Vitamin A serum level in children with visceral leishmaniasis

Vitamin A is considered an anti-infectious disease vitamin, and its deficiency is associated with severe infections such as in measles. In developing countries the low concentrations of vitamin A are a public health problem. The aim of this study is to describe serum vitamin A concentrations among children with visceral leishmaniasis (VL). Blood sample was collected from 22 children with VL, and stored in a freezer, 9 siblings, with no clinical signs of the VL patients had their blood collected for a control group. Samples were assayed by high performance liquid chromatography. The median vitamin A concentration in the LV group was 21.38µg/100ml and in the control group it was 31.39µg/100. The mean in the LV was statistically lower than in the control group, using Student's t test, p<0.01.A vitamina A tem sido considerada uma vitamina anti-infecciosa e sua deficiência está associada a um maior risco de infecções graves, como ocorre por exemplo no sarampo. Nos países em desenvolvimento a hipovitaminose A é um grave problema de saúde pública. O objetivo deste estudo é quantificar o nível sérico da vitamina A em pacientes pediátricos portadores da leismaniose visceral (LV). Amostras de sangue foram coletadas de 22 crianças portadoras de LV, estocadas em freezer e posteriormente, quantificado o nível de vitamina A usando-se a cromatrografia líquída de alta eficiência, nove irmãos assintomáticos dos pacientes foram usados como controles. A média do nível sérico da vitamina A nos portadores de LV foi de 21,38µg/100ml e no grupo controle foi de 31,39µg/100ml. Entre os pacientes estudados com LV a média do nível sérico de vitamina A encontrado foi significativamente menor, utilizando-se o teste t de Student para um p<0,01 que dos controles.Universidade Federal do Rio Grande do NorteUniversidade Federal de São Paulo (UNIFESP)Universidade de São Paulo Faculdade de Saúde PúblicaUNIFESPSciEL

Presence of antibodies against Leishmania chagasi in haemodialysed patients

SOUZA,Roberto Mascarenhas et al.Presence of antibodies against Leishmania chagasi in haemodialysed patients.Transactions of the Royal Society of Tropical Medicine and Hygiene,v. 103, p.749-751, 2009.In the last decades there has been an increase in cases of visceral leishmaniasis complicating the post-transplant phase, mainly following kidney transplantation. The aim of this study was to evaluate the reactivity of haemodialysed patients using IFAT. Blood samples of 310 individuals from Natal, RN, Brazil, were collected and analysed. Data regarding blood transfusion, cause of end-stage renal disease and duration of haemodialysis were also analysed. In total, 69 patients (22.3%) were positive by IFAT. This study suggests that antibody detection should be performed in this group of patients since they are possible candidates for kidney transplantatio

The decline of dengue in the Americas in 2017: discussion of multiple hypotheses

OBJECTIVE: Since the 1980s, dengue incidence has increased 30-fold. However, in 2017, there was a noticeable reduction in reported dengue incidence cases within the Americas, including severe and fatal cases. Understanding the mechanism underlying dengue's incidence and decline in the Americas is vital for public health planning. We aimed to provide plausible explanations for the decline in 2017. METHODS: An expert panel of representatives from scientific and academic institutions, Ministry of Health officials from Latin America and PAHO/WHO staff met in October 2017 to propose hypotheses. The meeting employed six moderated plenary discussions in which participants reviewed epidemiological evidence, suggested explanatory hypotheses, offered their expert opinions on each and developed a consensus. RESULTS: The expert group established that in 2017, there was a generalised decreased incidence, severity and number of deaths due to dengue in the Americas, accompanied by a reduction in reported cases of both Zika and chikungunya virus infections, with no change in distribution among age groups affected. This decline was determined to be unlikely due to changes in epidemiological surveillance systems, as similar designs of surveillance systems exist across the region. Although sudden surveillance disruption is possible at a country or regional level, it is unlikely to occur in all countries simultaneously. Retrospective modelling with epidemiological, immunological and entomological information is needed. Host or immunological factors may have influenced the decline in dengue cases at the population level through immunity; however, herd protection requires additional evidence. Uncertainty remains regarding the effect on the outcome of sequential infections of different dengue virus (DENV) types and Zika virus (ZIKV), and vice versa. Future studies were recommended that examine the epidemiological effect of prior DENV infection on Zika incidence and severity, the epidemiological effect of prior Zika virus infection on dengue incidence and severity, immune correlates based on new-generation ELISA assays, and impact of prior DENV/other arbovirus infection on ZIKV immune response in relation to number of infections and the duration of antibodies in relation to interval of protection. Follow-up studies should also investigate whether increased vector control intensification activities contributed to the decline in transmission of one or more of these arboviruses. Additionally, proposed studies should focus on the potential role of vector competence when simultaneously exposed to various arboviruses, and on entomological surveillance and its impact on circulating vector species, with a goal of applying specific measures that mitigate seasonal occurrence or outbreaks. CONCLUSIONS: Multifactorial events may have accounted for the decline in dengue seen in 2017. Differing elements might explain the reduction in dengue including elements of immunity, increased vector control, and even vector and\or viruses changes or adaptations. Most of the results of this expert consensus group meeting are hypothetical and based on limited evidence. Further studies are needed

