Detection of IgG Anti-Giardia duodenalis Antibodies in Sera by Indirect Immunofluorescence and Western Blotting Assays.

INTRODUCTION: Serological assays are alternative laboratory tools for the diagnosis of parasitic infections. The aim of this work was to evaluate the performance of the indirect fluorescent antibody test (IFAT) and Western blotting (WB) for the detection of IgG anti-Giardia antibodies in human sera. METHODOLOGY: Sera from individuals infected with Giardia duodenalis, other parasites or non-parasitized were selected for serological assays. Ninety-seven sera were tested by IFAT at 1:20 and 1:40 dilutions and of these, 40 samples were also analyzed by WB. RESULTS: The sensitivity and specificity of the IFAT was 97% and 46.9% at 1:20 sera dilution, and 39.4% and 59.4% at 1:40 sera dilution. The low molecular weight polypeptides fractions of 25 kDa, 27-31 kDa and 45-55 kDa were the most frequently identified by the sera of individuals infected with G. duodenalis, along with low cross-reactivity, presenting an individual sensitivity of 42.8%, 50.0% and 57.1%, and specificity of 83.3%, 83.3% and 91.7%, respectively. The highest overall sensitivity of WB (85.7%) was based on the immunoreactivity of sera with at least one of those proteins. The concordance between the detection of G. duodenalis in feces by microscopy and the WB results was considered substantial (Kappa = 0.61). CONCLUSION: Constant exposure to Giardia infection throughout a lifetime can maintain high levels of specific antibodies in serum, even without active infection. Moreover, proteins found in intestinal amoebas may hinder the serological diagnosis of giardiasis in endemic areas due to cross-reactivity, which can be partially solved using Giardia low molecular weight proteins.

Seroepidemiological Survey of Chronic Chagas Disease in a Rural Community in Southern Bahia, Brazil, Using Recombinant Chimeric Antigens.

Chagas disease (CD), caused by the parasite Trypanosoma cruzi, is a neglected tropical disease with life-threatening implications. In this study, we conducted a seroepidemiological survey to determine the prevalence and clinical profiles of CD in 217 individuals from an impoverished rural community in Southern Bahia, Brazil. The overall prevalence of CD in the studied community was 0.92%, detected through latent class analysis (LCA). Two individuals tested positive for anti-T. cruzi IgG, both being male farmers. One case was a 22-year-old man born in Camamu, with no evidence of congenital transmission, suggesting other routes of transmission such as vector-borne transmission due to migratory activities. The other case was a 69-year-old man born in São Felipe, who had lived in an adobe/brick house and had a pacemaker due to cardiac involvement caused by CD. The prevalence in this community was lower than expected, given the socioeconomic conditions and environmental factors that contribute to T. cruzi transmission. This could be attributed to the implementation of preventive measures and vector control programs by the Brazilian Government. However, continuous monitoring and surveillance are essential to sustain control efforts and detect any potential re-emergence of the disease. While the overall prevalence was low, the detection of positive cases underscores the need for continued surveillance and control measures in vulnerable populations, such as rural communities. Active surveillance, early diagnosis, and timely treatment are crucial in preventing disease progression and complications, thereby enhancing the effectiveness of screening and treatment programs.

Modulation of circulating cytokine production in alcoholic patients infected with Strongyloides stercoralis.

Strongyloidiasis control is associated with a Th2 immune response. However, alcohol ingestion plays an important role in modulating the immune system. The aim of this study is to evaluate the occurrence of Strongyloides stercoralis infection in alcoholic patients, the levels of circulating cytokines (IFN-γ, IL-2, IL-4, IL-5, IL-10, IL-15 and IL-17), and its correlation with modulation of parasitic load in alcoholic individuals infected with S. stercoralis. A total of 336 alcoholic patients, treated at the Alcoholic Care and Treatment Center were included in this study. The cytokine levels were measured by a commercial ELISA in 80 sera divided into four groups with 20 individuals each: alcoholics infected (ASs+) and not infected (ASs-) with S. stercoralis and non-alcoholics infected (NASs+) and not infected (NASs-) with the helminth. S. stercoralis frequency in alcoholic patients was 16.1% (54/336). The parasitic load varied from 1 to 546 larvae/g of faeces, median and interquartile range (IQR) of 9 and 1.0-62.5 larvae/g of faeces, while in non-alcoholic individuals the parasitic load was less than 10 larvae/g of faeces. Levels of circulating IL-4 were significantly higher in ASs+ when compared with NASs- group (p < .05). An inverse correlation between serum levels of IFN-γ and parasitic load in alcoholic patients infected with S. stercoralis was observed (r = -601; p < 0.01). These results suggest that modulation of IFN-γ production occurs in alcoholic individuals with high parasitic burden.

