In 1995, the first Venezuelan equine encephalitis (VEE) outbreak in Colombia in 22 years caused an estimated 75,000 human cases, 3000 with neurologic complications and 300 fatal, in La Guajira State. Of the state's estimated 50,000 equines, 8% may have died. An epizootic IC virus, probably introduced from Venezuela, was rapidly amplified among unvaccinated equines. Record high rainfall, producing high densities of vector Aedes taeniorhynchus, led to extensive epidemic transmission (30% attack rate) in the four affected municipalities. Native Wayuu Indians, constituting 24% of the state's population, were at increased risk of infection (risk ratio, 3.3; 95% confidence interval, 2.2-5.3). Epidemiologic studies found no evidence of human-to-human transmission. A higher-than-expected number of abortions during the outbreak confirmed a previously suspected abortifacient role of VEE infection. Pesticide applications and a mass equine vaccination program contributed to preventing the outbreak's spread south of La Guajira.

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.

Villavicencio, the capital city of the Department of Meta, Colombia, is at high risk for the urbanization of malaria because of the region's ecological conditions, as well as the permanent presence of infected human populations arriving from rural areas. From August to November 2002 and in April 2003, anopheline collections were undertaken in the area. Isofamilies were obtained from 331 wild females, which were then recorded according to their abundance as follows: Anopheles marajoara, Anopheles rangeli, Anopheles braziliensis, Anopheles darlingi, and Anopheles apicimacula. Anopoheles darlingi showed the highest biting activity (3.0) between 1800 and 1900 h. Forty-five breeding places were sampled, 64% of which were fish ponds, 6.7% flooded meadows, and 6.7% drainpipes, with these being the most representative locations. All sampled breeding sites were positive for anophelines. Anopheles marajoara could play an important role as an auxiliary vector in Villavicencio's urban area. Control measures should be aimed at weeding the marginal areas around fish ponds and at evaluating the use of impregnated bed-nets.

This article focuses on the epidemiological methods and results of a global Ecohealth study that explored the complexity of the relationship between ecological, biological, economical, social and political factors and vector presence. The study was carried out in two dengue endemic areas of Colombia. A transdisciplinary team gathered quantitative and qualitative data. A survey in randomly sampled households was applied and, simultaneously, direct observation of potential breeding sites was carried out. Logistic regressions and qualitative techniques were used. Qualitative and quantitative data were compared using triangulation. The presence of low water containers increases seven-fold the risk of finding immature forms ofAedes aegypti in the household (OR = 7.5; 95%CI: 1.7-32.2). An inverse association between socioeconomic stratum and presence of the vector was identified (Low stratum OR = 0.9; 95%CI: 0.6-1.4; High stratum OR =0.4; 95%CI: 0.07-1.7). Water management is a complex social dynamic associated with the presence of Ae. aegypti. Dengue control is a challenge for public health authorities and researchers as they should address promotion and prevention strategies that take into account cultural, behavioral, socioeconomic and health factors.

Se presenta la distribución geográfica y la importancia epidemiológica en la transmisión de la enfermedad de Chagas de las 23 especies de triatominos presentes en Colombia, tomando como base los registros bibliográficos existentes en el pais y las colecciones de referencia del Laboratorio de Entomologia del Instituto Nacional de Salud y del Centro de Investigaciones en Microbiologia y Parasitologia Tropical de la Universidad de los Andes; además, se realiza un análisis de las condiciones ecológicas en las cuales han sido registrados triatominos en los paises con fronteras con Colombia para poder establecer la presencia de posibles especies que aún no se han registrado en nuestro pais. De esta manera. existe la posibilidad de tener en Colombia especies con hábitos silvestres como: Alberprosenia malheiroi. Belminus lapofiei y Cavernicola lenti, preentes todas ellas en los departamentos amazónicos; Triatoma nigromaculata en la Cordillera Oriental y con hábitos intradomiciliarios; Panstrongylus chinai con posibilidad de encontrarse en hábitats selváticos o en las viviendas de los colonos de la Amazonia debido a su atracción por la luz y Alberprosenia goyovargasien hábitats silvestres de la frontera con Venezuela. Se resalta la importancia de la vigilancia entomológica a nivel nacional como estrategia para reforzar los estudios de triatominos silvestres en Colombia.Palabras clave: Triatominae, distribución geográfica, enfermedad de Chagas. Colombia. Present distribution and epidemiological importance of triatomine (Reduviidae: Triatominae) species in ColombiaWe present the geographical distribution and epidemiological importance for Chagas' disease transmission of 23 triatomine species in Colombia. based on bibliographical reports available in the country and on reference collections housed in the Entomology Laboratory at the lnstituto Nacional de Salud and the Tropical Microbiology and Parasitology Research Center at Universidad de los Andes. We also discuss the ecological conditions under wich triatomines in countries bordering Colombia have been reported. airned at establishing the possible presence of species that have not been reported yet in our country. We, therefore, reportpossible presence in Colombia of species with wild habitats such as Alberprosenia malheiroi, Belminus lapofiei, and Cavernicola lenti, al1 of them located in the Amaron region; Triatoma nigromaculata. which shows intradomiciliary habits, in the Eastern mountain range; Panstrongylus chinai, probably located in wild habitats and also in settlers' dwellings in the Amazon region dueto its attraction to light, and Alberprosenia goyovargasi, located in wild habitats in our border with Venezuela. The importance of national surveillance programs is highlighted as an aid strategy for the study of triatomine species in 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.ResultsA 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.ConclusionsAlthough 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.

