Comprehensive Survey of Domiciliary Triatomine Species Capable of Transmitting Chagas Disease in Southern Ecuador

Background

Chagas disease is endemic to the southern Andean region of Ecuador, an area with one of the highest poverty rates in the country. However, few studies have looked into the epidemiology, vectors and transmission risks in this region. In this study we describe the triatomine household infestation in Loja province, determine the rate of Trypanosoma cruzi infection in triatomines and study the risk factors associated with infestation.

Methodology/Principal Findings

An entomological survey found four triatomine species (Rhodnius ecuadoriensis, Triatoma carrioni, Panstrongylus chinai, and P. rufotuberculatus) infesting domiciles in 68% of the 92 rural communities examined. Nine percent of domiciles were infested, and nymphs were observed in 80% of the infested domiciles. Triatomines were found in all ecological regions below 2,200 masl. We found R. ecuadoriensis (275 to 1948 masl) and T. carrioni (831 to 2242 masl) mostly in bedrooms within the domicile, and they were abundant in chicken coops near the domicile. Established colonies of P. chinai (175 to 2003 masl) and P. rufotuberculatus (404 to 1613 masl) also were found in the domicile. Triatomine infestation was associated with surrogate poverty indicators, such as poor sanitary infrastructure (lack of latrine/toilet [w = 0.95], sewage to environment [w = 1.0]). Vegetation type was a determinant of infestation [w = 1.0] and vector control program insecticide spraying was a protective factor [w = 1.0]. Of the 754 triatomines analyzed, 11% were infected with Trypanosoma cruzi and 2% were infected with T. rangeli.

Conclusions/Significance

To date, only limited vector control efforts have been implemented. Together with recent reports of widespread sylvatic triatomine infestation and frequent post-intervention reinfestation, these results show that an estimated 100,000 people living in rural areas of southern Ecuador are at high risk for T. cruzi infection. Therefore, there is a need for a systematic, sustained, and monitored vector control intervention that is coupled with improvement of socio-economic conditions.     

Effect of domestic processing on bioactive compounds

Nowadays, most of the consumed foods are rarely ready for direct consumption. Food can be purchased at the local supermarket as fresh raw product such as meat, fruit, fish etc. or as manufactured product after an industrial processing (canned meat, dried fish, packed fruit etc.). But later on, both food types are usually submitted to culinary treatments which will transform the selected food into a cooked dish ready to eat. Domestic methods of food processing have been developed over the centuries to make the final product more attractive in flavour, appearance, taste and consistency. But, until the last centuries, none of the gourmets realize that at the same time, the cooking process was making their foods more digestible, microbiologically safer and more or less nutritive depending on the selected cooking technology. Besides consumer preferences, the selected cooking method is an important factor affecting not only the food chemical composition, but also the intake of bioactive compounds under normal dietary conditions. Therefore, in this work, the different culinary treatments and domestic cooking methods will be compared to define the optimal process to reduce the degradation of biologically active metabolites present in foods commonly consumed as an elaborated dish. Compounds such as carotenoids, glucosinolates, flavonoids and other phenolic compounds, ω-3 fatty acids, tocopherols, phytosterols, etc. have been pointed as bioactive compounds beneficial for human health. Apparently, they are able to prevent cardiovascular diseases (CVD), tumour formation, hiper-cholesterolemia in blood and other deleterious disorders. An adequate domestic practice might help to increase in taking of those functional molecules enhancing their functionality and reducing the risk of chronic diseases.     

Diagnosis of mycobacterial infection in acquired immunodeficiency syndrome (AIDS) patients and HIV carriers.

Differences in tuberculosis diagnosis between infected and non-infected HIV patients were described. In Barcelona, tuberculosis is present in 41.6% of 851 patients in whom AIDS was detected between 1981 and the first quarter of 1990. We reviewed the results of the methods used for tuberculosis diagnosis in 270 AIDS patients controlled in our hospital, in whom tuberculosis was detected (33.3%), and we compared these data with the results obtained in HIV carriers with tuberculosis and with tuberculous patients without HIV infection. Statistically significant differences were found between the three groups with respect to sex, age, results of Ziehl-Neelsen stain in pulmonary specimens and skin test reaction; between AIDS patients and the non-HIV infected population differences were observed in tuberculosis site. Positive skin test reaction diminished from tuberculous individuals non-HIV infected (95%), to HIV carriers with tuberculosis (71.8%) and AIDS patients with tuberculosis (21.8%). Acid-fast smears from pulmonary specimens were positive in 35.7%, 23.5% and 43.7% respectively. Statistically significant differences were found in tuberculosis localization between tuberculous patients non-HIV infected and tuberculous patients with AIDS, in the last group tuberculosis lymphadenitis was the most frequent localization (33.3%) of extrapulmonary tuberculosis, followed by abdominal tuberculosis (15.5%). The incidence of HIV infection among tuberculous patients was 4.6 in our study, but could be higher if patients between 19 and 30 years old were always checked for anti-HIV antibodies.     

