Estudo aborda redução de casos de esquistossomose e ancilostomíase no Brasil

Inquéritos realizados no Brasil, entre os anos de 1947 e 2015, para verificar a prevalência de duas importantes doenças causadas por vermes, a esquistossomose e a ancilostomíase, constataram uma diminuição na ocorrência dessas enfermidades. Agora, uma pesquisa da Fiocruz Minas avaliou os fatores relacionados a essa redução, verificando, principalmente, a influência das melhorias sanitárias.

Nematicidal and ovicidal activity of Bacillus thuringiensis against the zoonotic nematode Ancylostoma caninum.

Ancylostoma caninum is a gastrointestinal parasite that affect dogs and humans, considered a worldwide public health problem. The control of these parasitosis is increasingly difficult due to the development of multi-drug resistance. Bacillus thuringiensis is an insecticidal, spore forming bacterium, often species specific. The strain GP526 of B. thuringiensis has toxic effect on the cestode Dipylidium caninum and the trematode Centrocestus formosanus, both of them zoonotic parasites. The high degrees of specificity and environment safe make B. thuringiensis suitable for use against pathogen parasites, especially those resistant to synthetic chemical insecticides. The objective of the current work was to evaluate the in vitro effect of B. thuringiensis on Ancylostoma caninum. Spore-crystal mixture of the strains was co-incubated with 120 adult nematodes (males, non-pregnant females and pregnant females) or with 4800 eggs. GP526 showed a nematicidal effect with an LT50 of 35.8 h and an LC50 of 60 µg/ml. It also showed an ovicidal effect with an LC50 of 94.9 µg/ml. Histological analyses showed detachment of the cuticle and of the uterus in adult females, and vacuolization with destruction of the eggs. The effects of GP526 strain were comparable to those of albendazole, allowing us to propose GP526 for A. caninum control, in both, the adult stage at a gastrointestinal level, and in egg stage in the environment. In addition, GP526 can be proposed as a potential broad spectrum antiparasitic drug.

Soil-transmitted helminth infection in school age children in Sierra Leone after a decade of preventive chemotherapy interventions.

BACKGROUND: Baseline mapping of soil-transmitted helminth (STH) infections among school age children (SAC) in 2008-2009 found high or moderate prevalence in 13 of the 14 districts in Sierra Leone. Following these surveys, mass drug administration (MDA) of mebendazole/albendazole was conducted biannually at national level targeting pre-school children (PSC) aged 12-59 months and intermittently at sub-national level targeting SAC. In addition, MDA with ivermectin and albendazole for eliminating lymphatic filariasis (LF) has been conducted nationwide since 2010 targeting individuals over 5 years of age. Each MDA achieved high coverage, except in 2014 when all but one round of MDA for PSC was cancelled due to the Ebola emergency. The objective of the current study was to determine the prevalence and intensity of STH infections among SAC after a decade of these deworming campaigns. METHODS: Seventy-three schools in 14 districts were purposefully selected, including 39 schools from the baseline surveys, with approximately two sites from each of low, moderate and high prevalence categories at baseline per district. Fresh stool samples were collected from 3632 children aged 9-14 years (male 51%, female 49%) and examined using the Kato Katz technique. RESULTS: The prevalence of STH infections in Sierra Leone decreased in 2016 compared to 2008: Ascaris lumbricoides 4.4% (95% confidence interval [CI]: 3.7-5.1%) versus 6.6% (95% CI: 0-25%), Trichuris trichiura 0.7% (95% CI: 0.5-1.1%) versus 1.8% (95% CI: 0-30.2%), hookworm 14.9% (95% CI: 13.8-16.1) versus 38.5% (95% CI: 5.4-95.1%), and any STH 18.3% (95% CI:17.0-19.5%) versus 48.3% (CI: 5.4-96.3%), respectively. In 2016, no district had high hookworm prevalence and four districts had moderate prevalence, compared with eight and four districts respectively in 2008. In 2016, the arithmetic mean hookworm egg count in all children examined was light: 45.5 eggs per gram (EPG) of faeces, (95% CI:\ 35.96-55.07 EPG); three (0.08%) children had heavy infections and nine (0.25%) children had moderate infections. CONCLUSIONS: Sierra Leone has made considerable progress toward controlling STH as a public health problem among SAC. As LF MDA phases out (between 2017 and 2021), transition of deworming to other platforms and water and sanitation strategies need to be strengthened to maintain STH control and ultimately interrupt transmission.

