Experimental infection of Rhodnius robustus Larrousse, 1927 (Hemiptera, Reduviidae, Triatominae) with Trypanosoma cruzi (Chagas, 1909) (Kinetoplastida, Trypanosomatidae) IV.

Vector competence of triatomines (kissing bugs) for Trypanosoma cruzi transmission depends on the parasite-vector interaction and the genetic constitution of both. This study evaluates the susceptibility and vector competence of Rhodnius robustus experimentally infected with T. cruzi IV (TcIV). Nymphs were fed on infected mice or an artificial feeder with blood containing culture-derived metacyclic trypomastigotes (CMT) or blood trypomastigotes (BT). The intestinal contents (IC) and excreta of the insects were examined by fresh examination and kDNA-PCR. The rate of metacyclogenesis was also determined by differential counts. Fifth instar nymphs fed with CMT ingested a greater blood volume (mean of 74.5 µL) and a greater amount of parasites (mean of 149,000 CMT/µL), and had higher positivity in the fresh examination of the IC. Third instar nymphs fed with CMT had higher positivity (33.3%) in the fresh examination of the excreta. On the 20th day after infection (dai), infective metacyclic trypomastigote (MT) forms were predominant in the excreta of 3/4 experimental groups, and on the 30th dai, the different parasitic forms were observed in the IC of all the groups. Higher percentages of MT were observed in the excreta of the 5th instar nymphs group (84.1%) and in the IC of the 3rd instar nymphs group (80.0%). Rhodnius robustus presented high susceptibility to infection since all nymphs were infected, regardless of the method used for blood meal, in addition these insects demonstrated vector competence for TcIV with high rates of metacyclogenesis being evident.

Comparative analysis of routine parasitological methods for recovery of cysts, molecular detection, and genotyping of Giardia duodenalis.

In order to improve the diagnosis of giardiasis, fecal samples (high/medium/low concentration of cysts) were processed by the parasitological methods used in the routine: Faust, Lutz e Ritchie modified (replacement of formaldehyde by distilled water). The cysts were quantified; the DNA was extracted and amplified by semi-nested PCR (GDH gene). Fifteen clinical samples were analyzed to validate the study by PCR-RFLP. The results showed that the parasite was only detected and genotyped correctly when samples from children with high, medium, and low parasitic load, belonging to genotype AII, were processed by the modified Ritchie method, different from what was observed for the other methods used in laboratory routine (Faust and Lutz). The modified Ritchie method proved to be more suitable, recovering a greater number of cysts from samples, regardless of parasitic load, which reduces the chance of false negative results and has epidemiological repercussions since individuals with low parasite load are usually asymptomatic and the main disseminators of this infection.

BOWEL FREQUENCY AND SYMPTOMS OF CONSTIPATION AND ITS RELATION WITH THE LEVEL OF PHYSICAL ACTIVITY IN PATIENTS WITH CHAGAS DISEASE.

BACKGROUND: Intestinal constipation (IC) in patients with the digestive form of Chagas disease is one of the main reasons for seeking medical care. Population data indicate that the practice of physical activity improves gastrointestinal motility. OBJECTIVE: This study evaluated the bowel frequency and symptoms of constipation and their relationship with the level of physical activity in patients with and without Chagas disease. METHODS: Patients (n=120) of both genres, aged between 35 and 84 years, in which 50% (n=60) were in the Chagas group and 50% (n=60) were in the control group, were evaluated regarding the level of IC using the Constipation Assessment Scale (CAS) and regarding the level of physical activity using the International Physical Activity Questionnaire (IPAQ). RESULTS: - Patients in the Chagas group classified as active (IPAQ 2) had higher proportion (P=0.0235) of moderate IC with severe abdominal distension (P=0.0159) and decreased evacuation frequency (P=0.0281) than the patients in the control group, considered to be very active (IPAQ 1). The sedentary lifestyle was greater (P=0.0051) in the Chagas group with duration, intensity and frequency of physical activity lower than the control group. The health perception in the Chagas group was regular for 46.7% (P=0.0035) and poor for 8.3% (P=0.0244). CONCLUSION: There is a lower risk of developing intestinal constipation in more active individuals, evidencing that the level of physical activity interferes with bowel frequency and symptoms of constipation in patients with and without Chagas disease. The level of physical activity and health perception were worse in the Chagas group, reinforcing the disease stigma, which should be modified by the training of health professionals who routinely attend these patients.

