Fauna triatominae do estado da Bahia, Brasil: IV - Triatoma Melanocephala Neiva & Pinto, 1923

Triatoma melanocephala - Neiva & Pinto, 1923, espécie rara e de distribuição geográfica restrita, é redescrita no presente trabalho. Exemplares adultos foram coletados em domicílio e adultos e ninfas foram pela primeira vez encontrados em gravatás no ambiente silvestre, infectados pelo Trypanosoma cruzi. A espécie foi criada em laboratório com dificuldades, gastando cerca de 350 dias no mínimo para o desenvolvimento de ovo a adulto; mostrando-se bem susceptível á infecção experimental pelo T. cruzi.

Orientation of the snail Biomphalaria straminea (Dunker, 1848) in response to light in a situation of selection

The behavioral response of Biomphalaria straminea to light was evaluted in terms of location of the snail in a Y-shaped aquarium in a situation of selection and of the rate (cm/hour) and direction of locomotion under homogeneous 9vertical) or differential (horizontal) lighting upon only one arm of the aquarium. The light source consisted of daylight fluorescent lamps with a spectrum close to that of natural light, with illumination varying from 28 to 350 lux. Analysis of the data showed that all animals, whether in groups or isolated, were attracted to light, although the time needed to approach the light source was 50% shorter for the former than for the latter. The rate of locomotion of B. straminea was 35% higher than observed in B. glabrata and 51% higher than that observed in B. tenagophila studied under similar conditions. The results are discussed in terms of social factors and geographical distribution of the three species.

Aspergillus fumigatus fungus ball in hospitalized patients with chronic pulmonary disease: usefulness of double immunodiffusion test as a screening procedure

Double immunodiffusion (DID) was used as a screening test for the diagnosis of aspergillosis. Three hundred and fifty patients were tested, all of them referred from a specialized chest disease hospital and without a definitive etiological diagnosis. When DID was positive addtional information such as clinical history and radiographic findings were requested and also surgical specimens were obtained whenever possible. Specific precipitin hamds for Aspergillus fumigatus antigen were found in 29 (8.3%) of 350 patients sera. Nineteen (65.5%) of the 29 patients with positive serology were recognized as having a fungus ball by X-rays signs in 17 or by pathological examination in 2 or by both in 8 patients. This two-year prospective study has shown that pulmonary aspergillos is a considerable problem among patiens admitted to a Chest Diseases Hospital, especially in those with pulmonary cavities or bronchiectasis.

Ultrastructural studies of the hemocytes of Panstrongylus megistus (Hemiptera: Reduvidae)

Ultrastructural analyses revealed the presence of six hemocyte types in the hemolymph of Panstrogylus megistus, partially confirming our previous results obtained through light microscopy. Prohemocytes: small, round hemocytes with a thin cytoplasm layer, espcieally rich in free ribosomes and poor in membranous systems. Plasmatocytes: polymorphic cells, whose cytoplasm contains many lysosomes and a well developed rough endoplasmic reticulum (RER).They are extremely phagocytic. Sometimes, they show a large vacuolation. Granulocytes: granular hemocytes whose granules show different degrees of electrondensity. Most of them, have an internal structuration. Coagulocytes: oval or elongated hemocytes, which show pronounced perinuclear cisternae as normally observed in coagulocytes. The cytoplasm is usually electrondense, poor in membranous systems and contains many labile granules. Oenocytoids: large and very stable hemocytes, whose homogeneous cytoplasme is rich in loose ribosomes and poor in membranous systems. Adipohemocytes: large cells, containing several characteristic lipid droplets. The cytoplasm is also rich in glycogen, RER and large mitochondria. The total and differential hemocyte count (THC and DHC) were also calculated for this reduviid. THC increases from 2,900 hemocytes/cubic millimeter of hemolymph in the 4th intar to 4,350 in the 5th and then, decreases to 1,950 in the adults. Plasmatocytes and coagulocytes are the predominant hemocyte types.

