Comparison of two rapid tests for anti-phenolic glycolipid-I serology in Brazil and Nepal

The diagnosis of leprosy continues to be based on clinical symptoms and early diagnosis and treatment are critical to preventing disability and transmission. Sensitive and specific laboratory tests are not available for diagnosing leprosy. Despite the limited applicability of anti-phenolic glycolipid-I (PGL-I) serology for diagnosis, it has been suggested as an additional tool to classify leprosy patients (LPs) for treatment purposes. Two formats of rapid tests to detect anti-PGL-I antibodies [ML immunochromatography assay (ICA) and ML Flow] were compared in different groups, multibacillary patients, paucibacillary patients, household contacts and healthy controls in Brazil and Nepal. High ML Flow intra-test concordance was observed and low to moderate agreement between the results of ML ICA and ML Flow tests on the serum of LPs was observed. LPs were "seroclassified" according to the results of these tests and the seroclassification was compared to other currently used classification systems: the World Health Organization operational classification, the bacilloscopic index and the Ridley-Jopling classification. When analysing the usefulness of these tests in the operational classification of PB and MB leprosy for treatment and follow-up purposes, the ML Flow test was the best point-of-care test for subjects in Nepal and despite the need for sample dilution, the ML ICA test yielded better performance among Brazilian subjects. Our results identified possible ways to improve the performance of both tests.

Use of the Kala-Azar Detect® and IT-LEISH® rapid tests for the diagnosis of visceral leishmaniasis in Brazil

The performances of two rapid tests and a standard serological test for the diagnosis of visceral leishmaniasis (VL) were compared using sera from 193 patients with VL and 85 controls. The Kala-Azar Detect®, IT-LEISH® and IFI-LH® assays showed sensitivities of 88.1%, 93.3% and 88.6%, respectively, and specificities of 90.6%, 96.5% and 80%, respectively. The sensitivity values were similar for both rapid tests, but the specificity and positive predictive values of IT-LEISH® were higher than the corresponding values for IFI-LH®. Both rapid tests showed satisfactory performances and can be used in primary health care settings; however, IT-LEISH® permits the use of whole blood, making this assay more suitable for bedside diagnosis.

Caracterização e propriedades catalíticas da zeolita HZSM5 modificada com nióbio

HZSM5 zeolite was modified by exchanging proton by niobium (V). Several samples were obtained with various degrees of exchange. Pore volumes and acidity were measured to characterize these exchanged zeolites. Catalytic properties were evaluated with two reaction tests: m-xylene transformation and n-heptane cracking. The introduction of niobium on HZSM5 zeolite decreases the diffusion coefficient of 2-methyl-pentane and increases the zeolite acidity. The sample containing niobium are initially more active in cracking of n-heptane and m-xylene isomerization than HZSM5 alone.

Effect of hormone replacement on exercise cardiopulmonary reserve and recovery performance in subclinical hypothyroidism

Subclinical hypothyroidism (SH) patients present cardiopulmonary, vascular and muscle dysfunction, but there is no consensus about the benefits of levothyroxine (L-T4) intervention on cardiopulmonary performance during exercise. The aim of the present study was to investigate the effects of L-T4 on cardiopulmonary exercise reserve and recovery in SH patients. Twenty-three SH women, 44 (40-50) years old, were submitted to two ergospirometry tests, with an interval of 6 months of normalization of thyroid-stimulating hormone (TSH) levels (L-T4 replacement group) or simple observation (TSH = 6.90 μIU/mL; L-T4 = 1.02 ng/dL). Patients with TSH >10 μIU/mL were excluded from the study to assure that they would receive treatment in this later stage of SH. Twenty 30- to 57-year-old women with no thyroid dysfunction (TSH = 1.38 μIU/mL; L-T4 = 1.18 ng/dL) were also evaluated. At baseline, lower values of gas exchange ratio reserve (0.24 vs 0.30; P < 0.05) were found for SH patients. The treated group presented greater variation than the untreated group for pulmonary ventilation reserve (20.45 to 21.60 L/min; median variation = 5.2 vs 25.09 to 22.45 L/min; median variation = -4.75, respectively) and for gas exchange ratio reserve (0.19 to 0.27; median variation = 0.06 vs 0.28 to 0.18; median variation = -0.08, respectively). There were no relevant differences in cardiopulmonary recovery for either group at baseline or after follow-up. In the sample studied, L-T4 replacement improved exercise cardiopulmonary reserve, but no modification was found in recovery performance after exercise during this period of analysis.

