A molecular and morphological study of Ascaris suum in a human-pig contact scenario in northeastern Brazil.

The aim of the present study was to assess morphologic and genetic data on ascariasis in swine (Sus scrofa domesticus) and humans in low-resource rural and periurban communities in the state of Piauí, Brazil. Our cross-sectional survey included 100 fecal samples obtained from swine and 682 samples from humans. Fifteen pigs were necropsied. Human and porcine fecal samples were examined to identify Ascaris eggs. Parasites obtained in the swine necropsies were studied using scanning electron microscopy (SEM), and the mitochondrial gene encoding the cytochrome oxidase 1 (cox1) enzyme was partially amplified and sequenced for molecular taxonomy and phylogenetic analyses. The overall prevalence of Ascaris eggs in the swine fecal samples was 16/100 (16%). No Ascaris eggs were identified in the human fecal samples. SEM of six worms recovered from pigs demonstrated morphological characteristics of A. suum. Cox1 sequences were compatible with A. suum reference sequences. Original and reference (GenBank) nucleotide sequences were organized into clusters that did not segregate the parasites by host species or and region. The largest haplogroups were dominated by haplotypes H01, H02 and H31. In the communities studied, there was no epidemiological evidence of the zoonotic transmission of ascariasis at the human-swine interface.

Trend of morbidity and mortality indicators due to acute diarrheal disease in children under five years old in the State of Piauí (2000-2019) / Tendência de indicadores de morbimortalidade por doenças diarreicas agudas em menores de cinco anos no estado do Piauí (2000-2019)

Abstract Objectives: to analyze the trend of morbidity and mortality indicators due to acute diarrheal diseases in children under five years old in Piauí. Methods: ecological study with data from the Information Technology Department at the Public Health System. The indicators of hospitalization rate and coefficient of mortality from the disease between 2000 and 2019 were calculated. A descriptive analysis of the indicators was carried out in the studied period and by the macro-regions in the State. For trend analysis, the simple linear regression model with log-transformation was used. Trends were classified as increasing, decreasing and stable, with a significance level of 5%. Results: the average on hospitalization rate was higher in the semi-arid macro-region (36.6/1000 children under five years old) and lower in Teresina (14.9/1000 children under five years old). The mean mortality coefficients were higher in the coastal macro-region (0.98/1000 live births) and lower in Teresina (0.47/1000 live births). The indicators showed a downward trend in all analyzed locations (p<0.05). A turning point was noted from 2009, with a significant reduction in hospitalization rates in the savanna and semi-arid macro-regions. Conclusion: indicators of morbidity and mortality due to acute diarrheal diseases in children under five years old showed a downward trend in Piauí between 2000 and 2019, with differences in trends between the evaluated macro-regions.

Resumo Objetivos: analisar a tendência de indicadores de morbimortalidade por doenças diarreicas agudas em menores de cinco anos no Piauí. Métodos: estudo ecológico com dados do Departamento de Informática do Sistema Único de Saúde. Calculou-se os indicadores taxa de internação e coeficiente de mortalidade pela doença entre 2000 e 2019. Realizou-se análise descritiva dos indicadores no período estudado e pelas macrorregiões do estado. Para análise da tendência, foi utilizado o modelo de regressão linear simples com log-transformação. As tendências foram classificadas como crescentes, decrescentes e estáveis, com nível de significância de 5%. Resultados: a média das taxas de internação foi maior na macrorregião semiárido (36,6/1000 menores de cinco anos) e menor em Teresina (14,9/1000 menores de cinco anos). A média dos coeficientes de mortalidade foi maior na macrorregião litoral (0,98/1000 nascidos vivos) e menor em Teresina (0,47/1000 nascidos vivos). Os indicadores mostraram tendência de redução em todos os locais analisados (p<0,05). Notou-se um ponto de inflexão a partir de 2009, com redução significativa das taxas de internação nas macrorregiões cerrados e semiárido. Conclusão: os indicadores de morbimortalidade por doenças diarreicas agudas em menores de cinco anos mostraram tendência de redução no Piauí entre 2000 e 2019, com diferenças das tendências entre as macrorregiões avaliadas.

