The second coming of urban yellow fever in the Americas: looking the past to see the future.

Yellow fever (YF) epizootics in South America during the 21st century have an unprecedented recorded magnitude and geographical dispersion. The YF spread progressively involved areas considered previously free of risk reaching the edge of cities with large unvaccinated populations, and urban outbreaks were frequently forecasted. We critically reviewed the initial stages and enhancing contexts of YF urban epidemics since the 17th century in the Americas, and the modeling attempts of YF epidemic risk by of Aedes-Human transmission, to find common factors that increase the probability of these events in the current scenarios. The YF urban outbreaks of the past showed as necessary conditions the multiple introduction by viremic carriers clustered in time and space, coincident with population peaks of Aedes. These conditions are not met in the current outbreaks in the Americas by sylvatic YF cycles, besides the protective impact of vector control campaigns, vaccination coverage, improved surveillance, and case management. Therefore, urban Aedes-Human YF outbreaks in the Americas are still possible but with low probability or very focal transmission, while the conditions reported in the past were avoided, and the surveillance and control measures sustained, including the vaccination of the population at risk.

Atividade leishmanicida in vitro de Eugenia uniflora e Momordica charantia / Antileishmanial in vitro activity of Eugenia uniflora and Momordica charantia

A Leishmaniose Tegumentar Americana no Brasil é causada por uma variedade de espécies de Leishmania e uma grande diversidade destes parasitas pode ser encontrada na Região Amazônica. Revisões recentes na quimioterapia de leishmaniose enfatizam as deficiências dos agentes terapêuticos atualmente disponíveis e mostram a necessidade urgente de novos candidatos. Uma alternativa para substituir esses medicamentos são extratos naturais de Eugenia uniflora e Momordica charantia. Foram preparados extratos etanólicos das folhas de E. uniflora e M. charantia. Para os testes in vitro de Leishmania brasiliensis foram utilizadas formas promastigotas. O ensaio de citotoxicidade foi realizado com linhagens de fibroblastos. Nossos resultados indicam que E. uniflora foi eficaz contra a cepa de parasita testada, representando uma fonte alternativa de produtos naturais com atividade contra L. brasiliensis.

Cutaneous leishmaniasis is caused in Brazil by several species of the genus Leishmania and a wide variety of these protozoan parasites can be found in Brazil, mainly in the Amazon region. Recent reviews on the chemotherapy of leishmaniasis show the low effectiveness of the usual therapeutic agents, demonstrating the need for new drugs. An interesting possible alternative to the conventional drugs is offered by natural products extracted from Eugenia uniflora and Momordica charantia. Ethanol extracts were prepared from the leaves of Eugenia uniflora and Momordica charantia and assayed in vitro against Leishmania brasiliensis promastigotes and fibroblasts to assess their antileishmanial and cytotoxic activities, respectively. Our results indicate that E. uniflora was active against the parasitic forms of L. brasiliensis

Clinical and epidemiological characterization of trypanosoma cruzi infected patients attending a referral center of chagas disease in Paraguay, preliminary results

A pesar de que la transmisión vectorial de la tripanosomiasis americana se ha interrumpido y las tasas de nuevas infecciones se han reducido en grandes áreas de América Latina, todavía existen muchos pacientes infectados crónicos. Determinamos las características clínicas y epidemiológicas de pacientes infectados con Trypanosoma cruzi que asistieron al Departamento de Medicina Tropical del Instituto de Investigaciones en Ciencias de la Salud (IICS) desde 1985 al 2007 analizando sus fichas clínicas manteniendo el anonimato y la confidencialidad. El paquete estadístico SPSS 11.5 se usó para analizar 1.024 fichas de pacientes de los cuales el 70,1 por cento (723/1024) estaba en el grupo etario de 21-60 años (38,7±10,5); 74,5 por cento (763/1024) nació en departamentos endémicos, 13,2 por cento (135/1024) en el Departamento Central, 5,9 por cento (60/1024) en Asunción y 6,4 por cento(66/1024) en otros departamentos. En el momento de la consulta, 38,2 por cento (391/1024) vivía en departamentos endémicos, 27,8 por cento (285/1024) en el Departamento Central, 22,6 por cento (231/1024) en Asunción y 11,4 por cento (117/1024) en otros. Los motivos de consulta fueron: palpitaciones (43,5 por cento; 445/1024), disnea de esfuerzo (34,1 por cento; 349/1024), decaimiento (32,8 por cento; 336/1024), cefalea (26,1 por cento; 267/1024), constipación (24,7 por cento; 253/1024) entre otros...

