Rio Santiago Research Articles

Challenges of the black communities; the conservation of the Santiago Cayapas river commune

This article addresses the case of Afro-descendants in the Rio Santiago Cayapas Commune, Ecuador. Chapter I contextualizes Esmeraldas within the Chocó Biogeographic region. Chapter II analyzes the history from African slaves to the resistance stronghold. Chapter III explores how the resource-rich Rio Santiago Cayapas Commune faces state-driven displacement, logging industry, oil palm agriculture, and mining, prioritizing resource exploitation, impacting local communities. Logging, oil palm, and mining lead to deforestation, territory loss, conflicts, and environmental degradation, straining life in the Rio Santiago Cayapas Commune.

Digital geologic map, petrography and U-Pb geochronology of the Río Santiago Shear Zone, southernmost Sierra Madre Occidental, western Mexico

The boundary between the Sierra Madre Occidental (SMO) and the Trans-Mexican Volcanic Belt (TMVB) is well exposed along the Santiago River, on the border of the states of Nayarit and Jalisco. This region includes a polydeformed belt produced by the relative motion between the Jalisco Block and the SMO, here defined as the “Rio Santiago Shear Zone” (RSSZ). In this work, we present detailed geological cartography, petrographic descriptions, and new zircon U-Pb ages that allow us to establish the stratigraphy of the region surrounding the RSSZ, providing temporal constraints to its tectonic evolution. In the mapped area, the base of the SMO stratigraphic column consists of a succession of massive andesitic lava flows intruded by felsic dikes and a felsic subvolcanic body of 27.5 and 27.2 Ma, and it is covered by a series of ignimbrites of 26.8 and 25.3 Ma. A red beds succession separates a second package of ignimbrites of ∼20-19 Ma, in turn capped by rhyolitic lava domes of 19.7 and 18.6 Ma and a rhyodacitic lava flows of 15.6 Ma, this Miocene succession is also intruded by a felsic body of 18.3 Ma west of the La Yesca dam. The SMO succession is covered by rocks belonging to the bimodal volcanism of the TMVB, emplaced between the end of the Miocene and the Pleistocene. The RSSZ developed through several deformation phases that occurred since the end of the Oligocene. The Oligocene succession of the SMO is affected by NE-SW and WNW-ESE trending lateral faults, NW-SE open folds and WNW-ESE and E-W trending reverse oblique faults. Some of the reverse oblique faults were later reactivated as normal faults. WNW-ESE trending normal faults associated with the Tepic-Zacoalco Rift affected the area south of the Santiago River during the Pliocene and Pleistocene. Normal faulting produced an accumulated vertical offset up to 700 m between the northern and southern regions of the Santiago River.

Yaws elimination in Ecuador: Findings of a serological survey of children in Esmeraldas province to evaluate interruption of transmission.

The WHO roadmap for neglected tropical diseases includes yaws eradication requiring certification of elimination of transmission in all endemic and formerly endemic countries worldwide. A community-based programme for yaws control was considered to have achieved elimination of the infection in the endemic focus in Ecuador after 1993. We did a serosurvey of children in this focus to provide evidence for interruption of transmission. Survey of serum samples collected from children aged 2 to 15 years living in the formerly endemic and in geographically contiguous areas. A convenience sample of sera collected between 2005 were 2017 from non-yaws studies, were analyzed using immunochromatic rapid tests to screen (OnSite Syphilis Ab Combo Rapid Test) for Treponema pallidum-specific antibodies and confirm (DPP Syphilis Screen and Confirm) seroreactivity based on the presence antibodies to treponemal and non-treponemal antigens. Seroreactivity was confirmed in 6 (0.14%, 95% CI 0.06-0.30) of 4,432 sera analyzed and was similar in formerly endemic (0.11%, (95% CI 0.01-0.75) and non-endemic (0.14%, 95% CI 0.06-0.34) communities. All seroreactors were of Afro-Ecuadorian ethnicity and most were male (4/6) and aged 10 or more years (5/6), the latter possibly indicating venereal syphilis. Only 1 seroreactor lived in a community in the Rio Santiago, that was formerly hyperendemic for yaws. We observed very low levels of treponemal transmission in both formerly endemic and non-endemic communities which might be indicative of congenital or venereal syphilis and, if yaws, would likely be insufficient to maintain transmission of this endemic childhood infection. Additional surveys of children aged 1 to 5 years are planned in Rio Santiago communities to exclude yaws transmission.