A molecular and morphological study of Ascaris suum in a human-pig contact scenario in northeastern Brazil / Estudo molecular e morfológico de Ascaris suum em um cenário de contato entre suínos e humanos no nordeste brasileiro

The aim of the present study was to assess morphologic and genetic data on ascariasis in swine (Sus scrofa domesticus) and humans in low-resource rural and periurban communities in the state of Piauí, Brazil. Our cross-sectional survey included 100 fecal samples obtained from swine and 682 samples from humans. Fifteen pigs were necropsied. Human and porcine fecal samples were examined to identify Ascaris eggs. Parasites obtained in the swine necropsies were studied using scanning electron microscopy (SEM), and the mitochondrial gene encoding the cytochrome oxidase 1 (cox1) enzyme was partially amplified and sequenced for molecular taxonomy and phylogenetic analyses. The overall prevalence of Ascaris eggs in the swine fecal samples was 16/100 (16%). No Ascaris eggs were identified in the human fecal samples. SEM of six worms recovered from pigs demonstrated morphological characteristics of A. suum. Cox1 sequences were compatible with A. suum reference sequences. Original and reference (GenBank) nucleotide sequences were organized into clusters that did not segregate the parasites by host species or and region. The largest haplogroups were dominated by haplotypes H01, H02 and H31. In the communities studied, there was no epidemiological evidence of the zoonotic transmission of ascariasis at the human-swine interface.(AU)

O presente estudo teve como objetivo acessar dados morfológicos e genéticos sobre a ascaridíase em suínos (Sus scrofa domesticus) e humanos, em comunidades rurais e periurbanas no estado do Piauí. O estudo transversal incluiu 100 amostras fecais de suínos e 682 amostras obtidas de humanos. Quinze suínos foram necropsiados. Amostras fecais suínas e humanas foram examinadas para detecção de ovos de Ascaris. Os parasitas adultos, obtidos nas necropsias, foram estudados através de microscopia eletrônica de varredura (MEV), e o gene mitocondrial codificante da enzima citocromo oxidase 1 (cox1) foi parcialmente amplificado e sequenciado para análises filogenéticas e de taxonomia molecular. A prevalência de Ascaris em amostras fecais de suínos foi 16/100 (16%), não sendo identificado nenhum caso de infecção por este parasita em humanos. A análise por MEV de parasitas recuperados de suínos demonstrou características morfológicas de Ascaris suum. As sequências nucleotídicas de cox1 foram compatíveis com A. suum. As sequências originais e de referência (obtidas no GeneBank) foram organizadas em clusters que não segregaram os parasitas por hospedeiro ou região geográfica. Os maiores haplogrupos foram dominados pelos haplótipos H01, H02 e H31. Nas comunidades estudadas, não foi evidenciada transmissão zoonótica de A. suum na interface suíno-humana.(AU)

Cytochrome c oxidase subunit 1 gene reveals species composition and phylogenetic relationships of Oesophagostomum spp. infecting pigs in northeastern Brazil.

Helminths of the genus Oesophagostomum cause enteric diseases and affect domestic animals such as pigs. The aim of this study was to explore the species composition and genetic diversity of Oesophagostomum spp. infecting pigs in close contact with humans in the state of Piauí, Brazil. Eighty-seven fecal samples were collected for parasitological tests and molecular analysis. Through microscopy, the overall positivity rate for strongyliform eggs was 81.6% among the pigs studied. Forty-two strongyliform egg samples were subjected to PCR and six cox1 sequences (637 bp) were identified for the genus Oesophagostomum. The sequences were identified as Oesophagostomum dentatum, O. quadrispinulatum and O. columbianum. In the phylogenetic tree and haplotype network, 89 sequences were separated into seven clusters, which also included reference sequences from GenBank. Oesophagostomum dentatum and O. quadrispinulatum were seen to be closely related species and formed a monophyletic group related to O. aculeatum. Oesophagostomum columbianum showed similarity with sequences from parasites infecting small ruminants and the clade was positioned closer to O. bifurcum. High interspecific diversity was found and intraspecific diversity varied according to the species. This was the first study to characterize Oesophagostomum DNA sequences obtained from pigs in Brazil.

