Culicoides Latreille (Diptera, Ceratopogonidae) of Colombia: records from the collection of insects of medical importance from National Institute of Health.

Background: The collection of insects of medical importance from the Instituto Nacional de Salud, INS (Bogotá, Colombia: https://www.ins.gov.co/Paginas/Inicio.aspx), was started in 1934 with the aim of being an institutional and national repository of the biodiversity of insects involved in vector-borne diseases of importance in public health. Today, the entomological collection includes more than 7,500 specimens.The ceratopogonid insects are one group of Diptera that are represented in this collection. Within the Ceratopogonidae, the genus Culicoides Latreille, 1809 is relevant in public health because of the nuisance caused by their bites when they are presented in great abundance and because of their role as vectors of several agents (virus, protozoa and nematodes) that cause diseases to humans and to animals (Mellor et al. 2000, Mullen 2002). An overview of the Ceratopogonidae, represented in this collection, is presented here. A total of 801 individuals, mainly adults of the genus Culicoides (90%) are represented. The collection is the result of the effort of several researchers of the Group of Entomology at INS. These researchers collected ceratopogonids when they went to different transmission scenarios of vector-borne diseases in Colombia, with the purpose of making entomological characterisations including the processing, assembly and identification of the specimens in the laboratory. New information: New information about the geographical distribution of 39 species of the genus Culicoides in Colombia. All data have been uploaded to GBIF and are publicly available there.

The decline of dengue in the Americas in 2017: discussion of multiple hypotheses.

OBJECTIVE: Since the 1980s, dengue incidence has increased 30-fold. However, in 2017, there was a noticeable reduction in reported dengue incidence cases within the Americas, including severe and fatal cases. Understanding the mechanism underlying dengue's incidence and decline in the Americas is vital for public health planning. We aimed to provide plausible explanations for the decline in 2017. METHODS: An expert panel of representatives from scientific and academic institutions, Ministry of Health officials from Latin America and PAHO/WHO staff met in October 2017 to propose hypotheses. The meeting employed six moderated plenary discussions in which participants reviewed epidemiological evidence, suggested explanatory hypotheses, offered their expert opinions on each and developed a consensus. RESULTS: The expert group established that in 2017, there was a generalised decreased incidence, severity and number of deaths due to dengue in the Americas, accompanied by a reduction in reported cases of both Zika and chikungunya virus infections, with no change in distribution among age groups affected. This decline was determined to be unlikely due to changes in epidemiological surveillance systems, as similar designs of surveillance systems exist across the region. Although sudden surveillance disruption is possible at a country or regional level, it is unlikely to occur in all countries simultaneously. Retrospective modelling with epidemiological, immunological and entomological information is needed. Host or immunological factors may have influenced the decline in dengue cases at the population level through immunity; however, herd protection requires additional evidence. Uncertainty remains regarding the effect on the outcome of sequential infections of different dengue virus (DENV) types and Zika virus (ZIKV), and vice versa. Future studies were recommended that examine the epidemiological effect of prior DENV infection on Zika incidence and severity, the epidemiological effect of prior Zika virus infection on dengue incidence and severity, immune correlates based on new-generation ELISA assays, and impact of prior DENV/other arbovirus infection on ZIKV immune response in relation to number of infections and the duration of antibodies in relation to interval of protection. Follow-up studies should also investigate whether increased vector control intensification activities contributed to the decline in transmission of one or more of these arboviruses. Additionally, proposed studies should focus on the potential role of vector competence when simultaneously exposed to various arboviruses, and on entomological surveillance and its impact on circulating vector species, with a goal of applying specific measures that mitigate seasonal occurrence or outbreaks. CONCLUSIONS: Multifactorial events may have accounted for the decline in dengue seen in 2017. Differing elements might explain the reduction in dengue including elements of immunity, increased vector control, and even vector and\or viruses changes or adaptations. Most of the results of this expert consensus group meeting are hypothetical and based on limited evidence. Further studies are needed.

