Arboviral diseases in the Western Brazilian Amazon: a perspective and analysis from a tertiary health & research center in Manaus, State of Amazonas

The Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), located in Manaus, the capital of the State of Amazonas (Western Brazilian Amazon), is a pioneering institution in this region regarding the syndromic surveillance of acute febrile illness, including arboviral infections. Based on the data from patients at the FMT-HVD, we have detected recurrent outbreaks in Manaus by the four dengue serotypes in the past 15 years, with increasing severity of the disease. This endemicity has culminated in the simultaneous circulation of all four serotypes in 2011, the first time this has been reported in Brazil. Between 1996 and 2009, 42 cases of yellow fever (YF) were registered in the State of Amazonas, and 71.4% (30/42) were fatal. Since 2010, no cases have been reported. Because the introduction of the yellow fever virus into a large city such as Manaus, which is widely infested by Aedes mosquitoes, may pose a real risk of a yellow fever outbreak, efforts to maintain an appropriate immunization policy for the populace are critical. Manaus has also suffered silent outbreaks of Mayaro and Oropouche fevers lately, most of which were misdiagnosed as dengue fever. The tropical conditions of the State of Amazonas favor the existence of other arboviruses capable of producing human disease. Under this real threat, represented by at least 4 arboviruses producing human infections in Manaus and in other neighboring countries, it is important to develop an efficient public health surveillance strategy, including laboratories that are able to make proper diagnoses of arboviruses.

Quality perception in research laboratories from Fiocruz after QMS implementation

Quality Management System has been implemented at the René Rachou Research Center since 2003. This study investigated its importance for collaborators (Cs) in laboratories. This was a quantitative and descriptive study performed in a group of 113 collaborators. It was based on the World Health Organization handbook: Quality Practices in Basic Biomedical Research. The questionnaires evaluated the parameters using the Likert scale. Biosafety, training and ethics were considered to be the most important parameters. Supervision and quality assurance, data recording, study plan, SOPs and file storage achieved intermediate evaluation. The lower frequency of responses was obtained for result report, result verification, personnel and publishing practices. Understanding the perception of the collaborators allows the development of improvement actions aiming the construction of a training program directing strategies for disseminating quality.

Heart rate variability under resting conditions in postmenopausal and young women

The aim of the present study was to compare the modulation of heart rate in a group of postmenopausal women to that of a group of young women under resting conditions on the basis of R-R interval variability. Ten healthy postmenopausal women (mean ± SD, 58.3 ± 6.8 years) and 10 healthy young women (mean ± SD, 21.6 ± 0.82 years) were submitted to a control resting electrocardiogram (ECG) in the supine and sitting positions over a period of 6 min. The ECG was obtained from a one-channel heart monitor at the CM5 lead and processed and stored using an analog to digital converter connected to a microcomputer. R-R intervals were calculated on a beat-to-beat basis from the ECG recording in real time using a signal-processing software. Heart rate variability (HRV) was expressed as standard deviation (RMSM) and mean square root (RMSSD). In the supine position, the postmenopausal group showed significantly lower (P<0.05) median values of RMSM (34.9) and RMSSD (22.32) than the young group (RMSM: 62.11 and RMSSD: 49.1). The same occurred in the sitting position (RMSM: 33.0 and RMSSD: 18.9 compared to RMSM: 57.6 and RMSSD: 42.8 for the young group). These results indicate a decrease in parasympathetic modulation in postmenopausal women compared to young women which was possibly due both to the influence of age and hormonal factors. Thus, time domain HRV proved to be a noninvasive and sensitive method for the identification of changes in autonomic modulation of the sinus node in postmenopausal women.

