Abstract Fecal Immunochemical Test (FIT) followed by a colonoscopy is an efficacious strategy to improve the adenoma detection rate and Colorectal Cancer (CRC). There is no organized national screening program for CRC in Brazil. The aim of this research was to describe the implementation of an organized screening program for CRC through FIT followed by colonoscopy, in an urban low-income community of São Paulo city. The endpoints of the study were: FIT participation rate, FIT positivity rate, colonoscopy compliance rate, Positive Predictive Values (PPV) for adenoma and CRC, and the rate of complications. From May 2016 to October 2019, asymptomatic individuals, 50-75 years old, received a free kit to perform the FIT. Positive FIT (≥ 50 ng/mL) individuals were referred to colonoscopy. 10,057 individuals returned the stool sample for analysis, of which (98.2%) 9,881 were valid. Women represented 64.8% of the participants. 55.3% of individuals did not complete elementary school. Positive FIT was 7.8% (776/9881). The colonoscopy compliance rate was 68.9% (535/776). There were no major colonoscopy complications. Adenoma were detected in 63.2% (332/525) of individuals. Advanced adenomatous lesions were found in 31.4% (165/525). CRC was diagnosed in 5.9% (31/525), characterized as adenocarcinoma: in situ in 3.2% (1/31), intramucosal in 29% (9/31), and invasive in 67.7% (21/31). Endoscopic treatment with curative intent for CRC was performed in 45.2% (14/31) of the cases. Therefore, in an urban low-income community, an organized CRC screening using FIT followed by colonoscopy ensued a high participation rate, and high predictive positive value for both, adenoma and CRC.

RESUMO Objetivo: Descrever um caso incomum de infecção por Strongyloides stercoralis (S. stercoralis) em paciente de quatro meses de idade e ressaltar a importância do diagnóstico precoce. Descrição do caso: Paciente masculino, procedente e residente de Videira, Santa Catarina, Brasil, nasceu pré-termo, parto cesárea, peso de nascimento 1.655 g, e permaneceu na Unidade de Terapia Intensiva neonatal e intermediária por 20 dias. Aos quatro meses de idade, começou a evacuar fezes sanguinolentas e foi feita hipótese de alergia à proteína do leite de vaca, em razão da sintomatologia e do uso da fórmula infantil para o primeiro semestre, para o qual foi indicada a substituição por fórmula infantil com proteína hidrolisada. Foram solicitados a pesquisa de leucócitos e o exame parasitológico das fezes). Ambos se mostraram positivos e o parasitológico revelou a presença de larva rabditoide de S. stercoralis. O clínico manteve a hipótese inicial e a dieta, mas solicitou a coleta de três amostras de fezes, que resultaram em uma amostra para larvas rabditoide, em muda, de S. stercoralis. Como a criança apresentava dor abdominal, vômito e as fezes permaneciam sanguinolentas, foi iniciado o tratamento com tiabendazol - duas vezes/dia por dois dias -, repetido após sete dias, e, em seguida, realizado o exame parasitológico de fezes, tendo sido negativo. Comentários: A estrongiloidíase, apesar de ser uma infecção parasitária frequentemente leve, em pacientes imunocomprometidos pode se apresentar de forma grave e disseminada. Deve-se suspeitar desse agente em pacientes que vivem em áreas endêmicas, sendo o diagnóstico estabelecido por meio da pesquisa das larvas do S. stercoralis na secreção traqueal e nas fezes.

ABSTRACT Objective: To describe an uncommon case of infection by Strongyloides stercoralis (S. stercoralis) in a 4-month-old child and to highlight the importance of early diagnosis. Case description: The patient was a male child from the city of Videira, State of Santa Catarina, Southern Brazil, who was born preterm by Cesarean-section, weighing 1,655 g, and stayed in the neonatal intensive care unit for 20 days. At four months of age, the child started presenting blood in stools and the possibility of cow’s milk protein allergy was considered, given the symptoms and the use of infant formula in his 1st semester of life, which was then replaced by infant formula with hydrolyzed protein. White blood cell count and a parasitological stool sample were requested. Both tested positive and the stool ova and parasite examination showed a rhabditoid larva of S. stercoralis. The clinician maintained the initial hypothesis and diet, but requested three new stool samples, which tested positive for rhabditoid larvae of S. stercoralis. Since the child presented abdominal pain and vomiting, and there was still blood in stools, treatment with thiabendazole was initiated twice a day for two days. Treatment was repeated after seven days along with a new parasitological examination, which was then negative. Comments: Although strongyloidiasis is usually a mild parasitic infection, it may be severe and disseminated in immunocompromised patients. This agent must be considered in patients who live in endemic areas, and the diagnosis should be established by searching S. stercoralis larvae in tracheal secretions and in stools.

SUMMARY Strongyloidiasis is a potentially serious infection in immunocompromised patients. Thus, the availability of sensitive and specific diagnostic methods is desirable, especially in the context of immunosuppressed patients in whom the diagnosis and treatment of strongyloidiasis is of utmost importance. In this study, serological and molecular tools were used to diagnose Strongyloides stercoralis infections in immunosuppressed patients. Serum and stool samples were obtained from 52 patients. Stool samples were first analyzed by Lutz, Rugai, and Agar plate culture methods, and then by a quantitative real time polymerase chain reaction (qPCR). Serum samples were evaluated by an enzyme-linked immunosorbent assay (ELISA) using a soluble (AS) or a membrane fractions antigen (AM) obtained from alkaline solutions of the filariform larvae of Strongyloides venezuelensis. Of the 52 immunosuppressed patients, three (5.8%) were positive for S. stercoralis by parasitological methods, compared to two patients (3.8%) and one patient (1.9%) who were detected by ELISA using the AS and the AM antigens, respectively. S. stercoralis DNA was amplified in seven (13.5%) stool samples by qPCR. These results suggest the utility of qPCR as an alternative diagnostic tool for the diagnosis of S. stercoralis infection in immunocompromised patients, considering the possible severity of this helminthiasis in this group of patients.

