Dynamics of transmission of Trypanosoma cruzi in a rural area of Argentina: III. Persistence of T. cruzi parasitemia among canine reservoirs in a two-year follow-up

A new cross-sectional survey of household- associated mongrel dogs as well as follow-up of previously parasitemic individuals was carried out in 1984 toy means of xenodiagnosis and serologic techniques to get a deeper insight into the relationship of T. cruzi parasitemia and age among canine hosts in a rural area of Argentina. Persistence of detectable parasitemia was age-independent, or at most, loosely related to age, confirming the pattern observed in 1982. Similarly no significant age-decreasing effect was recorded among seropositive dogs in: a) the probability of detecting parasites in a 2-year follow-up; b) their intensity of infectiousness (=infective force) for T. infestans 3rd-4th instar nymphs, as measured by the percentage of infected bugs observed in each dog xenodiagnosis. Moreover, not only was the infective force of seropositive dogs for bugs approximately constant through lifetime, but it was significantly higher than the one recorded for children in the present survey, and for human people by other researchers. Therefore, and since T. infestans field populations show high feeding frequencies on dogs, the latter are expected to make the greatest contribution to the pool of infected vectors in the rural household of Argentina. This characteristic should be sufficient to involve canine reservoirs definitely as a risk factor for human people residing in the same house. The increased severity of parasitemia observed among dogs in this survey may be related to the acute undernutrition characteristic of canine populations of poor rural areas in our country, which is expected to affect the ability of the host to manage the infection.

Interrelation between parasitic infections and hypovitaminosis A: Schistosoma mansoni infection and the retinol blood levels in an endemic area of State of Minas Gerais (Brazil)

The interrelation between schistosomiasis and the retinol blood levels was studied in a double blind method, by comparing the serum vitamin A of the infected and non-infected group of an endemic area of Schistosoma mansoni infection. The infected group was characterized by 106 parasitized persons in the intestinal and hepatointestinal forms, who eliminated less than 500 eggs/gram of feces (Modified Kato's method); the non-infected group was characterized by 112 inhabitants of this endemic area without eggs in the stools and presenting negative intradermal reactions, and absence of previous specific treatment. The blood levels of retinol was determinated using trifluoracetic acid method, regarding the normal levels > 20,0mg/100ml. The results of this study point out the absence of correlation between S. mansoni infection and blood levels of vitamin A.

A multivariate analysis of socio-demographic factors, water contact patterns and Schistosoma mansoni infection in an endemic area in Brazil

Associations between socio-demographic factors, water contact patterns and Schistosoma mansoni infection were investigated in 506 individuals (87% of inhabitants over 1 year of age) in an endemic area in Brazil (Divino), aiming at determining priorities for public health measures to prevent the infection. Those who eliminated S. mansoni eggs (n = 198) were compared to those without eggs in the stools (n = 308). The following explanatory variables were considered: age, sex, color, previous treatment with schistosomicide, place of birth, quality of the houses, water supply for the household, distance from houses to stream, and frequency and reasons for water contact. Factors found to be independently associated with the infection were age (10-19 and > 20 yrs old), and water contact for agricultural activities, fishing, and swimming or bathing (Adjusted relative odds = 5.0, 2.4, 3.2, 2.1 and 2.0, respectively). This suggests the need for public health measures to prevent the infection, emphasizing water contact for leisure and agricultural activities in this endemic area.

Miocene marine-continental correlations in the Lisbon area and some discussion related to personnal experience

Sandpit exploitation near Lisbon allowed collecting of many Miocene, non marine fossils. These sands are part of the mostly marine Miocene series in the Lower Tagus basin. The particularly favourable situation led several researchers to deal with marine-continental correlations. Difficulties often concern methodologic aspects. Some poorly based interpretations exerced a lasting influence. A critical approach is presented. Analysis requires data. Methods based upon models often lead to the temptation of fitting data in order to confirm a priori conclusions, or of mixing up data as if of equal statistic value while they have not at all the same weight. Erroneous interpretations' uncritical repetition for many years "upgraded" them into absolute truth. Another point is endemism vs. europeism. Miocene mammals from Lisbon compared well with corresponding French, contemporaneous taxa, while this was apparently not true for Spanish ones. Too much accent had been put on the endemic character of Spanish, or even regional, mammalian faunas. Nationalist bias and sensationalism also weigh, albeit negatively. Meanwhile nearly all the more evident examples as the rhinoceros Hispanotherium are discredited as Iberian endemisms. Taxa may appear as endemic just because they have not yet been found elsewhere. At least for the medium to large-sized mammals, with their huge geographic distribution, faunal differences depend much more on ecology, climate and environmental conditions. Emphasis on differences may also result from researchers that are often in a precarious situation and need very much to achieve short-term, preferably sensational results. Overvalued differences may mask real similarities. Unethic and not scientific behaviour are further enhanced by "nomina nuda" tricks that may simply be a way to circunvent or cheat the Priority Rule. On the other hand, access to communication networks may present as sensational novelties items that are not new at all, misleading the audience. A new class of "science people" arose, created by the media and not by the value of their real achievements. Discussion is presented on sedimentation processes and discontinuities that are often regarded as absolute precision dating tools, as well as on some geochemical and paleomagnetic interpretations. A very good chronologie frame has been obtained for the basin under study on the basis of an impressive set of data, providing a rather detailed and accurate frame for Miocene marine-continental correlations.

