Prevalence of human cryptosporidiosis in the Americas: systematic review and meta-analysis

ABSTRACT Cryptosporidiosis is a disease caused by the Cryptosporidium spp parasite. As some species of Cryptosporidium have a wide host spectrum, the characterization of the pathogen at the species or genotype level is of great importance to define the sources of infection for humans and the potential for public health. This study investigated the diversity of the genus Cryptosporidium spp. in humans from all over the American continent and observed whether the method used to search for the parasite influenced the prevalence found in the Americas. This systematic review was carried out using the Pubmed, Science direct, Lilacs, Scielo, and Scopus databases with publications from January 1, 2010, to December 31, 2020. For data synthesis, the PRISMA flowchart was used and for the meta-analysis we used the MetaXL program. Of the selected publications, 57, 9 and 16 belonged to the region of South, Central and North America, respectively. The prevalence found for South, Central, and North America was 7%, 7%, and 8%, respectively, when analyzing publications that used only the microscopy method. When we analyzed the publications that used immunological and molecular methods, we found prevalences of 10%, 9%, and 21% for South, Central, and North America, respectively. The C. hominis subtype IbA10G2 was the most reported in the American continent, followed by subtype IeA11G3T3 and, for C. parvum, subtype IIaA15G2RI was the most reported. In conclusion, Cryptosporidium spp. is present throughout the American continent and its prevalence is higher when immunological and/or molecular methods are used, in addition to direct microscopic examination.

Genetic diversity of Cryptosporidium identified in clinical samples from cities in Brazil and Argentina

The identification and characterisation of Cryptosporidiumgenotypes and subtypes are fundamental to the study of cryptosporidiosis epidemiology, aiding in prevention and control strategies. The objective was to determine the genetic diversity ofCryptosporidium in samples obtained from hospitals of Rio de Janeiro, Brazil, and Buenos Aires, Argentina. Samples were analysed by microscopy and TaqMan polymerase chain reaction (PCR) assays forCryptosporidium detection, genotyped by nested-PCR-restriction fragment length polymorphism (RFLP) analysis of the 18S rRNA gene and subtyped by DNA sequencing of the gp60 gene. Among the 89 samples from Rio de Janeiro, Cryptosporidium spp were detected in 26 by microscopy/TaqMan PCR. In samples from Buenos Aires,Cryptosporidium was diagnosed in 15 patients of the 132 studied. The TaqMan PCR and the nested-PCR-RFLP detected Cryptosporidium parvum, Cryptosporidium hominis, and co-infections of both species. In Brazilian samples, the subtypes IbA10G2 and IIcA5G3 were observed. The subtypes found in Argentinean samples were IbA10G2, IaA10G1R4, IaA11G1R4, and IeA11G3T3, and mixed subtypes of Ia and IIa families were detected in the co-infections. C. hominis was the species more frequently detected, and subtype family Ib was reported in both countries. Subtype diversity was higher in Buenos Aires than in Rio de Janeiro and two new subtypes were described for the first time.

Frequency of amoebiasis and other intestinal parasitoses in a settlement in Ilheus City, State of Bahia, Brazil

Introduction: This study evaluated the frequency of intestinal parasites, emphasizing the identification and differentiation of Entamoeba spp. Methods: Multiplex polymerase chain reaction (PCR), coproantigen tests and morphometric analysis were performed for Entamoeba spp. differentiation. Results: The overall frequency of intestinal parasites was 65%. Entamoeba histolytica was detected by the coproantigen test, and the PCR showed that Entamoeba dispar predominated in the population. In contrast, morphometric analysis was important for identifying Entamoeba hartmanni. Conclusions: It is possible to identify the causative agent of amoebiasis and to differentiate this agent from other species by combining techniques. .

A conventional polymerase chain reaction-based method for the diagnosis of human schistosomiasis in stool samples from individuals in a low-endemicity area

The aim of this study was to evaluate the efficacy of a polymerase chain reaction (PCR)-based method to detect Schistosoma mansoni DNA in stool samples from individuals living in a low-endemicity area in Brazil. Of the 125 initial stool samples, 80 were ELISA reactive and eggs were identified in 19 of the samples by parasitological examination. For the PCR evaluations, 56 stool samples were selected and divided into five groups. Groups I-IV were scored negative for S. mansoni eggs by parasitological examination. Groups I and II were ELISA reactive, whereas Groups III and IV were ELISA nonreactive. Groups II and III were positive for other intestinal parasites. PCR testing scored eight samples as positive from these four groups. Group V represented the S. mansoni -positive group and it included ELISA-reactive samples that were scored positive for S. mansoni by one or more parasitological examinations (6/19 were positive by Kato-Katz method, 9/17 by saline gradient and 10/13 by Helmintex®). PCR scored 13 of these 19 samples as positive for S. mansoni . We conclude that while none of these methods yielded 100% sensitivity, a combination of techniques should be effective for improving the detection of S. mansoni infection in low-endemicity areas.