Epidemiology, species composition and genetic diversity of tetra- and octonucleated Entamoeba spp. in different Brazilian biomes.

BACKGROUND: Entamoeba species harbored by humans have different degrees of pathogenicity. The present study explores the intra- and interspecific diversity, phylogenetic relationships, prevalence and distribution of tetra- and octonucleated cyst-producing Entamoeba in different Brazilian regions. METHODS: Cross-sectional studies were performed to collect fecal samples (n = 1728) and sociodemographic data in communities located in four Brazilian biomes: Atlantic Forest, Caatinga, Cerrado, and Amazon. Fecal samples were subjected to molecular analysis by partial small subunit ribosomal DNA sequencing (SSU rDNA) and phylogenetic analysis. RESULTS: Light microscopy analysis revealed that tetranucleated cysts were found in all the studied biomes. The highest positivity rates were observed in the age group 6-10 years (23.21%). For octonucleated cysts, positivity rates ranged from 1 to 55.1%. Sixty SSU rDNA Entamoeba sequences were obtained, and four different species were identified: the octonucleated E. coli, and the tetranucleated E. histolytica, E. dispar, and E. hartmanni. Novel haplotypes (n = 32) were characterized; however, new ribosomal lineages were not identified. The Entamoeba coli ST1 subtype predominated in Atlantic Forest and Caatinga, and the ST2 subtype was predominant in the Amazon biome. E. histolytica was detected only in the Amazon biome. In phylogenetic trees, sequences were grouped in two groups, the first containing uni- and tetranucleated and the second containing uni- and octonucleated cyst-producing Entamoeba species. Molecular diversity indexes revealed a high interspecific diversity for tetra- and octonucleated Entamoeba spp. (H ± SD = 0.9625 ± 0.0126). The intraspecific diversity varied according to species or subtype: E. dispar and E. histolytica showed lower diversity than E. coli subtypes ST1 and ST2 and E. hartmanni. CONCLUSIONS: Tetra- and octonucleated cyst-producing Entamoeba are endemic in the studied communities; E. histolytica was found in a low proportion and only in the Amazon biome. With regard to E. coli, subtype ST2 was predominant in the Amazon biome. The molecular epidemiology of Entamoeba spp. is a field to be further explored and provides information with important implications for public health.

Perfil epidemiológico e conhecimento de gestantes sobre aleitamento materno em um município do nordeste brasileiro / Epidemiological profile and knowledge of pregnant women regarding breastfeeding in a city in northeastern Brazil

O aleitamento materno exclusivo propicia saúde ao recém-nascido e à mulher, fortalece o vínculo mãe e filho e leva à redução na mortalidade infantil. Objetivo: Identificar o perfil e os conhecimentos sobre aleitamento materno de gestantes atendidas em Unidades Básicas de Saúde, durante o pré-natal, no município de Gilbués, Piauí, Brasil. Material e Métodos: Trata-se de um estudo descritivo e abordagem quantitativa, com coleta de dados por meio de um formulário sobre as características sociodemográficas e conhecimentos em relação ao aleitamento materno. O estudo foi realizado com 40 gestantes nas Unidades Básicas de Saúde dos bairros São José e Santo Antônio. Resultados: Das gestantes, 75% estavam na segunda gestação ou mais e 47,5% no segundo trimestre gestacional. A maioria apresentou idade entre 18 e 30 anos, era solteira, possuía o ensino fundamental, não exercia atividade profissional e possuía renda familiar de até um salário mínimo. Quanto aos conhecimentos sobre aleitamento materno, houve orientação no pré-natal, porém, com pouca incorporação acerca dos benefícios que essa prática pode proporcionar à mãe. Apontaram-se, ainda, dúvidas e/ou inseguranças das gestantes sobre a quantidade de leite produzido e sua capacidade de nutrição, surgimento de fissuras na mama e transmissão de doenças por meio da amamentação. Conclusão: As atividades de educação em saúde no pré-natal são fundamentais para a saúde da criança e da mulher, promovendo estratégias de promoção, apoio e incentivo ao aleitamento materno.