Plasmodium falciparum outbreak in native communities of Condorcanqui, Amazonas, Per\xfa

BackgroundMalaria remains a serious health threat in the Amazonas Region of Peru and approximately 95% of the cases, mainly Plasmodium vivax, are found in native communities of The Rio Santiago District, Condorcanqui Province. In 2019, more than one thousand malaria cases were reported, with an unusual number of Plasmodium falciparum autochthonous cases. The present study aims to report this P. falciparum outbreak while describing the epidemiology of malaria and the risk factors associated in the native communities of Amazonas, Peru.MethodsThe DIRESA-Amazonas in collaboration with the Condorcanqui Health Network and the Institute of Tropical Diseases of the UNTRM carried out a malaria Active Case Detection (ACD III) between January 31st and February 10th of 2020. A total of 2718 (47.4%) individuals from 21 native communities grouped in eight sanitary districts, were screened for malaria infections. Each participant was screened for malaria using microscopy. Follow-up surveys were conducted for all malaria positive individuals to collect socio-demographic data. Spatial clustering of infection risk was calculated using a generalized linear model (GLM). Analysis of risk considered factors such as gender, age, type of infection, symptomatology, and parasitaemia.ResultsThe study suggests that the P. falciparum index case was imported from Loreto and later spread to other communities of Rio Santiago during 2019. The ACD III reported 220 (8.1%) malaria cases, 46 P. falciparum, 168 P. vivax and 6 mixed infections. SaTScan analysis detected a cluster of high infection risk in Middle Rio Santiago and a particular high P. falciparum infection risk cluster in Upper Rio Santiago. Interestingly, the evaluation of different risk factors showed significant associations between low parasitaemia and P. falciparum asymptomatic cases.ConclusionThis is the first report of a P. falciparum outbreak in native communities of Condorcanqui, Amazonas. Timely identification and treatment of symptomatic and asymptomatic cases are critical to achieve malaria control and possible elimination in this area. However, the current malaria situation in Condorcanqui is uncertain, given that malaria ACD activities have been postponed due to COVID-19.

Astilleros estatales e industria naval argentina: trayectoria reciente y desafíos futuros

Este trabajo aborda el estudio de la trayectoria reciente de la industria naval pesada argentina y los astilleros públicos (Astillero Río Santiago y Talleres Navales Dársena Norte). Nuestra hipótesis implica una fuerte relación entre el Estado regulador, productor, y financiador y la industria naval pesada argentina, en particular los astilleros públicos. Desde un punto de vista conceptual, nuestro objetivo es el de contribuir a un debate más amplio sobre las relaciones entre el Estado y la industrialización. Desde un punto de vista empírico, explicamos a través de este vínculo el desempeño de un sector industrial. Las consecuencias de las políticas ortodoxas en la industria naval pesada argentina han afectado sistemáticamente la actividad, provocando el cierre de los astilleros, y la casi desaparición de los proveedores de piezas navales. Los cambios en el curso de la política pública desde el inicio del siglo XXI han creado las condiciones de posibilidad de los astilleros públicos.

Distribution of Malpighia mexicana in Mexico and its implications for Barranca del Río Santiago

Wild plants represent relatively unexplored resource of high economic potential, especially as an alternative to developing new crops and, even more relevant, for improving existing crops and contributing to nutrition and health. The wild species Malpighia mexicana (manzanita) has a wide tradition of food, medicinal and ornamental use in Mexico. It is part of the American-origin group of tropical shrubs that produce edible red fruits, such as Acerola, which is considered the most important natural source of vitamin C in the world. Given the role played by M. mexicana in Mexico, and particularly in Barranca del Rio Santiago (Santiago River Canyon), we modelled its potential distribution in both geographical areas. We used species’ records from databases, local herbaria and records collected by the authors as well as climatic variables representing long term average, variability and extreme conditions of temperature and precipitation. To fit the models we used the modelling algorithm Maxent and selected an adequate configuration by testing a range of model complexity settings. The results indicate a clear species preference for warm-dry tropical forest, most extensively in the Balsas river depression and the central valleys of Oaxaca. The probability of the species presence in the western region was also high, although the probability was also high for smaller surface areas, such as the region of Santiago river canyons, which are covered by warm-dry tropical forests.