Cryptosporidium diagnosis in different groups of children and characterization of parasite species.

BACKGROUND: Microscopy and enzyme-linked immunosorbent assay (ELISA) are routinely used for Cryptosporidium diagnosis, without differentiating the parasite species. METHODS: Children's feces were analyzed by modified Ziehl-Neelsen (mZN) and ELISA for Cryptosporidium diagnosis and by polymerase chain reaction-restriction fragment length polymorphism for species identification. RESULTS: Cryptosporidium frequency was 2.6%. The sensitivity and specificity of ELISA were 85.7% and 99.7%, respectively, with excellent concordance with mZN (kappa=0.854). Parasite species were characterized as Cryptosporidium hominis (78.3%), Cryptosporidium felis (17.4%), and Cryptosporidium parvum (4.3%). CONCLUSIONS: Coproantigen ELISA is as efficient as mZN for Cryptosporidium diagnosis. Cryptosporidium genotyping suggests anthroponotic and zoonotic transmission to children.

Ineffectiveness of TF-Test® and Coproplus® Methods in Strongyloides stercoralis Infection Diagnosis.

PURPOSE: S. stercoralis diagnosis is currently performed by parasitological methods, mainly by Baermann-Moraes (BM), although Agar Plate Culture (APC) presents a higher sensitivity. New techniques, such as TF-Test® and Coproplus® have been suggested as more practical alternatives. The aim of this study was to evaluate the sensitivity of TF-Test® and Coproplus®, compared with APC, BM and Spontaneous Sedimentation (SS) methods. METHODS: One-hundred and forty male alcoholic patients, who provided three stools samples collected on alternate days, were included in this study. The most frequently found parasite was S. stercoralis, 20% (28/140), and the most sensitive method was APC, 96.4% (27/28), followed by BM, 89.3% (25/28) and SS, 57.1% (16/28). TF-Test® and Coproplus® presented a sensitivity of 46.4 (13/28) and 39.3% (11/28), respectively. In samples with a parasitic load of 1-10 larvae/g of feces, which occurred in 39.3% (11/28) of the infected patients, both the TF-Test® and Coproplus® methods demonstrated sensitivities of 18.2% (2/11), while APC and BM methods reached a sensitivity of 100% (11/11) (p < 0.05). For other intestinal helminth infections, TF-Test® and Coproplus® sensitivities were 22.2 (4/18) and 11.1% (2/18), respectively, this being lower than the SS, 66.7% (12/18) (p < 0.05). On the other hand, for protozoa infection diagnosis, TF-Test® and Coproplus® presented the highest sensitivities, 62.2 (46/74) and 43.2% (32/74), respectively. CONCLUSION: TF-Test® and Coproplus® methods presented the lowest sensitivities for S. stercoralis and other helminth infection diagnosis; therefore, they can be indicated for use in parasitological diagnosis, only when associated with other more effective methods of helminth identification.

Cryptosporidium diagnosis in different groups of children and characterization of parasite species

ABSTRACT Background: Microscopy and enzyme-linked immunosorbent assay (ELISA) are routinely used for Cryptosporidium diagnosis, without differentiating the parasite species. Methods: Children's feces were analyzed by modified Ziehl-Neelsen (mZN) and ELISA for Cryptosporidium diagnosis and by polymerase chain reaction-restriction fragment length polymorphism for species identification. Results: Cryptosporidium frequency was 2.6%. The sensitivity and specificity of ELISA were 85.7% and 99.7%, respectively, with excellent concordance with mZN (kappa=0.854). Parasite species were characterized as Cryptosporidium hominis (78.3%), Cryptosporidium felis (17.4%), and Cryptosporidium parvum (4.3%). Conclusions: Coproantigen ELISA is as efficient as mZN for Cryptosporidium diagnosis. Cryptosporidium genotyping suggests anthroponotic and zoonotic transmission to children.

Perfil epidemiológico das parasitoses intestinais em moradores de uma comunidade da Ilha de Boipeba, Bahia, Brasil / Epidemiological profile of intestinal parasites in residents of a community on the island of Boipeba, Bahia, Brazil