Exclusive breastfeeding provides health to both the newborn and the mother, strengthening the bond between mother and child and leading to a reduction in infant mortality. Objective: Identify the profile and knowledge about breastfeeding of pregnant women attended at the Basic Health Units during prenatal care in the city of Gilbués, Piauí, Brazil. Methodology: This is a descriptive study, with a quantitative approach collected through a form on sociodemographic characteristics and knowledge regarding breastfeeding. The study was performed considering 40 pregnant women seen at the UBSs in the São José and Santo Antônio neighborhood. Results: Among the patients, 75% were in their second pregnancy or more, and 47.5% in the second gestational trimester. Most of them were aged between 18 and 30 years old, single, had only elementary education, did not work, and had family income up to a minimum wage. Regarding the knowledge about breastfeeding, they received guidance in the prenatal care, but with little emphasis on the benefits that exclusive breastfeeding can also provide to the mother. The doubts and/or insecurities of pregnant women were related to the amount of milk produced and its nutritional capacity, the appearance of cracks on the breast, and the transmission of diseases through breastfeeding. Conclusions: Prenatal health education activities are essential for the health of the child and the pregnant woman by providing strategies to promote, support, and encourage breastfeeding.

Socioenvironmental Factors Influencing Distribution and Intensity of Soil-Transmitted Helminthiasis in the Brazilian Amazon: Challenges for the 2030 Agenda.

Soil-transmitted helminthiasis (STHs) are poverty-related diseases with high prevalence rates in developing countries. The present study aims to describe the epidemiological scenario of STHs in an urban population in the Brazilian Amazon. A cross-sectional survey (n = 349 children aged 1-15 years) was carried out to obtain faecal samples and sociodemographic and sanitation data. Among the children, 143 (41%) were positive for at least one STH. Prevalence rates of infections by A. lumbricoides, T. trichiura, and hookworms were 24.4%, 42.6%, and 9%, respectively. A logistic regression multivariate model showed that infection with A. lumbricoides is significantly more frequent in children aged 11-15 years (odds ratio [OR] = 2.38; 95% confidence interval [CI] = 1.15-4.94; p=0.018) and the presence of latrines inside houses is a protection factor against ascariasis (OR = 0.38; 95% CI = 0.17-0.85; p=0.019). Positivity for T. trichiura is higher in the 5-10 (OR = 3.31; 95% IC = 1.85-5.89; p=0.001) and 11-15 age groups (OR = 3.16; 95% IC = 1.66-6.00; p=0.001), in children living in poor families (OR = 1.78; 95% IC = 1.01-3.14; p=0.045) and practicing open evacuation (OR = 2.07; 95% IC = 1.07-3.99; p=0.029). Hookworm infection is more frequent in children aged 11-15 years (OR = 6.70; 95% IC = 1.91-23.43; p=0.002), males (OR = 6.35; 95% IC = 2.00-20.14; p=0.002), and those living in stilt houses (OR = 3.52; 95% IC = 1.22-10.12; p=0.019). The use of albendazole in the last six months was a protection factor against hookworm infection (OR = 0.31; 95% IC = 0.10-0.96; p=0.042). The proportion of mild, moderate, and severe infections was 55.2%, 37.8%, and 7%, respectively, for A. lumbricoides, 72.4%, 24.3%, and 3.3% for T. trichiura, and 93.8%, 3.1%, and 3.1% for hookworms. Significantly higher worm burdens in T. trichiura and hookworm infections were associated with practicing open defecation and living in stilt houses. The data points to the need to improve sanitation infrastructure in Amazonian cities with similar sociodemographic and environmental characteristics.

Interactions between malnutrition, soil-transmitted helminthiasis and poverty among children living in periurban communities in Maranhao State, Northeastern Brazil.