Astilleros y Fábricas Navales del Estado. Demanda estatal, diversificación y orientación de la producción a la industria no militar en un proyecto empresarial de la Armada (1953 y 1976)

Este escrito busca aportar al conocimiento de la administración de empresas públicas realizada por la Armada Argentina a partir de la identificación de políticas empresariales desarrolladas en la empresa Astilleros y Fábricas Navales del Estado, que buscaron asegurar su viabilidad económica. Analiza una serie de estrategias productivas y de gestión técnica, económica y administrativa en el Astillero Río Santiago (1953-1976) a partir de documentación empresarial, libros contables y el registro de las negociaciones paritarias. La orientación singular de estas estrategias es construida a la luz de un conjunto de cuestiones como la relación con la Marina de Guerra; la diversificación y la orientación de la producción; la inserción en la estructura estatal y la calificación de la fuerza de trabajo.

La Barranca del Rio Santiago as Tourist and Eco Touristic Attraction for the Brand Guadalajara Guadalajara, Focused on a National Tourism

The main purpose of this research is to show if the Barranca del Rio Santiago is a tourist attraction and ecotourism should be included in the Guadalajara brand, focused on national tourism. The research is exploratory and descriptive in nature, as it seeks to know if the Rio de Santiago Canyon is an ecotourism and tourist attraction so that it can be included in the Guadalajara brand. The analysis was conducted under a database issued by the state of Jalisco, which is the 2016 Yearbook of the State of Jalisco. SECTUR establishes in the latest competitiveness agenda of tourist destinations in Mexico that Guadalajara has a large number of natural destinations, including the Barranca del Río Santiago, this destination has a high ecological, recreational and landscaping value, which is very little known by the local population, and consequently it can become a new product for the ecotourism sector.

Procesos de comunalización y etnización en la construcción de identidades colectivas de la gente afro del Ecuador

En estas páginas presento algunas reflexiones frente a los procesos de construcción de identidades colectivas de las poblaciones afro del norte del Ecuador, mostrando cómo la formación discursiva de las comunas y las etnias expresan representaciones identitarias, resultado de tensiones, negociaciones y posicionamientos políticos de las poblaciones, en su agencia colectiva frente al Estado. Las identidades, serán entonces consideradas como escenarios de lucha, donde se negocian y se intentan subvertir relaciones de poder. Para esto, inicialmente hago referencia a algunos hitos históricos que permiten ubicar el poblamiento afro de Esmeraldas como escenario de resistencia, momentos que van dibujando, a su vez, el lugar de esta zona en el ideario nacional ecuatoriano; posteriormente me refiero a la constitución de la Comuna Rio Santiago Cayapas, para mostrar las maneras particulares como se dio en este escenario lo que llamo proceso de comunalización, y finalmente retomo algunos elementos relevantes frente a la etnización como resultado adelantado por el movimiento afroecuatoriano.

Estado y territorio: política paternalista en una comunidad industrial argentina en la segunda mitad del siglo XX

A lo largo del siglo XX los Estados Latinoamericanos han intervenido en sus espacios territoriales de disimiles maneras. En este articulo nos concentramos en la republica Argentina y nos preguntamos acerca de la posicion que ha tenido el Estado nacional, en su caracter de empresario, como configurador de territorios en los ultimos cincuenta anos del siglo XX. En particular nos interesa recuperar y analizar el rol del Estado en tanto creador y gerenciador de empresas publicas radicadas en espacios locales concretos. Para ello presentamos un estudio de las empresas estatales industriales Yacimientos Petroliferos Fiscales (YPF) y Astillero Rio Santiago (ARS) y estudiamos la configuracion material y simbolica de la localidad de Ensenada (Provincia de Buenos Aires). A partir de la utilizacion de una metodologia cualitativa, se analizan las estrategias de intervencion de las citadas empresas en el marco del paradigma de gestion paternalista de la fuerza de trabajo, la cual tuvo manifestaciones especificas tanto sobre los trabajadores de dichas empresas como sobre la comunidad y el territorio local.

Rare Moss-Built Microterraces in a High-Altitude, Acid Mine Drainage-Polluted Stream (Cordillera Negra, Peru).

