Moving beyond the state of the art of understanding resistance mechanisms in hookworms: confirming old and suggesting new associated SNPs.

Hookworms represent a serious problem for human and animal health in different parts of the world. One of the suggested control strategies for parasitosis caused by members of the Ancylostomatidae family is mass drug aministration with benzimidazole compounds. This strategy has been proven to lead to the establishment of resistant strains in several nematodes related to SNPs at codons 167, 198 and 200 of the beta-tubulin isotype-1 gene. Through bioassay and in vivo analysis, we successfully isolated an albendazole-resistant A. ceylanicum strain by drug selective pressure. We observed a strong correlation between the presence of SNPs at codon 198 and drug resistance. We also described for the first time, in hookworms, the presence of SNP A200L, already described at low frequencies in ruminant nematodes. The results presented here are important for updating the current knowledge about anthelmintic resistance in hookworms. The answers and the new questions raised may provide a basis for the establishment of more effective control strategies.

First identification of the benzimidazole resistance-associated F200Y SNP in the beta-tubulin gene in Ascaris lumbricoides.

The main control strategy for Ascaris lumbricoides is mass drug administration (especially with benzimidazoles), which can select strains of parasites resistant to treatment. Mutations in the beta-tubulin isotype-1 gene at codons 167, 198 and 200 have been linked to benzimidazole resistance in several nematodes. The mutation in codon 200 is the most frequent in different species of parasites, as previously observed in Necator americanus and Trichuris trichiura; however, this mutation has never been found in populations of A. lumbricoides. This study aimed to screen for single nucleotide polymorphisms (SNPs) in the beta-tubulin isotype-1 gene at codon 200 in A. lumbricoides. We developed a technique based on an amplification refractory mutation system (ARMS-PCR) for the analysis of 854 single A. lumbricoides eggs collected from 68 human stool samples from seven Brazilian states. We detected the mutation in codon 200 at a frequency of 0.5% (4/854). This is the first report of this mutation in A. lumbricoides. Although the observed frequency is low, its presence indicates that these parasite populations have the potential to develop high levels of resistance in the future. The methodology proposed here provides a powerful tool to screen for the emergence of anthelmintic resistance mutations in parasitic nematode populations.

PCR-RFLP screening of polymorphisms associated with benzimidazole resistance in Necator americanus and Ascaris lumbricoides from different geographical regions in Brazil.

Ascaris lumbricoides and Necator americanus are soil-transmitted parasites with global geographic distribution, and they represent some of the most common and neglected infections in the world. Periodic treatment with mass drug administration (MDA) in endemic areas is the recommended action put forth by the World Health Organization. However, MDA can cause the selection of subpopulations that possess the genetic ability to overcome the mechanism of drug action. In fact, beta-tubulin gene mutations (codons 167, 198 and 200) are correlated with benzimidazole resistance in nematodes of veterinary importance. It is possible that these SNPs also have strong correlation with treatment resistance in the human geohelminths A. lumbricoides, Trichuris trichiura and hookworms. Here, we aimed to investigate the presence of some of these canonical molecular markers associated with parasite resistance to benzimidazole in N. americanus and A. lumbricoides collected from six Brazilian states. Nested-PCR and PCR-RFLP were used to detect mutations at codons 167 and 198 in 601 individual eggs of A. lumbricoides collected from 62 human stool samples; however, no mutations were found. Codons 198 and 200 were tested in 552 N. americanus eggs collected from 48 patients using the same methodology, which presented a relative frequency of 1.4% and 1.1%, respectively. The presence of these SNPs in N. americanus eggs is an important finding, indicating that with high benzimidazole drug pressure there is potential for benzimidazole resistance to be selected in this hookworm. However, at these low frequencies it does not indicate that there is at present any benzimidazole resistance problem. This is the first systematic study performed in South America, and the study yielded a landscape of the genetic variants in the beta-tubulin gene and anthelmintic resistance to soil-transmitted parasites detected by a simple, rapid and affordable genotyping assay of individual eggs.

Fatores intervenientes na implantação da estratégia saúde da família nos municípios brasileiros / Factors involved in the implementation of the family health strategy in brazilian municipalities

A Estratégia Saúde da Família (ESF) é uma aposta de mudançado modelo assistencial e tem por objetivo prestaruma assistência contínua à população, visando melhoraras condições de saúde e de vida. O objetivo deste estudoé analisar os fatores intervenientes na implantação daESF nos municípios brasileiros. Trata-se de um estudo derevisão bibliográfica; foram realizadas buscas retrospectivassobre o tema, publicações em periódicos científicos esites oficiais, no período de 2004 a 2013. Os resultados encontradosrevelam a falta de capacitação e alta rotatividadefuncional, falta de recursos financeiros, problemas deinfraestrutura física e equipamentos, falhas no processode referência e contrarreferência e problemas relativos àspeculiaridades dos grandes municípios, como a violênciaurbana. Conclui-se que, apesar das dificuldades, os indicadoresde sáude e o acesso aos serviços melhoraram nosúltimos anos, mas ainda há necessidade de maior investimentona Atenção Primária à Saúde.

The Family Health Strategy (FHS) is a bid to change thecare model and aims to provide continuous assistanceto the population in order to improve health and livingconditions. The aim of this study is to report on thefactors involved in FHS implementation in Brazilianmunicipalities. In this bibliographic review, retrospectivesearches were conducted on the topic, as publishedin scientific journals and official sites, from 2004 to2013. The results showed a lack of training and highfunctional turnover, lack of financial resources, physicalinfrastructure and equipment problems, failures in thereferral and counter-referral process, and problemsrelated to the peculiarities of the big cities, such as urbanviolence. We conclude that despite the difficulties, healthindicators and access to services have improved in recentyears, but there is still a need for greater investment inprimary health care.