En los últimos años, el número de casos de malaria urbana en Buenaventura, Colombia, ha aumentado de 576 en 1987 a 3 296 en 1991 y 2 017 en 1992, por lo que se desarrolló un estudio epidemiológico para identificar patrones de transmisión de la malaria en este municipio del litoral pacífico colombiano. Se describen los hallazgos entomológicos en relación con los vectores, los criaderos y el comportamiento de las especies de Anopheles durante el período comprendido entre junio de 1993 y mayo de 1994. De los 469 posibles criaderos del área urbana, 28 fueron positivos a anofelinos. En la zona rural vecina de Buenaventura 20 de 80 posibles criaderos fueron positivos a las formas inmaduras del mosquito. Los sitios donde se encontró con más frecuencia Anopheles albimanus fueron las excavaciones de minería, los lagos y los estanques para piscicultura. Los criaderos de Anopheles nuñeztovari fueron los pozos de lluvia y estanques de peces. Anopheles neivai se recolectó en bromelias. De las capturas intra y peridomiciliarias de mosquitos adultos, 90% correspondieron a Anopheles albimanus. De las hembras, 54,8% habían realizado al menos una ovipostura. Esta especie tuvo una actividad peridomiciliaria máxima entre las 18.00 y 22.00 horas. La mayor tasa de picadura peridomiciliaria fue de 7,1 y correspondió a marzo de 1994. Se espera que esta información entomológica permita poner en marcha un importante proceso de participación comunitaria e implementar medidas de control que estén orientadas por nuestros resultados.

BackgroundAs many neglected tropical diseases are co-endemic and have common risk factors, integrated control can efficiently reduce disease burden and relieve resource-strained public health budgets. Diarrheal diseases and dengue fever are major global health problems sharing common risk factors in water storage containers. Where provision of clean water is inadequate, water storage is crucial. Fecal contamination of stored water is a common source of diarrheal illness, but stored water also provides breeding sites for dengue vector mosquitoes. Integrating improved water management and educational strategies for both diseases in the school environment can potentially improve the health situation for students and the larger community. The objective of this trial was to investigate whether interventions targeting diarrhea and dengue risk factors would significantly reduce absence due to diarrheal disease and dengue entomological risk factors in schools.Methodology/Principal FindingsA factorial cluster randomized controlled trial was carried out in 34 rural primary schools (1,301 pupils) in La Mesa and Anapoima municipalities, Cundinamarca, Colombia. Schools were randomized to one of four study arms: diarrhea interventions (DIA), dengue interventions (DEN), combined diarrhea and dengue interventions (DIADEN), and control (CON). Interventions had no apparent effect on pupil school absence due to diarrheal disease (p = 0.45) or on adult female Aedes aegypti density (p = 0.32) (primary outcomes). However, the dengue interventions reduced the Breteau Index on average by 78% (p = 0.029), with Breteau indices of 10.8 and 6.2 in the DEN and DIADEN arms, respectively compared to 37.5 and 46.9 in the DIA and CON arms, respectively. The diarrhea interventions improved water quality as assessed by the amount of Escherichia coli colony forming units (CFU); the ratio of Williams mean E. coli CFU being 0.22, or 78% reduction (p = 0.008).Conclusions/SignificanceIntegrated control of dengue and diarrhea has never been conducted before. This trial presents an example for application of control strategies that may affect both diseases and the first study to apply such an approach in school settings. The interventions were well received and highly appreciated by students and teachers. An apparent absence of effect in primary outcome indicators could be the result of pupils being exposed to risk factors outside the school area and mosquitoes flying in from nearby uncontrolled breeding sites. Integrated interventions targeting these diseases in a school context remain promising because of the reduced mosquito breeding and improved water quality, as well as educational benefits. However, to improve outcomes in future integrated approaches, simultaneous interventions in communities, in addition to schools, should be considered; using appropriate combinations of site-specific, effective, acceptable, and affordable interventions.Trial RegistrationClinicalTrials.gov no. ISRCTN40195031