Influência da temperatura na biologia de triatomíneos: IX. Rhodnius nasutus Stal, 1859 (Hemiptera, Reduviidae)

Estudou-se a influência da temperatura na biologia de Rhodnius nasutus Stal, 1859 (Hemiptera, Reduviidae), tendo em vista a sua criação em grande escala, em laboratório, para serem utilizados no xenodiagnóstico e fornecer informações que subsidien as ações de controle. Os experimentos realizaram-se em duas câmaras climatizadas, a 25 ± 0,5ºC e 3º ± 1ºC, com umidade relativa de 70 ± 5% e fotoperíodo de 12 horas. Apresentam-se os dados relativos ao ciclo evolutivo, pré-postura, fecundidade, fertilidade, sobrevivência ao jejum e quantidade de sangue ingerido. A duração média do ciclo evolutivo foi de 145,7 dias a 25ºC e de 114,2 dias, a 30ºC. A quantidade de sangue ingerido para completar o ciclo evolutivo foi de 304,3mg e 350,3 mg, a 25º e 30ºC, respectivamente. A sobrevivência ao jejum absoluto foi significativamente maior a 25º do que a 30ºC, ao nível de 1%.

Nectomys squamipes (Rodentia: Cricetidae) as an experimental model for schistosomiasis mansoni

Twenty specimens of Nectomys squamipes born in captivity, were infected with 500 cercariae by the transcutaneous route. Coprologic examinations were carried out from the 5th to 23rd week after infection. On the 7th, 8th, 12th, 16th, and 23rd weeks the animals were sacrificed and perfused. The oogram was performed in segments of the small intestine (proximal, medial and distal portions) and the large intestine. The average pre-patent period was of 42 days. The average number of eggs varied from 350 on 6th week, to 800 on the 13th. From the 14th week on, the average number of eggs eliminated was lower than 50 per gram of feces. The recovery of worms kept steady on the 7th, 8th, and 12th week (16.85%; 15.45% and 11.95%), decreasing to 7.70% on the 16th week and 8.45% on the 23rd week. The proportion of male/female worms was about the same on the first two weeks, but from the 12th week on, the proportion was: 1,4/1 on the 12th week; 2,5/1 on the 16thweek and 1,8/1 on the 23rd weekThese observations suggest that N. squamipes may used as an experimental model for schistosomiasis mansoni, to wich it develops resistance mechanism, useful for immunity studies.

Dynamics of evolution and resistance to starvation of Triatoma vitticeps (Stal 1859) (Reduviidae: Triatominae), submitted to two different regimens of food deprivation

The resistance to starvation of Triatoma vitticeps has been analyzed comparatively, according to different regimens of food deprivation under laboratory conditions. One cohort, composed of 100 specimens of each evolutionary nymphal stage, was submitted to continuous fasting until death; the second group, arranged in the same way, was fed once on chicken. Through this work, it was possible not only to compare the results obtained from the first group with other authors' results but, also, to analyze the dynamics of evolution, molting, longevity and the increase in insect longevity, in the second group. The average values recorded for survival time revealed statistical differences between the two groups. Among the important results detected, there is one that deserves to be emphasized: the incredible increase in longevity among insects that received only one feed - an average increase in survival time that reached 2.95 to 3.30 times in nymphs of 3rd and 4th stages, respectively. One 5th stage nymph survived for up to 350 days and the females may triplicate their survival rate, what represents an important epidemiological factor. The knowledge about this type of biological characteristic of T. vitticeps may contribute to prevent the domiciliation of this species, what seems to be incipient in some municipal districts, in Brazil.

A Multiplex-PCR approach to identification of the Brazilian intermediate hosts of Schistosoma mansoni

Due to difficulties concerning morphological identification of planorbid snails of the genus Biomphalaria, and given a high variation of characters and in the organs with muscular tissue, we designed specific polymerase chain reaction (PCR) primers for Brazilian snail hosts of Schistosoma mansoni from available sequences of internal transcribed spacer 2 (ITS2) of the ribosomal RNA gene. From the previous sequencing of the ITS2 region, one primer was designed to anchor in the 5.8S conserved region and three other species-specific primers in the 28S region, flanking the ITS2 region. These four primers were simultaneously used in the same reaction (Multiplex-PCR), under high stringency conditions. Amplification of the ITS2 region of Biomphalaria snails produced distinct profiles (between 280 and 350 bp) for B. glabrata, B. tenagophila and B. straminea. The present study demonstrates that Multiplex-PCR of ITS2-DNAr showed to be a promising auxiliary tool for the morphological identification of Biomphalaria snails, the intermediate hosts of S. mansoni.