Evaluation of different methods for Plasmodia detection, in well defined population groups in an endemic area of Brazil

In Brazil, more than 500,000 new cases of malaria were notified in 1992. Plasmodium falciparum and P.vivax are the responsible species for 99.3% of the cases. For adequate treatment, precoce diagnosis is necessary. In this work, we present the results of the traditional Plasmodia detection method, thick blood film (TBF), and the results of alternative methods: Immunofluorescence assay (IFA) with polyclonal antibody and Quantitative Buffy Coat method (QBC)® in a well defined population groups. The analysis were done in relation to the presence or absence of malaria clinical symptoms. Also different classes of immunoglobulins anti-P.falciparum were quantified for the global analysis of the results, mainly in the discrepant results. We concluded that alternative methods are more sensitive than TBF and that the association of epidemiological, clinical and laboratory findings is necessary to define the presence of malaria.

Teaching and learning with social software in higher education: content management systems integrated with Web-based applications as a key factor for success

The change of paradigm imposed by the Bologna process, in which the student will be responsible for their own learning, and the presence of a new generation of students with higher technological skills, represent a huge challenge for higher education institutions. The use of new Web Social concepts in teaching process, supported by applications commonly called Web 2.0, with which these new students feel at ease, can bring benefits in terms of motivation and the frequency and quality of students' involvement in academic activities. An e-learning platform with web-based applications as a complement can significantly contribute to the development of different skills in higher education students, covering areas which are usually in deficit.

Radioactivity studies in Porto urban area: gamma radiation of Paranhos sector

A set of radiation measurements were carried out in several public and private institutions. These were selected with basis on the people affluence and passage to these sites. These measurements were registration formed either indoor, outdoor or underground and were compiled in three Case Studies. Radiation doses measurements were also made, surface and underground locations, and compiled in other two Case Studies. There were sampled, at the same time, humidity, temperature, atmospheric pressure and relevant construction materials at sampling locations. They were collected and registration formed to analyse if there is any relation or contribution for the measured value in each specific place. Geostatistical models were used to elaborate maps of the results both for radiation values and for doses. Preliminary relations were established among the measured parameters.

Epidemiological aspects of the Brazilian spotted fever: serological survey of dogs and horses in an endemic area in the State of São Paulo, Brazil

In order to obtain information on Brazilian spotted fever, a study in domestic animals was performed in the County of Pedreira, State of São Paulo, Brazil, where 17 human cases had been notified. Serum samples obtained from animals were tested by indirect immunofluorescence for detectable antibodies to spotted fever-group rickettsiae. Seropositivity was revealed in 12 (36.4%) of 33 dogs and seven (77.8%) of nine horses from the endemic area. For comparison, blood samples from dogs and horses from non endemic area were tested and four (12.9%) of 31 dogs and three (27.3%) of 11 horses were positive. The highest titers of antibodies by IFA (IgG > 1:1024) were found only in three dogs and six horses from endemic area. The results suggest that dogs as horses may serve as environmental sentinels for estabilishing the prevalence of foci of spotted fever in Brazil.

A case of human rabies in the Urban Area of Ribeirão Preto, SP, Brazil

A 39-year old male patient was admitted to the University Hospital of the Faculty of Medicine of Ribeirão Preto with signs and symptoms of sudden dyspnea, generalized myalgia and behavioral disorders. The initial suspicion was alcohol abstinence syndrome and the patient was referred for psychiatric and neurologic care. The evolution of the patient with a worsening of signs and symptoms, presence of crises of tachypnea, agitation, difficulty to swallow, irritability and hydrophobia, and his report of having been bitten by a suspected dog raised the hypothesis of rabies. The diagnosis was confirmed by examination of a corneal impression, biological tests in the cerebrospinal fluid (CSF) and saliva and visualization of Negri bodies in nervous tissue (direct immunofluorescence). The patient evolved with agitation, aggressiveness, and worsening tachypnea intercalating with apnea, and died on the 4th day after admission

Frequency of dermatophytes in the metropolitan area of Porto Alegre, RS, Brazil

In order to evaluate the distribution of dermatophytes in Porto Alegre, the capital of the state of Rio Grande do Sul, Brazil, they were isolated from the skin, hairs and nails samples and retrospectively analyzed from June 1981 to June 1995, in two different institutions in the city of Porto Alegre: (i) the Serviço de Micologia do Instituto de Pesquisas Biológicas Jandyr Maya Faillace, da Secretaria de Saúde e Meio Ambiente do Rio Grande do Sul which attends the low income population (low and middle classes) and, (ii) Laboratório Weinmann, a clinical pathology laboratory which attends predominantly the higher income population (middle and upper classes), both which attend in the metropolitan area of Porto Alegre. The dermatophyte predominance of Trichophyton rubrum was confirmed (55.33%) followed by T. mentagrophytes (21.46%). The data obtained were compared with the existing prevalence data which were collected in the interior of the state over a period of 32 years (1960-1992). T. verrucosum, T. simii, Microsporum persicolor, T. schöenleinii, M. nanum and M. cookei were isolated in the interior and have not been found in the capital so far. On the other side, T. violaceum was, isolated in the capital and has not been found in the interior so far.