Effects of Highly Diluted Drugs on Experimental Infection with Trypanosoma cruzi In Vivo: Systematic Review.

Objective: To investigate, through a systematic review, the effects of the use of highly diluted drugs in the treatment of experimental infection with Trypanosoma cruzi. Design: The authors searched for scientific publications in the databases PubMed, Web of Science, SCOPUS, LILACS, and the Google Scholar search system, from 2000 to 2018, following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. According to the criteria established, a total of 22 studies were included. Settings/Location: The study took place at the State University of Maringá, Maringá, PR, Brazil. Subjects: Male mice (Mus musculus) or rats (Rattus norvegicus). Interventions: Highly diluted drugs. Outcome measures: The parameters evaluated in the studies were parasitological, clinical, immunological, histopathological and hematological. Results: The studies demonstrated that the effects of highly diluted drugs are related to their dynamizations, treatment regimen, and host susceptibility to T. cruzi infection, and depend on the initial information transmitted to the treated organism, making this information the "model" of how the treated organism will react. Regardless of the mechanism of action, these drugs provide a decrease in inflammation, which is one of the central phenomena of the pathogenesis of T. cruzi infection. Conclusions: This systematic review brings out the importance of the T. cruzi infection model as a reliable and valid model for studying different effects produced by highly diluted drugs. Considering the findings and in a broader perspective, this study contributes to considering these drugs as a possible way of dealing with "treatment" in general, presents the need to reexamine the biochemical model and develop a model for the effect of high dilutions in general, as well as for the treatment of parasitic infections.

Improvement in cyst recovery and molecular detection of Giardia duodenalis from stool samples.

Molecular detection of Giardia duodenalis by polymerase chain reaction (PCR) is difficult in faecal samples due to inhibitors that contaminate DNA preparations, or due to low cyst concentrations. In order to eliminate inhibitors, improve cyst recovery and molecular detection of G. duodenalis, different types of water, distillates (MDs), deionized (MDz), injection (MI) or Milli-Q® (MM) were used instead of formaldehyde (F) in the laboratory routine method (Ritchie). Cysts were isolated from faecal samples with low cyst concentrations (< 1 cyst/field), medium (1-2 cysts/field) or high (> 2 cysts/field). Cyst recovery was improved using all water types (MDs, MDz, MI, MM) compared to formaldehyde. At all cyst concentrations, the use of MM consistently showed the greatest recovery of G. duodenalis cysts . DNA samples from recovered cysts were tested for the glutamate dehydrogenase (GDH) and ß-giardin (ßg) genes. The use of Milli-Q® water allowed to detect both genes in all cyst concentrations, including low. The method processed with the other types of water amplified these genes at high and medium cyst concentrations. GDH and ßg genes were not detected when the sample was processed with formaldehyde. These experimental results were confirmed in clinical samples. The results suggest that Milli-Q® water provides the highest cyst recovery from stool samples and, correspondingly, the highest sensitivity for detecting G. duodenalis by microscopy or PCR for GDH and ßg genes, even at low concentration of cysts.

Linear mixed model for weight analysis in mice infected by Trypanosoma cruzi

The use of linear mixed models for nested structure longitudinal data is called hierarchical linear modeling. Thismodeling takes into account the dependence of existing data within each level and between hierarchical levels. The process of modeling, estimating and analyzing diagnoses was illustrated through data on the weights of mice experimentally infected by Trypanosoma cruzi, divided into different treatment groups, with the purpose of verifying the evolution of their body weight as a result of usingdifferent types of biotherapeutics produced from Gallus gallus domesticus(chicken) serum to treat Trypanosoma cruzi. Through the model selection criteria AIC and BIC and the likelihood ratio test, a model was chosen to describe the data correctly. Model diagnoses were then performed by means of residual analysis for both levels and an analysis of influential observations to verify if any observations were signaled as influencing the fixed effects, the components of variance and the adjusted values. After the analysis, it was possible to notice that the observations that were signaled as influential had little impact on the Model chosen initially, so it was maintained, with no differences being evidenced between the treatments with the biotherapeutics tested; only the Time variable and the Random intercept were necessary to describe the weight of the mice.