Dominant character of the molecular marker of a Biomphalaria tenagophila strain (Mollusca: Planorbidae) resistant to Schistosoma mansoni

Biomphalaria tenagophila population from Taim (state of Rio Grande do Sul, Brazil) is totally resistant toSchistosoma mansoni, and presents a molecular marker of 350 bp by polymerase chain reaction and restriction fragment length polymorphism of the entire rDNA internal transcriber spacer. The scope of this work was to determine the heritage pattern of this marker. A series of cross-breedings between B. tenagophila from Taim (resistant) and B. tenagophila from Joinville, state of Santa Catarina (susceptible) was carried out, and their descendants F1 and F2 were submitted to this technique. It was possible to demonstrate that the specific fragment from Taim is endowed with dominant character, since the obtained segregation was typically mendelian.

Trypanosoma cruzi isolates from Mexican and Guatemalan acute and chronic chagasic cardiopathy patients belong to Trypanosoma cruzi I

Trypanosoma cruzi is classified into two major groups named T. cruzi I and T. cruzi II. In the present work we analyzed 16 stocks isolated from human cases and four isolated from triatomines from diverse geographical origins (Mexico and Guatemala). From human cases four were acute cases, six indeterminates, and six from chronic chagasic cardiophatic patients with diagnosis of dilated cardiomyopathy established based on the left-ventricular end systolic dimension and cardiothoracic ratio on chest X-radiography and impaired contracting ventricle and different degree conduction/rhythm aberrations. DNA samples were analyzed based on mini-exon (ME) polymorphism, using a pool of three oligonucleotide for the amplification of specific intergenic region of T. cruzi ME gene. All the Mexican and Guatemalan isolates regardless their host or vector origin generated a 350 bp amplification product. In conclusion T. cruzi I is dominant in Mexico and Guatemala even in acute and chronic chagasic cardiopathy patients. To our knowledge, this is the first study describing predominance of T. cruzi I in human infection for North and Central America.

Dispersal and survival of Nyssomyia intermedia and Nyssomyia neivai (Diptera: Psychodidae: Phlebotominae) in a cutaneous leishmaniasis endemic area of the speleological province of the Ribeira Valley, state of São Paulo, Brazil

The dispersal and survival of the phlebotomines Nyssomyia intermedia and Nyssomyia neivai (both implicated as vectors of the cutaneous leishmaniasis agent) in an endemic area was investigated using a capture-mark-release technique in five experiments from August-December 2003 in municipality of Iporanga, state of São Paulo, Brazil. A total of 1,749 males and 1,262 females of Ny. intermedia and 915 males and 411 females of Ny. neivai were marked and released during the five experiments. Recapture attempts were made using automatic light traps, aspiration in natural resting places and domestic animal shelters and Shannon traps. A total of 153 specimens (3.48%) were recaptured: 2.59% (78/3,011) for Ny. intermedia and 5.35% (71/1,326) for Ny. neivai. Both species were recaptured up to 144 h post-release, with the larger part of them recaptured within 48 h. The median dispersion distances for Ny. intermedia and Ny. neivai, respectively, were 109 m and 100 m. The greatest dispersal range of Ny. intermedia was 180 m, while for Ny. neivai one female was recaptured in a pasture at 250 m and another in a pigsty at 520 m, showing a tendency to disperse to more open areas. The daily survival rates calculated based on regressions of the numbers of marked insects recaptured on the six successive days after release were 0.746 for males and 0.575 for females of Ny. intermedia and 0.649 for both sexes of Ny. neivai. The size of the populations in the five months ranged from 8,332-725,085 for Ny. intermedia males, 2,193-104,490 for Ny. intermedia females, 1,687-350,122 for Ny. neivai males and 254-49,705 for Ny. neivai females.

