First record of human trichinosis in Chile associated with consumption of wild boar (Sus scrofa)

The first South American case of human trichinosis, resulting from the consumption of roast wild boar (Sus scrofa) is reported in Chile. The patient presented fever, diarrhea, myalgias, facial edema, sub-conjunctival reddening, photophobia, eosinophilia, and elevated glutamic oxalacetic transaminase. The diagnosis was confirmed by two immunoenzymatic tests (ELISA) using somatic and excretion-secretion antigens.

Effect of food on immature development, consumption rate, and relative growth rate of Toxorhynchites splendens (Diptera: Culicidae), a predator of container breeding mosquitoes

Food utilization by the larvae of Toxorhynchites splendens (Wiedemann) was studied in the laboratory by offering larvae of Aedes aegypti Linnaeus, Anopheles stephensi (Liston), and Culex quinquefasciatus (Say). Quantitative analyses of data indicated that immature development was significantly faster with increase in food availability. The regression analysis showed that the degrees of the relationship between immature duration (Id) and food availability were higher when offered early instars of prey (first and second instars) than late instars. Consumption rate (Cr) of the predator increased with increase in food availability and this relationship was highly significant when larvae of An. stephensi were offered as food. Consumption rate to food level decreased with increase in the age class of the prey. There was a significant negative correlation between Id and Cr. This aspect helps to increase population turnover of T. splendens in a shorter period when the prey is abundant. Conversely, the predator compensated the loss in daily food intake at low food level by extending Id thereby attains the minimum threshold pupal weight for adult emergence. There was an increase in the relative growth rate (RGR) of the predator when An. stephensi was offered as prey and this was related to the high protein content of the prey per body weight. There was a positive correlation between Cr and RGR. This adaptive life characteristic strategy of this predator is useful for mass-rearing for large scale field release programmes in the control of container breeding mosquitoes is discussed.

The resumption of consumption: a review on tuberculosis

Among all infectious diseases that afflict humans, tuberculosis (TB) remains the deadliest. At present, epidemiologists estimate that one-third of the world population is infected with tubercle bacilli, which is responsible for 8 to 10 million new cases of TB and 3 million deaths annually throughout the world. Approximately 95% of new cases and 98% of deaths occur in developing nations, generally due to the few resources available to ensure proper treatment and where human immunodeficiency virus (HIV) infections are common. In 1882, Dr Robert Koch identified an acid-fast bacterium, Mycobacterium tuberculosis, as the causative agent of TB. Thirty-nine years later, BCG vaccine was introduced for human use, and became the most widely used prophylactic strategy to fight TB in the world. The discovery of the properties of first-line antimycobacterial drugs in the past century yielded effective chemotherapies, which considerably decreased TB mortality rates worldwide. The later introduction of some additional drugs to the arsenal used to treat TB seemed to provide an adequate number of effective antimicrobial agents. The modern, standard short-course therapy for TB recommended by the World Health Organization is based on a four-drug regimen that must be strictly followed to prevent drug resistance acquisition, and relies on direct observation of patient compliance to ensure effective treatment. Mycobacteria show a high degree of intrinsic resistance to most antibiotics and chemotherapeutic agents due to the low permeability of its cell wall. Nevertheless, the cell wall barrier alone cannot produce significant levels of drug resistance. M. tuberculosis mutants resistant to any single drug are naturally present in any large bacterial population, irrespective of exposure to drugs. The frequency of mutants resistant to rifampicin and isoniazid, the two principal antimycobacterial drugs currently in use, is relatively high and, therefore, the large extra-cellular population of actively metabolizing and rapidly growing tubercle bacilli in cavitary lesions will contain organisms which are resistant to a single drug. Consequently, monotherapy or improperly administered two-drug therapies will select for drug-resistant mutants that may lead to drug resistance in the entire bacterial population. Thereby, despite the availability of effective chemotherapy and the moderately protective vaccine, new anti-TB agents are urgently needed to decrease the global incidence of TB. The resumption of TB, mainly caused by the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains and HIV epidemics, led to an increased need to understand the molecular mechanisms of drug action and drug resistance, which should provide significant insight into the development of newer compounds. The latter should be effective to combat both drug-susceptible and MDR/XDR-TB.