The Rio Santiago in the Cordillera Negra of Peru is severely contaminated by acid mine drainage in its headwaters. In a strongly acid stream, at about 3800 m above sea level (masl), microterraces were found with terrace walls built up of dead moss, with encrustations and interstitial fine, creamy sediment. The stream water was turbid due to the presence of similar suspended sediment, which also occurred as a thin basal layer in inter-rim basins. The moss was identified as the rare bryophyte Anomobryum prostratum (Müll. Hal.) Besch. Chemical and mineralogical analyses show that green, living parts of the moss are gradually coated by Al/Fe (hydr)oxides, inducing their senescence and death. The necromass is covered by creamy crusts through precipitation of schwertmannite-type material from the stream water and simultaneous ‘capture’ of fine sediment. The latter consists of a mixture of precipitate and fine detrital primary minerals. These processes are held responsible for the formation of the microterraces, which regarding their composition and environment seem to be unique. Remarkable is the high As content of the creamy crusts and sediment, attributed to strong sorption of As, whereas its solute concentration is relatively low. This calls for more attention to suspended fine sediment in the assessment of environmental risks of stream water use. Lastly, the results raise serious doubts about the use of aquatic bryophytes as bioindicator for chemical pollution in acid mine drainage-polluted streams.Electronic supplementary materialThe online version of this article (doi:10.1007/s11270-015-2390-x) contains supplementary material, which is available to authorized users.

El confinamiento de la basura urbana y la contaminación de las fuentes de agua en México

Este artículo aborda el problema de la contaminación del agua a causa de los escurrimientos de líquidos (lixiviados) provenientes de sitios de disposición final de residuos sólidos municipales. Actualmente el entierro de basuras urbanas se realiza a gran escala, tal es el caso de la ciudad de Zapopan que genera más de 1,200 toneladas diarias, pero los dos rellenos sanitarios en su territorio reciben más de 2,500 toneladas de residuos sólidos. Los lixiviados peligrosos de los sitios de disposición final de residuos escapan en 74% de los casos estudiados (24% de manera regular más un 50% durante los cuatro meses de la temporada de lluvias). El cromo, el plomo y el cianuro son residuos peligrosos comúnmente identificados en muestras de lixiviados de los sitios de disposición final, al escaparse los lixiviados del sitio de confinamiento pueden alcanzar cauces de arroyos, ríos, represas, lagunas y mantos freáticos. En el caso de Huaxtla en el municipio de Zapopan, Jalisco se ha constatado la contaminación por lixiviados del cauce del Arroyo Grande de Milpillas, al cual descargan lixiviados tres sitios de disposición final ubicados a unos kilómetros de distancia cuesta arriba. Los sitios de El Taray ya clausurado, así como los sitios de Hasar´s y Picachos, en operación actual, han ocasionado la degradación ambiental de una amplia zona de la barranca. El Arroyo Grande de Milpillas está contaminado, además tal contaminación ha impactado la zona adyacente al cauce del arroyo, y también ha afectado la producción frutal en huertas que eran regadas con agua del arroyo.

Trayectorias empresariales divergentes frente a contextos de privatización. Un estudio comparativo de dos empresas públicas argentinas

En este artículo se analizan las trayectorias de dos importantes empresas argentinas: Yacimientos Petrolíferos Fiscales (ypf) y Astillero Río Santiago (ars) que enfrentaron la privatización, por parte del gobierno nacional, de manera diversa. El estudio comparativo de ambas empresas evidencia que las articulaciones entre los actores participantes y las condiciones del contexto socioeconómico nunca están predeterminadas, ya que son el resultado, siempre particular, de juegos relacionales.

Les réponses divergentes des entreprises face au contexte de restructuration productive. Une comparaison entre deux firmes publiques argentines

Dans les années 1990, presque toutes les entreprises publiques ont été privatisées en Argentine. En réponse à la transformation du système économique qui impose de nouvelles règles du jeu, certains acteurs ont mis en place des stratégies divergentes. Cet article analyse les différentes trajectoires de deux importantes entreprises argentines : Yacimientos Petrolíferos Fiscales (YPF) et Astillero Río Santiago (ARS). Leur étude comparative nous a permis de percevoir que les articulations entre les acteurs et le système socio-économique ne sont jamais prédéterminées. La politique publique mise en œuvre pour chacune des entreprises a été le résultat d’une interaction particulière entre l’action des acteurs et les restrictions imposées par le système. Nous distinguons dans cette analyse, d’un côté une stratégie de marché imposée aux acteurs (le cas d’YPF), de l’autre une action de résistance des acteurs ayant réussi à faire face au contexte (le cas d’ARS).

Trade, Progress, and Patriotism

Valparaíso, Chile, defined itself as a relatively autonomous, cosmopolitan port city during the nineteenth century. As the leading Pacific port in South America, it played a key role in the Chilean economy. A strong foreign presence, rapid growth, and omnipresent commerce accompanied local prosperity. Local leaders sought the latest urban technologies to bring “progress”—essentially, to mitigate problems created by rapid growth. Although Valparaíso's mercantile elite favored practical solutions rather than the Haussmann-esque urban renewal seen in Rio de Janeiro, Buenos Aires, and Santiago de Chile, the city tackled planning challenges aggressively and succeeded notably in some areas. It successfully negotiated tensions over its residents' dual allegiances to the Chilean state and to international trading communities until the early twentieth century. At that point, political centralization in Chile subordinated Valparaíso to Santiago's power while economic and transportation changes diminished its importance as an entrepot and the city's cosmopolitan identity receded.

