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.

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.

Avaliação da anemia e outros biomarcadores em pacientes alcoolistas / Evaluation of anemia and other biomarkers in alcoholic patients

Introdução: os transtornos por uso de álcool afetam milhões de pessoas em todo o mundo e podem comprometer vários órgãos e sistemas, em muitos casos devido à deficiência de micronutrientes. O objetivo deste artigo é avaliar a frequência e caracterizar a anemia e os biomarcadores metabólicos e hepáticos em pacientes alcoolistas. Metodologia: trata-se de um estudo transversal, no qual foram incluídos 65 pacientes alcoolistas, do sexo masculino, internados no Centro de Acolhimento e Tratamento de Alcoolistas, das Obras Sociais Irmã Dulce. Resultados: a maioria dos indivíduos avaliados apresentou contagem de hemácias, teor de hemoglobina e hematócrito abaixo dos valores de referência, com uma frequência de 61,5% (40/65) para todos os parâmetros e uma média de 4,1x106/uL, 13,0 g/dL e 38,6%, respectivamente. Entre os 40 indivíduos que apresentaram anemia, prevaleceu um padrão normocítico (25/40) e normocrômico (32/40) e uma frequência de anisocitose de 35,0% (14/40). Observou-se elevada frequência de indivíduos com altos níveis de AST e GGT, 64,6 (42/65) e 76,9% (50/61), respectivamente, enquanto apenas 13,8 (9/65) e 3,1% (2/63) apresentaram alterações na concentração plasmática de albumina e no tempo de protrombina, respectivamente. Conclusão: neste trabalho, foi possível observar uma elevada frequência de anemia normocítica e normocrômica, bem como altos níveis de AST e GGT, enquanto os biomarcadores da função hepática estavam dentro do valor de referência. Estes resultados contribuem para o entendimento da saúde do indivíduo alcoolista, podendo auxiliar na elaboração de medidas públicas que atuem na prevenção e promoção da saúde desses pacientes.

Introduction: alcohol use disorders affect millions of people around the world and can compromise many organs and systems. The aim of the essay is to evaluate frequency and characterize anemia and metabolic and hepatic biomarkers in alcoholic patients. Methods: it is a cross-sectional study in which 65 male alcoholic patients admitted to treatment at Center for Reception and Treatment for Alcoholics at Sister Dulce Social Works. Results: most evaluated individuals had red blood cell count, hemoglobin content and hematocrit below reference values, with frequency of 61.5% (40/65) for all parameters and a mean of 4.1x106/uL, 13.0 g/dL and 38.6%, respectively. Among 40 individuals who presented anemia, a normocytic (25/40) and normochromic (32/40) pattern prevailed, and anisocytosis frequency of 35.0% (14/40). A high frequency of individuals with increased AST and GGT levels was observed, 64.6 (42/65) and 76.9% (50/61), respectively, while only 13.8 (9/65) and 3.1% (2/63) presented alterations in albumin levels and prothrombin time, respectively. Conclusion: study shows that it was possible to observe a high frequency of normocytic and normochromic anemia, as well as high levels of AST and GGT, while liver function biomarkers were within reference value. Results contribute to the understanding of alcoholic individuals' health, and may help with elaboration of public measures to prevention and promotion of health for these patients

Development of rSs-NIE-1 and rSs-IR Recombinant Antigen-Based Immunoblot for Detection of Antibody to Strongyloides stercoralis.

Strongyloides stercoralis is a soil-transmitted nematode that can cause life-threatening conditions in immunocompromised persons. In the United States, strongyloidiasis should be considered mainly in immigrants, refugees, or travelers. The confirmatory laboratory diagnosis is usually performed by detecting larvae from the stool, duodenal material, and sputum. In persons who are immunocompromised with severe strongyloidiasis, adult worms and eggs can be detected from duodenal material. For serological diagnosis, most assays use crude antigens to detect anti-S. stercoralis IgG. Recently, recombinant proteins such as rSs-NIE-1 and rSs-IR have been used to detect IgG antibodies. We used rSs-NIE-1 and rSs-IR recombinant antigens to develop a biplex Western blot assay to detect the IgG4 antibody in individuals with strongyloidiasis. The sensitivities of rSs-NIE-1 and rSs-IR were 97.4% and 90.8%, respectively, whereas the specificities were 97.6% and 98%, respectively. In conclusion, the biplex rSs-NIE-1 and rSs-IR immunoblot performs well in detecting IgG4 antibody in S. stercoralis-infected persons.

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.

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.

Alterations in serum paraoxonase-1 activity and lipid profile in chronic alcoholic patients infected with Strongyloides stercoralis.

The objective of this study was to investigate paraoxonase-1 (PON1) activity, cortisol levels, and the lipid profile in the sera of alcoholic and non-alcoholic Strongyloides stercoralis-infected and uninfected individuals in a sample of 276 individuals attended at the National Health System in Salvador, Bahia, Brazil. The activity of PON1 was measured by the Beltowski method, serum lipids, and cortisol levels using commercial kits. PON1 activity was low in both alcoholic and non-alcoholic individuals infected with S. stercoralis. A positive correlation was observed between PON1 activity and cortisol concentration in alcoholic individuals who were not infected with S. stercoralis; whereas a negative correlation occurred in S. stercoralis-infected nonalcoholic individuals. The levels of triglycerides, LDL-C, and VLDL-C in S. stercoralis-infected alcoholic individuals were significantly lower than in uninfected alcoholic individuals. The high level of HDL-C and the low level of LDL-C, VLDL, triglycerides and PON1 activity in alcoholic patients infected with S. stercoralis evidenced an anti-atherogenic pattern.