Discursive media strategies in the journalistic construction of schistosomiasis in Jaboticatubas, Minas Gerais

Using media discourse analysis for material published by the press on schistomisasis in the city of Jaboticatubas, the possible determining factors of narrative and discursive constructions in the diffusion of information are discussed. It was observed that media discourse treats schistosomiasis in 1962 as something from the natural order. By 1997 and 1998, the media discourse strategies reveal ideological treatment in favor of certain social segments. Situations are identified in which social agents in specific contexts construct the meanings of this endemic disease. It was concluded that the economic organization of space was a determining factor in the production and circulation of the media discourses.

Toxoplasma gondii in animals used for human consumption

Food-borne toxoplasmosis in humans may result from exposure to different stages of Toxoplasma gondii, in particular from the ingestion of tissue cysts or tachyzoites contained in meat, primary offal (viscera) or meat-derived products of many different animals, or the ingestion of sporulated oocysts that are contained in the environment and may contaminate food and water. Although the potential for transmission of the parasite to humans via food has been known for several decades, it is not known which routes are most important from a public health point of view. It is likely that transmission of the parasite to humans is influenced not only by the potential contamination of various food sources, but also by the individual behaviour of consumers in different ethnic groups and geographical regions. Most current methods for detection of T. gondii in meat-producing animals, in products of animal origin, or in the environment are insufficient because they do not allow quantification of infectious stages. Hence, most studies report only qualitative data from which it is difficult to assess the true risk of infection in individual cases. There is a need for quantitative data so that efficient strategies to reduce food-borne transmission of T. gondii to humans can be developed.

Growth, cysts and kinetics of Borrelia garinii (Spirochaetales: Spirochaetacea) in different culture media

The aim of the present paper was to evaluate cyst formation and growth parameters of Borrelia garinii in a range of media differing in formulation and cost. A qualitative assessment of morphology and motility of B. garinii was conducted. All media were prepared aseptically and used in test tubes or Petri dishes. For each medium, the initial spirochete concentration was standardized to 10³ spirochets/mL. The following culture media were suitable to grow B. garinii: Barbour-Stoenner-Kelly, brain heart infusion and PMR. Growth was minimal at six weeks post-inoculation and maximum spirochete density was observed between 9-12 weeks. Often, the cultures developed cysts of different sizes, isolated or in groups, with a spiraled portion of variable sizes, mainly in unfavorable culture media. Brazilian Lyme disease-like illness, also known as Baggio-Yoshinari syndrome (BYS), is a new and interesting emerging tick-borne disease, caused by Borrelia burgdorferi sensu lato spirochetes, only during its cystic forms. It has been assumed that the peculiar clinical and laboratory features of BYS are consequential to the absence of a human sucker Ixodes ricinus complex tick at risk areas in Brazil, supporting the concept that the borrelia phenotypic expression pattern is modified as it is transmitted through the host.

Practices in primary health care oriented toward the harmful consumption of drugs

Objective To analyze the practices of primary care focused on the harmful consumption of drugs. Method This is a qualitative study, developed with a dialectical-critical approach. Data collection was carried out through semi-structured interviews with 10 employees of a basic health unit (UBS). Results The demands are not accepted, and if they go beyond the barriers shaped by the historical absence of health care practices for drug users and moralistic and preconceived ideologies, they are not reinterpreted as health needs; practices that meet these demands and go beyond the barriers are poor; the functionalist approach, which explains drug use as a disease and considers drug users as deviants, supports the few existing practices. Conclusion primary health care is mistakenly focused on addiction; it lacks structural elements of the production process in health and internal dynamics of the working processes that would foster the development of collective practices.