Although vector transmission of American trypanosomiasis has been interrupted and there are decreased rates of new infections in large areas of Latin America, there are still many chronically infected patients. We determined the clinical and epidemiological characteristics of Trypanosoma cruzi infected patients attending the Department of Tropical Medicine of the Institute of Research in Health Sciences (IICS) from 1985 to 2007 by analyzing their clinical records, maintaining anonymity and confidentiality. The SPSS 11.5 statistical package was used to analyze 1024 patient records of whom 70.1 percent (723/1024) were in the age group of 21-60 years (38.7±10.5); 74.5 percent (763/1024) were born in endemic departments, 13.2 percent (135/1024) in the Central department, 5.9 percent (60/1024) in Asunción and 6.4 percent (66/1024) in other departments. At consultation, 38.2 percent (391/1024) lived in endemic departments, 27.8 percent (285/1024) in Central Department, 22.6 percent (231/1024) in Asunción and 11.4 percent (117/1024) in others. Consultation reasons were: beatings (43.5 percent; 445/1024), effort dyspnea (34.1percent; 349/1024), enervation (32.8percent; 336/1024), headache (26.1percent; 267/1024) and constipation (24.7percent; 253/1024), among others...

Avaliação da atividade anti-Trypanosoma e anti-Leishmania de Mentha arvensis e Turnera ulmifolia / Evaluation of the anti-Trypanosoma and anti-Leishmania activity of Mentha arvensis and Turnera ulmifolia

Tripanosomiasis or “Chagas disease”, caused by Trypanosoma cruzi, affect 10 million people in Latin America. Today, the chemotherapy is the only specific treatment against this disease, being the most used drugs the nifurtimox and benznidazole. Leishmaniasis is a disease caused by parasites of the genus Leishmania, mainly founded in regions with forests, as the Amazonia. Recent reports about the Leishmaniasis indicate a deficit of therapeutical drugs available against this disease and reinforce the necessity of the discovering of new drugs. An interesting approach against these diseases is the use of natural products, as the extracts of plants as Mentha arvensis and Turnera ulmifolia. For the in vitro assays against T. cruzi and Leishmania, was used the clone CL-B5 and promastigote forms, respectively. The cytotoxic assay was performed using fibroblasts. Our results indicated that M. arvensis was active against all strains assayed, inhibiting 65 e 47 percent of the assayed strains (IC50 = 192.3 and 531.9 ug/mL respectively), representing an interesting and alternative source of natural products with anti-kinetoplastida activity.

Doença de Chagas, causada por Trypanosoma cruzi, afeta cerca de 10 milhões de pessoas nas Américas. Atualmente, a quimioterapia é o único tratamento específico disponível para esta doença, onde os medicamentos utilizados são nifurtimox e benzonidazol. Leishmaniose tegumentar Americana no Brasil é causada por uma variedade de espécies de Leishmania e uma grande diversidade destes parasitos pode ser encontrada na Região Amazônica. Revisões recentes na quimioterapia de leishmaniose enfatizam as deficiências dos agentes terapêuticos atualmente disponíveis e mostram a necessidade urgente de novos candidatos. Uma alternativa para substituir esses medicamentos são extratos naturais de Mentha arvensis e Turnera ulmifolia. Foram preparados extratos etanólicos das folhas de M. arvensis e T. ulmifolia. Para os testes in vitro de T. cruzi, foi utilizado o clone CL-B5 e para Leishmania brasiliensis foram utilizadas formas promastigotas. O ensaio de citotoxicidade foi realizado com linhagens de fibroblastos. Nossos resultados indicam que M. arvensis foi eficaz contra as cepas de parasitos testadas apresentando 65 e 47 por cento de inibição em uma concentração de 500 ug/mL (respectivamente, CE50 = 192.3 e 531.9 ug/mL), sendo considerada uma fonte alternativa de produtos naturais com atividade contra T. cruzi e L. brasiliensis.