OBJECTIF: Depuis les années 1980, l'incidence de la dengue a été multipliée par 30. Cependant, en 2017, il y a eu une réduction notable du nombre de cas d'incidence de dengue rapportés dans les Amériques. Nous voulions fournir des explications plausibles à la baisse en 2017. MÉTHODES: Un groupe d'experts constitué de représentants d'institutions scientifiques et académiques, d'officiels des Ministères de la Santé d'Amérique Latine et de membres du personnel de l'OPS/OMS s'est réuni en octobre 2017 pour proposer et évaluer des hypothèses. RÉSULTATS: En 2017, il y a eu une baisse généralisée de l'incidence, de la sévérité et du nombre de décès dus à la dengue dans les Amériques, accompagnée d'une réduction des cas rapportés d'infections par le virus Zika et par le virus du chikungunya, sans modification dans la répartition entre les groupes d'âge affectés. Il a été déterminé que ce déclin était peu probablement dû aux changements dans les systèmes de surveillance épidémiologique, étant donné que des systèmes de surveillance similaires existaient dans toute la région. Bien que des perturbations soudaines dans la surveillance soient possibles au niveau national ou régional, il est peu probable que cela se produise simultanément dans tous les pays. Une modélisation rétrospective avec des informations épidémiologiques, immunologiques et entomologiques est nécessaire. Des facteurs liés à l'hôte ou immunologiques peuvent avoir influencé le déclin des cas de dengue au niveau de la population par le biais de l'immunité; cependant, l'évidence d'une protection conférée par l'effet du troupeau nécessite des données supplémentaires. Une incertitude subsiste quant à l'effet sur le résultat des infections séquentielles de différents types du virus de la dengue (DENV) et du virus Zika (ZIKV), et vice-versa. Les études à venir devraient examiner (1) l'effet épidémiologique d'une infection antérieure par le DENV sur l'incidence et la sévérité du virus Zika, (2) l'effet épidémiologique d'une infection antérieure par le virus Zika sur l'incidence et la sévérité de la dengue, (3) les corrélats immunitaires basés sur des tests ELISA de nouvelle génération, (4) l' impact d'une infection antérieure à DENV/autres arbovirus sur la réponse immunitaire au ZIKV en fonction du nombre d'infections et de la durée des anticorps en fonction de l'intervalle de protection, (5) si des activités d'intensification de la lutte antivectorielle ont contribué à la diminution de la transmission d'un ou plusieurs de ces arbovirus, (6) le rôle potentiel de la compétence vectorielle lorsqu'ils sont exposés simultanément à différents arbovirus, (7) la surveillance entomologique et son impact sur la circulation d'espèces de vecteurs, dans le but d'appliquer des mesures spécifiques qui réduisent l'occurrence saisonnière d'épidémies. CONCLUSIONS: Des événements multifactoriels pourraient expliquer le déclin observé de la dengue en 2017. La plupart des résultats de cette réunion du groupe de consensus d'experts sont hypothétiques, reposent sur des données limitées et requièrent des investigations supplémentaires.

[Factors that delay malaria diagnosis and treatment in the municipality of Riberalta in Bolivia]. / Factores que retardan el diagnóstico y el tratamiento de la malaria en el municipio de Riberalta en Bolivia.

