Schistosomiasis risk mapping in the state of Minas Gerais, Brazil, using a decision tree approach, remote sensing data and sociological indicators

Schistosomiasis mansoni is not just a physical disease, but is related to social and behavioural factors as well. Snails of the Biomphalaria genus are an intermediate host for Schistosoma mansoni and infect humans through water. The objective of this study is to classify the risk of schistosomiasis in the state of Minas Gerais (MG). We focus on socioeconomic and demographic features, basic sanitation features, the presence of accumulated water bodies, dense vegetation in the summer and winter seasons and related terrain characteristics. We draw on the decision tree approach to infection risk modelling and mapping. The model robustness was properly verified. The main variables that were selected by the procedure included the terrain's water accumulation capacity, temperature extremes and the Human Development Index. In addition, the model was used to generate two maps, one that included risk classification for the entire of MG and another that included classification errors. The resulting map was 62.9% accurate.

Current epidemiological status of schistosomiasis in the state of Pernambuco, Brazil

Uncontrolled peripheral urbanisation coupled with environmental degradation has affected the status of schistosomiasis in Pernambuco (PE), Brazil. This endemic disease continues to perpetuate its transmission in rural areas and has also become a cause for concern in coastal towns of the state. The lack of basic infrastructure (sanitation and health programmes) to support the new urban areas leads to faecal contamination of natural aquatic environments, resulting in consequent infection of vector snails and the emergence of new sources of schistosomiasis transmission. In the present paper, we discuss the current epidemiological status of schistosomiasis in PE. We have consolidated and analysed information from parasitological, malacological and morbidity surveys undertaken by the group of researchers at the Laboratory of Schistosomiasis, Centro de Pesquisas Aggeu Magalhães-Fiocruz. The results of our analysis show: (i) the maintenance of the levels of schistosomiasis in the rural Zona da Mata, PE, (ii) the record of the human cases of schistosomiasis and the foci of infected snails detected along the coast of PE through 2007, (iii) the high record of the severe clinical form of schistosomiasis in the metropolitan region of Recife (RMR) and (iv) new breeding sites of schistosomiasis vector snails that were identified in a 2008 survey covering the RMR and the coastal localities of PE.

Feeding behavior of Triatoma vitticeps (Reduviidae: Triatominae) in the state of Minas Gerais, Brazil

The objective of this study was to evaluate the feeding behavior of Triatoma vitticeps through the identification of its food sources and the characterization of the blood ingestion process. In addition, we aimed to verify if the saliva of this vector interferes with the perception of the host during the feedings by creating a nervous impulse. Here, we demonstrated that the T. vitticeps saliva reduces, gradually and irreversibly, the amplitude of the compound action potential of the nervous fibre, which helps decrease the perception of the insect by the host. The precipitin reaction demonstrated the feeding eclecticism of this vector, with the identification of eight food sources - most of them found simultaneously in the same insect. The analysis of the electrical signals produced by the cibarial pump during meals demonstrated that the best feeding performance of T. vitticeps nymphs that fed on pigeons is mainly due to the higher contraction frequency of the pump. The longer contact period with the host to obtain a complete meal compared with other triatominae species of the same instar could favor the occurrence of multiple blood sources in T. vitticeps under natural conditions, as it was evidenced by the precipitin test.

Evaluation of two coproscopic techniques for the diagnosis of schistosomiasis in a low-transmission area in the state of Minas Gerais, Brazil

This population study, which evaluated two parasitological methods for the diagnosis of schistosomiasis mansoni, was performed in a low-transmission area in Pedra Preta, Montes Claros, Minas Gerais, Brazil. A total of 201 inhabitants of the rural area participated in this research. Four stool samples were obtained from all participants and analysed using the Kato-Katz method (18 slides) and a commercial test, the TF-Test®, which was performed quantitatively. The data were analysed to determine prevalence, the sensitivity of the diagnostic methods, the worm burden and the definition of the "gold standard", which was obtained by totalling the results of all samples examined using the Kato-Katz technique and the TF-Test®. The results showed that the prevalence obtained from the examination of one Kato-Katz slide (the methodology adopted by the Brazilian control programme) was 8% compared to 35.8% from the "gold standard", which was a 4.5-fold difference. This result indicates that the prevalence of schistosomiasis in so-called low-transmission areas is significantly underestimated.