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.

Human infection by Trichostrongylus spp. in residents of urban areas of Salvador city, Bahia, Brazil / Infección humana por Trichostrongylus spp. en residentes de zonas urbanas de la ciudad de Salvador, Bahia, Brasil

Introduction: Nematodes of Trichostrongylus genus are mainly parasites of herbivores, although sporadic human infections have been reported in many countries. Objective: To describe the frequency and seasonality of Trichostrongylus spp. infection in individuals attended at a public clinical laboratory. Materials and methods: Fecal samples of 9,283 individuals were evaluated by spontaneous sedimentation (Lutz) in the Parasitology Laboratory of the Pharmacy College, Federal University of Bahia, Brazil, from January of 2006 to May of 2008. The positive samples for either Trichostrongylus spp. or hookworms were further examined to evaluate the morphometry of nematode eggs. Results: One-hundred and ten patients (1.2%) were confirmed to be infected by Trichostrongylus spp. The positive cases were significantly more frequent in females (1.6%; p <0.05), with higher distribution in the age group between 11-20 years (1.9%), compared to those aged 51-60 (0.8%) and older than 60 years (0.9%)( p <0.05), independent of gender. Trichostrongylus spp. infections were more common from March to May (40 cases) and showed a homogeneous distribution over the other periods of the year (21-25 cases). The hematological analyses of 60 Trichostrongylus -infected patients showed normal levels of eosinophils in most of the positive cases. Conclusions: The data reveal that the occurrence of infection by Trichostrongylus spp. in residents of Salvador is more frequent than those reported in other urban regions and that it is essential to distinguish the parasite from other nematodes in routine parasitological examination.

Introducción. Los nematodos del género Trichostrongylus son parásitos principalmente herbívoros, aunque se hayan descrito en muchos países infecciones humanas esporádicas. Objetivo. Describir la frecuencia y estacionalidad de la infección por Trichostrongylus spp. en individuos atendidos en un laboratorio clínico público. Materiales y métodos. Las muestras fecales de 9.283 individuos fueron analizadas mediante sedimentación espontánea (Lutz) en el Laboratorio de Parasitología de la Facultad de Farmacia de la Universidad Federal de Bahía, Brasil, desde enero de 2006 a mayo de 2008. Las muestras positivas para Trichostrongylus o Ancylostoma fueron reexaminadas para evaluar la morfometría de los huevos de nematodos. Resultados. La infección por Trichostrongylus spp. se confirmó en 110 pacientes (1,2 %), con mayor frecuencia en el sexo femenino (1,6 %; p<0,05). La frecuencia fue mayor en el grupo de edad de 11 a 20 años (1,9 %), independientemente del sexo, en comparación con las personas de 51 a 60 (0,8 %) y con los mayores de 60 años (0,9 %) (p < 0,05). Las infecciones por Trichostrongylus spp. fueron más frecuentes entre marzo y mayo (40 casos) con una distribución homogénea en otros periodos del año (21 a 25 casos). Los análisis hematológicos de 60 pacientes infectados con Trichostrongylus spp. presentaron niveles normales de eosinófilos en la mayoría de los casos positivos. Conclusiones. Los datos revelan que la incidencia de la infección por Trichostrongylus spp. en individuos residentes en Salvador es más frecuente que las descritas en otras áreas urbanas y, por ello, es esencial distinguir dicho parásito de otros nematodos en los exámenes parasitológicos de rutina.

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.

Human infection by Trichostrongylus spp. in residents of urban areas of Salvador city, Bahia, Brazil.

INTRODUCTION: Nematodes of Trichostrongylus genus are mainly parasites of herbivores, although sporadic human infections have been reported in many countries. OBJECTIVE: To describe the frequency and seasonality of Trichostrongylus spp. infection in individuals attended at a public clinical laboratory. MATERIALS AND METHODS: Fecal samples of 9,283 individuals were evaluated by spontaneous sedimentation (Lutz) in the Parasitology Laboratory of the Pharmacy College, Federal University of Bahia, Brazil, from January of 2006 to May of 2008. The positive samples for either Trichostrongylus spp. or hookworms were further examined to evaluate the morphometry of nematode eggs. RESULTS: One-hundred and ten patients (1.2%) were confirmed to be infected by Trichostrongylus spp. The positive cases were significantly more frequent in females (1.6%; p <0.05), with higher distribution in the age group between 11-20 years (1.9%), compared to those aged 51-60 (0.8%) and older than 60 years (0.9%)( p <0.05), independent of gender. Trichostrongylus spp. infections were more common from March to May (40 cases) and showed a homogeneous distribution over the other periods of the year (21-25 cases). The hematological analyses of 60 Trichostrongylus -infected patients showed normal levels of eosinophils in most of the positive cases. CONCLUSIONS: The data reveal that the occurrence of infection by Trichostrongylus spp. in residents of Salvador is more frequent than those reported in other urban regions and that it is essential to distinguish the parasite from other nematodes in routine parasitological examination.

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.