Detection and differentiation of Cryptosporidium by real-time polymerase chain reaction in stool samples from patients in Rio de Janeiro, Brazil

This study reports the first genetic characterisation of Cryptosporidium isolates in Brazil using real-time polymerase chain reaction (RT-PCR). A total of 1,197 faecal specimens from children and 10 specimens from human immunodeficiency virus-infected patients were collected between 1999-2010 and screened using microscopy. Forty-eight Cryptosporidium oocyst-positive isolates were identified and analysed using a generic TaqMan assay targeting the 18S rRNA to detect Cryptosporidium species and two other TaqMan assays to identify Cryptosporidium hominis and Cryptosporidium parvum. The 18S rRNA assay detected Cryptosporidium species in all 48 of the stool specimens. The C. parvum TaqMan assay correctly identified five/48 stool samples, while 37/48 stool specimens were correctly amplified in the C. hominis TaqMan assay. The results obtained in this study support previous findings showing that C. hominis infections are more prevalent than C. parvum infections in Brazil and they demonstrate that the TaqMan RT-PCR procedure is a simple, fast and valuable tool for the detection and differentiation of Cryptosporidium species.

Persistence of viable cysts in neurocysticercosis: a serial imaging study / Persistência de cistos viáveis na neurocisticercose: um estudo seriado de imagem

Introduction: Cysticercosis is an endemic disease in developing countries and is the most common parasitic infection of the central nervous system. The diagnosis is difficult and imaging may contribute to the confirmation. Objective: To report the evolution of brain lesions and the clinical response of a patient with a definitive diagnosis of neurocysticercosis (NCC). Methods: We analyzed six computed tomography (CT) and three magnetic resonance imaging (MRI) exams, performed in a period of six years. Results: The serial imaging study revealed the involution of nine viable cysts and two degenerating cysts out of 39 lesions. It occurred after six years of disease and four courses of treatment with Albendazole. The other 28 lesions were calcified. Clinically, there was reduction in frequency of seizures after treatment with Albendazole and the onset of regular use of anticonvulsants (six per year to 1.8 per year). Conclusion: This case illustrates an instance of partial NCC efficacy to antiparasitic therapy, and demonstrates the role of serial imaging studies in the monitoring the evolution of NCC lesions and in characterizing the diversity of lesion appearance over time.

Introdução: A cisticercose é uma doença endêmica nos países em desenvolvimento. Representa a infecção parasitária mais comum dosistema nervoso central. O diagnóstico é difícil e o exame de imagem pode contribuir para a confirmação. Objetivo: Relatar a evolução das lesõesencefálicas, assim como avaliar a resposta clínica de um paciente com um diagnóstico definitivo do NCC. Métodos: Foram analisadas seistomografias computadorizadas (TC) e três ressonâncias magnéticas (RM) realizadas durante o período de seis anos. Resultados: O estudode imagem seriada revelou a involução de nove cistos viáveis e dois cistos em degeneração de 39 lesões. Isso ocorreu após seis anos de evolução da doença e quatro cursos de tratamento com albendazol. As outras 28 lesões encontravam-se calcificadas e aumentaram para 36 em número. Clinicamente, houve redução na frequência das crises após o tratamento com albendazol e do início do uso regular de anticonvulsivantes (seis por ano para 1,8 por ano). Conclusão: O caso demonstra a importância dos estudos da imagem seriada no acompanhamento das lesões da neurocisticercose (NCC), considerando a possibilidade de resistência medicamentosa e a necessidade da repetição do tratamento.