A highly expressed intestinal cysteine protease of Ancylostoma ceylanicum protects vaccinated hamsters from hookworm infection.

BACKGROUND: Human hookworms (Necator americanus, Ancylostoma duodenale, and Ancylostoma ceylanicum) are intestinal blood-feeding parasites that infect ~500 million people worldwide and are among the leading causes of iron-deficiency anemia in the developing world. Drugs are useful against hookworm infections, but hookworms rapidly reinfect people, and the parasites can develop drug resistance. Therefore, having a hookworm vaccine would be of tremendous benefit. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the vaccine efficacy in outbred Syrian hamsters of three A. ceylanicum hookworm antigen candidates from two classes of proteins previously identified as promising vaccine candidates. These include two intestinally-enriched, putatively secreted cathepsin B cysteine proteases (AceyCP1, AceyCPL) and one small Kunitz-type protease inhibitor (AceySKPI3). Recombinant proteins were produced in Pichia pastoris, and adsorbed to Alhydrogel. Recombinant AceyCPL (rAceyCPL)/Alhydrogel and rAceySKPI3/Alhydrogel induced high serum immunoglobulin G (IgG) titers in 8/8 vaccinates, but were not protective. rAceyCP1/Alhydrogel induced intermediate serum IgG titers in ~60% of vaccinates in two different trials. rAceyCP1 serum IgG responders had highly significantly decreased hookworm burdens, fecal egg counts and clinical pathology compared to Alhydrogel controls and nonresponders. Protection was highly correlated with rAceyCP1 serum IgG titer. Antisera from rAceyCP1 serum IgG responders, but not nonresponders or rAceyCPL/Alhydrogel vaccinates, significantly reduced adult A. ceylanicum motility in vitro. Furthermore, rAceyCP1 serum IgG responders had canonical Th2-specific recall responses (IL4, IL5, IL13) in splenocytes stimulated ex vivo. CONCLUSIONS/SIGNIFICANCE: These findings indicate that rAceyCP1 is a promising vaccine candidate and validates a genomic/transcriptomic approach to human hookworm vaccine discovery.

Efficacy and safety of a new topical formulation of selamectin plus sarolaner in the treatment and control of natural infections of Ancylostoma tubaeforme and Toxocara cati in cats presented as veterinary patients in the United States.

A new topical formulation of selamectin plus sarolaner (Revolution® Plus/Stronghold® Plus, Zoetis) was evaluated in the treatment and control of naturally occurring infections of Ancylostoma tubaeforme and Toxocara cati in cats presented as veterinary patients in the United States. Three thousand three hundred three (3303) cats were screened in 25 veterinary practices in 15 states and 153 hookworm-positive cats (A. tubaeforme and/or A. braziliense), mainly from Alabama, Mississippi, Texas, and Hawaii, were identified; 135 cats met all the criteria for enrollment and were included on study. The cats were randomly assigned to treatment with Revolution® (at the label dosage, to provide a minimum dosage of 6 mg/kg selamectin) or selamectin plus sarolaner (at a dosage of 6-12 mg/kg plus 1-2 mg/kg, respectively). Treatments were administered at the time of enrollment and repeated 30 days later. Fecal samples were collected for differential fecal egg count prior to the first treatment (Day 0), prior to the second treatment (Day 30), and approximately 30 days later (Day 60). Efficacy was based on the percentage reductions in geometric mean fecal egg count for A. tubaeforme on Day 30 and Day 60 compared with Day 0. Where cats were co-infected with T. cati, efficacy against this species was also evaluated. Efficacy data were evaluated for A. tubaeforme for 40 cats on both Day 30 and Day 60 for the group treated with the selamectin/sarolaner combination and reductions in geometric mean fecal egg counts of 99.4% and 99.7% were demonstrated for Day 30 and Day 60, respectively. For the group treated with selamectin alone, 44 and 40 cats were evaluated and percent reductions for Day 30 and Day 60 were 99.5% and 99.9%, respectively. For T. cati, 14 cats were evaluated in the selamectin/sarolaner-treated group for Day 30 and for Day 60, and the reduction in geometric mean fecal egg count was 100% for both days. There were 11 and 9 cats evaluated for Day 30 and Day 60, respectively, for the selamectin-treated group and the reduction was again 100% for both days. The geometric mean fecal egg counts post-treatment were significantly lower than pre-treatment for both A. tubaeforme and T. cati, for both treatments, and for both periods of interest (P < 0.0001). No serious adverse events related to treatment with either product occurred during the study. Thus, both selamectin alone and the combination product of selamectin/sarolaner were safe and effective when administered on a monthly basis for the treatment and control of natural infections of A. tubaeforme and T. cati. The addition of sarolaner to the formulation did not interfere with the efficacy of selamectin against these nematodes.