Taxonomy and Evolution of Species of the Genus Euchroa Brullé (Subgenus Dyschromus Chaudoir) of Central Mexico and the Island of Hispaniola (Coleoptera: Carabidae: Pterostichini: Euchroina)

Provided are a key to, and descriptions of, adults of 35 species of Dyschromus Chaudoir, which is treated as a subgenus of Euchroa Brullé. Twenty-eight species are from central Mexico; seven are from the island of Hispaniola. Twenty-five species are new (type-localities in parentheses): Euchroa independencia n. sp. (DOMINICAN REPUBLIC, Independencia, 5.5 km. n.n.w. Angel Feliz), Euchroa pedernales n. sp. (DOMINICAN REPUBLIC, Pedernales, 1 km. s. Los Arroyos), Euchroa huautla n. sp. (MEXICO, Oaxaca, Rio Santiago, 11.7 km. e. Huautla de Jiminez), Euchroa cuiyachapa n. sp. (MEXICO, Veracruz, between Cuiyachapa and Ixtapa), Euchroa zongolica n. sp. (MEXICO, Veracruz, 5 km. s.w. San Andres de Tenejapa), Euchroa lasvigas n. sp. (MEXICO, Veracruz, 15.7 km. e. Las Vigas), Euchroa teotitlan n. sp. (MEXICO, Oaxaca, 24.5 km. e. Teotitlan Puerto de Soledad), Euchroa citlaltepetl n. sp. (MEXICO, Veracruz, Volcan Citlaltepetl, east slope), Euchroa perote n. sp. (MEXICO, Veracruz, 16 km. s. Las Vigas), Euchroa harrisoni n. sp. (MEXICO, Tamaulipas, 12.8 km. n.w. Gomez Farias), Euchroa soladevega n. sp. (MEXICO, Oaxaca, 14.9 km. n. Sola de Vega), Euchroa juchatengo n. sp. (MEXICO, Oaxaca, 32 km. s. Juchatengo), Euchroa nizavaguiti n. sp. (MEXICO, Oaxaca, n.w. of Santa Maria Nizavaguiti), Euchroa jalisco n. sp. (MEXICO, Jalisco, ca. 19.8 km. s. Tecalitlan), Euchroa tenancingo n. sp. (MEXICO, Mexico, Rio de Molino, near Valle de Bravo), Euchroa ixtapa n. sp. (MEXICO, Guerrero, crest of Sierra Madre del Sur, n.e. of Ixtapa), Euchroa atoyac n. sp. (MEXICO, Guerrero, 66.4 km. n.e. Atoyac de Alvarez), Euchroa puertogallo n. sp. (MEXICO, Guerrero, 32 km. n.w. Filo de Caballo), Euchroa filodecaballo n. sp. (MEXICO, Guerrero, 39.4 km. n.w. Filo de Caballo), Euchroa yucuyacua n. sp. (MEXICO, Oaxaca, Cerro Yucuyacua, summit e. of Nundaco), Euchroa santacatarina n. sp. (MEXICO, Oaxaca, 35.5 km. s. Juchatengo), Euchroa zempoaltepetl n. sp. (MEXICO, Oaxaca, 10.5 km. s. San Pedro y San Pablo Ayutla), Euchroa carbonera n. sp. (MEXICO, Oaxaca, 7.9 km. n.w. La Carbonera), Euchroa miahuatlan n. sp. (MEXICO, Oaxaca, 27.2 km. s. Miahuatlan), and Euchroa suchixtepec n. sp. (MEXICO, Oaxaca, 41.8 km. s. Suchixtepec). Larvae are also described of E. perote, E. harrisoni, E. soladevega, Euchroa dimidiata Chaudoir, E. atoyac, and E. filodecaballo. Species of the subgenus Dyschromus live on the ground under cover in montane forests of tropical to temperate aspect, at elevations of 900 to 3400 meters. Adults are flightless, and potentially long-lived. Adults of most species are metallic colored dorsally. All seven species from the island of Hispaniola are placed in the opaca group, and all 28 species from Mexico are placed in the nitidipennis group. The opaca group is divided into the opaca and cupripennis subgroups, but support for monophyly of the opaca subgroup is inconclusive.f The nitidipennis group is divided into the nitidipennis, soladevega, and dimidiata subgroups. The nitidipennis subgroup contains all species of the subgenus Dyschromus in the mountains of eastern Mexico, north of the Rio Santo Domingo; the dimidiata subgroup comprises most of the other species in Mexico, except for three species from western Oaxaca that make up the soladevega subgroup. Body color and the condition of the elytral striae and microsculpture of adults, and some traits of the larvae, as well as certain ecological and distributional correlates, provide evidence that each of the three subgroups is monophyletic, but structure of the distal part of the median lobe of the aedeagus indicates that four or five members of the dimidiata subgroup from Oaxaca, including the only species from eastern Oaxaca, as a group, actually belong to the nitidipennis subgroup, as does one of the three species in the soladevega subgroup, while the other two species in the soladevega subgroup really belong to the dimidiata subgroup. Just one species in Mexico is comparatively widespread, E. dimidiata, which