Introdução: as parasitoses intestinais constituem-se um importante problema de saúde pública mundial. Estas infecções são mais prevalentes em regiões tropicais impactando na morbimortalidade e aumento nos custos para o sistema de saúde. Objetivo: avaliar a prevalência das enteroparasitoses e sua associação com as condições socioeconômicas, sanitárias, ambientais e hábitos de vida em uma comunidade costeira do Nordeste brasileiro. Metodologia: estudo epidemiológico, descritivo e transversal, realizado de modo não probabilístico entre março a junho de 2017, com 105 moradores da Ilha de Boipeba, localizada no Sul da Bahia. O exame parasitológico de fezes foi realizado pelos métodos de sedimentação espontânea, Baermann-Moraes e FAUST. Um questionário foi aplicado para avaliar o perfil sociodemográfico da população. Resultados: do total de indivíduos avaliados, 52,4% eram do sexo feminino e 57,1% tinham entre 15 a 59 anos. Todos os indivíduos possuíam água encanada, porém não tratada, enquanto 91,4% referiu ingerir vegetais crus e 45,7% não higienizavam as mãos antes as refeições. Sintomas gastrointestinais foram relatados em 82,8% dos indivíduos e infecções enteroparasitárias foram diagnosticadas em 69,6%. Os parasitos mais frequentemente encontrados foram Ancilostomídeo (18,1%) e Entamoeba coli (43,8%). O principal fator de risco potencial para contrair a infecção por ancilostomídeos foi a não existência de poço artesiano na residência (RP=4,35), enquanto para Trichuris trichiura foi não dispor de pia no banheiro (RP=3,82). Conclusão: a comunidade analisada apresentou elevada prevalência de enteroparasitoses. Os hábitos precários de higiene e de acesso à água tratada, associados às condições ambientais e climáticas do local, podem ter contribuído para a elevada transmissão de geohelmintos observada.

Introduction: Intestinal parasitic infections are an important public health problem worldwide. They are more prevalent in tropical regions impacting in morbidity and mortality and costs for the health system. Objective: To evaluate the prevalence of enteroparasitosis and its association with socioeconomic, sanitary and environmental conditions and lifestyle habits in a coastal community in the Northeast Brazil. Methodology: This is an epidemiological, descriptive and cross-sectional study, carried out in a non-probabilistic manner between March and June 2017, with 105 residents of Boipeba Island in the Southern Bahia. The parasitological examination of feces was carried out by the methods of spontaneous sedimentation, Baermann-Moraes and FAUST. A questionnaire was applied to assess the sociodemographic profile of the population. Results: Of the total of individuals evaluated, 52.4% were female and 57.1% were between 15 and 59 years old. All individuals had piped, but untreated water, while 91.4% reported eating raw vegetables and 45.7% did not wash their hands before meals. Gastrointestinal symptoms were observed in 82.8% individuals and 69.6% were diagnosed with enteroparasitic infections. The most frequent parasites were the hookworm (18.1%) and Entamoeba coli (43.8%). The main potential risk factor for hookworm infection was the non-existence of an artesian well in the residence (PR=4.35) and Trichuris trichiura it was not having a sink in the toilet (PR=3.82). Conclusion: The analyzed community has a high prevalence of enteroparasitosis, in addition to environmental and climatic conditions that contribute to the transmission of these infections.

Specific IgG and IgA Antibody Reactivities in Sera of Children by Enzyme-Linked Immunoassay and Comparison With Giardia duodenalis Diagnosis in Feces.

BACKGROUND: Giardia duodenalis is conventionally diagnosed in fecal samples using parasitological methods. However, sensitivity is poor when only a single sample is analyzed, due to intermittent excretion of cysts in feces. Alternatively, the serum antibodies to G. duodenalis can be used for parasite diagnosis and epidemiological studies to determine previous exposure. We compared the rate of G. duodenalis infection between serum anti-Giardia IgG and IgA antibodies and fecal examination in Brazilian children. METHODS: Fecal and serum samples were tested from 287 children at a clinical laboratory and from 187 children at daycare centers. Fecal samples were processed using conventional parasitological methods and coproantigen detection for Giardia diagnosis. Serum samples were tested using an in-house ELISA for detection of anti-Giardia IgG and IgA. RESULTS: G. duodenalis was found in 8.2% (N=39) of the 474 children analyzed. The sensitivity and specificity of ELISA were 80.0% and 90.0% for IgG and 80.0% and 83.3% for IgA, respectively. The total positivity rate of anti-Giardia IgG and IgA in the sera was 13.9% (N=66) and 23.6% (N=112). The agreement between the positivity of specific antibodies and the detection of G. duodenalis in feces was moderate for ELISA-IgG, kappa index (95% CI)=0.543 (0.422-0.664), and mild for ELISA-IgA, kappa index (95% CI)=0.283 (0.162-0.404). Among the children infected with other enteroparasites, 11.6% (N=10) and 24.4% (N=21) showed reactivity to anti-Giardia IgG and to IgA, respectively. This cross-reactivity was more frequent in samples from children infected with Endolimax nana and Entamoeba coli. CONCLUSIONS: The higher frequency of specific antibody reactivity compared with G. duodenalis diagnosis in feces could reflect continuous exposure of children to G. duodenalis infection, resulting in long-lasting immunological memory and/or cross-reactivity with other intestinal amoebas.

Alcohol consumption alters anti-Strongyloides stercoralis antibodies production.