Analyzing weight evolution in mice infected by Trypanosoma cruzi

Concerning the specificities of a longitudinal study, the trajectories of a subject's mean responses not always present a linear behavior, which calls for tools that take into account the non-linearity of individual trajectories and that describe them towards associating possible random effects with each individual. Generalized additive mixed models (GAMMs) have come to solve this problem, since, in this class of models, it is possible to assign specific random effects to individuals, in addition to rewriting the linear term by summing unknown smooth functions, not parametrically specified, then using the P-splines smoothing technique. Thus, this article aims to introduce this methodology applied to a dataset referring to an experiment involving 57 Swiss mice infected by Trypanosoma cruzi, which had their weights monitored for 12 weeks. The analyses showed significant differences in the weight trajectory of the individuals by treatment group; besides, the assumptions required to validate the model were met. Therefore, it is possible to conclude that this methodology is satisfactory in modeling data of longitudinal sort, because, with this approach, in addition to the possibility of including fixed and random effects, these models allow adding complex correlation structures to residuals.

Phosphorus protects cardiac tissue by modifying the immune response in rats infected by Trypanosoma cruzi.

AIM: This study evaluates and correlates the number of myocarditis focuses and production of cytokines in Rattus norvegicus (Wistar lineage), experimentally infected with T. Cruzi and treated with Phosphorus. METHODS: In two blind, controlled and randomized trials, 53 45-day-old, male animals were allocated into groups Control (n=24): Control group infected and treated with 7% hydroalcoholic solution, the preparation vehicle of the test medication; and Phosphorus (n=24 on days 0, 5, 10 and 24 after infection): group infected and treated with Phosphorus 13cH, diluted 10-26 and dynamized (test medication). The animals were inoculated intraperitoneally with 5×106 blood trypomastigotes of T. cruzi-Y strain. The medication was administered overnight (16 consecutive hours), diluted in water (1mL/100mL) in amber water bottles. The animals were treated 2days before and 2, 4, and 6days after infection. Enumeration of inflammatory foci in cardiac tissue (Hematoxylin-Eosin) and dosage of cytokines TNF-α and IFN-γ in the serum were performed on days 0, 5, 10 and 24 after infection, using three animals/group. Mann-Whitney, Friedman ANOVA, Spearman correlation (p<0.05), and Statistica Single User Software version 13.2 were used for data analysis. RESULTS: The animals treated with Phosphorus 13cH had high concentration of INF-É£ on the 5th day of infection with significant decrease on the 10th and 24th days (p<0.05), and high concentration of TNF-α on the 5th and 10th days of infection with decrease on the 24th day (p<0.05). The treatment with Phosphorus caused a significant increase of INF-É£ and TNF-α on the 5th day of infection compared with the Control (p<0.05), with reestablishment on the 24th day, as well as in the Control group. The group treated with Phosphorus had 52.5% less number of myocarditis focuses in heart than Control group (p<0.05) on the 10th day of infection. The significant increase in cytokines on the5th day of infection in the Phosphorus group is related to a significant decrease in the number of inflammatory foci in cardiac tissue on the 10th day of infection in this group. DISCUSSION AND CONCLUSION: Treatment with Phosphorus 13cH promotes beneficial effects in T. cruzi infection in Wistar rats by modulating the secretion of IFN-γ and TNF-α with decreased inflammation in cardiac tissue. These results reinforce the importance of considering the use of homeopathy for establishing new therapeutic approaches in the management of patients with Chagas disease.

Sympatry influence in the interaction of Trypanosoma cruzi with triatomine.