A COMPARATIVE EPIDEMIOLOGIC STUDY OF SPECIFIC ANTIBODIES (IgM AND IgA) AND PARASITOLOGICAL FINDINGS IN AN ENDEMIC AREA OF LOW TRANSMISSION OF Schistosoma mansoni

The diagnostic potential of circulating IgM and IgA antibodies against Schistosoma mansoni gut-associated antigens detected by the immunofluorescence test (IFT) on adult worm paraffin sections was evaluated comparatively to the fecal parasitological method, for epidemiological purposes in low endemic areas for schistosomiasis. Blood samples were collected on filter paper from two groups of schoolchildren living in two different localities of the municipality of Itariri (São Paulo, Brazil) with different histories and prevalences of schistosomiasis. The parasitological and serological data were compared to those obtained for another group of schoolchildren from a non-endemic area for schistosomiasis. The results showed poor sensitivity of the parasitological method in detecting individuals with low worm burden and indicate the potential of the serological method as an important tool to be incorporated into schistosomiasis control and vigilance programs for determining the real situation of schistosomiasis in low endemic areas.

DETECTION OF IgM ANTIBODIES TO Schistosoma mansoni GUT-ASSOCIATED ANTIGENS FOR THE STUDY OF THE DYNAMICS OF SCHISTOSOMIASIS TRANSMISSION IN AN ENDEMIC AREA WITH LOW WORM BURDEN

For a period of 2 years, five follow-up measures of prevalence and incidence rates were estimated in a prospective study of S. mansoni infection in a group of schoolchildren who were living in a rural area of the Municipality of Itariri (São Paulo, Brazil), where schistosomiasis is transmitted by Biomphalaria tenagophila. Infection was determined by the examination of three Kato-Katz stool slides, and the parasitological findings were analyzed in comparison to serological data. In the five surveys, carried out at 6-month intervals (March-April and September-October), the prevalences were, respectively, 8.6, 6.8, 9.9, 5.8 and 17.2% by the Kato-Katz, and 56.5, 52.6, 60.8, 53.5 and 70.1% by the immunofluorescence test (IFT). Geometric mean egg counts were low: 57.8, 33.0, 35.6, 47.3 and 40.9 eggs per gram of feces, respectively. Of the total of 299 schoolchildren, who submitted five blood samples at 6-month intervals, one for each survey, 40% were IFT-positive throughout the study, and 22% were IFT-negative in all five surveys. Seroconversion from IFT negative to positive, indicating newly acquired S. mansoni infection, was observed more frequently in surveys carried out during March-April (after Summer holidays), than during September-October. Seasonal trends were not statistically significant for detection of S. mansoni eggs in stool. The results indicate that the use of IgM-IFT is superior to parasitological methods for detection of incidence of S. mansoni infection in areas with low worm burden.

Leishmaniasis in the genital area

Two patients from the gold mines of Bolivar State, Venezuela, presenting cutaneous leishmaniasis in the genital region, an unusual location, are described. The first patient showed an ulcerated lesion of the glans penis. Leishmanin skin test was positive. A biopsy specimen revealed a granulomatous infiltrate containing Leishmania parasites. In the second patient, Leishmanin skin test was positive, HIV and VDRL were negative. Leishmania parasites were present in a biopsy of an ulcerated lesion in the scrotum, with an indurated base, infiltrative borders with an yellowish exudate. Patients were treated with meglumine antimoniate and the lesions healed.

Intestinal parasites and commensals among individuals from a landless camping in the rural area of Uberlândia, Minas Gerais, Brazil

We evaluated the occurrence of intestinal parasites and commensals among children and adults from a landless camping in the rural area of Uberlândia, State of Minas Gerais, Brazil, from October to November 2001. Stool samples from 78 individuals were examined by both the Baermann-Moraes and Lutz methods. Fifty-one (65.4%; CI 54.8 - 76.0) individuals were found to be infected, 23 (45.1%) children and 28 (54.9%) adults, of whom 34 (66.7%) were mono-infected, 9 (17.6%) bi-infected, and 8 (15.7%) poly-infected. In conclusion, the high prevalence of intestinal parasites and commensals suggests that parasitological exams should be periodically carried out in addition to the sanitation education and health special care in this population.