Comparison of multiplex-PCR and antigen detection for differential diagnosis of Entamoeba histolytica

Amebiasis is an infection caused by Entamoeba histolytica. However, differentiation between E. histolytica and Entamoeba dispar, which are morphologically identical species, is essential for treatment decision, precaution of the invasive disease and public health. The purpose of the present study was to evaluate a Multiplex -PCR for detection and differentiation of E. histolytica from E. dispar from fresh stool samples in comparison with the coproantigen commercial ELISA. Microscopic examination of stools using the Coprotest method, detection of stool antigen by enzyme-linked immunosorbent assay kit and a home made Multiplex-PCR, were used for the diagnosis of amoebiasis infection. Analysis of the 127 stools samples by microscopy examination demonstrated that only 27 (21 percent) samples were positive for E. histolytica/E. dispar complex. Among these stool samples, 11 were positive by Multiplex-PCR, with nine presenting the diagnostic fragment characteristic of E. dispar (96 bp) and two presenting diagnostic fragment of E. histolytica (132 bp). Among negative samples detected by microscopic examination, three positive samples for E. dispar and one positive for E. histolytica by Multiplex-PCR was observed. This denotes a low sensibility of microscopic examination when a single stool sample is analyzed. Assay for detection of E. histolytica antigen was concordant with multiplex-PCR in relation to E. histolytica. Statistical analysis comparing the sensibility tests was not done because of the low number of E. histolytica cases. The results demonstrate the importance of the specific techniques use for the differentiation between E. histolytica and E. dispar.

Estudo do perfil lipídico em crianças e jovens do ambulatório pediátrico do hospital universitário Antônio Pedro associado ao risco de dislipidemias / Lipid profiles associated with dyslipidemic risk in children and teenagers from the pediatric clinic of the university hospital Antônio Pedro

O processo de formação da placa aterosclerótica inicia-se na infância e progride lentamente até a vida adulta, quando ocorrerão as manifestações clínicas da doença. O objetivo deste trabalho foi realizar um estudo da concentração plasmática de colesterol total (CT), colesterol da lipoproteína de baixa densidade (LDL-C), triglicéride (TG) e colesterol da lipoproteína de alta densidade (HDL-C) numa população na faixa etária de 2 a 19 anos, de ambos os sexos, atendida no ambulatório do Hospital Universitário Antônio Pedro (HUAP). Os dados dos prontuários foram obtidos entre dezembro/2004 e janeiro/2006 e as concentrações plasmáticas foram correlacionadas com os fatores de risco para dislipidemia. As dosagens foram feitas no Laboratório de Bioquímica Clínica do HUAP. Os níveis plasmáticos do CT, LDL-C, TG e HDL-c foram maiores no sexo feminino do que no masculino e este fato é compatível com a literatura. A média dos valores de TG, CT, LDL-C e HDL-C observada na população estudada mostrou-se elevada para esses parâmetros, principalmente em pacientes que apresentam doenças, como síndrome nefrótica, lúpus eritematoso sistêmico (LES) e diabetes mellitus (DM). Este trabalho reforça a tese da necessidade de utilização, no Brasil, de estudos sobre os intervalos de valores de referência do perfil lipídico nesta faixa etária e também sobre o perfil dos níveis desses lípides na população considerada sadia.

Atherosclerotic plaques form early in childhood and progress slowly until adult life, when clinical manifestations show. The goal of this study was to analyze the concentrations in plasma of total cholesterol, LDL-cholesterol (LDL-C), triglycerides (TG) and HDL-cholesterol (HDL-C) in a group of children of both sexes and up to 19 years of age, who are attending at the University Hospital Antônio Pedro (HUAP). Patient admission sheets between December 2004 and January 2006 were analyzed for dyslipidemic risk factors, and correlated with the respective lipid plasma concentrations, determined at the Laboratory of Clinical Chemistry (HUAP). The plasma levels of total cholesterol, LDL-C, TG and HDL-C in female patients were higher than in male patients, suggesting the influence of sexual maturation as described in the literature. The mean concentrations of total cholesterol, LDL-C, TG and HDL-C were elevated in the investigated group, mainly in patients presenting with other pathologies, such as nephrotic syndromes, diabetes mellitus and systemic lupus erythematosus. Our results suggest that, in Brazil, the reference value interval of lipoprotein levels should be investigated more thoroughly in this age group, as well as in children who are considered healthy.