Individuals infected with Strongyloides stercoralis have been reported to produce different immunoglobulins isotypes, yet few studies have evaluated their use in strongyloidiasis diagnosis. The aim of this work was to evaluate the immunoreactivity of different classes and subclasses of anti-S. stercoralis circulating antibodies in alcoholic patients by ELISA and to perform immunoblotting in samples with discordant results between parasitological and immunological methods. 345 male patients with a clinical diagnosis of alcoholism hospitalized at a reference center for alcoholics in Salvador, Bahia, Brazil, were included in this study. The fecal samples were examined by three different parasitological methods (spontaneous sedimentation, Baermann-Moraes and Agar Plate Culture methods). The ELISA was performed for the detection of IgG, IgG1, IgG4, IgE and IgA1 anti-S. stercoralis. Immunoblotting, for the detection of specific IgA1, was used to elucidate discordant results between parasitological and immunological methods. S. stercoralis infection frequency in alcoholic patients by parasitological methods was 21.4% (74/345). Although IgE-ELISA demonstrated a high sensitivity and specificity in non-alcoholic patients, about 30% (22/74) of alcoholics with larvae in feces were negative. IgG1-ELISA detected the lowest frequency of antibodies in alcoholic patients with larvae in feces, only 57% (42/74). IgG4-ELISA was the best assay for S. stercoralis infection immunodiagnosis. Immunoreactivity in the immunoblotting for IgA1 at 90, 75, 26 and/or 17 kDa bands was observed in 92% (33/36) of alcoholics with larvae excretion and negative ELISA for one or more antibody isotypes. In conclusion, IgG4-ELISA showed the highest sensitivity and specificity, thus demonstrating its superiority for strongyloidiasis immunodiagnosis in alcoholic and non-alcoholic individuals. Both, IgE and IgG1-ELISA presented high sensitivities and specificities for S. stercoralis infection diagnosis in non-alcoholics, however there was low reactivity in alcoholic individuals. This can be associated with an increased susceptibility to severe strongyloidiasis in these patients. IgA1-immunoblotting can be used to confirm S. stercoralis infection when there are discordant results between parasitological methods and ELISA.

Relação entre genótipo e insuficiência pancreática em crianças e adolescentes com fibrose cística de um centro de referência no Brasil / Relationship between genotype and pancreatic insufficiency in children and adolescents with cystic fibrosis in a referral center in Brazil

Introdução: fibrose cística (FC) é uma doença genética que culmina em alterações na proteína transmembrana CFTR, resultando na produção de muco mais espesso em diversos órgãos, destacando-se os tratos respiratório e digestório. A insuficiência pancreática (IP) acomete até 95% dos pacientes com FC. Objetivos: determinar a frequência de IP através da dosagem de elastase fecal-1 (EF-1) e compará-la com o genótipo de pacientes com FC assistidos em um centro de referência. Metodologia: foi realizado um estudo transversal, incluindo-se pacientes com FC de 0 a 20 anos. Após a inclusão dos sujeitos à pesquisa, foi realizada consulta ao prontuário para a obtenção de dados clinicos e demograficos e amostras de fezes foram obtidas para dosagem da (EF-1). Os pacientes foram submetidos à análise molecular das mutações por métodos convencionais, através da extração do DNA em sangue periférico. Quando duas mutações patológicas não foram identificadas, o sequenciamento de nova geração com utilização da plataforma Illumina HiSeq foi realizado em amostras da mucosa oral. Resultados: foram incluídos 31 pacientes, 17 (54,8%) do sexo feminino, mediana de idade de 10 anos, e apenas um paciente foi classificado como branco. Vinte e dois (70,9%) pacientes apresentaram dosagem de EF-1 inferior a 200 µg/g, compatível com o diagnóstico de IP. Destes, 21 (95,4%) apresentaram dosagem de EF-1 menor ou igual a 15µg/g, caracteristica de IP grave. Todos os pacientes com IP apresentavam duas mutações de classes I a III. Conclusão: a IP foi identificada em 70% dos pacientes, ocorrendo em todos os pacientes com duas mutações de classe I-III.

Introduction: cystic fibrosis (CF) is a genetic disease that culminates in alterations in the CFTR transmembrane protein, resulting in the production of thicker mucus in various organs, especially the respiratory and digestive tract. Pancreatic insufficiency (PI) affects up to 95% of CF patients. Objectives: To determine the frequency of PI by measuring fecal elastase-1 (FE-1) and comparing it with the genotype of CF patients assisted at a referral Center. Methodology: a cross-sectional study was conducted, including patients with CF from 0 to 20 years. After the inclusion of the subjects to the research, medical records were consulted to obtain clinical and demographic data and stool samples were obtained for the measurement of (FE-1). Patients were submitted to molecular analysis of mutations by conventional methods by DNA extraction in peripheral blood. When two pathological mutations were not identified, next-generation sequencing using the Illumina HiSeq platform was performed on oral mucosa samples. Results: thirty one patients were included, 17 (54.8%) female, median age 10 years, and only one patient was classified as white. Twenty-two (70.9%) patients had an FE-1 dosage of less than 200 µg / g, compatible with the diagnosis of pancreatic insufficiency (PI). Of these, 21 (95,4%) had an EF-1 dosage less than or equal to 15µg / g, characteristic of severe PI. All patients with two mutations class I to III were PI. Conclusion: PI was identified in 70% of patients, occurring in all patients with class I-III mutations.