INTRODUCTION: Trypanosoma cruzi, the etiologic agent of Chagas disease, is widely distributed in nature, circulating between triatomine bugs and sylvatic mammals, and has large genetic diversity. Both the vector species and the genetic lineages of T. cruzi present a varied geographical distribution. This study aimed to verify the influence of sympatry in the interaction of T. cruzi with triatomines. Methods: The behavior of the strains PR2256 (T. cruzi II) and AM14 (T. cruzi IV) was studied in Triatoma sordida (TS) and Rhodnius robustus (RR). Eleven fifth-stage nymphs were fed by artificial xenodiagnosis with 5.6 × 103 blood trypomastigotes/0.1mL of each T. cruzi strain. Every 20 days, their excreta were examined for up to 100 days, and every 30 days, the intestinal content was examined for up to 120 days, by parasitological (fresh examination and differential count with Giemsa-stained smears) and molecular (PCR) methods. Rates of infectivity, metacyclogenesis and mortality, and mean number of parasites per insect and of excreted parasites were determined. RESULTS: Sympatric groups RR+AM14 and TS+PR2256 showed higher values of the four parameters, except for mortality rate, which was higher (27.3%) in the TS+AM14 group. General infectivity was 72.7%, which was mainly proven by PCR, showing the following decreasing order: RR+AM14 (100%), TS+PR2256 (81.8%), RR+PR2256 (72.7%) and TS+AM14 (36.4%). CONCLUSIONS: Our working hypothesis was confirmed once higher infectivity and vector capacity (flagellate production and elimination of infective metacyclic forms) were recorded in the groups that contained sympatric T. cruzi lineages and triatomine species.

Sympatry influence in the interaction of Trypanosoma cruzi with triatomine

Abstract INTRODUCTION: Trypanosoma cruzi, the etiologic agent of Chagas disease, is widely distributed in nature, circulating between triatomine bugs and sylvatic mammals, and has large genetic diversity. Both the vector species and the genetic lineages of T. cruzi present a varied geographical distribution. This study aimed to verify the influence of sympatry in the interaction of T. cruzi with triatomines. Methods: The behavior of the strains PR2256 (T. cruzi II) and AM14 (T. cruzi IV) was studied in Triatoma sordida (TS) and Rhodnius robustus (RR). Eleven fifth-stage nymphs were fed by artificial xenodiagnosis with 5.6 × 103 blood trypomastigotes/0.1mL of each T. cruzi strain. Every 20 days, their excreta were examined for up to 100 days, and every 30 days, the intestinal content was examined for up to 120 days, by parasitological (fresh examination and differential count with Giemsa-stained smears) and molecular (PCR) methods. Rates of infectivity, metacyclogenesis and mortality, and mean number of parasites per insect and of excreted parasites were determined. RESULTS: Sympatric groups RR+AM14 and TS+PR2256 showed higher values of the four parameters, except for mortality rate, which was higher (27.3%) in the TS+AM14 group. General infectivity was 72.7%, which was mainly proven by PCR, showing the following decreasing order: RR+AM14 (100%), TS+PR2256 (81.8%), RR+PR2256 (72.7%) and TS+AM14 (36.4%). CONCLUSIONS: Our working hypothesis was confirmed once higher infectivity and vector capacity (flagellate production and elimination of infective metacyclic forms) were recorded in the groups that contained sympatric T. cruzi lineages and triatomine species.

Polymorphisms of blood forms and in vitro metacyclogenesis of Trypanosoma cruzi I, II, and IV.