Management of infection by the Zika virus

A panel of national experts was convened by the Brazilian Infectious Diseases Society in order to organize the national recommendations for the management of zika virus infection. The focus of this document is the diagnosis, both clinical and laboratorial, and appropriate treatment of the diverse manifestations of this infection, ranging from acute mild disease to Guillain-Barré syndrome and also microcephaly and congenital malformations.1

Comparação da gravidade dos casos de dengue segundo a classificação antiga e a classificação revisada

Introduction: two classifications stratify cases of dengue according to clinical and laboratory findings: the classification proposed in the 50s and the classification revised by the World Health Organization (WHO), which has been adopted in Brazil since January 2014. Our objective was to compare the two classification methods regarding their capability of identifying the severity of each case. Methods: Cross-sectional observational study with analysis and comparisons of dengue cases which occurred from 2011 to 2013 in a tertiary referral hospital in the city of Natal/RN, Brazil, according to the Dengue Classification and the Revised Dengue Classification. The equivalence adopted was: Classic Dengue and Dengue Hemorrhagic Fever (DHF) grade I&nbsp;with Dengue; DHF grade II with Dengue with warning signs and DHF III and IV with Severe Dengue. Results: 2,318 records were analyzed, with a mean age of 30.32 years ± 17.89, and a population 39% male and 61% female. Based on the designated equivalence, 428 cases were concordant, 699 were discordant (212 classified as Classic Dengue and Dengue with warning signs – mucosal bleed, 62 as Classic Dengue and Dengue with warning signs – abdominal pain) and 1,191 “without classification” (cases whose medical records did not allow classification). Conclusion: The two classifications were equivalent in clinical management when cases were severe. The old classification avoids an overestimation of mild and moderate cases by using more clinical and laboratory aspects than the new classification. Mucosal bleed, abdominal pain and vomiting did not represent signs that evolved to severity, demonstrating how the imprecise use of warning signs can overestimate the data.Introdução: Existem duas classificações que estratificam os casos de dengue pelo quadro clínico laboratorial: a classificação proposta nos anos 50 e a revisada pela Organização Mundial de Saúde, adotada em janeiro de 2014 no Brasil. Compará-las quanto à capacidade de identificar a gravidade do caso representa nosso objetivo. Métodos: Estudo observacional e transversal com análise e comparação dos casos de dengue de 2011 a 2013 de um hospital terciário de referência da cidade de Natal/RN, de acordo com a classificação antiga e a classificação revisada. As correspondências adotadas foram: Dengue Clássica e Febre Hemorrágica da Dengue (DHF) grau I com Dengue; DHF grau II com Dengue com sinais de alarme; DHF grau III e IV com Dengue grave. Resultados: 2.318 fichas foram analisadas, com a população predominantemente adulta, média de idade 30,32 anos ± 17,89, sendo 39% do sexo masculino, 61% do sexo feminino. A partir das correlações designadas, 428 casos foram concordantes, 699 discordantes e 1191 “sem classificação” (casos cujos dados dos prontuários não possibilitaram sua classificação). Conclusões: As duas classificações foram equivalentes no manejo clínico quando os casos de dengue foram graves. A classificação antiga evita a superestimação de casos leves e moderados por utilizar mais aspectos clínicos e laboratoriais que a classificação revisada. Sangramento de mucosa, dor abdominal e vômitos não representaram sinais que evoluíram para gravidade, demonstrando como a utilização dos sinais de alarme de maneira imprecisa pode superestimar os dados