Enteroparasitoses e aspectos socioeconômicos em pacientes alcoolistas / Intestinal parasites and socioeconomic aspects of alcoholic patients

Introdução: as enteroparasitoses constituem um problema de saúde pública que atinge as populações mais vulneráveis. O alcoolismo é um problema que afeta milhões de pessoas em todo o mundo, apresenta efeitos nocivos à saúde dos indivíduos e predispõe à infecção por S. stercoralis e às formas mais graves da estrongiloidíase. Objetivo: avaliar a prevalência da infecção das enteroparasitoses, bem como fatores socioeconômicos e sanitários de pacientes alcoolistas atendidos em um centro de tratamento especializado em Salvador, Bahia. Metodologia: trata-se de um estudo transversal, realizado com pacientes alcoolistas (n=277), do sexo masculino, atendidos em um centro de tratamento entre julho de 2014 e junho de 2017. O estudo foi realizado através da aplicação de um questionário estruturado para obtenção de dados socioeconômicos, demográficos e sanitários, sendo solicitadas, ainda, pelo menos duas amostras de fezes em dias alternados. O diagnóstico parasitológico foi realizado pelos métodos de sedimentação espontânea, Baermann-Moraes e cultura em placa de ágar. Resultados: a média de idade dos pacientes inclusos foi de 44,8 ± 9,5 anos. Verificouse que 35,7% dos pacientes estavam infectados com algum enteroparasito e, desses, 30,3% eram monoparasitados. Os parasitos mais frequentes foram S. stercoralis, Endolimax nana e ancilostomídeos, correspondendo 16,6%, 11,2% e 5,8%, respectivamente. Conclusão: dessa forma, S. stercoralis foi o parasito mais frequente, e a associação entre a infecção por esse parasito e o alcoolismo pode levar à estrongiloidíase grave. A elevada frequência de enteroparasitoses nesses pacientes, principalmente por protozoários, deve-se à ausência de higiene pessoal, pois esses indivíduos são suscetíveis à infecção oral fecal. A implementação de medidas de saneamento básico e de campanhas de conscientização para prevenção de infecções parasitárias é imprescindível para a saúde das populações mais vulneráveis.

Introduction: intestinal parasitoses are a public health issue that notably affects vulnerable populations. Alcoholism is a problem that affects millions worldwide by causing damaging effects to the health of individuals as it predisposes them to that infection through stercralisàs and more evolved forms of strongyloidiasis. Objective: evaluate the prevalence of intestinal parasite infections as well as socioeconomic and sanitation factors in a population of alcoholic patients at a specialized treatment facility in Salvador, Bahia. Methodology: this cross-sectional study was carried out with male alcoholic patients (n=277) at a treatment facility from July/2014 to June/2017. The research data were collected through a structured questionnaire aimed to obtain socioeconomic, demographic and sanitation information. Stool tests were ordered in alternate days. The parasitological diagnosis was based on methods of spontaneous sedimentation, Baermann-Moraes and Agar plate growth medium. Results: the patients' average age was 44,8 ± 9,5 years. A total of 35% of the patients was infected with a type of enteroparasite, of whom 30,3% was mono-infected. The most commonly found parasites were S. stercoralis, Endolimax nana and hookworm, corresponding to 16,6%, 11,2% e 5,8%, respectively. Conclusion: as such, S. Stercoralis was the most frequent parasite in this population and the association between the infection by this parasite and alcoholism may lead to severe strongyloidiasis. The high rates of enteroparasitism in those patients, particularly protozoa, are due to the lack of adequate personal hygiene, given those individuals are prone to acquire infections transmitted through the oral fecal route. An implementation of public health sanitation measures and the launch of public awareness campaigns in order to prevent parasite infections are vital to the health of vulnerable populations.

Case Report: Strongyloides stercoralis Hyperinfection in a Patient with HTLV-1: An Infection with Filariform and Rhabditiform Larvae, Eggs, and Free-Living Adult Females Output.