Spotted fever group Rickettsia infecting ticks (Acari: Ixodidae) in the state of Santa Catarina, Brazil

During 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of Santa Catarina (SC), Brazil, including areas where human cases of Brazilian spotted fever have been reported. Collected ticks belonging to nine species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma ovale, Amblyomma tigrinum, Dermacentor nitens, Rhipicephalus microplus and Rhipicephalus sanguineus) were tested by polymerase chain reaction (PCR) for rickettsial infection. Overall, eight (3.1%) ticks were found to be infected with Rickettsia species. After sequencing the PCR products, we determined that the sequences generated from three A. aureolatum, one A. ovale and one R. sanguineus from the municipality of Blumenau, one A. ovale from the municipality of Águas Mornas and one A. ovale from the municipality of Urussanga were identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia parkeri strain Atlantic rainforest. The sequence generated from one A. longirostre from Blumenau was 100% identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia amblyommii strain AL. Because R. parkeri strain Atlantic rainforest was recently shown to have caused two cases of human spotted fever in other states of Brazil, the role of this rickettsial agent as a possible etiological agent of spotted fever in SC is discussed.

Biological, biochemical and molecular features of Trypanosoma cruzi strains isolated from patients infected through oral transmission during a 2005 outbreak in the state of Santa Catarina, Brazil: its correspondence with the new T. cruzi Taxonomy Consensus (2009)

We examined strains of Trypanosoma cruzi isolated from patients with acute Chagas disease that had been acquired by oral transmission in the state of Santa Catarina, Brazil (2005) and two isolates that had been obtained from a marsupial (Didelphis aurita) and a vector (Triatoma tibiamaculata). These strains were characterised through their biological behaviour and isoenzymic profiles and genotyped according to the new Taxonomy Consensus (2009) based on the discrete typing unities, that is, T. cruzi genotypes I-VI. All strains exhibited the biological behaviour of biodeme type II. In six isolates, late peaks of parasitaemia, beyond the 20th day, suggested a double infection with biodemes II + III. Isoenzymes revealed Z2 or mixed Z1 and Z2 profiles. Genotyping was performed using three polymorphic genes (cytochrome oxidase II, spliced leader intergenic region and 24Sα rRNA) and the restriction fragment length polymorphism of the kDNA minicircles. Based on these markers, all but four isolates were characterised as T. cruzi II genotypes. Four mixed populations were identified: SC90, SC93 and SC97 (T. cruzi I + T. cruzi II) and SC95 (T. cruzi I + T. cruzi VI). Comparison of the results obtained by different methods was essential for the correct identification of the mixed populations and major lineages involved indicating that characterisation by different methods can provide new insights into the relationship between phenotypic and genotypic aspects of parasite behaviour.

Serological evidence of hantavirus infection in rural and urban regions in the state of Amazonas, Brazil

Hantavirus disease is caused by the hantavirus, which is an RNA virus belonging to the family Bunyaviridae. Hantavirus disease is an anthropozoonotic infection transmitted through the inhalation of aerosols from the excreta of hantavirus-infected rodents. In the county of Itacoatiara in the state of Amazonas (AM), Brazil, the first human cases of hantavirus pulmonary and cardiovascular syndrome were described in July 2004. These first cases were followed by two fatal cases, one in the municipality of Maués in 2005 and another in Itacoatiara in 2007. In this study, we investigated the antibody levels to hantavirus in a population of 1,731 individuals from four different counties of AM. Sera were tested by IgG/IgM- enzyme-linked immune-sorbent assay using a recombinant nucleocapsid protein of the Araraquara hantavirus as an antigen. Ten sera were IgG positive to hantavirus (0.6%). Among the positive sera, 0.8% (1/122), 0.4% (1/256), 0.2% (1/556) and 0.9% (7/797) were from Atalaia do Norte, Careiro Castanho, Itacoatiara and Lábrea, respectively. None of the sera in this survey were IgM-positive. Because these counties are distributed in different areas of AM, we can assume that infected individuals are found throughout the entire state, which suggests that hantavirus disease could be a local emerging health problem.