Invasion of Mexico by Two Dung Beetles Previously Introduced into the United States

Following the Australian CSIRO strategies, the United States Department of Agriculture introduced several dung beetle species as a biological control to decrease the dung accumulation and proliferation of different pest fly species therein. Of these, two species have been very successful: Digitonthophagus gazella and Euoniticellus intermedius. They have expanded from their release sites in the United States, and quickly invaded Mexican territory and dispersed rapidly. Here we report on 27 new capture sites in several Mexican states from 1994 to 1996 and discuss invasion routes as well as ecological conditions.     

Bottom-Water Conditions in a Marine Basin after the Cretaceous–Paleogene Impact Event: Timing the Recovery of Oxygen Levels and Productivity

An ultra-high-resolution analysis of major and trace element contents from the Cretaceous–Paleogene boundary interval in the Caravaca section, southeast Spain, reveals a quick recovery of depositional conditions after the impact event. Enrichment/depletion profiles of redox sensitive elements indicate significant geochemical anomalies just within the boundary ejecta layer, supporting an instantaneous recovery –some 10² years– of pre-impact conditions in terms of oxygenation. Geochemical redox proxies point to oxygen levels comparable to those at the end of the Cretaceous shortly after impact, which is further evidenced by the contemporary macrobenthic colonization of opportunistic tracemakers. Recovery of the oxygen conditions was therefore several orders shorter than traditional proposals (10⁴–10⁵ years), suggesting a probable rapid recovery of deep-sea ecosystems at bottom and in intermediate waters.     

Growth inhibition of Staphylococcus aureus by H2O2-producing Lactobacillus paracasei subsp. paracasei isolated from the human vagina

H2O2 production by certain Lactobacillus strains is one of the mechanisms that helps to regulate the vaginal ecosystem. This paper describes the kinetics of H2O2 production by two different strains of Lactobacillus paracasei subsp. paracasei under different culture conditions and the effect of this metabolite on the growth of Staphylococcus aureus. L. paracasei F2 produced 2.72 mmol 1-1 H2O2 while L. paracasei F28 produced 1.84 mmol l(-1), both in agitated cultures. Although L. paracasei F2 produced a higher H2O2 concentration than L. paracasei F28, H2O2 production per number of live bacterial cells was 10-fold higher for F28. The latter also showed a faster decrease in viability during the stationary phase. There were no detectable levels of H2O2 in cultures without agitation. H2O2-producing lactobacilli inhibited growth of S. aureus in a plaque assay and in mixed cultures, depending on the initial inoculum of the pathogen.     

The MLH1 c.1852_1853delinsGC (p.K618A) Variant in Colorectal Cancer: Genetic Association Study in 18,723 Individuals

Colorectal cancer is one of the most frequent neoplasms and an important cause of mortality in the developed world. Mendelian syndromes account for about 5% of the total burden of CRC, being Lynch syndrome and familial adenomatous polyposis the most common forms. Lynch syndrome tumors develop mainly as a consequence of defective DNA mismatch repair associated with germline mutations in MLH1, MSH2, MSH6 and PMS2. A significant proportion of variants identified by screening these genes correspond to missense or noncoding changes without a clear pathogenic consequence, and they are designated as “variants of uncertain significance”, being the c.1852_1853delinsGC (p.K618A) variant in the MLH1 gene a clear example. The implication of this variant as a low-penetrance risk variant for CRC was assessed in the present study by performing a case-control study within a large cohort from the COGENT consortium-COST Action BM1206 including 18,723 individuals (8,055 colorectal cancer cases and 10,668 controls) and a case-only genotype-phenotype correlation with several clinical and pathological characteristics restricted to the Epicolon cohort. Our results showed no involvement of this variant as a low-penetrance variant for colorectal cancer genetic susceptibility and no association with any clinical and pathological characteristics including family history for this neoplasm or Lynch syndrome.