Computerized invasive measurement of time-dependent intraocular pressure

Several methods have been described to measure intraocular pressure (IOP) in clinical and research situations. However, the measurement of time varying IOP with high accuracy, mainly in situations that alter corneal properties, has not been reported until now. The present report describes a computerized system capable of recording the transitory variability of IOP, which is sufficiently sensitive to reliably measure ocular pulse peak-to-peak values. We also describe its characteristics and discuss its applicability to research and clinical studies. The device consists of a pressure transducer, a signal conditioning unit and an analog-to-digital converter coupled to a video acquisition board. A modified Cairns trabeculectomy was performed in 9 Oryctolagus cuniculus rabbits to obtain changes in IOP decay parameters and to evaluate the utility and sensitivity of the recording system. The device was effective for the study of kinetic parameters of IOP, such as decay pattern and ocular pulse waves due to cardiac and respiratory cycle rhythm. In addition, there was a significant increase of IOP versus time curve derivative when pre- and post-trabeculectomy recordings were compared. The present procedure excludes corneal thickness and error related to individual operator ability. Clinical complications due to saline infusion and pressure overload were not observed during biomicroscopic evaluation. Among the disadvantages of the procedure are the requirement of anesthesia and the use in acute recordings rather than chronic protocols. Finally, the method described may provide a reliable alternative for the study of ocular pressure dynamic alterations in man and may facilitate the investigation of the pathogenesis of glaucoma.

Statistical analysis of event-related potential elicited by verb-complement merge in Brazilian Portuguese

An interesting fact about language cognition is that stimulation involving incongruence in the merge operation between verb and complement has often been related to a negative event-related potential (ERP) of augmented amplitude and latency of ca. 400 ms - the N400. Using an automatic ERP latency and amplitude estimator to facilitate the recognition of waves with a low signal-to-noise ratio, the objective of the present study was to study the N400 statistically in 24 volunteers. Stimulation consisted of 80 experimental sentences (40 congruous and 40 incongruous), generated in Brazilian Portuguese, involving two distinct local verb-argument combinations (nominal object and pronominal object series). For each volunteer, the EEG was simultaneously acquired at 20 derivations, topographically localized according to the 10-20 International System. A computerized routine for automatic N400-peak marking (based on the ascendant zero-cross of the first waveform derivative) was applied to the estimated individual ERP waveform for congruous and incongruous sentences in both series for all ERP topographic derivations. Peak-to-peak N400 amplitude was significantly augmented (P < 0.05; one-sided Wilcoxon signed-rank test) due to incongruence in derivations F3, T3, C3, Cz, T5, P3, Pz, and P4 for nominal object series and in P3, Pz and P4 for pronominal object series. The results also indicated high inter-individual variability in ERP waveforms, suggesting that the usual procedure of grand averaging might not be considered a generally adequate approach. Hence, signal processing statistical techniques should be applied in neurolinguistic ERP studies allowing waveform analysis with low signal-to-noise ratio.

Comparison of the Polar S810i monitor and the ECG for the analysis of heart rate variability in the time and frequency domains

The aim of the present study was to compare heart rate variability (HRV) at rest and during exercise using a temporal series obtained with the Polar S810i monitor and a signal from a LYNX® signal conditioner (BIO EMG 1000 model) with a channel configured for the acquisition of ECG signals. Fifteen healthy subjects aged 20.9 ± 1.4 years were analyzed. The subjects remained at rest for 20 min and performed exercise for another 20 min with the workload selected to achieve 60% of submaximal heart rate. RR series were obtained for each individual with a Polar S810i instrument and with an ECG analyzed with a biological signal conditioner. The HRV indices (rMSSD, pNN50, LFnu, HFnu, and LF/HF) were calculated after signal processing and analysis. The unpaired Student t-test and intraclass correlation coefficient were used for data analysis. No statistically significant differences were observed when comparing the values analyzed by means of the two devices for HRV at rest and during exercise. The intraclass correlation coefficient demonstrated satisfactory correlation between the values obtained by the devices at rest (pNN50 = 0.994; rMSSD = 0.995; LFnu = 0.978; HFnu = 0.978; LF/HF = 0.982) and during exercise (pNN50 = 0.869; rMSSD = 0.929; LFnu = 0.973; HFnu = 0.973; LF/HF = 0.942). The calculation of HRV values by means of temporal series obtained from the Polar S810i instrument appears to be as reliable as those obtained by processing the ECG signal captured with a signal conditioner.