Assessment of the treatment of chronic hepatitis C in the state of Mato Grosso, central Brazil

In Brazil, the treatment of hepatitis C virus (HCV) infection is funded by the national public health system (SUS). To evaluate treatment results in the state of Mato Grosso, central Brazil, we have consulted the files of the office of the State Department of Health responsible for supplying such medications. We obtained information on 232 treatments of 201 patients who underwent treatment in or prior to 2008. The study was conducted by reviewing medical records, making telephone calls and interviewing the assistant physicians. Thirty-nine patients (19.4%) had cirrhosis and HCV genotype 1 predominated (64.3%). Excluding patients with comorbidities or treatment without ribavirin we analysed 175 treatments (sustained virologic response occurred in 32.6% of cases). Twenty-six of these 175 were retreatments and the sustained virological response (SVR) rate among them was 30.8%; the SVR rate was 32.9% among those receiving treatment for the first time. The SVR rate of genotype 1 patients was 27.8%, whereas it was 37.5% in non-1 genotype patients. The adjusted multivariate analysis showed association of SVR with the absence of cirrhosis [odds ratio (OR): 7.7; confidence interval (CI) 95%: 2.5, 33.3], the use of pegylated interferon (OR: 5.8; CI 95%: 1.5, 21.4), non-1 genotype (OR: 5.3; CI 95%: 1.7, 16.7) and uninterrupted treatment (OR: 9.0; CI 95%: 3.3, 45.4). The SVR rates were similar to those found in other Brazilian studies about HCV, but lower than those found in national and international clinical trials. These data suggest that the treatments of chronic hepatitis C that are made available by SUS does not, under normal conditions, work as well as the original controlled studies indicated.

Coccidioidomycosis in armadillo hunters from the state of Ceará, Brazil

Coccidioidomycosis is a systemic mycosis with a variable clinical presentation. Misdiagnosis of coccidioidomycosis as bacterial pneumopathy leads to inappropriate prescription of antibiotics and delayed diagnosis. This report describes an outbreak among armadillo hunters in northeastern Brazil in which an initial diagnosis of bacterial pneumonia was later confirmed as coccidioidomycosis caused by Coccidioides posadasii. Thus, this mycosis should be considered as an alternative diagnosis in patients reporting symptoms of pneumonia, even if these symptoms are only presented for a short period, who are from areas considered endemic for this disease.

Triatoma jatai sp. nov. in the state of Tocantins, Brazil (Hemiptera: Reduviidae: Triatominae)

Triatoma jatai sp. nov. is the first new species of triatomine to be described in the state of Tocantins, in the northern region of Brazil. It was caught on rock outcrops in the wild environment and, more recently, invading homes. While T. jatai sp. nov. is morphologically similar to Triatoma costalimai, it is distinguished by its general colouring, differences in the blotches on the connexivum, wing size in females and external structures of the male genitalia. The type series has been deposited in the Entomological Collection and Herman Lent Collection, Oswaldo Cruz Institute-Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.

Nontuberculous mycobacteria in respiratory samples from patients with pulmonary tuberculosis in the state of Rondonia, Brazil

The main cause of pulmonary tuberculosis (TB) is infection with Mycobacterium tuberculosis (MTB). We aimed to evaluate the contribution of nontuberculous mycobacteria (NTM) to pulmonary disease in patients from the state of Rondônia using respiratory samples and epidemiological data from TB cases. Mycobacterium isolates were identified using a combination of conventional tests, polymerase chain reaction-based restriction enzyme analysis of hsp65 gene and hsp65 gene sequencing. Among the 1,812 cases suspected of having pulmonary TB, 444 yielded bacterial cultures, including 369 cases positive for MTB and 75 cases positive for NTM. Within the latter group, 14 species were identified as Mycobacterium abscessus, Mycobacterium avium, Mycobacterium fortuitum, Mycobacterium intracellulare, Mycobacterium gilvum, Mycobacterium gordonae, Mycobacterium asiaticum, Mycobacterium tusciae, Mycobacterium porcinum, Mycobacterium novocastrense, Mycobacterium simiae, Mycobacterium szulgai, Mycobacterium phlei and Mycobacterium holsaticum and 13 isolates could not be identified at the species level. The majority of NTM cases were observed in Porto Velho and the relative frequency of NTM compared with MTB was highest in Ji-Paraná. In approximately half of the TB subjects with NTM, a second sample containing NTM was obtained, confirming this as the disease-causing agent. The most frequently observed NTM species were M. abscessus and M. avium and because the former species is resistant to many antibiotics and displays unsatisfactory cure rates, the implementation of rapid identification of mycobacterium species is of considerable importance.

