. La importancia de las infecciones respiratorias y gastrointestinales en el absentismo fue evidente, mostrando tasas similares a las de otros estudios en escuelas urbanas. Los resultados de este estudio proporcionan conocimiento sobre la magnitud y las razones del absentismo en la población escolar rural

Knowledge, attitudes, and practices about dengue among pupils from rural schools in an endemic area in Colombia

INTRODUCTION: Dengue is a public health problem in tropical and subtropical regions of the world. Studies on dengue in rural areas are scarce since the disease is considered mainly urban. OBJECTIVE: To determine the knowledge (K), attitudes (A) and practices (P) of dengue in an endemic area in Colombia. MATERIALS AND METHODS: We conducted a cross-sectional study with 515 pupils (7-16 years old) in 34 rural schools in Anapoima and La Mesa municipalities during 2011. Each KAP category was evaluated independently by a scoring system and then categorized into high, medium or low. RESULTS: Pupils recognized knowledge variables such as the symptoms (fever, bone pain), transmission route (mosquito bites), and mosquito breeding sites (uncovered water tanks, solid waste). Average scores on attitude were high in both municipalities indicating a well-developed perception of disease severity. Seeking treatment in medical centers and self-medication for fever management and the use of mosquito net and space-spraying of insecticides were the most frequently identified practices. DISCUSSION: This is the first KAP dengue study performed in a rural area in Colombia and as such it contributes to the understanding of dengue perceptions by the inhabitants of these areas. It showed a medium level of knowledge about dengue and a lower level of preventive practices in pupils from rural schools. It also showed that pupils considered space-spraying as crucial for vector control. The presence of the vector in rural areas of the country underlines the need to improve surveillance and education to more effectively control the vector and promote prevention methods including community participation

Detection of all four dengue serotypes in Aedes aegypti female mosquitoes collected in a rural area in Colombia

The Aedes aegypti vector for dengue virus (DENV) has been reported in urban and periurban areas. The information about DENV circulation in mosquitoes in Colombian rural areas is limited, so we aimed to evaluate the presence of DENV in Ae. aegypti females caught in rural locations of two Colombian municipalities, Anapoima and La Mesa. Mosquitoes from 497 rural households in 44 different rural settlements were collected. Pools of about 20 Ae. aegypti females were processed for DENV serotype detection. DENV in mosquitoes was detected in 74% of the analysed settlements with a pool positivity rate of 62%. The estimated individual mosquito infection rate was 4.12% and the minimum infection rate was 33.3/1,000 mosquitoes. All four serotypes were detected; the most frequent being DENV-2 (50%) and DENV-1 (35%). Two-three serotypes were detected simultaneously in separate pools. This is the first report on the co-occurrence of natural DENV infection of mosquitoes in Colombian rural areas. The findings are important for understanding dengue transmission and planning control strategies. A potential latent virus reservoir in rural areas could spill over to urban areas during population movements. Detecting DENV in wild-caught adult mosquitoes should be included in the development of dengue epidemic forecasting models