A municipal level approach to the management of schistosomiasis control in Peri-Peri, MG, Brazil

A schistosomiasis control program was implemented between 1974/87 in Peri-Peri,. MG (622 inhabitants). Molluscicide (niclosamide) was applied at three monthly intervals in water sources with Biomphalaria glabrata, and individuals eliminating Schistosoma mansoni eggs in the feces were treated annually with oxamniquine. From 1974 to 1983 the control measures were undertaken by staff of the "René Rachou" Research Center FIOCRUZ (CPqRR), and from 1984 to 1987 these measures were included in the Capim Branco basic health network activities. During both periods, the prevalence, incidence, intensity of infection and hepatosplenic form as well as the number of infected snails decreased significantly. The prevalence decreased from 43.5 to 4.4%, the incidence from 19.0 to 2.9%, the overall intensity of S. mansoni from 281 to 87 and of the hepatosplenic form from 5.9 to 0.0%. The results obtained suggest that the municipal management of control measures was as effective as the vertical program conducted by CPqRR staff.

Diagnosis of hantavirus infection in humans and rodents in Ribeirão Preto, State of São Paulo, Brazil

INTRODUCTION: Hantavirus pulmonary and cardiovascular syndrome (HPCS) is an emerging serious disease in the Americas. Hantaviruses (Bunyaviridae) are the causative agents of this syndrome and are mainly transmitted through inhalation of aerosols containing the excreta of wild rodents. In the Ribeirão Preto region (state of São Paulo, Brazil), HPCS has been reported since 1998, caused by the Araraquara virus (ARAV), for which Necromys lasiurus is the rodent reservoir. This study aimed to show diagnostic results relating to infection in humans and rodents, obtained at the Virology Research Center of the Ribeirão Preto School of Medicine, University of São Paulo, between 2005 and 2008. METHODS: HPCS was diagnosed by means of ELISA and/or RT-PCR in 11 (21.2%) out of 52 suspected cases, and 54.4% of these were fatal. Furthermore, 595 wild rodents (Necromys lasiurus, Akodon sp, Calomys tener and Oligoryzomys sp) were caught between 2005 and 2008. RESULTS: Fifteen (2.5%) of these rodents presented antibodies for hantavirus, as follows: Necromys lasiurus (4%), Calomys tener (1.9%) and Akodon sp (1.5%). Nucleotide sequences obtained through RT-PCR from one HPCS patient and one Calomys tener rodent were compared with hantavirus sequences from GenBank, which showed that both were homologous with ARAV. CONCLUSIONS: This work corroborates previous studies showing that ARAV is the hantavirus causing HPCS in the Ribeirão Preto region. It also shows that rodents infected with hantavirus represent a constant risk of transmission of this virus to man.

Temporal distribution of tuberculosis in the State of Amazonas, Brazil

Tuberculosis (TB) is one of the infectious diseases that contributes most to the morbidity and mortality of millions of people worldwide. Brazil is one of 22 countries that accounts for 80% of the tuberculosis global burden. The highest incidence rates in Brazil occur in the States of Amazonas and Rio de Janeiro. The aim of this study was to describe the temporal distribution of TB in the State of Amazonas. Between 2001 and 2011, 28,198 cases of tuberculosis were reported in Amazonas, distributed among 62 municipalities, with the capital Manaus reporting the highest (68.7%) concentration of cases. Tuberculosis was more prevalent among males (59.3%) aged 15 to 34 years old (45.5%), whose race/color was predominantly pardo (64.7%) and who had pulmonary TB (84.3%). During this period, 81 cases of multidrug-resistant TB were registered, of which the highest concentration was reported from 2008 onward (p = 0.002). The municipalities with the largest numbers of indigenous individuals affected were São Gabriel da Cachoeira (93%), Itamarati (78.1%), and Santa Isabel do Rio Negro (70.1%). The future outlook for this region includes strengthening the TB control at the primary care level, by expanding diagnostic capabilities, access to treatment, research projects developed in collaboration with the Dr. Heitor Vieira Dourado Tropical Medicine Foundation .;Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD).; and financing institutions, such as the project for the expansion of the Clinical Research Center and the creation of a hospital ward for individuals with transmissible respiratory diseases, including TB.