Type of prey influences biology and consumption rate of Orius insidiosus (Say) (Hemiptera, Anthocoridae)

Generalist predators are capable of consuming different types of prey, and as each prey may have distinct nutritional values, each may have a distinct impact on the biology of the predator. Therefore, the aim of this study was to determine how the consumption of different prey influences certain biological characteristics and the predatory capacity of Orius insidiosus (Say). The investigation was performed in climatic chamber at 25 ±1 ºC, RH 70 ± 10% and fotophase 12. Eggs of Anagasta kuehniella (Zeller), adults of Caliothrips phaseoli (Hood) and nymphs of Aphis gossypii Glover were used as prey and were provided daily ad libitum for all the mobile stages of the predator. The results showed that biological parameters of O. insidiosus are affected differently depending on the type of prey ingested. The development time of the nymphal stage was 13.1, 11.23 and 10.25 days for O. insidiosus feeding on eggs of A. kuehniella, nymphs of A. gossypii and adults of C. phaseoli, respectively. Longevity was five times larger for adults fed on eggs of A. kuehniella (56.25 days) compared to that of adults that preyed on nymphs of A. gossypii (11.44 days), and four times larger when the prey were adults of C. phaseoli (13.58 days). The consumption of eggs of A. kuehniella by predator females resulted in a shorter pre-oviposition period (3.2 days) and a longer oviposition period (44.4 days) when compared to the consumption of other types of prey. In addition, fecundity was increased with the consumption of eggs of A. kuehniella (195.25 eggs laid / female) when compared to feeding on the other prey, C. phaseoli (70.00 eggs laid / female) or A. gossypii (22.50 eggs laid / female). However, the consumption of aphids was larger (148.28 nymphs/ nymphal stage) than that of thrips (74.10 thrips / nymphal stage) or eggs of A. kuehniella (37.03 eggs /nymphal stage) for all of the nymphal stages of the predator. The results indicate that the eggs of A. kuehniella are the type of prey best suited for rearing this predator insect under laboratory conditions. Also fecundity was better with this prey even though the predator consumed during its nymphal stage a lesser quantity of eggs compared to the other prey.

Leaf consumption and duration of instars of the cassava defoliator Erinnyis ello (L., 1758) (Lepidoptera, Sphingidae)

The objectives of this research were to evaluate leaf consumption and the developmental time of the larvae of Erynnyis ello (L., 1758) (Lepidoptera, Sphingidae) reared on cassava, in order to obtain information for the integrated management of this pest. The larvae were reared on excised cassava leaves in Petri dishes and later in gerbox, and kept in chambers at 24 ± 2 ºC and 75 ± 10% RH. The total leaf area consumed by the larva to complete its development was 589.67 cm²; each of the five instars consumed, respectively: 1.89 cm²; 5.74 cm²; 17.48 cm²; 76.66 cm²; and 487.90 cm². The consumption by the first three instars was insignificant, and did not reach 5% altogether; the 4th represented 13%; the 5th presented a consumption significantly higher, about 82.7%. The total time for the larval development was 22.61 days, and the duration for each of the five larval instar was, respectively: 4.35; 3.19; 3.32; 4.52; and 4.94 days. The pre-pupal period lasted 2.29 days. Since the highest consumption is by the 5th instar larva, the control should be applied before this age to avoid heavier damages to the cassava crop.