Strongyloides stercoralis is the main etiological agent of human strongyloidiasis. Severe strongyloidiasis is commonly associated to alcoholism, corticostereoid use, and human T cell lymphotropic virus type 1 (HTLV-1) coinfection. Herein, we report a case of a 13-year-old boy coinfected with S. stercoralis and HTLV-1, excreting several parasitic forms in the stool. The parasitological examination of his feces showed a large amount of filariform (about 3,000 larvae per gram of feces) and rhabditiform larvae (about 2,000 larvae per gram of feces). In addition, free-living adult females (about 50 parasites per gram of feces) and eggs (about 60 eggs per gram of feces) were detected. The main laboratory findings pointed to high immunoglobulin E (IgE) levels (228 UI/mL) and eosinophila (11.6%). The patient was treated with three courses of ivermectin (200 µg/kg twice, 2 weeks apart), achieving the parasitological cure. An increase of about 19 times in interleucin (IL)-17 level was observed following the parasitological cure, in addition to a decrease in the white blood cell, eosinophil counts, and IgE levels. This is the first case report, to our knowledge, in which an S. stercoralis adult free-living female was described in human feces and where an increase in IL-17 levels after Strongyloides treatment in a HTLV-1 coinfected individual was observed. This finding raises the need for further studies about IL-17 immunomodulation in S. stercoralis and HTLV-1 coinfected patients.

[Concordance between the zinc sulphate flotation and centrifugal sedimentation methods for the diagnosis of intestinal parasites].

INTRODUCTION: The diagnosis of intestinal parasitic infections depends on the parasite load, the specific gravity density of the parasite eggs, oocysts or cysts, and the density and viscosity of flotation or sedimentation medium where faeces are processed. OBJECTIVE: To evaluate the concordance between zinc sulphate flotation and centrifugal sedimentation in the recovery of parasites in faecal samples of children. MATERIALS AND METHODS: Faecal samples of 330 children from day care centers were evaluated by zinc sulphate flotation and centrifugal sedimentation techniques. The frequencies of detection of parasites by each method were determined and the agreement between the diagnostic techniques was evaluated using the kappa index, with 95% confidence intervals. RESULTS: The faecal flotation in zinc sulphate diagnosed significantly more cases of Trichuris trichiura infection when compared to centrifugal sedimentation (39/330; 11.8% vs. 13/330; 3.9%, p<0.001), with low diagnostic concordance between methods (kappa=0.264; 95% CI: 0.102-0.427). Moreover, all positive samples for Enterobius vermicularis eggs (n=5) and Strongyloides stercoralis larvae (n=3) were diagnosed only by zinc sulphate. No statistical differences were observed between methods for protozoa identification. CONCLUSIONS: The results showed that centrifugal flotation in zinc sulphate solution was significantly more likely to detect light helminths eggs such as those of T. trichiura and E. vermicularis in faeces than the centrifugal sedimentation process.

Ocorrência de anticorpos anti-Toxoplasma gondii em caprinos do semiárido baiano / Occurrence of antibodies to Toxoplasma gondii in the Bahia semi-arid goats

Este trabalho teve como objetivo avaliar a frequência de anticorpos IgG específicos contra Toxoplasma gondii em caprinos pertencentes a algumas cidades do semiárido baiano, através do ELISA (ensaio imunoadsorvente ligado à enzima) indireto. Primeiramente, foi realizado um estudo piloto com 49 caprinos para comparar os resultados do ELISA com a RIFI (reação de imunofluorescência indireta) para detecção de anticorpos séricos contra T. gondii. Foram observados 30,6% (15/49) de soropositivos pelo ELISA, enquanto pela RIFI houve 40,8% (20/49) de caprinos reagentes. Desta maneira, o ELISA apresentou 70% de sensibilidade e 96,5% de especificidade. Em seguida, foram analisadas amostras de soros de caprinos provenientes das cidades de Casa Nova, Curaçá, Jaguarari, Juazeiro, Sento Sé e Uauá. Dentre os 375 animais avaliados, 25,1% apresentaram títulos de IgG positivos no ELISA para T. gondii. As fêmeas tiveram um risco 1,236 vezes maior de serem soropositivas em relação aos machos. Não houve relação entre idade e presença de anticorpos anti-T. gondii nestes animais. A cidade com maior número de caprinos soropositivos foi Sento Sé, com 46,4% (39/84) e a menor frequência foi observada em Juazeiro, com 3,6% (2/55). Os resultados deste estudo confirmam que a infecção pelo T. gondii é comum em caprinos brasileiros do estado da Bahia, inclusive na região de clima semiárido, considerada mais desfavorável à transmissão