Trypanosoma cruzi is the etiologic agent of American trypanosomiasis has broad biological and genetic diversity. Remaining to be studied are polymorphisms of the blood forms and metacyclogenesis of different T. cruzi discrete typing units (DTUs). Our goal was to evaluate the relationship between T. cruzi DTUs, the morphology of blood trypomastigotes, and in vitro metacyclogenesis. T. cruzi strains that pertained to DTUs TcI, TcII, and TcIV from different Brazilian states were used. Parameters that were related to the morphology of eight strains were assessed in thin blood smears that were obtained from mice that were inoculated with blood or culture forms, depending on strain. The metacyclogenesis of 12 strains was measured using smears with Liver Infusion Tryptose culture medium and M16 culture medium (which is poor in nutrients and has a low pH) at the exponential phase of growth, both stained with Giemsa. The morphological pattern of TcII strains was consistent with broad forms of the parasite. In TcIV strains, slender forms predominated. The Y strain (TcII) was morphologically more similar to TcIV. Significant differences in polymorphisms were observed between DTUs. Metacyclogenesis parameters, although displaying large standard deviations, differed between the DTUs, with the following descending rank order: TcII > TcI > TcIV. The mean numbers of metacyclic trypomastigotes for TcII were significantly higher than the other DTUs. Although the DTUs presented overlapping characteristics, the general pattern was that different DTUs exhibited significantly different morphologies and metacyclogenesis, suggesting that the genetic diversity of T. cruzi could be related to parameters that are associated with the evolution of infection in mammalian hosts and its ability to disperse in nature.

Synergistic effects of fenbendazole and metronidazole against Giardia muris in Swiss mice naturally infected.

In this study were proposed different protocols for the treatment of mice naturally infected with Giardia muris. Male Swiss mice were divided into seven groups, with five animals each, in a blind, controlled, randomized by drawing lots and once-repeated experiment. Parasite detection and cure control were performed using the Faust method and search by trophozoites in the intestinal mucosa. Clinical parameters (weight, water and feed consumption, elimination of excreta, aspect of the fur and feces) were also evaluated. All animals were treated with metronidazole (M), fenbendazole (F), and probiotics (P), administered intragastrically, during 7 days. M1, FM1, and F1 groups were treated 1×/day; M3, FM3, and PM3 groups 3×/day; and ST (control group) received only water. After the 5th and 7th days of treatment, the animals in FM1/FM3 and PM3/M3 groups presented, respectively, negative results and remained negative in the following 10 days. Animals in F1 group consumed less water (p = 0.00010) compared with FM1/FM3/PM3. The animals in M1 group compared with FM3/M3, F1 compared with M3, and ST compared with FM1/FM3/M3/PM3 consumed a larger amount of feed (p = 0.00001). The animals in F1 group compared with FM3/M1/M3/PM3, FM1 compared with FM3, and ST compared with FM3/M1/M3/PM3 eliminated lower volume of excreta (p = 0.00001). The results show that the association between F and M potentiates the effects, indicating a synergistic action of these two drugs, and FM1 is the best protocol due to early negativity in the animals, lower concentrations of the drugs, lower risk of toxicity and stress, and less alterations in clinical parameters.

Predominance of Th1 response, increase of megakaryocytes and Kupffer cells are related to survival in Trypanosoma cruzi infected mice treated with Lycopodium clavatum.

We investigated the number of megakaryocytes, Kupffer cells and ratios of Th1/Th2 and Th1/Th17 cytokines in survival of mice infected with Y strain of Trypanosoma cruzi and treated with Lycopodium clavatum. In a blind, randomized and controlled assay, Swiss male mice, 8weeks-old, infected with 1400 trypomastigotes (Y strain) were divided into groups and treated with: GLy - Lycopodium clavatum dynamization13c and GCI - alcohol solution 7° GL (vehicle medicine). The treatment was offered two days before infection and on the 2nd, 4th and 6th days after infection, overnight (1mL/100mL) and ad libitum. Parameters assessed were: survival rate, number of megakaryocytes and Kupffer cells, cytokines dosage (TNF-α, IFN-γ, IL-2, IL-4, IL-6, IL-10, IL-17), Th1/Th2 and Th1/Th17 ratios. The increase in megakaryocytes, Kupffer cells, predominance of Th1 response, with increased TNF-α, IL-10, TNF-α/IL-4, TNF-α/IL-17 and decreased IL-6 IL-6/IL-4, are related to increased survival in mice infected with T. cruzi and treated with Lycopodium clavatum 13c. This result demonstrates the possibility of an alternative approach for the treatment of Chagas disease with dynamized drugs.

Highly diluted medication reduces tissue parasitism and inflammation in mice infected by Trypanosoma cruzi.