Serodiagnosis of strongyloidiasis. The application and significance

Parasitological diagnosis based on the faecal examination is frequently difficult in cases of chronic, low-level S. stercoralis infection. Even when a newly developed sensitive method (an agar plate culture) is applied, it is essential to examine faecal samples repeatedly to achieve a correct diagnosis. Additionally, it is important to note that a negative result does not necessarily indicate the unequivocal absence of the infection. On the other hand, several serological tests which have recently been developed for strongyloidiasis have proven reliable when used to complement parasitological examination. We have developed two serological tests, ELISA and GPAT, to demonstrate Strongyloides infection and possible applications of the serological tests for diagnosis, mass-screening, epidemiological study and postchemotherapy evaluation of strongyloidiasis were reviewed based on our recent studies.

On the possibility of autochthonous Chagas disease in Roraima, Amazon region, Brazil, 2000-2001

Chagas disease has been almost entirely eradicated from the arid zones in Central and Northeastern Brazil where rare or no autochthonous cases have been reported. However, in the last 10 years the disease has increasingly been registered in the Amazon Region. Aiming to investigate the possibility of the occurrence of autochthonous cycle of Chagas disease in Roraima, triatomine collections, vectorial susceptibility studies (this one to be shown elsewhere), parasitological and serological analyses were conducted in three agricultural settlement areas (Rorainópolis, Passarão Project and Ilha Community). Blood-donor candidates were also investigated. This is the first epidemiological survey on Chagas disease conducted in agricultural settlements in Roraima. Triatomine species found were Triatoma maculata, Rhodnius pictipes, Rhodnius robustus and Panstrongylus geniculatus. Trypanosoma cruzi detection analyses included xenodiagnosis, indirect immunofluorescence, indirect hemaglutination, ELISA and kinetoplast PCR amplification. Natural triatomine infection was not found in intestinal contents. Twenty-five adult settlers (1.4% out of 1821, all > 15 year-old, 20 migrants) presented anti-T. cruzi antibodies. Two migrant settlers (from Minas Gerais and Maranhão) tested positive for more than two serological tests, besides either being positive for xenodiagnosis or PCR. Results show that Chagas disease is not endemic in the areas studied. However, all elements of the transmission cycle are present, demanding for an adequate and continuous vigilance.

PREVALENCE OF CHAGAS DISEASE IN A RURAL AREA IN THE STATE OF CEARA, BRAZIL

SUMMARY Chagas disease is caused by Trypanosoma cruzi and affects about two to three million people in Brazil, still figuring as an important public health problem. A study was conducted in a rural area of the municipality of Limoeiro do Norte - CE, northeastern Brazil, aiming to determine the prevalence of T. cruzi infection. Of the inhabitants, 52% were examined, among whom 2.6% (4/154) were seropositive in at least two serological tests. All seropositive individuals were older than 50 years, farmers, with a low education and a family income of less than three minimum wages. Active surveillance may be an alternative for early detection of this disease.

Epidemiological profile of Trypanosoma cruzi-infected mothers and live birth conditions in the state of Minas Gerais, Brazil

INTRODUCTION: The aim of this study was to assess the epidemiological characteristics of Trypanosoma cruzi-infected mothers and the live birth conditions of neonates.METHODS:A serological survey with IgG-specific tests was conducted using dried blood samples from newborn infants in the State of Minas Gerais. T. cruzi infection was confirmed in mothers through positive serology in two different tests, and infected mothers were required to have their infants serologically tested after the age of 6 months. The birth conditions of the neonates were obtained from the System of Information on Live Births database.RESULTS:The study included 407 children born to T. cruzi-infected mothers and 407 children born to uninfected mothers. The average age of seropositive mothers was 32 years (CI95% 31.3-32.6), which was greater than the average age of seronegative mothers - 25 years (CI95% 24.8-25.2). The mothers' level of education was higher among uninfected mothers (41% had 8 or more years of education, versus 22% between the infected mothers). Vaginal delivery was more frequent among infected mothers. There was no evidence of inter-group differences with respect to the child's sex, gestational age, birth weight or Appearance, pulse, grimace, activity and respiration (APGAR) scores at 1 and 5 minutes.Conclusions:The level of education and the greater number of previous pregnancies and cases of vaginal delivery reflect the lower socioeconomical conditions of the infected mothers. In the absence of vertical transmission, neonates had similar health status irrespective of the infection status of their mothers.