The objective of this study was to evaluate the frequency of specific IgG antibodies against Toxoplasma gondii in goats belonging to some cities of Semi-Arid region of Bahia, by indirect ELISA (enzyme linked immunonosorbent assay). First, a pilot study was conducted with 49 goats to compare results from ELISA with those obtained by IFAT (indirect fluorescent antibody test) to detect serum antibodies against T. gondii. It was observed 30.6% (15/49) of seropositive by ELISA, while the IFAT showed 40.8% (20/49) reagents goats. Thus, ELISA showed 70% sensitivity and 96.5% specificity. Then, sera samples of goats from the cities Casa Nova, Curaçá, Jaguarari, Juazeiro, Sento Sé and Uauá were analyzed. Among the 375 evaluated animals, 25.1% had positive IgG titers in ELISA for T. gondii. Females have a 1.236 times higher risk of being seropositive compared to males. There was no correlation between age and the presence of anti-T. gondii antibodies in these animals. The city with the biggest number of seropositive goats was Sento Sé, with 46.4% (39/84) and the lowest rate was observed in Juazeiro, with 3.6% (2/55). The results of this study confirm that T. gondii infection is common in goats from the semi-arid climate region of Bahia, which is considered adverse for transmission

Strongyloides stercoralis infection in patients with systemic lupus erythematosus: diagnosis and prevention of severe strongyloidiasis.

AIM: Strongyloides stercoralis infection is usually chronic and asymptomatic and may persist undiagnosed for decades. However, in immunocompromised individuals, the infection can cause hyperinfection and dissemination. Therefore, early diagnosis is essential to prevent severe forms of strongyloidiasis. The aims of this study were: (i) to evaluate the frequency of S. stercoralis infection in patients with systemic lupus erythematous (SLE) and (ii) to estimate specific immunoglobulins G (IgG) and E (IgE) production using an enzyme-linked immunosorbent assay (ELISA) method. METHODS: Seventy-five SLE patients treated with prophylactic anthelmintic therapy were evaluated using the spontaneous sedimentation (SS), Baermann-Moraes (BM) and agar plate culture (APC) methods. Serum anti-S. stercoralis IgG and IgE antibodies were measured by ELISA. RESULTS: Using parasitological methods, the frequency of intestinal parasites was 10.7%, whereas the frequency of S. stercoralis infection was 1.3%. The sensitivity of the ELISA to detect anti-S. stercoralis IgG and IgE was 80% and 76.9%, respectively. Both assays presented the same specificity of 96.7%. The frequency of anti-S. stercoralis IgG and IgE was 16% and 28%, respectively. Six patients were positive for both antibodies. CONCLUSIONS: Diagnostic approaches using high-sensitivity parasitological methods and the detection of specific antibodies are essential for the diagnosis of strongyloidiasis in immunocompromised patients. Early detection of infection can alter the course of the disease via appropriate treatment, preventing the occurrence of severe strongyloidiasis.

Recurrence of strongyloides stercoralis infection in a patient with Hansen's disease: a case report.

In patients with immunosuppressive disorders, S. stercoralis infection may develop into a hyperinfection syndrome which, on rare occasions, may be a life-threatening condition. Therapy of S. stercoralis infection with thiabendazole has been limited, due to its numerous side effects, and has been replaced by albendazole and ivermectin. The present case report describes a case of Strongyloides Hyperinfection Syndrome (SHS) in a patient with Hansen's disease and lack of response to first-line anthelmintic treatment. A 38 year-old man was diagnosed as having borderline lepromatous leprosy. He developed Erythema Nodosum Leprosum and was treated with thalidomide and prednisone. In May 2010 he was diagnosed with S. stercoralis infection and was treated with albendazole. One year later, the stool examination showed continued presence of S. stercoralis larvae. He was treated with ivermectin (6 mg) in a double dose (given 1 month apart) which resulted in larvae excretion clearance. The absence of infection was confirmed three times during a 1 year followup period by stool examination and non-detection of anti-S. stercoralis IgG levels.

The role of glycosylated epitopes in the serodiagnosis of Strongyloides stercoralis infection.

Carbohydrates of pathogen antigens have been disrupted by periodate oxidation, in order to reduce nonspecific bindings and improve serodiagnosis of parasite infections. In the present study, the enzyme-linked immunosorbent assay (ELISA) was carried out with filariform larvae antigen treated, or not treated, with sodium metaperiodate. Groups of sera from patients with Strongyloides stercoralis infection, with other intestinal parasites and a normal control, were used. The oxidation of Strongyloides stercoralis glycosylated epitopes reduced the seroreactivity of sera from patients with S. stercoralis infection as demonstrated by ELISA, with a decrease in sera optical densities. The number of cross-reactions of IgG and IgE-ELISAs increased by 12% and 16%, respectively, after antigen treatment with metaperiodate. This was more often observed in patients infected with Schistosoma mansoni and hookworm. Moreover, the IgG depletion from sera tested by IgE-ELISA led to the detection of previous false-negative samples from S. stercoralis-infected patients.

