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)

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.

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.

Ancilostomíase e outras parasitoses intestinais na região dos Carnaubais: estudo transversal no Município de Nossa Senhora de Nazaré, Piauí / Hookworm and other intestinal parasites in the region of Carnaubais:Transversal study in the city of Nossa Senhora de Nazaré, Piauí

As estratégias brasileiras de controle das geohelmintíases têm sido alinhadas àquelas propostas pela Organização Mundial da Saúde, o tratamento periódico coletivo de crianças em idade escolar com drogas anti-helmínticas. Esta estratégia potencialmente leva a um desconhecimento dos cenários epidemiológicos regionais. O presente estudo visou estimar a prevalência e a distribuição das parasitoses intestinais em um município da Região dos Carnaubais, no estado do Piauí. Foi realizado um estudo transversal incluindo 81 famílias e 298 pessoas. As técnicas parasitológicas utilizadas foram o Ritchie, Faust, Kato-Katz e Baerman-Moraes. As prevalências dos diferentes parasitas intestinais foram as seguintes: ancilostomídeos, 14,1% (42/298); Strongyloides stercoralis,0,34% (1/298), Enterobius vermiculares, 3% (9/298) e Rodentolepis nana, 0,34% (1/298), Giardiaintestinalis, 8,4% (25/298) e E. histolytica/E. dispar, 1,3% (4/298). Dos participantes positivos,76,3% (87/114) estavam mono parasitados e 23,6% (27/114) apresentavam dois agentes parasitário sou mais. Entre as 42 pessoas com ancilostomíase, foi possível determinar a carga parasitária de 27(64,3%). Entre estas, 24 (89%) tinham infecções de baixa intensidade caracterizadas por carga parasitária inferior a 2.000 ovos por grama (opg) de fezes, com média de 318 ± 348 opg.Observaram-se 3 pessoas (11,1%) com infecções de média intensidade (2.000 a 3.999 opg). Há uma tendência de aumento da intensidade da infecção com a redução da idade (R = -0,26), porém sem significância estatística (p = 0,195). Foram medidos 17 exemplares de ovos de ancilostomídeos. O comprimento dos ovos variou entre 53,52 µm e 65,7 µm, com média de 61 ± 3,4 µm. A largura variou entre 37,32 µm e 43,15 µm, com média de 40,29 ± 1,94 µm. Desta forma, o comprimento e alargura de todos os ovos é compatível com ancilostomídeos, Observaram-se casos de ancilostomíase em quase todas as localidades pesquisadas...

Brazilian strategies for soil transmitted helminthiases (STH) control have been aligned to thoseproposed by the World Health Organization, the collective and periodic treatment of schoolchildren with anthelmintic drugs. This strategy potentially leads to a lack of regionalepidemiological scenarios. The present study aimed to estimate the prevalence and distributionof STHs in the state of Piaui. A cross-sectional study including 81 families and 298 subjects wasconducted. Parasitological techniques used were Ritchie, Faust, Kato-Katz and Baerman-Moraes.The prevalence of different intestinal parasites were: hookworms, 14.1% (42/298); Strongyloidesstercoralis, 0.34% (1/298), Enterobius vermicularis, 3% (9/298), Rodentolepis nana, 0.34%(1/298), Giardia intestinalis, 8.4% (25/298) and E. histolytica / E.dispar, 1.3% (4/298). Amongpositive participants, 76.3% (87/114) had one parasite and 23.6% (27/114) had two or moreparasitic organisms. Among 42 subjects with hookworms, we determined the parasite load of 27(64.3%). Among these, 24 (89%) had low intensity infections characterized by parasitic loadbelow 2,000 eggs per gram (EPG) of feces, averaging 318 ± 348 epg. Three persons wereobserved (11.1%) with moderate intensity of infection (2000-3999 epg). There is a trend ofincreasing intensity of infection with decreasing age (R = -0.26), but without statisticalsignificance (p = 0.195). 17 samples of hookworm eggs were measured. The length of the eggsranged between 53.52 m and 65.7 µm averaging 61 ± 3.4 µm. The width varied between 37.32µm and 43.15 µm averaging 40.29 ± 1.94 µm. Thus, the length and width of all eggs iscompatible with hookworms. Cases of hookworm infection were observed in almost all studiedlocations...