INTRODUCTION: Few studies on the causes of the delay of malaria diagnosis and treatment in Bolivia are published. OBJECTIVE: To know the factors that delay malaria diagnosis and treatment of malaria in the public service of the town of Riberalta, Bolivia. MATERIALS AND METHODS: The times between the onset of symptoms and treatment, between the onset of symptoms and diagnosis and between the diagnosis and the start of treatment were calculated. The averages of the calculated times were compared with respect to the site of infection, parasite species, level of care, place of diagnosis and diagnostic method and th patient's age was correlated with the calculated times. RESULTS: Between January and December 2010, 2,482 positive valid cases were studied. An average of 4.16 days was found between the onset of symptoms and the start of treatment, the average time between the onset of symptoms and diagnosis was 4.07 days, and between diagnosis and the start of treatment 0.10 days. Statistically significant (p<0.05) differences were found for factors related to the delay of diagnosis such as place of diagnosis, site of infection, level of care, parasite species and diagnostic method. The analysis of covariance showed a statistical association with the level of care and the parasite species (p<0.05). CONCLUSION: The delay in malaria diagnosis is influenced by factors such as the site of infection, place of diagnosis, level of care, parasite species and diagnostic method.

Electrochemical monitoring of the metabolic activity of mycobacteria in culture.

Mycobacterial metabolic activity is typically measured using time-consuming manual methods based on nutrient consumption, nucleic acid synthesis or reduction of tetrazolium salts. In this study, we propose much simpler electrochemical methods for continuous monitoring of the metabolic activity of mycobacteria in culture. Chronoamperometry and chronopotentiometry were used to detect metabolic activity of both slow-growing and fast-growing mycobacteria using a potentiostat with 2D-electrochemical cell. Electrochemical measurements were able to detect statistically significant differences in the metabolic activity of approximately 10(7) mycobacteria in different growth conditions, within less than 24 h of mycobacterial culture. The metabolic activity of mycobacteria measured by the used electrochemical methods correlated well with changes in general respiratory conditions within the cells as it was evaluated by different biochemical tests. Chronoamperometry and chronopotentiometry allowed measurement of mycobacterial metabolic activity without invasive chemical reactions, at minimal bacterial load and when metabolic response of mycobacteria occurs quickly. The proposed methodology is simple, rapid and cost-effective, and it is expected that both in vitro and in vivo metabolic activity of human mycobacterial pathogens as Mycobacterium tuberculosis can be measured when the implementation of this method to analyze virulent strains is adapted.

Factores que retardan el diagnóstico y el tratamiento de la malaria en el municipio de Riberalta en Bolivia / Factors that delay malaria diagnosis and treatment in the municipality of Riberalta in Bolivia

Introducción. Se publican pocos estudios sobre las causas del retardo del diagnóstico y el tratamiento de la malaria en Bolivia. Objetivo. Conocer los factores que retardan el diagnóstico y el tratamiento de la malaria en el servicio público del municipio de Riberalta, Bolivia. Materiales y métodos. Se calcularon los tiempos transcurridos entre el inicio de los síntomas y el tratamiento, entre el inicio de los síntomas y el diagnóstico, y entre el diagnóstico y el inicio del tratamiento; se compararon las medias de los tiempos calculados con el lugar de infección, la especie parasitaria, el nivel de atención, el lugar y el método de diagnóstico, y la edad se correlacionó con los tiempos calculados. Resultados. De 2.482 casos positivos válidos evaluados entre enero y diciembre de 2010, se encontró una media de 4,16 días entre el inicio de los síntomas y el inicio del tratamiento, de 4,07 días entre el inicio de los síntomas y el diagnóstico, y de 0,10 días entre el diagnóstico y el tratamiento. El retardo del diagnóstico y los factores, lugar de diagnóstico, lugar de infección, nivel de atención, especie parasitaria y método de diagnóstico, mostraron una diferencia estadística significativa (p<0,05). En el análisis de la covarianza se observó una asociación estadística con el nivel de atención y la especie parasitaria (p<0,05) Conclusión. Existe un retardo en el diagnóstico de la malaria, lo cual es influenciado por factores como el lugar de infección, lugar del diagnóstico, nivel de atención, especie parasitaria y método de diagnóstico.