Doenças negligenciadas: ancilostomíase em cem anos de história no Brasil / Neglected diseases: hookworm in one hundred years of history in Brazil

Esse texto pretende contrastar dois momentos distintos que integram a narrativa sobre ancilostomíase no Brasil, apontando algumas proximidades e e distinções que caracterizam a experiência de combate e controle da doença nesses dois contextos específicos.(AU)

Vaccination with a cocktail of Ancylostoma ceylanicum recombinant antigens leads to worm burden reduction in hamsters.

Hookworms, a group to which Ancylostoma ceylanicum belongs, are gastrointestinal nematodes that infect more than 700 million people around the world. They are a leading cause of anemia in developing countries. In order to effectively prevent hookworm infections research is conducted to develop an effective vaccine using recombinant antigens of the parasite. The aim of this study was to examine the influence of the hosts' on protection against ancylostomiasis and the shaping of the humoral immune response among Syrian hamsters after immunization with a cocktail of five A. ceylanicum recombinant antigens. Ace-ASP-3, Ace-ASP-4, Ace-APR-1, Ace-MEP-6 and Ace-MEP-7 were obtained in the pET expression system. Immunization with a vaccine cocktail resulted in a 33.5% worm burden reduction. The immunogenicity of the recombinant proteins were determined using ELISA. Statistical analysis showed that vaccinated hamsters developed stronger humoral responses to four of five recombinant antigens (the exception being Ace-ASP-3) compared to hamsters from the control group.

Hamsters vaccinated with Ace-mep-7 DNA vaccine produced protective immunity against Ancylostoma ceylanicum infection.

Hookworms are intestinal nematodes that infect up to 740 million people, mostly in tropical and subtropical regions. Adult worms suck blood from damaged vessels in the gut mucosa, digesting hemoglobin using aspartic-, cysteine- and metalloproteases. Targeting aspartic hemoglobinases using drugs or vaccines is therefore a promising approach to ancylostomiasis control. Based on homology to metalloproteases from other hookworm species, we cloned the Ancylostoma ceylanicum metalloprotease 7 cDNA (Ace-mep-7). The corresponding Ace-MEP-7 protein has a predicted molecular mass of 98.8 kDa. The homology to metallopeptidases from other hookworm species and its predicted transmembrane region support the hypothesis that Ace-MEP-7 may be involved in hemoglobin digestion in the hookworm gastrointestinal tract, especially that our analyses show expression of Ace-mep-7 in the adult stage of the parasite. Immunization of Syrian golden hamsters with Ace-mep-7 cDNA resulted in 50% (p < 0.01) intestinal worm burden reduction. Additionally 78% (p < 0.05) egg count reduction in both sexes was observed. These results suggest that immunization with Ace-mep-7 may contribute to reduction in egg count released into the environment during the A. ceylanicum infection.

New tools for NTD vaccines: A case study of quality control assays for product development of the human hookworm vaccine Na-APR-1M74.

Na-APR-1(M74) is an aspartic protease that is rendered enzymatically inactive by site-directed mutagenesis and is a candidate antigen component in the Human Hookworm Vaccine. The mutant protease exerts vaccine efficacy by inducing antibodies that neutralize the enzymatic activity of wild type enzyme (Na-APR-1wt) in the gut of the hookworm, thereby depriving the worm of its ability to digest its blood meal. Previously, canines immunized with Na-APR-1(M74) and challenged with Ancylostoma caninum were partially protected against hookworm challenge infection, especially from the loss in hemoglobin observed in control canines and canine immunoglobulin (Ig) G raised against Na-APR-1 was shown to inhibit the enzymatic activity of Na-APR-1 wt in vitro, thereby providing proof of concept of Na-APR-1(M74) as a vaccine antigen. The mutated version, Na-APR-1(M74), was then expressed at the cGMP level using a Nicotiana benthamiana expression system (Fraunhofer, CMB, Delaware, MD), formulated with Alhydrogel®, and used to immunize mice in a dose-ranging study to explore the enzyme-neutralizing capacity of the resulting anti- Na-APR-1(M74) IgG. As little as 0.99 µg of recombinant Na-APR-1(M74) could induce anti Na-APR-1(M74) IgG in mice that were capable of inhibiting Na-APR-1w t-mediated digestion of a peptide substrate by 89%. In the absence of enzymatic activity of Na-APR-1(M74) as a surrogate marker of protein functionality, we developed an assay based on the binding of a quenched fluorescence-labeled inhibitor of aspartic proteases, BODIPY-FL pepstatin A (BDP). Binding of BDP in the active site of Na-APR-1 wt was demonstrated by inhibition of enzymatic activity, and competitive binding with unlabelled pepstatin A. BDP also bound to Na-APR-1(M74) which was assessed by fluorescence polarization, but with an ∼ 50-fold reduction in the dissociation constant. Taken together, these assays comprise a "toolbox" that could be useful for the analyses of Na-APR-1(M74) as it proceeds through the clinical development as part of the Human Hookworm Vaccine pipeline.

