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.

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)

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.

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.

Fatores socioambientais associados à distribuição e à intensidade das geo-helmintíases em uma área urbana da Região de Marajó, estado do Pará, Brasil / Social and environmental factors associated with the distribution and intensity of geohelminthiasis in an urban area of ​​the Marajó Region, Pará State, Brazil

Introdução: As geo-helmintíases são doenças relacionadas à pobreza com altas taxas de prevalência em países em desenvolvimento. Objetivo: O presente estudo teve como objetivo descrever o cenário epidemiológico das geohelmintíases em uma população urbana da Amazônia brasileira. Metodologia: Foi realizado um inquérito transversal (n = 349 crianças e adolescentes de 1 a 15 anos) para obter amostras fecais, dados sociodemográficos e de saneamento. As técnicas parasitológicas utilizadas foram Kato-Katz e Ritchie. As análises estatísticas do estudo compreenderam as medidas de associação razão de chances (odds ratios; ORs). O teste exato de Fisher foi utilizado para avaliação da significância estatística com intervalos de confiança de 95%. Nos modelos bi e multivariado as associações foram consideradas estatisticamente significativas quando p < 0,05. Resultados: Entre as crianças e adolescentes, 143 (41%) eram positivos para pelo menos um geo-helminto. As taxas de prevalência de infecções por A. lumbricoides, T. trichiura e ancilostomídeos foram de 17,5%, 36,4% e 7,4%, respectivamente. Um modelo multivariado de regressão logística mostrou que a infecção por A. lumbricoides é significativamente mais frequente em crianças de 11-15 anos (odds ratio [OR] = 2,38; intervalo de confiança de 95% [IC] = 1,15-4,94; p = 0,018) e que a presença de latrinas dentro das casas é fator de proteção contra ascaridíase (OR = 0,38; IC 95% = 0,17-0,85; p = 0,019). A positividade para T. trichiura é maior nos grupos de 6-10 (OR = 3,31; IC 95% = 1,85-5,89; p <0,001) e de 11-15 anos (OR = 3,16; IC 95% = 1,66-6,00; p <0,001), em crianças que vivem em famílias pobres (OR = 1,78; IC 95% = 1,01-3,14; p <0,045) e praticando evacuação aberta (OR = 2,07; IC 95% = 1,07-3,99; p <0,029).

A ancilostomíase é mais frequente em crianças de 11-15 anos (OR = 6,70; IC 95% = 1,91-23,43; p = 0,002), no sexo masculino (OR = 6,35; IC 95% = 2,00-20,14; p = 0,002) e naqueles que moravam em palafitas (OR = 3,52; IC 95% = 1,22-10,12; p = 0,019). O uso de albendazol nos últimos seis meses foi fator de proteção contra a ancilostomíase (OR = 0,31; IC95% = 0,10-0,96; p = 0,042). A proporção de infecções leves, moderadas e pesadas foi, respectivamente, 55,2%, 37,8% e 7% para A. lumbricoides, 72,4%, 24,3% e 3,3% para T. trichiura e 93,8%, 3,1% e 3,1% para ancilostomídeos. Nas infecções por T. trichiura e ancilostomídeos maiores cargas parasitárias foram associadas à prática de defecação a céu aberto e morar em casas de palafitas. Conclusões: Os dados apontam para a necessidade de melhoria da infraestrutura de saneamento em localidades amazônicas estudadas com características sociodemográficas e ambientais semelhantes. (AU)