A water-borne hepatitis A outbreak in Rio de Janeiro

An excess of hepatitis cases, in the research center of Petrobrás located in the Fundaão Island, within the city of Rio de Janeiro, was notified during the second half of March 1980. In recent years this center has had an average of four cases per year, but between March 5th and April 25th, sixteen cases were reported. The cause and possible source of infection were investigated. A serologic diagnosis of hepatitis A was made by showing IgG serum antibodies against this virus in patients. No subclinical cases among a group of 60 healthy employees could be identified. A questionnaire was circulated to investigate a possible commom source of infection. Evaluation of the water supply system indicated that it had recently been contaminated. Information obtained from other medical services in the island failed to reveal that the episode was part of a larger outbreak.

Competitive interactions between species of freshwater snails: I. Laboratory: Ia. General methodology

For the development of laboratory experiments on the competitive interacitons between freshwater snail populations, special snail rooms were set up in the main building of the Research Center "Aggeu Magalhães". In the current paper, the first of a series on this subject, the general methodology of the laboratory work is described in detail. Using indoor cement channels in which a uniform seminatural environment was created, interactions of freshwater snail populations can be studied with minimal interference of the usual variables. Controlled indoor environmental techniques, as described in the current paper, may also be utilized in different types of experiments in malacology, and represent a substantial technical advance in malacological work.

Sporotrichosis: an emergent zoonosis in Rio de Janeiro

During the period from 1987 to 1998, 13 cases of human sporotrichosis were recorded at the Research Center Evandro Chagas Hospital (CPqHEC) in Rio de Janeiro. Two of these patients related scratch by a sick cat. During the subsequent period from July 1998 to July 2000, 66 human, 117 cats and 7 dogs with sporotrichosis were diagnosed at the CPqHEC. Fifty-two humans (78.8%) reported contact with cats with sporotrichosis, and 31 (47%) of them reporting a history of a scratch or bite. This epidemic, unprecedented in the literature, involving cats, dogs and human beings may have started insidiously before 1998.

Postharvest nitrous oxide emissions from a subtropical oxisol as influenced by summer crop residues and their management

Nitrous oxide (N2O) is the most important non-CO2 greenhouse gas and soil management systems should be evaluated for their N2O mitigation potential. This research evaluated a long-term (22 years) experiment testing the effect of soil management systems on N2O emissions in the postharvest period (autumn) from a subtropical Rhodic Hapludox at the research center FUNDACEP, in Cruz Alta, state of Rio Grande do Sul. Three treatments were evaluated, one under conventional tillage with soybean residues (CTsoybean) and two under no-tillage with soybean (NTsoybean) and maize residues (NTmaize). N2O emissions were measured eight times within 24 days (May 2007) using closed static chambers. Gas flows were obtained based on the relations between gas concentrations in the chamber at regular intervals (0, 15, 30, 45 min) analyzed by gas chromatography. After soybean harvest, accumulated N2O emissions in the period were approximately three times higher in the untilled soil (164 mg m-2 N) than under CT (51 mg m-2 N), with a short-lived N2O peak of 670 mg m-2 h-1 N. In contrast, soil N2O emissions in NT were lower after maize than after soybean, with a N2O peak of 127 g m-2 h-1 N. The multivariate analysis of N2O fluxes and soil variables, which were determined simultaneously with air sampling, demonstrated that the main driving variables of soil N2O emissions were soil microbial activity, temperature, water-filled pore space, and NO3- content. To replace soybean monoculture, crop rotation including maize must be considered as a strategy to decrease soil N2O emissions from NT soils in Southern Brazil in a Autumn.