Identification of Ancylostoma ceylanicum in children from a tribal community in Tamil Nadu, India using a semi-nested PCR-RFLP tool.

BACKGROUND: It is generally assumed that hookworm infections in humans are caused by Necator americanus and Ancylostoma duodenale. However, previous studies have also reported the presence of the animal hookworm A. ceylanicum in human stools. METHODS: We determined hookworm infections in children in a tribal community in Tamil Nadu, India, using a semi-nested PCR-RFLP approach. RESULTS: The results indicate that human species account for a majority of the hookworm infections (N. americanus 39/41 [95%]; A. duodenale 6/41 [15%]), whereas the animal hookworm A. ceylanicum only accounts for a minority of the infections (5%; 2/41). CONCLUSIONS: The results emphasize the need to consider zoonotic ancylostomiasis while developing strategies to control hookworm infections.

Molecular cloning and analysis of Ancylostoma ceylanicum glutamate-cysteine ligase.

Glutamate-cysteine ligase (GCL) is a heterodimer enzyme composed of a catalytic subunit (GCLC) and a modifier subunit (GCLM). This enzyme catalyses the synthesis of γ-glutamylcysteine, a precursor of glutathione. cDNAs of the putative glutamate-cysteine ligase catalytic (Ace-GCLC) and modifier subunits (Ace-GCLM) of Ancylostoma ceylanicum were cloned using the RACE-PCR amplification method. The Ace-gclc and Ace-gclm cDNAs encode proteins with 655 and 254 amino acids and calculated molecular masses of 74.76 and 28.51kDa, respectively. The Ace-GCLC amino acid sequence shares about 70% identity and 80% sequence similarity with orthologs in Loa loa, Onchocerca volvulus, Brugia malayi, and Ascaris suum, whereas the Ace-GCLM amino acid sequence has only about 30% sequence identity and 50% similarity to homologous proteins in those species. Real-time PCR analysis of mRNA expression in L3, serum stimulated L3 and adult stages of A. ceylanicum showed the highest level of Ace-GCLC and Ace-GCLM expression occurred in adult worms. No differences were detected among adult hookworms harvested 21 and 35dpi indicating expression of Ace-gclc and Ace-gclm in adult worms is constant during the course of infection. Positive interaction between two subunits of glutamate-cysteine ligase was detected using the yeast two-hybrid system, and by specific enzymatic reaction. Ace-GCL is an intracellular enzyme and is not exposed to the host immune system. Thus, as expected, we did not detect IgG antibodies against Ace-GCLC or Ace-GCLM on days 21, 60 and 120 of A. ceylanicum infection in hamsters. Furthermore, vaccination with one or both antigens did not reduce worm burdens, and resulted in no improvement of clinical parameters (hematocrit and hemoglobin) of infected hamsters. Therefore, due to the significant role of the enzyme in parasite metabolism, our analyses raises hope for the development of a successful new drug against ancylostomiasis based on the specific GCL inhibitor.

Biological control of infective larvae of Ancylostoma spp. in beach sand.