Poverty, malnutrition and neglected tropical diseases such as soil-transmitted helminthiases (STHs) interact in a multi-causal feedback network. This study aimed to assess the relationships between STHs, income and nutritional status of children in impoverished communities in the city of Caxias, Maranhao State, Northeastern Brazil. A cross-sectional survey (n=259 children) was carried out with the collection of fecal samples and assessment of sociodemographic, anthropometric, dietary and sanitation data. Hookworm infection and ascariasis presented prevalence rates of 14.3% and 9.3%, respectively. The logistic regression analysis showed that hookworm infection was more frequent in males (odds ratio [OR]=3.43; 95% confidence interval [CI]=1.45-8.08), children aged 11-15 years old (OR=3.72; 95% CI=1.19-11.62), children living in poor families (OR=2.44; 95% CI=1.04-5.68) and those living in rented houses (OR=5.74; 95%CI=1.91-17.25). Concerning ascariasis, living in the Caldeiroes community (OR=0.01; 95%CI=0-0.17) and belonging to the 11-15 years age group (OR=0.21; 95%CI=0.04-1.02) were protection factors. Poor children have a significantly lower frequency of consumption of meat, milk, vegetables, tubers and fruits than not poor children. The frequent consumption of meat, milk and tubers was associated with significant higher values in the parameter height-for-age, whereas the consumption of meat and milk positively influenced the weight-for-age. The frequencies of stunting, underweight and wasting were 8.1%, 4.9% and 2.9%, respectively. The multivariate model demonstrated that stunting was significantly associated with economic poverty (OR=2.82; 95%CI=1.03-7.70) and low weight was associated with male sex (OR=6.43; 95% CI=1.35-30.68). In conclusion, the study describes the interactions between the dimensions of development represented by income, STHs and nutritional status revealing the importance of raising income levels to improve the living conditions of families in impoverished communities in Northeastern Brazil.

Mitochondrial DNA reveals species composition and phylogenetic relationships of hookworms in northeastern Brazil.

Hookworm infection persists focally in rural communities in Brazil. In this study, we analyze the mitochondrial nucleotide sequences obtained from hookworms infecting humans in order to characterize species composition and assess their genetic diversity and phylogenetic relationships. Field expeditions and cross-sectional surveys were carried out in three Brazilian municipalities from 2013 to 2017: Nossa Senhora de Nazaré (n = 605) and Teresina (n = 297), in the state of Piauí, and Russas (n = 213) in the State of Ceará. Parasitological methods were used to evaluate fecal samples. Hookworm-positive samples had a partial mtDNA cox1 amplified and sequenced. Maximum-likelihood and Bayesian analysis demonstrated two strongly-supported clades, including Group A, corresponding to Necator americanus, and Groups B and C, corresponding to Necator sp. Group A was divided into three main clusters: A1 grouped with Asian sequences, A2 grouped with African sequences, and A3 had only Asian sequences. Group B was closely related to Necator sp., showing a sequence similarity of 98%-99% with African samples circulating zoonotically among humans and non-human primates. Twenty three N. americanus haplotypes were identified. N. americanus Median-Joining network revealed three distinct groups, designated again as A1, A2, and A3. Group A1 presented a star-like shape, with one dominant haplotype. The molecular dating suggested that the two clades dividing N. americanus and Necator sp. began to diverge during the middle Pleistocene. The most recent common ancestor among N. americanus groups was dated to the late Pleistocene. Hookworms circulating in the studied communities are structured in well-defined subpopulations presenting both Asian and African genetic backgrounds. This reveals a double origin for hookworms in northeastern Brazil and opens up new possibilities in phylogeographic, evolutionary, and molecular epidemiological studies in regions where hookworms persists focally, despite control efforts. The presence of potentially zoonotic species and the specific identification of Necator sp. should be further investigated.

Focal persistence of soil-transmitted helminthiases in impoverished areas in the State of Piaui, Northeastern Brazil.