Introduction. Few studies on the causes of the delay of malaria diagnosis and treatment in Bolivia are published. Objective. To know the factors that delay malaria diagnosis and treatment of malaria in the public service of the town of Riberalta, Bolivia. Materials and methods. The times between the onset of symptoms and treatment, between the onset of symptoms and diagnosis and between the diagnosis and the start of treatment were calculated. The averages of the calculated times were compared with respect to the site of infection, parasite species, level of care, place of diagnosis and diagnostic method and th patient’s age was correlated with the calculated times. Results. Between January and December 2010, 2,482 positive valid cases were studied. An average of 4.16 days was found between the onset of symptoms and the start of treatment, the average time between the onset of symptoms and diagnosis was 4.07 days, and between diagnosis and the start of treatment 0.10 days. Statistically significant (p<0.05) differences were found for factors related to the delay of diagnosis such as place of diagnosis, site of infection, level of care, parasite species and diagnostic method. The analysis of covariance showed a statistical association with the level of care and the parasite species (p<0.05). Conclusion. The delay in malaria diagnosis is influenced by factors such as the site of infection, place of diagnosis, level of care, parasite species and diagnostic method.

[Epidemiological environment and response to the HIV epidemic in Bolivia]. / Entorno epidemiológico y respuesta a la epidemia del VIH en Bolivia.

With AIDS/HIV, early detection is of key importance to public health, as well as disseminating prevention information and providing timely and appropriate treatment. In Bolivia, at the end of 2006 approximately 50% had AIDS at the time of diagnosis, detection having occurred late in the illness. The HIV/AIDS epidemic in Bolivia is concentrated, with prevalence rates over 5% among the at-risk population, primarily men who have sex with men. From January 1984 through October 2006, the total number of HIV/AIDS cases reported in Bolivia rose to 2 190, with 1 239 HIV and 951 AIDS cases, and underreporting estimated to be over 70% country-wide. The United National Joint Program on AIDS (UNAIDS) estimated that by the end of 2006 there would be 6 700 people living with HIV/AIDS in Bolivia. In the context of this scenario, the article describes the challenges facing the HIV/AIDS program and the strategies developed to address the epidemic in Bolivia. In addition, the UNAIDS/PAHO strategies are stressed and must get underway for HIV/AIDS prevention and control activities in the country.

A population genetics study of Anopheles darlingi (Diptera: Culicidae) from Colombia based on random amplified polymorphic DNA-polymerase chain reaction and amplified fragment lenght polymorphism markers.

The genetic variation and population structure of three populations of Anopheles darlingi from Colombia were studied using random amplified polymorphic markers (RAPDs) and amplified fragment length polymorphism markers (AFLPs). Six RAPD primers produced 46 polymorphic fragments, while two AFLP primer combinations produced 197 polymorphic fragments from 71 DNA samples. Both of the evaluated genetic markers showed the presence of gene flow, suggesting that Colombian An. darlingi populations are in panmixia. Average genetic diversity, estimated from observed heterozygosity, was 0.374 (RAPD) and 0.309 (AFLP). RAPD and AFLP markers showed little evidence of geographic separation between eastern and western populations; however, the F ST values showed high gene flow between the two western populations (RAPD: F ST = 0.029; Nm: 8.5; AFLP: F ST = 0.051; Nm: 4.7). According to molecular variance analysis (AMOVA), the genetic distance between populations was significant (RAPD:phiST = 0.084; AFLP:phiST = 0.229, P < 0.001). The F ST distances and AMOVAs using AFLP loci support the differentiation of the Guyana biogeographic province population from those of the Chocó-Magdalena. In this last region, Chocó and Córdoba populations showed the highest genetic flow.

Random amplified polymorphic DNA analysis of Anopheles nuneztovari (Diptera: Culicidae) from Western and northeastern Colombia.