AIM: To evaluate the effects of Kalium causticum, Conium maculatum, and Lycopodium clavatum 13cH in mice infected by Trypanosoma cruzi. MATERIALS AND METHODS: In a blind, controlled, randomized study, 102 male Swiss mice, 8 weeks old, were inoculated with 1400 trypomastigotes of the Y strain of T. cruzi and distributed into the following groups: CI (treated with 7% hydroalcoholic solution), Ca (treated with Kalium causticum 13cH), Co (treated with Conium maculatum 13cH), and Ly (treated with Lycopodium clavatum 13cH). The treatments were performed 48 h before and 48, 96, and 144 h after infection. The medication was repertorized and prepared in 13cH, according to Brazilian Homeopathic Pharmacopoeia. The following parameters were evaluated: infectivity, prepatent period, parasitemia peak, total parasitemia, tissue tropism, inflammatory infiltrate, and survival. Statistical analysis was conduced considering 5% of significance. RESULTS: The prepatent period was greater in the Ly group than in the CI group (p = 0.02). The number of trypomastigotes on the 8th day after infection was lower in the Ca group than in the CI group (p < 0.05). Total parasitemia was significantly lower in the Ca, Co, and Ly groups than in the CI group. On the 12th day after infection, the Ca, Co, and Ly groups had fewer nests and amastigotes/nest in the heart than the CI group (p < 0.05). Decreases in the number of nests and amastigotes in the intestine were observed in the Ly group compared with the CI group (p < 0.05). In the liver (day 12), Ly significantly prevented the formation of inflammatory foci compared with the other groups. In skeletal muscle, Co and Ly decreased the formation of inflammatory foci compared with CI (p < 0.05). Ly afforded greater animal survival compared with CI, Ca, and Co (p < 0.05). The animals in the Co group died prematurely compared with the CI group (p = 0.03). CONCLUSIONS: Ly with 13cH potency had significantly more benefits in the treatment of mice infected with T. cruzi, reducing the number of blood parasites, amastigote nests in tissue, and the number of amastigotes per nest and increasing animal survival.

Evaluation of the reference value for the Montenegro skin test.

INTRODUCTION: The Montenegro skin test (MST) has good clinical applicability and low cost for the diagnosis of American tegumentary leishmaniasis (ATL). However, no studies have validated the reference value (5mm) typically used to discriminate positive and negative results. We investigated MST results and evaluated its performance using different cut-off points. METHODS: The results of laboratory tests for 4,256 patients with suspected ATL were analyzed, and 1,182 individuals were found to fulfill the established criteria. Two groups were formed. The positive cutaneous leishmaniasis (PCL) group included patients with skin lesions and positive direct search for parasites (DS) results. The negative cutaneous leishmaniasis (NCL) group included patients with skin lesions with evolution up to 2 months, negative DS results, and negative indirect immunofluorescence assay results who were residents of urban areas that were reported to be probable sites of infection at domiciles and peridomiciles. RESULTS: The PCL and NCL groups included 769 and 413 individuals, respectively. The mean ± standard deviation MST in the PCL group was 12.62 ± 5.91mm [95% confidence interval (CI): 12.20-13.04], and that in the NCL group was 1.43 ± 2.17mm (95% CI: 1.23-1.63). Receiver-operating characteristic curve analysis indicated 97.4% sensitivity and 93.9% specificity for a cut-off of 5mm and 95.8% sensitivity and 97.1% specificity for a cut-off of 6mm. CONCLUSIONS: Either 5mm or 6mm could be used as the cut-off value for diagnosing ATL, as both values had high sensitivity and specificity.

Food handlers as a link in the chain of transmission of Giardia duodenalis and other protozoa in public schools in southern Brazil.