This study aims to describe the prevalence, distribution, and factors associated with soil-transmitted helminthiases (STHs) in rural localities in Piaui, Brazil. Two cross-sectional surveys (n=605 subjects; 172 families) were carried out in order to obtain socio-demographic, anthropometric, spatial and parasitological data. Parasites were evaluated using Kato-Katz and centrifugal sedimentation techniques. Eggs were measured to assess infection with zoonotic Strongylida parasites. Kernel maps were constructed with Q-GIS. The prevalence of hookworm infection was 12.4% (75/605). Other helminthes found were Trichuris trichiura (n=1; 0.2%) and Hymenolepis nana (n=1; 0.2%). The hookworm positivity rate was significantly lower among subjects who had used albendazole when compared with individuals who had not used anthelmintics or had used antiprotozoal drugs in the last 6 months (8/134 [6.0%] vs. 59/415 [14.2%]; p=0.009). A total of 39/172 (22.7%) families had at least one infected member. The association between the number of dwellers and hookworm positivity in the family was present in a logistic regression multivariate model. Assessment of worm burdens showed 92.2% light, 6.2% moderate, and 1.6% heavy infections. Hookworm eggs (n=34) measured 57.2 - 75.4 µm in length and 36.4 - 44.2 µm in width (mean ± SD = 65.86 ± 4.66 µm L and 40.05 ± 1.99 µm W), commensurate with human hookworms. Hotspots suggest that transmission has a focal pattern. STHs persist in impoverished rural areas in Northeastern Brazil where currently available control strategies (mass drug administration) apparently do not allow the elimination of the infection.

Genetic diversity of Giardia duodenalis circulating in three Brazilian biomes.

Giardia duodenalis has a wide genetic variety, and its characterization helps in the understanding of its transmission dynamics and in the development control strategies. This study aimed to assess the genetic diversity of G. duodenalis obtained in different Brazilian biomes and estimate their phylogenetic relationships. Three surveys including 944 participants were carried out in the municipalities of Russas (RSS, Caatinga semiarid biome), Santa Isabel do Rio Negro (SIRN, Amazon rainforest biome) and Nossa Senhora de Nazaré (NSN, Cerrado-Caatinga transition biome). G. duodenalis-positive fecal samples were submitted to amplification of gene fragments encoding ß-giardin (ßG, N = 71), glutamate dehydrogenase (GDH, N = 42), and triosephosphate isomerase (TPI, N = 27). Overall detection rates of assemblage A in G. duodenalis-positive samples through ßG, GDH and TPI were 22/71 (31%), 13/42 (31%), and 13/27 (48.1%), respectively. Concerning assemblage B, rates with distinct genetic markers were 49/71 (69%), 29/42 (69%), and 14/27 (51.9%), respectively. In the Amazon, assemblage B was more prevalent (77.8%, 71.8% and 65% through ßG, GDH and TPI, respectively), while in the Cerrado biome assemblage A predominated (50%, 66.6%, and 85.7%, through ßG, GDH and TPI, respectively). In Caatinga biome assemblage A also predominated (71.4%, through ßG). Thirty new sub-assemblages are described for assemblage B (24 ßG and six TPI), as well as three new sub-assemblages are described for assemblage A (one GDH and 2 TPI). Higher genetic diversity of assemblage B in the Amazon may be related to demographic concentration leading to a more complex transmission network within a poorer sanitation background. The high genetic divergence between assemblages A and B (5.5-6.3%) support the proposal of taxon separation in distinct species.

Giardia intestinalis infection associated with malnutrition in children living in northeastern Brazil.

INTRODUCTION: The present study aimed to determine the prevalence and factors associated with Giardia intestinalis infection, verifying its impact on the nutritional status of children in northeastern Brazil. METHODOLOGY: A cross-sectional study was conducted to obtain parasitological, sociodemographic, and anthropometric data in two municipalities in the states of Piauí and Ceará, northeastern Brazil. RESULTS: Prevalence of giardiasis was 55/511 (10.8%). G. intestinalis was more frequent in people living in poverty (30/209 [14.4%], p = 0.041), performing open evacuation (26/173 [15%], p = 0.034), and drinking rainwater stored in cisterns (9/56 [16.1%], p = 0.005). The proportion of stunting and being underweight in children infected with G. intestinalis was significantly higher than that in uninfected children (5/23 [21.7%] vs. 10/179 [5.6%], p = 0.017, OR = 4.69, 95% confidence interval [CI] = 1.44-15.25 and 5/23 [21.7%] vs. 13/179 [7.3%], p = 0.038, OR = 3.54, 95% CI = 1.13-11.09, respectively). Infection with G. intestinalis remained significantly associated with stunting and being underweight after adjustment for poverty, municipality, sex, and age in a logistic regression multivariate model. CONCLUSIONS: In rural areas in northeastern Brazil, giardiasis has acquired great public health importance in the soil-transmitted helminths control era, impacting the nutritional status of children and requiring new approaches to diagnosis and treatment and translational research that could generate applicable solutions at the community level.