Avaliação da frequência de parasitos intestinais e do estado nutricional em escolares de uma area periurbana de Salvador, Bahia, Brasil / Evaluation of intestinal parasitic infections prevalence and nutritional status of school children from a peri-urban area of Salvador, Bahia, Brazil

A elevada prevalência de parasitos intestinais nos países subdesenvolvidos se deve, principalmente, às precárias condições de saneamento básico e ao baixo nível de escolaridade da população. Este trabalho avaliou a associação entre frequência dos parasitos intestinais e estado nutricional e também o perfil socioeconômico dos alunos da primeira à quarta série de uma escola municipal do bairro Jardim Valéria, subúrbio de Salvador, Bahia, Brasil. A análise parasitológica foi realizada em 200 estudantes pelo método de Hoffman-Pons-Janer. O estado nutricional foi avaliado segundo a classificação de Waterlow, utilizando-se a curva padrão adotada pelo National Center of Health Statistic. Os resultados demonstraram uma prevalência de 94por cento (188/200) de infecção porenteroparasitos, sendo a faixa etária mais atingida a de 6 a 9 anos. Os parasitos com frequência mais elevada foram: Entamoeba coli (43,5por cento), Ascaris lumbricoides (25por cento), Endolimax nana (22por cento) eEntamoeba histolytica/E. dispar (21,5por cento). Em relação à diversidade de parasitos, 39por cento das crianças infectadas apresentavam monoparasitismo; 33por cento, biparasitismo e 22por cento, multiparasitismo. A análise do estado nutricional de 147 alunos na faixa etária de 6 a 10 anos mostrou que 15por cento tinham déficit nutricional. No entanto, não foi demonstrada uma correlação positiva entre crianças parasitadas edéficit nutricional, em razão da elevada frequência de crianças parasitadas (78,9por cento) classificadas como eutróficas. Os dados deste estudo confirmam a elevada prevalência de parasitos intestinais e má nutrição entre os escolares de populações de baixa renda. Em consequência, destaca-se aimportância de programas de educação em saúde para prevenção de infecções parasitárias e da adoção de medidas que melhorem o estado nutricional das crianças.

An experimental protocol for the establishment of dogs with long-term cellular immune reactions to Leishmania antigens.

Domestic dogs are considered to be the main reservoirs of zoonotic visceral leishmaniasis. In this work, we evaluated a protocol to induce Leishmania infantum/Leishmania chagasi-specific cellular and humoral immune responses in dogs, which consisted of two injections of Leishmania promastigote lysate followed by a subcutaneous inoculation of viable promastigotes. The primary objective was to establish a canine experimental model to provide positive controls for testing immune responses to Leishmania in laboratory conditions. After inoculation of viable promastigotes, specific proliferative responses of peripheral blood mononuclear cells (PBMCs) to either Leishmania lysate or recombinant proteins, the in vitro production of interferon-γ by antigen-stimulated PBMCs and a significant increase in circulating levels of anti-Leishmania antibodies were observed. The immunized dogs also displayed positive delayed-type hypersensitivity reactions to Leishmania crude antigens and to purified recombinant proteins. An important finding that supports the suitability of the dogs as positive controls is that they remained healthy for the entire observation period, i.e., more than seven years after infection. Following the Leishmania antigen lysate injections, the infection of dogs by the subcutaneous route appears to induce a sustained cellular immune response, leading to an asymptomatic infection. This provides a useful model for both the selection of immunogenic Leishmania antigens and for immunobiological studies on their possible immunoprotective activities.

An experimental protocol for the establishment of dogs with long-term cellular immune reactions to Leishmania antigens

Domestic dogs are considered to be the main reservoirs of zoonotic visceral leishmaniasis. In this work, we evaluated a protocol to induce Leishmania infantum/Leishmania chagasi-specific cellular and humoral immune responses in dogs, which consisted of two injections of Leishmania promastigote lysate followed by a subcutaneous inoculation of viable promastigotes. The primary objective was to establish a canine experimental model to provide positive controls for testing immune responses to Leishmania in laboratory conditions. After inoculation of viable promastigotes, specific proliferative responses of peripheral blood mononuclear cells (PBMCs) to either Leishmania lysate or recombinant proteins, the in vitro production of interferon-γ by antigen-stimulated PBMCs and a significant increase in circulating levels of anti-Leishmania antibodies were observed. The immunized dogs also displayed positive delayed-type hypersensitivity reactions to Leishmania crude antigens and to purified recombinant proteins. An important finding that supports the suitability of the dogs as positive controls is that they remained healthy for the entire observation period, i.e., more than seven years after infection. Following the Leishmania antigen lysate injections, the infection of dogs by the subcutaneous route appears to induce a sustained cellular immune response, leading to an asymptomatic infection. This provides a useful model for both the selection of immunogenic Leishmania antigens and for immunobiological studies on their possible immunoprotective activities.