The antiplasmodium effects of a traditional South American remedy: Zanthoxylum chiloperone var. angustifolium against chloroquine resistant and chloroquine sensitive strains of Plasmodium falciparum

Zanthoxylum chiloperone var. angustifolium Engl., Rutaceae, is used in traditional medicine to treat fungal and protozoal infections in the central area of South America. Considering the increasing resistance of Plasmodium falciparum in malarial ridden areas, we explored the anti-plasmodial effects of three compounds isolated from Z. chiloperone. The pyranocoumarin transavicennol and the canthinone alkaloids, canthin-6-one and 5-methoxycanthin-6-one, were found to have IC50 on chloroquine/mefloquine resistant and sensitive strains of P. falciparum of 0.5-2.7, 2.0-5.3 and 5.1-10.4 ƒÊg/mL, respectively. Moreover, the formation of heme adducts by these compounds is described by a novel alternative method based on MS-CID methods. The alkylamide sanshool was also identified, for first time in this plant, in the dichloromethanic and ethanolic extracts and the extracts were found to be notably non-toxic and displayed good anti-plasmodial effects.

A new antifungal and antiprotozoal depside from the Andean lichen Protousnea poeppigii.

Extracts from the Andean lichens Protousnea poeppigii and Usnea florida displayed antimicrobial activity against the pathogenic fungi Microsporum gypseum, Trichophyton mentagrophytes and T. rubrum with MIC values between 50 and 100 microg/mL. From the active extracts, four main metabolites were isolated and identified as the new depside, isodivaricatic acid, and the known metabolites 5-propylresorcinol, divaricatinic acid and usnic acid. Isodivaricatic acid and divaricatinic acid presented antifungal effect towards M. gypseum with a MIC of 50 microg/mL and against T. mentagrophytes and T. rubrum and with MIC values of 50 and 100 microg/mL, respectively. The new isodivaricatic acid was active towards Leishmania amazonensis, Leishmania brasiliensis and Leishmania infantum promastigotes with 100% lysis at 100 microg/mL.The activity of the new compound decreased on acetylation of the hydroxy groups as well as on methylation of the acid function. The structures were elucidated by spectroscopic means. The spectroscopic data of isodivaricatic acid are presented here for the first time.

Residual effect of lambdacyhalothrin on Triatoma infestans

Insecticidal residual effect and triatomine infestation rates in houses of a community fumigated with lambdcyhalothrin (Icon) are reported. No mortality was observed in 5th-instar Triatoma infestans nymphs in 72-hr exposure test on three different surfaces, one month after fumigation for a dose of 31.5 mg am/m2. However, during post-exposure observation a mortality of 60 was recorded for those insect exposed on sprayed woodboard. The results observed with mud-containing treated walls, were markedly poorer (0 of mortality). Twelve month after spraying 40 of mortality was observed on first-instar T. infestans nymphs in 72-hr exposure test on woodboard, but lower mortality rates were observed in mud-containing materials. When the effect of deltamethrin (109 mg ai/m2) and lambdcyhalothrin (94 mg ai/m2) was compared, the former did not appear to be superior at similar loads. Both have showed a mortality rate of 30 on 5th-instar T. infestans nymphs three months post-fumigation. The dose utilized in the field fumigation was enough to get a significant (p < 0.0001) control of triatomine domestic infestation, since it was sufficient to keep 95 of the houses uninfested throughout 21 months following treatment, when compared with baseline situation. A remarkable knock-down effect on adult and nymphs forms of the insect and a high in situ mortality were observed as a result of its application, even at very low doses.