Consumption of Cinara spp. (Hemiptera, Aphididae) by Cycloneda sanguinea (Linnaeus, 1763) and Hippodamia convergens Guérin-Méneville, 1842 (Coleoptera, Coccinellidae)

Adults and larvae of coccinellids were observed feeding on populations of the giant conifer aphids Cinara spp. on Pinus spp., in Southern Brazil. The objective of this research is to evaluate the consumption capacity of Cycloneda sanguinea (Linnaeus, 1763) and Hippodamia convergens Guérin-Méneville, 1842 (Coleoptera, Coccinellidae) on these aphid species, in order to obtain information for biological control programs. Ten larvae of each predator species were fed with aphids of small size (nymphs of 1st and 2nd instars), and 10 with aphids of medium size (nymphs of 3rd and 4th instars), maintained under 15ºC, 20ºC and 25ºC, 12 h photophase and 70 ± 10% relative humidity. The aphids were counted every 24 hours, replacing those that were consumed. The total consumption of Cinara by the larvae of C. sanguinea was not statistically different at the three temperatures: 325.5; 322.2 and 324.8 of small aphids and 121.3; 140.4 and 109.9 of medium ones, respectively at 15ºC, 20ºC and 25ºC. The consumption by H. convergens was higher than by C. sanguinea and increased noticeably with temperature: 444 aphids at 15ºC; 491.3 at 20ºC and 513.3 at 25ºC, considering the small aphids, and 187.1; 205.1 and 216.6 of medium aphids at the three temperatures. The small aphids weigh about half as much as medium ones and were preferred by all larval instars probably because they are easier to manipulate than the large ones. Both predators, especially the 4th instar larvae, showed high consumption capacity on the Cinara nymphs at all temperatures and can be regarded as promising biological control agents.

Comparison of the methane oxidation rate in four media

Landfill gas emissions are one of the main sources of anthropogenic methane (CH4), a major greenhouse gas. In this paper, an economically attractive alternative to minimize greenhouse gas emissions from municipal solid waste landfills was sought. This alternative consists in special biofilters as landfill covers with oxidative capacity in the presence of CH4. To improve the quality/cost ratio of the project, compost was chosen as one of the cover substrates and soil (Typic red yellow-silt-clay Podzolic) as the other. The performance of four substrates was studied in laboratory experiments: municipal solid waste (MSW) compost, soil, and two soil-compost at different proportions. This study aimed to evaluate the suitability and environmental compatibility as a means of CH4 oxidation in biofilters. Four biofilters were constructed in 60 cm PVC tubes with an internal diameter of 10 cm. Each filter contained 2.3 L of oxidizing substrate at the beginning of the experiment. The gas used was a mixture of CH4 and air introduced at the bottom of each biofilter, at a flow of 150 mL min-1, by a flow meter. One hundred days after the beginning of the experiment, the best biofilter was the MSW compost with an oxidation rate of 990 g m-3 day-1 , corresponding to an efficiency of 44 %. It can be concluded that the four substrates studied have satisfactory oxidative capacity, and the substrates can be used advantageously as cover substrate of MSW landfills.

Oxygen consumption of Litopenaeus vannamei juveniles in heterotrophic medium with zero water exchange

This work aimed at determining the dissolved oxygen consumption rate of Litopenaeus vannamei juveniles maintained in a microbial biofloc raceway system at high density with no aeration. Three 4 L bottles were filled for each treatment, sealed hermetically, and placed in an enclosed greenhouse raceway system. Four shrimp (13.2±1.42 g) were assigned to two sets of the bottles, which underwent the following treatments: light conditions with no shrimp; dark conditions with no shrimp; light conditions with shrimp; and dark conditions with shrimp. Dissolved oxygen content was measured every 10 min for 30 min. A quadratic behavior was observed in dissolved oxygen concentration over time. Significant differences for oxigen consumption were observed only at 10 and 20 min between shrimp maintained in the dark and those under light conditions. At 10 min, a higher value was observed in shrimp maintained under light, and at 20 min, in the dark. Significant differences between 10 and 20 min and between 10 and 30 min were observed when oxygen consumption was analyzed over time in the presence of light. Under dark conditions there were significant differences only between 20 and 30 min. Lethal oxygen concentration (0.65 mg L-1) would be reached in less than one hour either under light or dark conditions with no aeration.