Random amplified polymorphic DNA (RAPD) markers were used to analyze 119 DNA samples of three Colombian Anopheles nuneztovari populations to study genetic variation and structure. Genetic diversity, estimated from heterozygosity, averaged 0.34. Genetic flow was greater between the two populations located in Western Colombia (F ST: 0.035; Nm: 6.8) but lower between these two and the northeastern population (F ST: 0.08; Nm: 2.8). According to molecular variance analysis, the genetic distance between populations was significant (phi ST 0.1131, P < 0.001). The variation among individuals within populations (phi ST 0.8869, P < 0.001)was also significant, suggesting a greater degree of population subdivision, not considered in this study. Both the parameters evaluated and the genetic flow suggest that Colombian An. nuneztovari populations are co-specific.

Random amplified polymorphic DNA analysis of Anopheles nuneztovari (Diptera: Culicidae) from Western and Northeastern Colombia

Random amplified polymorphic DNA (RAPD) markers were used to analyze 119 DNA samples of three Colombian Anopheles nuneztovari populations to study genetic variation and structure. Genetic diversity, estimated from heterozygosity, averaged 0.34. Genetic flow was greater between the two populations located in Western Colombia (F ST: 0.035; Nm: 6.8) but lower between these two and the northeastern population (F ST: 0.08; Nm: 2.8). According to molecular variance analysis, the genetic distance between populations was significant (phiST 0.1131, P < 0.001). The variation among individuals within populations (phiST 0.8869, P < 0.001)was also significant, suggesting a greater degree of population subdivision, not considered in this study. Both the parameters evaluated and the genetic flow suggest that Colombian An. nuneztovari populations are co-specific

Hallazgo de Mesocyclops Aspericornis (Daday)(Copepoda: Cyclopidae) Depredador de Larvas de Aedes Aegypti en Anapoima-Colombia. (1) / Finding of Mesocycolps Aspericonis (DaDay) (Copepoda: Cyclopidae) Depredator of Aedes Aegipty in Anapoima-Colombia. (1)

En Anapioma, Colombia, se encontro que el Copepodo Mesocyclops Aspericornis era depredador de larvas del mosquito Aedes Aegypti. Este encuentro representa el primer hallazgo de este Copepodo en recipientes artificiales en la region neotropical, y el primer hallazgo como depredador de larvas de Aedes Aegypti

Comportamiento de Anopheles (Kerteszia) Lepidotus Zavortink, 1973, y su Incriminacion como posible Vector de Malaria en el Departamento del Tolima, Colombia (1) / Behavior of the Anopheles (Kerteszia) Lepidotus Zavortink, 1973, and its incrimination as possible vector of Malaria at the Department of Tolima, Colombia

En un foco de transmision de malaria en el Departamento del Tolima, que comprende 16 localidades de los municipios de Cunday, Villarrica, Dolores, Prado y Purificacion; y donde se encuentran unicamente casos autoctonos de Plasmodium se realizaron estudios entomologicos desde abril de 1981 hasta mayo de 1983. Se colectaron con cebo humano 2.209 mosquitos Anopheles, todos del subgenero Kerteszia, de los cuales el 99.5% (2.209) fue Anopheles Lepidotus Zavortink, 1973 y los restantes 10(0,5%) An. Boliviensis Theobald, 1905. Se concluye, con evidencia epidemiologica, que An. Lepidotus es el posible vector en este foco. Es el primer registro conocido en que esta especie se incrimina como posible vector de malaria en Colombia. Antiguas observaciones en este foco habian incrementado como responsable de la transmision de malaria a An. Boliviensis, debido a confusiones taxonomicas, aclaradas en los ultimos 10 anos. Las mas altas densidades de An. Lepidotus ocurrieron de enero a junio y el pico de densidad precedio por cerca de 2 meses al pico de casos de malaria. Se encontro que An. Lepidotus es altamente exofagica (3,7 veces mayor actividad de picadura fuera de las casas que dentro) y exofilica (92% de las hembras que picaron, salieron son reposar en las superficies dentro de las casas). Su habito de picadura es diurno, con un pico de actividad entre las 15:00 y 18:00 horas. No se encontro..