Diagnóstico da estrongiloidíase humana: importância e técnicas / Diagnosis of human strongyloidiasis: needs and techniques

A estrongiloidiase é causada pelo nematóide intestinal Strongyloides stercoralis e ocorre de forma assintomática na maior parte dos indivíduos infectados. Entretanto, é considerada de grande importância por causar hiperinfecção e disseminação em pacientes imunodeprimidos, principalmente durante o uso de corticóides. O diagnóstico definitivo normalmente é feito mediante a detecção de larvas nas fezes, mas torna-se extremamente difícil em razão da baixa quantidade de parasitos, na maioria dos casos, e da reduzida e irregular eliminação de larvas. As técnicas sorológicas, principalmente as imunoenzimáticas, podem ser uma boa alternativa para o diagnóstico da estrongiloidíase. Uma das principais limitações encontradas no desenvolvimento de testes sorológicos mais sensíveis e específicos é a dificuldade em se obter quantidades suficientes de antígenos que permitam seu posterior fracionamento e análise. Sendo assim, são necessários novos estudos que levem ao desenvolvimento de testes sorológicos confiáveis para o diagnóstico da estrongiloidíase, que não dependam de larvas como fonte antigênica.

Estudo soroepidemiológico da cisticercose humana em um município do Estado do Piauí, Região Nordeste do Brasil / Seroepidemiological survey of human cysticercosis in a municipality of Piaui State, Northeast Brazil

Integrando as pesquisas sobre parasitoses na região do entorno do Parque Nacional Serra da Capivara, Piauí, Brasil, realizadas entre 1999 e 2001, o presente estudo tem como objetivo avaliar a situação epidemiológica da cisticercose humana no Município de João Costa, no Nordeste do Brasil. Foram obtidas informações clínico-epidemiológicas e coletadas amostras de sangue para testes sorológicos imunoenzimáticos (ELISA e Western blot), empregando cisticercos de Taenia crassiceps como antígeno. Na primeira etapa, em 1999, foram investigadas 169 pessoas com história confirmada ou suspeita de infecção/doença pelo complexo teníase-cisticercose, e seus familiares. Na análise, 13,6 por cento das pessoas apresentaram soros reagentes para cisticercose pelo método ELISA. Na segunda etapa, em 2001, foram avaliadas 92 amostras de soro de indivíduos reativos para cisticercose detectados no primeiro momento e seus familiares, sendo que 24,0 por cento das amostras de soro foram reagentes para cisticercose pelo ELISA, e 29,0 por cento, pelo WB. Nessa mesma etapa, realizou-se inquérito coprológico em 701 pessoas, incluindo voluntários. A prevalência de parasitoses intestinais foi de 51,0 por cento, tendo sido observada uma maior prevalência de protozoários (95,0 por cento) em relação aos helmintos (5,0 por cento). Os resultados do estudo indicam o caráter endêmico da cisticercose na área, além da elevada freqüência de protozooses intestinais.

Avaliaçäo de testes imunológicos para o diagnóstico da neurocisticercose / Evaluation of immunological tests for the diagnosis of neurocysticercosis

Introduçäo: O diagnóstico da neurocisticercose (NCC) deve ser feito pela associaçäo de técnicas de imagem com métodos Elisa e Western blot (Wb), utilizandoðse como antígeno extrato bruto salino da larva da Taenia solium, o Cysticercus cellulosae e Wb, empregandoðse como antígeno cisticercos da Taenia crassiceps em amostras de soro, para o diagnóstico da NCC. Materiais e métodos: Foram avaliadas amostras de soro de 43 pacientes com diagnóstico de NCC: 21 por clínica, tomografia computadorizada de crânio (TC) e presença de anticorpos anticisticerco no líquido cefalorraquiano (LCR); 22 por clínica e TC e 229 pacientes com diferentes parasitoses. Para as análises desses materiais biológicos foram empregados os métodos Elisa, usandoðse como antígeno C. cellulosae, e Wb, usandoðse como antígeno C. cellulosae e Cysticercus longicollis. Resultado: O método Elisa utilizando C. cellulosae como antígeno apresentou especificidade de 95 por cento e sensibilidade de 71 por cento. O método Wb utilizando C. cellulosae ou C. longicollis como antígeno apresentou sensibilidade de 86 por cento e especificidade de 99 por cento. Conclusões: Os métodos imunológicos no LCR säo importantes para a definiçäo da NCC. Entretanto o método Elisa no soro ainda näo é adequado pela sua baixa sensibilidade, podendo auxiliar no diagnóstico da NCC, possibilitando sugerir a existência de forma transicional da doença, näo demonstrada pela TC