BACKGROUND: Food handlers (FHs) may facilitate transmission and dissemination of pathogens. The importance of FHs as a link in the epidemiological chain of transmission of Giardia duodenalis and other intestinal protozoa was assessed. METHODS: Fecal and subungual material from 27 FHs were analyzed using parasitological methods. G. duodenalis was identified by direct immunofluorescence and genotyped by PCR-RFLP for the bg and gdh genes, and gdh was sequenced. RESULTS: At least one protozoan was detected in 30% (8/27) of the FHs and G. duodenalis (19%; 5/27) was the most common species. The AII and BIV genotypes were found in 20% (1/5) and 60% (3/5) of FHs infected with G. duodenalis, respectively. CONCLUSIONS: FHs can be involved in the chain of transmission of G. duodenalis and other protozoa. GENBANK ACCESSION NUMBERS: KJ741310 - KJ741313.

Evaluation of the reference value for the Montenegro skin test

The Montenegro skin test (MST) has good clinical applicability and low cost for the diagnosis of American tegumentary leishmaniasis (ATL). However, no studies have validated the reference value (5mm) typically used to discriminate positive and negative results. We investigated MST results and evaluated its performance using different cut-off points.

Identical assemblage of Giardia duodenalis in humans, animals and vegetables in an urban area in southern Brazil indicates a relationship among them.

BACKGROUND: Giardia duodenalis infects humans and other mammals by ingestion of cysts in contaminated water or food, or directly in environments with poor hygiene. Eight assemblages, designated A-H, are described for this species. METHODOLOGY/PRINCIPAL FINDINGS: We investigated by microscopy or by direct immunofluorescence technique the occurrence of G. duodenalis in 380 humans, 34 animals, 44 samples of water and 11 of vegetables. G. duodenalis cysts present in samples were genotyped through PCR-RFLP of ß giardin and glutamate dehydrogenase (gdh) genes and sequencing of gdh. The gdh gene was amplified in 76.5% (26/34) of the human faeces samples with positive microscopy and in 2.9% (1/34) of negative samples. In 70.4% (19/27) of the positive samples were found BIV assemblage. In two samples from dogs with positive microscopy and one negative sample, assemblages BIV, C, and D were found. Cysts of Giardia were not detected in water samples, but three samples used for vegetable irrigation showed total coliforms above the allowed limit, and Escherichia coli was observed in one sample. G. duodenalis BIV was detected in two samples of Lactuca sativa irrigated with this sample of water. BIV was a common genotype, with 100% similarity, between different sources or hosts (humans, animals and vegetables), and the one most often found in humans. CONCLUSIONS/SIGNIFICANCE: This is the first study in Brazil that reports the connection among humans, dogs and vegetables in the transmission dynamics of G. duodenalis in the same geographic area finding identical assemblage. BIV assemblage was the most frequently observed among these different links in the epidemiological chain.

A pattern of adult involvement in highway acidentes / Um padrão de envolvimento dos adultos em acidentes rodoviários

This study aimed to identify the set of circumstances that contributed to the involvement of adults in traffic accidents. The study was of the cross-sectional type using secondary data. The patterns were identified through cluster analysis using a method called Hierarchical Ascendant Classification. Five classes were identified. Three classes involved males with minor injuries resulting from accidents between vehicles or vehicle-object, during the daytime and with dry road surface conditions. Two classes involved females, resulting in severe injuries, and were notable for occurring during the night and with a lower rate of use of seat belts. The findings of this study, especially in relation to the more serious accidents involving the female drivers, draw attention to this situation and point to a need for further studies involving these classes, which are increasingly common in traffic patterns.

Este estudo objetivou identificar o conjunto de circunstâncias que contribuíram para o envolvimento de adultos em acidentes de trânsito. Estudo descritivo transversal, utilizando dados secundários. Os padrões são identificados por meio de análise de grupo, através de um método chamado de Classificação Hierárquica Ascendente. Cinco classes foram identificadas. Três envolvendo homens resultando em agravos leves, a partir de acidentes entre veículos ou veículo-objeto, período diurno e em condições de pista seca. Duas envolvendo mulheres, resultando em gravidade, destacando-se a direção noturna e menor utilização do cinto de segurança. Os achados deste estudo, principalmente no que se refere aos acidentes graves envolvendo motoristas mulheres, chama a atenção e aponta novos estudos envolvendo estas, cada vez mais presentes no trânsito.