BACKGROUND: Geohelminths are parasites that stand out for their prevalence and wide distribution, depending on the soil for their transmission. AIMS: The aim of this work was to evaluate the predatory capacity of the fungal isolate of the genus Duddingtonia (CG768) on third stage larvae (L3) of Ancylostoma spp. in beach sand under laboratory conditions. METHODS: In the assay A five treatment groups and 1 control group were formed. The treatment groups contained 5000, 10,000, 15,000, 20,000 or 25,000 chlamydospores of the fungal isolate and 1000 Ancylostoma spp. L3 in pots containing 30g of sand. The control group (without fungus) contained only 1000 Ancylostoma spp. L3 and distilled water in pots with 30g of sand. RESULTS: Evidence of predatory activity was observed at the end of 15 days, where we observed the following percentages of reduction of L3: Group 1 (4.5%); Group 2 (24.5%); Group 3 (59.2%); Group 4 (58.8%); Group 5 (63%). However, difference was noted (p<0.01) only at concentrations 15,000, 20,000 and 25,000 in relation to control group. In the assay B two groups were formed in Petri dishes of 9cm in diameter containing agar water 2% medium. In the treated group, each Petri dish contained 500 Ancylostoma spp. L3 and 5g of sand containing the isolate CG 768 at a concentration of 25,000 chlamydospores/g of sand, and the control group (without fungus) contained only 500 L3. At the end of 7 days the non-predation L3 of Petri dishes using the method of Baermann were recovered. Difference (p<0.01) between groups on reducing the average number of Ancylostoma spp. L3 (percent reduction of 84%) was observed. CONCLUSIONS: The results of this study confirm earlier work on the efficiency of the Duddingtonia genus in the control of Ancylostoma spp. infective larvae.

[Looking beyond the campaign to eradicate ancylostomiasis: the diary of the American physician Alan Gregg]. / Para além do combate à ancilostomíase: o diário do médico norte-americano Alan Gregg.

Between 1916 and 1923, the Federal District and 11 Brazilian states entered into cooperation agreements with the International Health Board of the Rockefeller Foundation to combat a rural endemic disease, namely ancylostomiasis. This paper presents the diary of Alan Gregg, one of the American physicians who worked in Brazil from 1919 to 1922. An interesting source to discuss issues relating to the history of public health in Brazil, in addition to information about the activities to combat ancylostomiasis developed by the Rockefeller Foundation in the country, the diary of the physician presents his impressions concerning nature, culture, politics and society in Brazil. In the diary excerpts presented here, however, aspects related to the professional activities performed by Gregg are prioritized.

Ancylostoma ceylanicum metalloprotease 6 DNA vaccination induces partial protection against hookworm challenge infection.

Hookworms are blood feeding intestinal nematodes that infect more than 500 million people and cause iron deficiency anemia. Infected children suffer from physical and cognitive growth retardation. Because of potential anthelminthic drug resistance, the need for vaccine development is urgent. Numerous antigens have been tested in animal models as vaccines against hookworm infection, but there is no effective human vaccine. We cloned a cDNA encoding Ancylostoma ceylanicum metalloprotease 6 (Acemep-6). Ace-MEP-6 is a protein with a predicted molecular mass of 101.87 kDa and based on computational analysis it is very likely to be engaged in food processing via hemoglobin digestion. Groups of hamsters were immunized with an Ace-mep-6 cDNA vaccine, either once or three times. Animals that were administered one dose developed high resistance (80%, p < 0.01) against challenge infection, whereas triple immunization resulted in no worm burden reduction. These results suggest that DNA vaccines can be powerful tools in ancylostomiasis control, although the mechanisms through which protection is conferred remain unclear.

“An international problem of serious proportions”: a cooperação entre a Fundação Rockefeller e o governo do estado do Rio Grande do Sul no combate à ancilostomíase e seus desdobramentos (1919-1929) / "An international problem of serious proportions": the cooperation between the Rockefeller Foundation and the government of state of Rio Grande do Sul to fighting ancylostomiasis and its consequences (1919-1929)