ENTOMOLOGICAL EVALUATION BY POOL SCREEN POLYMERASE CHAIN REACTION OF ONCHOCERCA VOLVULUS TRANSMISSION IN ECUADOR FOLLOWING MASS MECTIZAN™ DISTRIBUTION

The prevalence of infected and infective black flies was estimated by pool screen polymerase chain reaction (PCR) amplification in the three river basins in Ecuador endemic for onchocerciasis. Mass distribution of ivermectin (Mectizan) resulted in dramatic declines in the prevalence of infected and infective flies. In the Rio Santiago river basin, no infections were detected, suggesting that transmission had ceased. The ratio of infected to infective flies in Simulium exiguum was 10-fold lower than the corresponding ratio for Simulium quadrivittatum, suggesting that S. exiguum is a more-competent vector for Onchocerca volvulus than S. quadrivittatum. However, the prevalence of infective flies in the two species was not different, suggesting that S. quadrivittatum may play an important vectorial role where it is the dominant human-biting species. The data demonstrate that pool screen PCR is an efficient way to monitor transmission in areas subject to control, and to certify an area as free of O. volvulus transmission.

The life history of the Long-wattled UmbrellabirdCephalopterus penduligerin the Andean foothills of north-west Ecuador: leks, behaviour, ecology and conservation

SummaryThe rare and threatened Long-wattled UmbrellabirdCephalopterus penduligerinhabits the canopy and mid-storey level of humid to wet foothill and montane forests (150–1,800 m)of the Andean slopes of south-west Colombia and western Ecuador. Here we report on male activity pattern and display behaviour observed at one of two leks recently discovered in the vicinity of Playa de Oro, Rio Santiago, Esmeraldas Province, north-west Ecuador. Courtship behaviour of C.penduligeris compared with the Central American and Amazonian congeners (Bare-necked UmbrellabirdC. glabricollisand Amazonian Umbrellabird C.ornatus). The lek of C.penduligerwas active during the whole study period (February 1997 to January 1998), but both lek structure and daytime activity pattern changed markedly within the observation period.

Minimidochium parvum, a new species of hyphomycete from Argentina

Minimidochium parvum sp. nov. is described from floating litter collected in polluted water from the Rio Santiago.

Successful control of onchocerciasis with community-based ivermectin distribution in the Rio Santiago focus in Ecuador.

Onchocerciasis is a major blinding disease in equatorial Africa and Central and South America. Ivermectin is a safe and effective drug in the treatment of this disease and now forms the basis of disease control in most endemic areas. We report the findings of long-term control of this infection in the Río Santiago focus in Ecuador, between January 1990 and December 1996, using a strategy of giving ivermectin treatments biannually in hyperendemic communities and annually in meso- and hypoendemic communities. Ivermectin was administered by local health workers from each community. A high level of compliance to ivermectin was achieved, with 81.9% to 98.0% of those eligible receiving the drug at each treatment instance. The impact of ivermectin therapy was monitored using a cohort of 120 randomly selected infected individuals from 8 hyperendemic communities. The geometric mean microfilarial density of this group declined from 19.3 to 0 mf/mg over the 84-month observation period. Ivermectin had a significant impact on anterior segment ocular disease, acute onchodermatitis and sowda. The rate of infection of blackflies declined from 1.1% in 1989-0.08% in 1996, which is below the vectorial capacity of the Simulium vector and, as no new nodules were detected after 1994 and no children under 5 became infected over the observation period, it is likely that the transmission of this infection was interrupted in the study area.