Distribution and habitat preferences of the genus Biomphalaria (Gastropoda: Planorbidae) in Cuba

A study was carried out to determine the distribution and habitat preferences of several species of the genus Biomphalaria. Samples were taken at 350 freshwater locations in Cuba. Three species of Biomphalaria (Biomphalaria havanensis, Biomphalaria helophila and Biomphalaria pallida) were recorded based on their distribution. Of the three species, B. havanensis has the weakest distribution because it was identified in only one locality. The other species, B. helophila and B. pallida, are abundant in rivers and dams and have large populations in Cuba. However, the only species that appears to occur in ecosystems shared with thiarids is B. pallida, possibly due to recent introduction of thiarids, but always in fewer numbers. Here we discuss the possibility of these species to act as intermediary hosts of Schistosoma mansoni in Cuba over the basis of occurrence in natural and anthropic habitats.

Molecular characterisation of hepatitis B virus in the resident Chinese population in Panama City

Despite the effectiveness of current hepatitis B virus (HBV) vaccines, it is estimated that 350 million individuals suffer from chronic HBV infection and more than 50% of these affected individuals live on the Asian continent. Panama is a country with a great diversity of foreign groups; the Chinese community is a large example of this phenomenon. There is an urgent need to perform studies that evaluate the prevalence and the genetic diversity of HBV in this community. This study aimed to evaluate the prevalence of HBV and its genotypes and mutant variants in the Chinese population residing in Panama. In total, 320 subjects were enrolled in the study. Forty-two subjects (13.1%) were positive for HBsAg and HBV-DNA from 18 subjects revealed the presence of genotypes B2 and C1. Secondary mutations associated with drug resistance at positions rtV207L and rtN239T of the reverse transcriptase gene were identified. Additionally, the mutation pair A1762T/G1764A was found in three samples and the mutation G1896A was detected in an HBeAg-negative subject. In conclusion, to our knowledge, this is the first study to report high HBV prevalence rates in resident ethnic Chinese in Central America and the presence of genotypes B2 and C1 in this region.

Efficacy of entecavir and tenofovir in chronic hepatitis B under treatment in the public health system in southern Brazil

There are about 350 million hepatitis B virus (HBV) carriers worldwide and chronic HBV is considered a major public health problem. The objective of the present study was to assess the effectiveness of the nucleos(t)ide analogues tenofovir (TDF) and entecavir (ETV) in the treatment of chronic HBV. A cross-sectional study was carried out from March-December 2013, including all patients with chronic HBV, over 18 years of age, undergoing therapy through the public health system in southern Brazil. Only the data relating to the first treatments performed with TDF or ETV were considered. Retreatment, co-infection, transplanted or immunosuppressed patients were excluded. Six hundred and forty patients were evaluated, of which 336 (52.5%) received TDF and 165 (25.8%) ETV. The other 139 (21.7%) used various combinations of nucleos(t)ide analogues and were excluded. The negativation of viral load was observed in 87.3% and 78.8% and the negativation of hepatitis B e antigen was achieved in 79% and 72% of those treated with ETV or TDF, respectively. Negativation of hepatitis B surface antigen was not observed. There was no occurrence of adverse effects. This is a real-life study demonstrating that long-term treatment with ETV and TDF is both safe and effective.

Avaliação cognitiva de pessoas idosas cadastradas na estratégia saúde da família: município do Sul de Minas

Avaliar a cognição de pessoas idosas. Estudo descritivo, quantitativo, transversal. Amostra de 350 pessoas, com idade > 60 anos. Instrumentos: Questionário sociodemográfico e de saúde e MEEM. A amostra tinha 60,0% de mulheres, idade média 70,3 anos, 54,0% cursaram ensino fundamental incompleto, 61,1% casados e renda média de 1,54 SM. Foram 38,6% os que percebiam o estado atual de saúde como regular; 49,4% o consideravam igual ao do último ano, 37,4% acreditavam estar melhor do que pessoas da mesma idade. MEEM: nos 76 sem escolaridade encontrou-se 5,3% com declínio cognitivo, nos 265 com baixa e média escolaridade 4,9%, nos de nível superior (9) não se encontrou. As menores médias encontradas foram nos domínios memória e atenção. 4,9% (17) dos idosos podem estar desenvolvendo déficit cognitivo.