A proposta é analisar, levando em consideração aspectos do contexto internacional, nacional e local, a cooperação entre a divisão internacional de saúde – International Health Board – da Fundação Rockefeller e o governo estadual do Rio Grande do Sul no combate a uma endemia rural, a ancilostomíase, na década de 1920, e os desdobramentos, as consequências desta cooperação na saúde pública estadual, tanto no que se refere ao combate à ancilostomíase em si quanto à organização da saúde no estado. A partir da discussão de bibliografia pertinente ao tema e da análise de documentação produzida, principalmente, pela Fundação Rockefeller (relatórios, correspondência e publicações) e pelo governo do estado do Rio Grande do Sul (Relatórios da Secretaria de Estado dos Negócios do Interior e Exterior), enfocaremos as atividades de combate à doença realizadas em municípios gaúchos a partir da cooperação entre a Fundação e o governo estadual, orientadas pela instituição norte-americana e realizadas através da Diretoria de Higiene estadual entre 1920 e 1923. Além disso, discutiremos também o trabalho de combate à ancilostomíase mantido pelo governo estadual após o término da cooperação com a Fundação, com a organização do Serviço de Postos de Profilaxia Rural estadual em funcionamento entre 1924 e 1929. Por fim, abordaremos a atuação da Fundação na formação de profissionais de saúde pública, pois, durante a cooperação entre a instituição e o governo estadual, um médico da Diretoria de Higiene, Fernando de Freitas e Castro, recebeu uma bolsa para realizar estudos em saúde pública nos Estados Unidos entre 1922 e 1923. Em 1929, Freitas e Castro, então à frente da pasta da saúde no Rio Grande do Sul, pôs fim às atividades do Serviço de Postos de Profilaxia Rural a partir da proposta de uma Reforma Sanitária que introduzia, no estado, os health centers ou centros de saúde, um modelo de organização em saúde pública difundido pela Fundação. (AU)

Teatro na educação de crianças e adolescentes participantes de ensaio clínico / Theater in the education of children and teenagers participating in a clinical trial / Teatro en la educación de niños y adolescentes participantes de ensayo clínico

OBJETIVO: Analisar os efeitos de uma intervenção pedagógica na aprendizagem de crianças e adolescentes participantes de pesquisa clínica. MÉTODOS: Estudo quantitativo, quasi-experimental e longitudinal, parte de um conjunto de estudos envolvidos no teste de uma vacina contra ancilostomíase. Amostra por conveniência com 133 estudantes de dez a 17 anos, de ambos os sexos, da Escola Municipal de Maranhão, MG, Brasil, 2009. Utilizou-se um questionário estruturado aplicado pré e pós-intervenção. O dispositivo pedagógico foi o Teatro do Oprimido. As variáveis dependentes foram o conhecimento específico e global sobre pesquisa clínica e sobre verminoses; a variável independente foi a participação na intervenção educativa. RESULTADOS: Houve aumento do conhecimento sobre sinais e sintomas, susceptibilidade à reinfecção e modo de contágio da verminose após a intervenção educativa. Aumentaram acertos relativos à duração da pesquisa clínica, aos procedimentos previstos, à possibilidade de desistência da participação e de ocorrência de eventos adversos. Permaneceu a noção de que o propósito primário da pesquisa é terapêutico, embora tenha reduzido o percentual de participantes que associaram a pesquisa ao tratamento médico. O Teatro do Oprimido possibilitou que as discussões acerca da helmintose e da pesquisa clínica fossem contextualizadas e materializadas. Os sujeitos puderam se despojar ou reduzir suas representações prévias. CONCLUSÕES: A participação de crianças e adolescentes em ensaios clínicos deve ser precedida de intervenção educativa, já que indivíduos dessa faixa etária nem sequer reconhecem que têm direito a decidir por si próprios.

OBJECTIVE: To analyze the effects of a pedagogical intervention on the learning of children and teenagers participating in a clinical research. METHODS: Quantitative, quasi-experimental and longitudinal study, part of a group of studies conducted to test a vaccine against ancylostomiasis. Convenience sample with 133 students aged 10-17 years, of both sexes, from the school Escola Municipal de Maranhão (Southeastern Brazil), 2009. A structured questionnaire was used, which was administered before and after the intervention. The pedagogical device was the "Theater of the Oppressed". The dependent variables were specific and global knowledge about clinical research and about parasitic worms; the independent variable was participation in the educational intervention. RESULTS: There was an increase in knowledge about signals and symptoms, susceptibility to reinfection and way of contagion after the educational intervention. We observed an increase in the number of right answers concerning duration of clinical research, procedures, the possibility of quitting participation, and occurrence of adverse events. The notion that the research's primary purpose is therapeutic remained, but the percentage of participants who associated the research with medical treatment decreased. The "Theater of the Oppressed" enabled that the discussions about helminthiasis and clinical research were contextualized and materialized. The subjects could dispose of or reduce their previous representations. CONCLUSIONS: Participation of children and adolescents in clinical trials must be preceded by an educational intervention, since individuals of that age group do not even recognize they have the right to decide for themselves.