A comparative study on IgG-ELISA, IgM-IFT and Kato-Katz methods for epidemiological purposes in a low endemic area for schistosomiasis

The high sensitivity and the possibility of automation of the enzyme-linked-immunosorbent-assay (ELISA) has indicated this technique as one of the most useful serological test for epidemiological studies. In the present study, an ELISA for detection of IgG antibodies against adult worm antigens (IgG-ELISA) was investigated for epidemiological purposes, in a rural area of the municipality of Itariri (São Paulo, Brazil). Blood on filter paper (1,180 samples) from about 650 schoolchildren were submitted to ELISA and the data compared to the results of the parasitological method of Kato-Katz and also to the IgM-IFT (immunofluorescence test for IgM antibodies to gut associated antigens). The prevalence rates respectively of 8.5%, 43.0%, and 56.2% by the Kato-Katz, IgG-ELISA, and IgM-IFT methods suggest the poor sensitivity of the parasitological method for detection of Schistosoma mansoni eggs in individuals with low worm burden, situation commonly observed in low endemic areas. These results can partially explain the poor degree of agreement between the IgG-ELISA and the Kato-Katz, as suggested by the Kappa index of 0.170. Otherwise, the Kappa index of 0.675 showed substantial agreement between the two serological tests. Some discrepancy of results between the two serological techniques must be better investigated.

Human Immunodeficiency Virus Seroprevalence among Inmates of the Penitentiary Complex of the Region of Campinas, State of São Paulo, Brazil

Six hundred and ninety three male inmates from three penitentiaries, two (A and B) maximum-security systems and one (C) minimum-security facility, located in Campinas, State of São Paulo, Brazil were studied for the presence of human immunodeficiency virus (HIV) antibodies, using a cross-sectional design. The search for anti-HIV antibodies in 693 samples of sera collected was carried out by two serological tests: (a) the Microparticle enzyme immunoassay-HIV-1 and HIV-2 (MEIA) (Abbott Laboratories) and (b) the Western Blot-HIV-1 (WB) (Cambridge Biotech Corporation) to confirm positive results with MEIA. Sera reactivity for HIV antibodies was 14.4%. The highest frequency of anti-HIV antibodies was found in the A and B maximum-security prisons: 17% and 21.5%, respectively. In prison C, the frequency of reagents was 10.9%. Seventy three inmates, initially negative in the MEIA test, were checked again five and seven months later. Three of them, all from the maximum-security facilities, became reactive in the MEIA test, with confirmation in the WB, suggesting that serological conversion had occurred after imprisonment.

Ultrastructure and cytochemistry of the tegument of Atriaster heterodus (Platyhelminthes: Monogenea)

The tegument of the polyopisthocotylean monogenean Atriaster heterodus Lebedev & Parukhin, 1969 was studied using transmission electron microscopy. The outer syncytial layer of the tegument is connected to the internal cell bodies by cytoplasmic extensions which interweave between the muscular fibres. The free surface of the syncytium has projections of the external membrane which are similar to microvilli. The undulating basal membrane, with numerous narrow elongate projections, is associated with the basal lamina situated between the syncytial and muscular layers. The cell bodies and syncytial layer of the tegument exhibit two types of vesicles, one with fibrous contents and one with electron-dense contents; these were analysed using two cytochemical tests, the E-PTA and alcian blue methods, used for the first time on monogeneans.

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.

Propolis: anti-Staphylococcus aureus activity and synergism with antimicrobial drugs

Propolis is a natural resinous substance collected by bees from tree exudates and secretions. Its antimicrobial activity has been investigated and inhibitory action on Staphylococcus aureus growth was evaluated. The in vitro synergism between ethanolic extract of propolis (EEP) and antimicrobial drugs by two susceptibility tests (Kirby and Bauer and E-Test) on 25 S. aureus strains was evaluated. Petri dishes with sub-inhibitory concentrations of EEP were incubated with 13 drugs using Kirby and Bauer method and synergism between EEP and five drugs [choramphenicol (CLO), gentamicin (GEN), netilmicin (NET), tetracycline (TET), and vancomycin (VAN)] was observed. Nine drugs were assayed by the E-test method and five of them exhibited a synergism [CLO, GEN, NET, TET, and clindamycin (CLI)]. The results demonstrated the synergism between EEP and antimicrobial drugs, especially those agents that interfere on bacterial protein synthesis.

Color preference of Anastrepha obliqua (Diptera, Tephritidae)

The color preference of A. obliqua was evaluated in two-choice tests. The results showed that both sexes were attracted to wavelengths ranging from 340 nm to 670 nm, although the broad major peak of attraction occurred between 380 and 570 nm.

Absorção de bário por plantas de arroz (Oryza sativa L.) e mobilidade em solo tratado com baritina sob diferentes condições de potencial redox

Two parallel tests were carried out to evaluate barium solubility in soils treated with barite under reducing conditions: one in leaching columns and another with potted plants cultivated with rice. Soils were treated with three doses of barite and kept at two humidity levels. The reduction (-200 mV) condition promoted an increase in barium in the geochemical fraction of higher liability, higher concentrations of barium in the leached extracts, and higher absorption by rice plants. As a result of increased uptake and accumulation of barium, the plants showed stunted growth