Perimicrovillar membrane assembly: the fate of phospholipids synthesised by the midgut of Rhodnius prolixus

In this study, we describe the fate of fatty acids that are incorporated from the lumen by the posterior midgut epithelium of Rhodnius prolixus and the biosynthesis of lipids. We also demonstrate that neutral lipids (NL) are transferred to the haemolymphatic lipophorin (Lp) and that phospholipids remain in the tissue in which they are organised into perimicrovillar membranes (PMMs). 3H-palmitic acid added at the luminal side of isolated midguts of R. prolixus females was readily absorbed and was used to synthesise phospholipids (80%) and NL (20%). The highest incorporation of 3H-palmitic acid was on the first day after a blood meal. The amounts of diacylglycerol (DG) and triacylglycerol synthesised by the tissue decreased in the presence of Lp in the incubation medium. The metabolic fates of 3H-lipids synthesised by the posterior midgut were followed and it was observed that DG was the major lipid released to Lp particles. However, the majority of phospholipids were not transferred to Lp, but remained in the tissue. The phospholipids that were synthesised and accumulated in the posterior midgut were found to be associated with Rhodnius luminal contents as structural components of PMMs.

Polycystic echinococcosis in the state of Acre, Brazil: contribution to patient diagnosis, treatment and prognosis

The lack of knowledge regarding polycystic hydatid disease results in delayed or even incorrect diagnosis. The lack of systematic information regarding treatment also makes it difficult to assess the results and prognosis in patients with peritoneal and hepatic lesions caused by Echinococcus vogeli. Here we describe the clinical features of patients, propose a radiological classification protocol and describe a therapeutic option for the treatment of hydatid disease that previously had only been used for cases of cystic echinococcosis (Echinococcus granulosus). A prospective cohort study was initiated in 1999 and by 2009 the study included 60 patients. These patients were classified according to the PNM classification (parasite lesion, neighbouring organ invasion and metastases) and placed in one of three therapeutic modalities: (i) chemotherapy with albendazole at a dose of 10 mg/kg/day, (ii) surgical removal of cysts or (iii) percutaneous puncture of the cysts via puncture, aspiration, injection and re-aspiration (PAIR). The results were stratified according to therapeutic outcome: "cure", "clinical improvement", "no improvement", "death" or "no information". The PNM classification was useful in indicating the appropriate therapy in cases of polycystic hydatid disease. In conclusion, surgical therapy produced the best clinical results of all the therapies studied based on "cure" and "clinical improvement" outcomes. The use of PAIR for treatment requires additional study.

Diversity and distribution of sandflies (Diptera: Psychodidae: Phlebotominae) in a military area in the state of Amazonas, Brazil

This study reports the distribution, ecotopes and fauna diversity of sandflies captured in five training bases on a military reserve in Manaus, state of Amazonas (AM). A total of 10,762 specimens were collected, which were distributed among 58 species, with the highest number recorded at Base Instruction 1 (BI1). A higher rate of species richness was found at the Base Instruction Boina Rajada and low levels of diversity associated with a high abundance index with the clear dominance of Lutzomyia umbratilis, Lutzomyia ruii and Lutzomyia anduzei were found at BI1. The abundance of Lu. umbratilis raises the possibility of outbreaks of American cutaneous leishmaniasis by the main vector of the disease in AM.

Molecular identification of Sporothrix species involved in the first familial outbreak of sporotrichosis in the state of Espírito Santo, southeastern Brazil

Sporotrichosis is a widespread subcutaneous mycosis caused by the dimorphic fungi now known as the Sporothrix schenckii complex. This complex is comprised of at least six species, including Sporothrix albicans, Sporothrix brasiliensis, Sporothrix globosa, Sporothrix luriei, Sporothrix mexicana and S. schenckii. Cases of sporotrichosis have significantly increased in Brazil over the past decade, especially in the state of Rio de Janeiro (RJ), where an epidemic among cat owners has been observed. The zoonotic transmission from cats to humans suggests a common source of infection and indicates that animals can act as vectors. We performed a molecular characterisation of samples collected during the first outbreak of familial sporotrichosis caused by S. brasiliensis in the state of Espírito Santo, Brazil. These results represent the first description of such an outbreak outside the endemic area of zoonotic sporotrichosis in RJ.