Chemical and structural characterization of soil humic substances under agroforestry and conventional systems

Studies have proven that the agroforestry systems in the semi-arid region of the State of Ceará, Brazil, induce an increase in soil organic C levels. Notwithstanding, there is no information if this increase also results in qualitative changes in different pools of soil organic matter. The objective of this study was to verify the possible chemical and structural alterations in fulvic and humic acids of a Luvisol in areas adopting agroforestry, traditional intensive cultivation and native forest in a long-term experiment conducted in the semi-arid region of Ceará State, Brazil. The study was conducted in an experimental area of the National Goat Research Center (Embrapa) in Sobral, CE. The following treatments were evaluated: agrosilvopasture (AGP), silvopasture (SILV), intensive cultivation under fallow (ICF), and areas with native forest (NF). Soil fulvic and humic acids fractions were extracted from the 0-6 and 6-12 cm layers and characterized by elemental composition, thermogravimetry and infrared spectroscopy analyses. The elemental composition analysis of humic acids confirmed the data found for fulvic acids, showing reduction in the C, H and N levels, followed by an increase in O contents in the AGP and ICF treatments over SILV and NF. In all treatments, except to SILV in the 0-6 cm layer, the percentage of mass loss was highest (300-600 °C) for humic acids in the thermally most stable region. Despite the similarity between infrared spectra, soil fulvic acids in the SILV treatment extracted from 6-12 cm depth decrease the absorption bands at 1708 and 1408 cm-1 followed by an increase in the absorption band at 1608 cm-1 attributed to aromatic C=C groups. This behavior suggests an increase in the aromatic character of the structure. The AGP and ICF treatments, which increase the soil tilling, favored the maintenance of humic substances with a more aromatic character in the soil than SILV and NF. The less aromatic humic substances in the SILV treatment resulted in an increase of exchange sites of soil organic matter, indicating improved nutrient cycling and maintenance of productivity in the system.

Relations between soil surface roughness, tortuosity, tillage treatments, rainfall intensity and soil and water losses from a red yellow latosol

The soil surface roughness increases water retention and infiltration, reduces the runoff volume and speed and influences soil losses by water erosion. Similarly to other parameters, soil roughness is affected by the tillage system and rainfall volume. Based on these assumptions, the main purpose of this study was to evaluate the effect of tillage treatments on soil surface roughness (RR) and tortuosity (T) and to investigate the relationship with soil and water losses in a series of simulated rainfall events. The field study was carried out at the experimental station of EMBRAPA Southeastern Cattle Research Center in São Carlos (Fazenda Canchim), in São Paulo State, Brazil. Experimental plots of 33 m² were treated with two tillage practices in three replications, consisting of: untilled (no-tillage) soil (NTS) and conventionally tilled (plowing plus double disking) soil (CTS). Three successive simulated rain tests were applied in 24 h intervals. The three tests consisted of a first rain of 30 mm/h, a second of 30 mm/h and a third rain of 70 mm/h. Immediately after tilling and each rain simulation test, the surface roughness was measured, using a laser profile meter. The tillage treatments induced significant changes in soil surface roughness and tortuosity, demonstrating the importance of the tillage system for the physical surface conditions, favoring water retention and infiltration in the soil. The increase in surface roughness by the tillage treatments was considerably greater than its reduction by rain action. The surface roughness and tortuosity had more influence on the soil volume lost by surface runoff than in the conventional treatment. Possibly, other variables influenced soil and water losses from the no-tillage treatments, e.g., soil type, declivity, slope length, among others not analyzed in this study.