OBJETIVO: Analizar los efectos de una intervención pedagógica en el aprendizaje de niños y adolescentes participantes de investigación clínica. MÉTODOS: Estudio cuantitativo, cuasi-experimental y longitudinal, parte de un conjunto de estudios envueltos en la prueba de una vacuna contra anquilostomiasis. La muestra por conveniencia estaba constituida por 13 estudiantes de diez a 17 años, de ambos sexos, de la Escuela Municipal de Maranhao, MG, Brasil, 2009. Se utilizó un cuestionario estructurado aplicado pre y post intervención. El dispositivo pedagógico fue el Teatro del Oprimido. Las variables dependientes fueron el conocimiento específico y global sobre la investigación clínica y sobre helmintiasis; la variable independiente fue la participación en la intervención educativa. RESULTADOS: Hubo aumento del conocimiento sobre señales y síntomas, susceptibilidad a la reinfección y modo de contagio de la helmintiasis posterior a la intervención educativa. Aumentaron los aciertos relativos a la duración de la investigación clínica, a los procedimientos previstos, a la posibilidad de desistencia de la participación y de ocurrencia de eventos adversos. Permaneció la noción de que el propósito primario de la investigación es terapéutico, a pesar de que hubo reducción en el porcentaje de participantes que asociaron la investigación al tratamiento médico. El Teatro del Oprimido posibilitó que las discusiones sobre helmintiasis y de la investigación clínica fueran contextualizadas y materializadas. Los individuos pudieron despojarse o reducir sus representaciones previas. CONCLUSIONES: La participación de niños y adolescentes en ensayos clínicos debe ser precedida por intervención educativa, ya que individuos de ese grupo etario no pudieron siquiera reconocer que tienen derecho a decidir por sí mismos.

[Theater in the education of children and teenagers participating in a clinical trial]. / Teatro na educação de crianças e adolescentes participantes de ensaio clínico.

OBJECTIVE: To analyze the effects of a pedagogical intervention on the learning of children and teenagers participating in a clinical research. METHODS: Quantitative, quasi-experimental and longitudinal study, part of a group of studies conducted to test a vaccine against ancylostomiasis. Convenience sample with 133 students aged 10-17 years, of both sexes, from the school Escola Municipal de Maranhão (Southeastern Brazil), 2009. A structured questionnaire was used, which was administered before and after the intervention. The pedagogical device was the "Theater of the Oppressed". The dependent variables were specific and global knowledge about clinical research and about parasitic worms; the independent variable was participation in the educational intervention. RESULTS: There was an increase in knowledge about signals and symptoms, susceptibility to reinfection and way of contagion after the educational intervention. We observed an increase in the number of right answers concerning duration of clinical research, procedures, the possibility of quitting participation, and occurrence of adverse events. The notion that the research's primary purpose is therapeutic remained, but the percentage of participants who associated the research with medical treatment decreased. The "Theater of the Oppressed" enabled that the discussions about helminthiasis and clinical research were contextualized and materialized. The subjects could dispose of or reduce their previous representations. CONCLUSIONS: Participation of children and adolescents in clinical trials must be preceded by an educational intervention, since individuals of that age group do not even recognize they have the right to decide for themselves.

A history of hookworm vaccine development.

The human hookworms Necator americanus and Ancylostoma duodenale remain among the most common infections of humans in areas of rural poverty in the developing regions of the world, with an estimated 1 billion people infected with one or more of these parasites. Herein, we review the nearly 100 years of research, development, animal testing, and fieldwork that have led to our current progress in recombinant hookworm vaccines. We begin with the identification of hookworm at the start of the 20th century in Southern US, then discuss the progress in developed countries to eliminate human hookworm infection, and then the industrial development and field use in the 1970s a canine hookworm vaccine(Ancylostoma caninum), and finally our progress to date in the development and clinical testing of an array of recombinant antigens to prevent human hookworm disease from N. americanus infection. Special attention is given to the challenges faced in the development of a vaccine against a blood-feeding nematode, including the epidemiology of infection (high prevalence of infection), pathogenesis (chronic infection that increases with the age of the host), and a robust immune response that fails to confer the protection in the host and a concomitant absence of correlates of protection by a successful vaccine could be developed and tested. Finally, we provide the optimal and acceptable profiles of a human hookworm vaccine, including the proposed indication, target population, and route of administration, as developed by the Human Hookworm Vaccine Initiative, the only group currently working on vaccines targeting this parasite.