RESUMO O objetivo deste estudo foi avaliar seis frações antigênicas diferentes de fêmeas parasitas de Strongyloides venezuelensis para o diagnóstico sorológico da estrongiloidíase humana. As frações solúveis e de membrana de fêmeas parasitas de S. venezuelensis foram preparadas em solução salina tamponada (SSF e SMF, respectivamente), Tris-HCl (TSF e TMF, respectivamente) e tampão alcalino (ASF e AMF, respectivamente). As amostras de soro obtidas de pacientes com estrongiloidíase, com outras parasitoses e indivíduos saudáveis, foram analisadas pelo ensaio imunoenzimático (ELISA). As frações solúveis SSF, TSF e ASF apresentaram sensibilidade de 85,0%, 75,0%, e 80,0% e especificidade de 93,1%, 93,1% e 87,5%, respectivamente. As frações de membrana, SMF, TMF e AMF demonstraram sensibilidade de 80,0%, 75,0%, e 85,0%, e especificidade de 95,8%, 90,3% e 91,7%, respectivamente. Em conclusão os presentes resultados sugerem que as frações obtidas a partir de fêmeas parasitas, especialmente o SSF e SMF, podem ser utilizadas como fonte alternativa de antígenos no imunodiagnóstico da estrongiloidiase humana.

SUMMARY The aim of this study was to evaluate six different antigenic fractions from Strongyloides venezuelensis parasitic females for the immunodiagnosis of human strongyloidiasis. Soluble and membrane fractions from S. venezuelensis parasitic females were prepared in phosphate-buffered saline (SSF and SMF, respectively), Tris-HCl (TSF and TMF, respectively), and an alkaline buffer (ASF and AMF, respectively). Serum samples obtained from patients with strongyloidiasis or, other parasitic diseases, and healthy individuals were analyzed by enzyme-linked immunosorbent assay (ELISA). Soluble fractions SSF, TSF, and ASF showed 85.0%, 75.0%, and 80.0% sensitivity and 93.1%, 93.1%, and 87.5% specificity, respectively. Membrane fractions SMF, TMF, and AMF showed 80.0%, 75.0%, and 85.0% sensitivity, and 95.8%, 90.3%, and 91.7% specificity, respectively. In conclusion, the present results suggest that the fractions obtained from parasitic females, especially the SSF and SMF, could be used as alternative antigen sources in the serodiagnosis of human strongyloidiasis.

Com a finalidade de melhor conhecer a sensibilidade do método de Ritchie (centrífugos edimentação em formol-éter), quanto ao diagnóstico de parasitoses intestinais pelo exame das fezes, foi investigada a capacidade dele no sentido de detectar ovos “pesados" de helmintos (Schistosoma mansoni e Ascaris lumbricoides inférteis). Houve comparação com o desempenho do processo da sedimentação espontânea em água, usado com o mesmo intuito. Os resultados obtidos e a respectiva avaliação estatística demonstraram que a técnica da sedimentação espontânea em água é mais eficiente, tendo sido analisadas 300 amostras de fezes, metade das quais certamente contendo os dois tipos de ovos citados e a outra parte considerada em trabalho laboratorial rotineiro.

The sensitivity of Ritchie’s technique (centrifugal sedimentation in formol-ether) in the diagnosis of intestinal parasitic diseases was investigated, regarding the detection of heavy helminth eggs (Schistosoma mansoni and infertile Ascaris lumbricoides eggs) in stool specimens. Its performance was compared to that obtained with the technique of spontaneous sedimentation in water. Statistical evaluation of the results in 300 stool specimens yields a higher efficacy with the technique of spontaneous sedimentation in water. Half of the stool specimens examined were known to contain both above-mentioned eggs and the others were part of the laboratory routine.

Verificaram os Autores que o albendazol é muito eficiente no tratamento da enterobíase. Usando dose única de 10 mg/kg, obtiveram 100% de curas quando administraram esse anti-helmíntico a 29 crianças. Foi comprovada tolerância bastante satisfatória e o estudo realizado contribuiu para a melhor demarcação do espectro de atividade antiparasitária do composto referido.

Albendazole was shown to be very effective in the treatment of enterobiasis. A cure rate of 100% was noticed, when a single dose of 10 mg/kg was given to 29 children. The drug was quite well tolerated by all recipients. This trial has brought additional evidence of the efficacy of albendazole as an antihelminthic agent, contributing to the proper establishment of its spectrum of activity.

Foi verificado que é possível diagnosticar a giardíase através de exame de fezes realizado pelo método de Kato-Katz, hoje bastante utilizado no Brasil. Todavia, para reconhecimento da protozoose em questão, a eficácia do processo da centrífugo-fiutuação em sulfato de zinco mostrou-se maior. As sensibilidades das técnicas de Kato-Katz e da sedimentação espontânea em água foram equiparáveis, afigurando-se mais produtivas, a propósito do emprego da primeira, as análises efetuadas imediatamente ou após 24 horas em relação à ocasião do preparo.

The Kato-Katz technique for stool examination, now widely employed in Brazil, has been shown to be useful in the diagnosis of giardiasis. However, the efficacy of a concentration method, using zinc sulphate, was higher. The sensitivity of both the Kato-Katz technique and the gravity sedimentation method were compared andyielded similar results. As far as stool examination by the Kato-Katz technique are concerned, the best results were obtained after immediate analysis or 24 hours later.