Frequency and molecular characterisation of Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, and Entamoeba hartmanni in the context of water scarcity in northeastern Brazil.

This study aimed to estimate the frequency, associated factors, and molecular characterisation of Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, andEntamoeba hartmanni infections. We performed a survey (n = 213 subjects) to obtain parasitological, sanitation, and sociodemographic data. Faecal samples were processed through flotation and centrifugation methods.E. histolytica, E. dispar, E. moshkovskii, and E. hartmanni were identified by nested-polymerase chain reaction (PCR). The overall prevalence of infection was 22/213 (10.3%). The infection rate among subjects who drink rainwater collected from roofs in tanks was higher than the rate in subjects who drink desalinated water pumped from wells; similarly, the infection rate among subjects who practice open defecation was significantly higher than that of subjects with latrines. Out of the 22 samples positive for morphologically indistinguishableEntamoeba species, the differentiation by PCR was successful for 21. The species distribution was as follows: 57.1% to E. dispar, 23.8% to E. histolytica, 14.3% toE. histolytica and E. dispar, and 4.8% E. dispar and E. hartmanni. These data suggest a high prevalence of asymptomatic infection by the group of morphologically indistinguishable Entamoeba histolytica/dispar/moshkovskiicomplex and E. hartmanni species. In this context of water scarcity, the sanitary and socioenvironmental characteristics of the region appear to favour transmission.

Frequency and molecular characterisation of Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, and Entamoeba hartmanni in the context of water scarcity in northeastern Brazil

This study aimed to estimate the frequency, associated factors, and molecular characterisation of Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, andEntamoeba hartmanni infections. We performed a survey (n = 213 subjects) to obtain parasitological, sanitation, and sociodemographic data. Faecal samples were processed through flotation and centrifugation methods.E. histolytica, E. dispar, E. moshkovskii, and E. hartmanni were identified by nested-polymerase chain reaction (PCR). The overall prevalence of infection was 22/213 (10.3%). The infection rate among subjects who drink rainwater collected from roofs in tanks was higher than the rate in subjects who drink desalinated water pumped from wells; similarly, the infection rate among subjects who practice open defecation was significantly higher than that of subjects with latrines. Out of the 22 samples positive for morphologically indistinguishableEntamoeba species, the differentiation by PCR was successful for 21. The species distribution was as follows: 57.1% to E. dispar, 23.8% to E. histolytica, 14.3% toE. histolytica and E. dispar, and 4.8% E. dispar and E. hartmanni. These data suggest a high prevalence of asymptomatic infection by the group of morphologically indistinguishable Entamoeba histolytica/dispar/moshkovskiicomplex and E. hartmanni species. In this context of water scarcity, the sanitary and socioenvironmental characteristics of the region appear to favour transmission.

Diagnóstico diferencial entre a febre maculosa brasileira e o dengue no contexto das doenças febris aguda / Differential diagnosis between the Brazilian spotted fever and dengue in the context of acute febrile diseases

Doenças febris agudas são comuns e frequentemente associadas com agentes infecciosos em países tropicais como o Brasil. Com manifestações clínicas inespecíficas de difícil diferenciação de uma série de doenças endêmicas como dengue, leptospirose e outras doenças graves, a febre maculosa brasileira raramente tem sido considerada no diagnóstico. Este fato tem retardado o tratamento antimicrobiano específico e, por isso, determinado a elevada letalidade frequentemente observada no País. Neste artigo, discute-se a dificuldade do diagnóstico diferencial entre a febre maculosa brasileira e o dengue, uma das doenças infecciosas mais importantes e frequentes no Brasil e causadora de epidemias relatadas periodicamente, visto que a possibilidade de erros no diagnóstico em virtude da semelhança clínica é uma realidade.

