Previous studies have shown that variation in the distribution of vectors associated to the transmission of Leishmania species may be related to climatic changes. However, the potential implications of these ecological changes in human health need to be further defined in various endemic populations where leishmaniasis carries a substantial burden of disease such as in Northeastern Colombia. Herein, we report the impact of El Niño Southern Oscillation climatic fluctuations during 1985-2002 in the occurrence of cases of leishmaniasis in two northeastern provinces of Colombia. During this period, we identified that during El Niño, cases of leishmaniasis increased, whereas during La Niña phases, leishmaniasis cases decreased. This preliminary data show how climatic changes influence the occurrence of leishmaniasis in northeastern Colombia and contributes to the growing body of evidence that shows that the incidence of vector-borne diseases is associated with annual changes in weather conditions.

Belminus ferroae (Hemiptera: Reduviidae) was collected from houses in the localities of San Alberto and Santa Catalina in the municipality of Toledo, Department of Norte de Santander, Colombia. Precipitin tests revealed that the main hosts of B. ferroae are insects belonging to the order Blattodea, whose haemolymph serves as food (89.43%). A low rate of haematophagy was indicated on rodents, dogs and humans (7.32%) and no natural infection with Trypanosoma cruzi was found by either microscopic examination or polymerase chain reaction. The finding of B. ferroae inside houses, feeding primarily on Blattodea with only a minor tendency to feed on vertebrate blood, is indicative of both the evolutionary path from predator to blood-sucker taken by Triatominae and their tendency to adapt from silvatic to domestic habitats.

The Triatomine bug Belminus herreri, previously known only from Panama, is reported for the first time from Colombia. Three adult B. herreri were collected from a chicken coop and a viable egg was found on a Bactris palm at Carmen municipality in humid forest zone at 680 m altitude. From 44 eggs produced, five progeny were reared to adulthood. During early instars they were unable to take bloodmeals directly from vertebrate hosts, but they fed successfully by cleptohaematophagy on blood from replete Rhodnius prolixus.

No abstract

All members of Triatominae subfamily (Heteroptera: Reduviidae), potential vectors of Trypanosoma cruzi, etiologic agent of the Chagas disease, feed on blood. Through evolution, these bugs have fixed special morphological, physiological, and behavioral aptations (adaptations and exaptations) adequate to feed on blood. Phylogeny suggests that triatomines evolved from predator reduvids which in turn descended from phytophagous hemipterans. Some pleisiomorphic traits developed by the reduvid ancestors of the triatomines facilitated and modeled hematophagy in these insects. Among them, mouthparts, saliva composition, enzymes, and digestive symbionts are the most noticeable. However, the decisive step that allowed the shift from predation to hematophagy was a change of behavior. The association of a predator reduvid with nesting vertebrate (≈110 to 32 Ma) permitted the shift from an arthropod prey to a vertebrate host. In this work, we review the phylogeny and dispersion of triatomines and the current controversy over the monophyly or polyphyly of this group. We also discuss how these insects were able to overcome, and even have taken advantage of, diverse ancestral and physical barriers to adapt to sucking blood of nidicolous vertebrates. We provide a Spanish version of this work.

Belminus ferroae, a new triatomine species, is described on the basis of specimens collected in dwellings of the Andean oriental mountain range, municipality Toledo, Departament of North Santander, Colombia. It differs from other species of the genus in the color pattern of the body, corium light colored, cells of the membrane light brown, with secondary venation that gives a reticular aspect to the wing, in design of the connexivum, and phallic structures of the male. Illustrations of male genitalia of Belminus herreri, a related species, are included.

Leishmaniasis in the Americas is transmitted by Lutzomyia spp., which have many animal reservoirs. Previous studies indicated potential changes in vectors of climate-related distribution, but impact outcomes need to be further studied. We report climatic and El Niño events during 1985-2002 that may have had an impact on leishmaniasis in 11 southern departments of Colombia: Amazonas, Caquetá, Cauca (Ca), Huila, Meta (Mt), Nariño, Putumayo (Py), Tolima, Valle (Va), Vaupes (Vp), and Vichada. Climatic data were obtained by satellite and epidemiologic data were obtained from the Health Ministry. NOAA climatic classification and SOI/ONI indexes were used as indicators of global climate variability. Yearly variation comparisons and median trend deviations were made for disease incidence and climatic variability. During this period there was considerable climatic variability, with a strong El Niño for 6 years and a strong La Niña for 8. During this period, 19,212 cases of leishmaniasis were registered, for a mean of 4756.83 cases/year. Disease in the whole region increased (mean of 4.98%) during the El Niño years in comparison to the La Niña years, but there were differences between departments with increases during El Niño (Mt 6.95%, Vp 4.84%), but the rest showed an increase during La Niña (1.61%-64.41%). Differences were significant in Va (P= 0.0092), Py (P= 0.0001), Ca (P= 0.0313), and for the whole region (P= 0.0023), but not in the rest of the departments. The importance of climate change is shown by shifts in insect and animal distributions. These data reflect the importance of climate on transmission of leishmaniasis and open further investigations related to forecasting and monitoring systems, where understanding the relationship between zoonoses and climate variability could help to improve the management of these emerging and reemerging diseases.

ResumenDebido al registro, en los últimos cinco años, de ciento venticinco casos urbanos de leishrnaniasis cutánea en la ciudad de Bucaramanga, se desarrolló el presente estudio con el fin de determinar las especies del género Lutzomyia existentes en la ciudad y sus implicaciones en salud pública. La búsqueda de los flebotomineos se hizo en ocho zonas de la ciudad en los meses de septiembre a diciembre de 1996, utilizando como técnicas de muestre0 trampas de luz tipo CDC y aspiración directa en cebo humano protegido y en sitios de reposo. Los insectos fueron preservados en alcohol al 70% y aclarados con KOH y fenol. Se capturaron 212 especímenes pertenecientes a once especies del género Lutzomyia y una del género Brumptomyia. Entre las especies antropofílicas encontradas, L. ovallesi y L. gomezi se destacan por ser reconocidas como vectores de Leishmania braziliensfs. L. ovallesi fue la especie de mayor distribución en la ciudad, L. gomezi la más abundante en las capturas con cebo humano; las dos se encontraron en barrios donde se ha informado el mayor número de casos de la enfermedad. El hallazgo de estas especies en la ciudad sugiere la posibilidad de que los habitantes de Bucaramanga puedan infectarse en el área urbana y crea la necesidad de continuar estudios que contribuyan a interrumpir el ciclo de transmisión.Lutzomyia species (Diptera: Psychodidae) possible leishmaniasls vector i n the city of Bucaramanga, Santander, Colombia One hundred and twenty five urban cases of cutaneous leishmaniasis have been reported within the city of Bucaramanga in the last five years. This study was carried out to determine the species of Lutzomyia present in the city and their role in public health. The search for sand flies was carried out in eight of the city's zones, from September to December 1996, using CDC light traps and direct aspiration in resting cites and on protected human bait. 212 specimens from eleven Lutzomyia species and one species of Brumptomyia were collected. Amongst the anthropophillic species found, L. ovallesiand L. gomeziare known vectors of L. braziliensis. L. ovallesi had the greatest distribution throughout the city and L. gomezi was the most frequent capture with human bait. Both were found in the dwelllngs frorn which most cases of the disease were reported. The finding of these species in the city suggests the possibility ~ of infection within the urban area and the need to pursue studies to cut the transmission cycle.