Tropical terrestrial model ecosystems for evaluation of soil fauna and leaf litter quality effects on litter consumption, soil microbial biomass and plant growth

The aim of this work was to evaluate whether terrestrial model ecosystems (TMEs) are a useful tool for the study of the effects of litter quality, soil invertebrates and mineral fertilizer on litter decomposition and plant growth under controlled conditions in the tropics. Forty-eight intact soil cores (17.5-cm diameter, 30-cm length) were taken out from an abandoned rubber plantation on Ferralsol soil (Latossolo Amarelo) in Central Amazonia, Brazil, and kept at 28ºC in the laboratory during four months. Leaf litter of either Hevea pauciflora (rubber tree), Flemingia macrophylla (a shrubby legume) or Brachiaria decumbens (a pasture grass) was put on top of each TME. Five specimens of either Pontoscolex corethrurus or Eisenia fetida (earthworms), Porcellionides pruinosus or Circoniscus ornatus (woodlice), and Trigoniulus corallinus (millipedes) were then added to the TMEs. Leaf litter type significantly affected litter consumption, soil microbial biomass and nitrate concentration in the leachate of all TMEs, but had no measurable effect on the shoot biomass of rice seedlings planted in top soil taken from the TMEs. Feeding rates measured with bait lamina were significantly higher in TMEs with the earthworm P. corethrurus and the woodlouse C. ornatus. TMEs are an appropriate tool to assess trophic interactions in tropical soil ecossistems under controlled laboratory conditions.

Growth regulators, culture media and antibiotics in the in vitro shoot regeneration from mature tissue of citrus cultivars

The objective of this study was to evaluate the effects of 6-benzylaminopurine (BAP) and α-naphthaleneacetic acid (NAA) combinations, basal media and beta-lactam antibiotics on in vitro organogenesis from mature stem segments of 'Pêra', 'Valência' and 'Bahia' sweet oranges and 'Cravo' rangpur lime. For induction of shoot regeneration, the segments of the four cultivars were placed on Murashige and Skoog (MS) medium containing the following BAP/NAA concentrations: 0.0/0.0; 0.25/0.0; 0.25/0.25; 0.5/0.0; 0.5/0.5; 1.0/0.0; 2.0/0.0; 2.0/0.25; 2.0/0.5; and 2.0/1.0 mg L-1. In order to test the influence of the culture media on shoot-bud induction, (MS), Murashige and Tucker (MT), and woody plant medium (WPM) formulations were evaluated, associated with the best combination of plant growth regulators obtained in the previous experiment. The influence of four beta-lactam antibiotics (timentin, cefotaxime sodium salt, meropenem trihydrate and augmentin) on shoot regeneration was determined. Better regeneration responses were achieved when internodal segments were cultured onto MS-based medium with 500 mg L-1 cefotaxime with the following BAP/NAA concentrations: 0.5 + 0.25 mg L-1 for 'Cravo', 1.0 + 0.25 mg L-1 for 'Valência' and 'Bahia', and 1.0 + 0.5 mg L-1 for 'Pêra'. Genotype, growth regulators, basal media and beta-lactam antibiotics affect the morphogenetic response in mature tissues of citrus.

Guidelines for irrigation scheduling of banana crop in São Francisco Valley, Brazil. II - Water consumption, crop coefficient, and physiologycal behavior

The water consumption and the crop coefficient of the banana cv. Pacovan were estimated in Petrolina County, northeastern Brazil, in order to establish guidelines to irrigation water management. Evaluations were carried out since planting in January 1999 to the 3rd harvest in September 2001 on a microsprinkler irrigated orchard, with plants spaced in a 3 x 3 m grid. Average daily water consumption was 3.9, 4.0, and 3.3 mm in the 1st, 2nd and 3rd growing seasons, respectively. Crop coefficient values increased from 0.7 (vegetative growth) to 1.1 (flowering). Even with high soil water availability, transpiration was reduced due to high evaporative demand.