Acute febrile diseases are common and often associated with infectious agents in tropical countriessuch as Brazil. As it has nonspecific clinical manifestations and is hard to differentiate from a numberof endemic diseases such as dengue, leptospirosis, and other fatal diseases, Brazilian spotted fever(FMB) has rarely been considered in diagnosis, a fact that has lead to a consequent delay in thespecific antimicrobial treatment, and has determined the high lethality often observed in this country.In this article the authors discuss the difficulty of the differential diagnosis of FMB and dengue,one of the most important and frequent infectious diseases in Brazil, where epidemics are reportedregularly and the possibility of errors in diagnosis due to clinical similarity is a reality.

Estudo molecular da febre maculosa brasileira no diagnóstico diferencial com dengue no estado do Rio de Janeiro durante o período de 2010 a 2011 / Molecular study of brazilian spotted fever in the differential diagnosis with dengue in the state of Rio de Janeiro during the period from 2010 to 2011

Doenças febris agudas são comuns e frequentemente associadas com agentes infecciosos em países tropicais como o Brasil. Com manifestações clínicas inespecíficas de difícil diferenciação com uma série de doenças endêmicas como dengue, leptospirose e outras doenças fatais, a febre maculosa brasileira (FMB) raramente tem sido considerada no diagnóstico, fato que, com o consequente retardo no tratamento antimicrobiano específico, tem determinado a elevada letalidade frequentemente observada em nosso país. A dengue é uma das doenças infecciosas mais importantes e frequentes no Brasil, onde epidemias são relatadas periodicamente no estado do Rio de Janeiro...

Acute febrile diseases are common and often associated with infectious agents in tropical countries such as Brazil. With nonspecific clinical manifestations and hard to differentiate with a number of endemic diseases such as dengue, leptospirosis, and other fatal diseases, Brazilian Spotted Fever (BSF) has rarely been considered in the diagnosis, fact that with the consequent delay in the specific antimicrobial treatment, has determined high lethality often observed in our country. Dengue is one of the most important and frequent infectious diseases in Brazil, where epidemics are reported periodically in the State of Rio de Janeiro.

Lower richness of small wild mammal species and chagas disease risk.

A new epidemiological scenario involving the oral transmission of Chagas disease, mainly in the Amazon basin, requires innovative control measures. Geospatial analyses of the Trypanosoma cruzi transmission cycle in the wild mammals have been scarce. We applied interpolation and map algebra methods to evaluate mammalian fauna variables related to small wild mammals and the T. cruzi infection pattern in dogs to identify hotspot areas of transmission. We also evaluated the use of dogs as sentinels of epidemiological risk of Chagas disease. Dogs (n = 649) were examined by two parasitological and three distinct serological assays. kDNA amplification was performed in patent infections, although the infection was mainly sub-patent in dogs. The distribution of T. cruzi infection in dogs was not homogeneous, ranging from 11-89% in different localities. The interpolation method and map algebra were employed to test the associations between the lower richness in mammal species and the risk of exposure of dogs to T. cruzi infection. Geospatial analysis indicated that the reduction of the mammal fauna (richness and abundance) was associated with higher parasitemia in small wild mammals and higher exposure of dogs to infection. A Generalized Linear Model (GLM) demonstrated that species richness and positive hemocultures in wild mammals were associated with T. cruzi infection in dogs. Domestic canine infection rates differed significantly between areas with and without Chagas disease outbreaks (Chi-squared test). Geospatial analysis by interpolation and map algebra methods proved to be a powerful tool in the evaluation of areas of T. cruzi transmission. Dog infection was shown to not only be an efficient indicator of reduction of wild mammalian fauna richness but to also act as a signal for the presence of small wild mammals with high parasitemia. The lower richness of small mammal species is discussed as a risk factor for the re-emergence of Chagas disease.