Evaluation of the immunohistological alterations of the thin intestine mucosa in patients with visceral leishmaniasis

INTRODUÇÃO: A leishmaniose visceral é uma doença que acomete cerca de 500 mil pessoas por ano no mundo e se caracteriza principalmente por um quadro de febre, hepatoesplenomegalia e pancitopenia. Há uma imunossupressão específica frente a Leishmania chagasi. Classicamente esta resposta é modulada pelas células dendríticas, que são as primeiras células que entram em contato com o parasita. Estas células, a partir de vários determinantes, elaboram uma resposta do tipo Th1, com a produção de citocinas capazes de ativar os macrófagos a eliminar o parasita ou uma resposta do tipo Th2, que se caracteriza por uma produção de citocinas que são incapazes de ativar o macrófago parasitado. Com o objetivo de se estudar a resposta imune tecidual, esta investigação avaliou a resposta imune na mucosa duodenal de crianças portadoras da leishmaniose visceral plenamente manifesta. MÉTODOS: Um grupo de 13 crianças com calazar foi submetido à biópsia perioral de duodeno, com cápsula de Watson. Nove crianças assintomáticas foram utilizadas como controles e foram submetidas à biópsia duodenal endoscópica. Ambos os grupos foram submetidos a pesquisa do parasita, a análise morfométrica e a análise semiquantitativa da produção local de TNF-&#945;, &#948;-interferon, IL-4 e IL-10 e fenotípica das seguintes células imunes: CD4, CD8, CD68. RESULTADOS: A análise morfomérica revelou que nos casos havia um infiltrado linfoplasmocitário com discreta atrofia vilositária. Não se verificou a presença de eosinófilos ou neutrófilos. A presença de leishmania foi verificada em todos os casos e esteve ausente nos controles. A análise da produção de citocinas revelou que tanto nos casos como nos controles havia uma média de produção de IL-10 semelhante, com p=0,8968 (teste T de Student); que não se detectou IL-4 nos casos e nos controles; que a freqüência da produção de &#948;-interferon nos controles foi maior que nos casos, com p=0,046 (teste de Fischer); que a freqüência da produção de TNF-&#945; foi semelhante nos casos e controles (teste de Fischer) com p=0,41; havia um infiltrado macrofágico significativamente superior nos casos com p=0,005757 (teste T de Student); a média de contagem de CD4 nos casos foi significativamente maior que nos controles, utilizando-se o teste de Mann-Withney com p=0,040, teste da mediana p=0,019; e que a média da contagem de CD8 foi semelhante nos casos e controles com p=0,396 (teste T de Student). CONCLUSÕES: A mucosa duodenal por ser um ambiente imunotolerante, pela produção natural de IL-10, permitiria a presença e multiplicação da leishmania. Que o infiltrado linfoplasmocitário composto por células CD4, CD8 e CD68 foi incapaz de montar uma resposta imune eficaz contra o parasita, principalmente pela baixa produção local do &#948;-interferon.INTRODUCTION: Visceral leishmaniasis is a disease that strikes around 500 thousand people in the world per year and its major characteristics are fever hepatoesplenomegaly and pancytopenia. There is a specific imunnosupression in face of the Leishmania chagasi. Classically this response is modulated by the dendritic cells that are the first cells to get in contact with the parasite. These cells, from various determinants, elaborate a Th1 type response, with the production of cytokines capable of activating the macrophages and eliminate the parasite or a Th2 type response, that is characterized by cytokines production that are incapable of activating the macrophages under the parasite action. With the purpose of studying the tissue immune response this investigation evaluated the immune response on the duodenal mucosa of children carrying fully manifested visceral leishmaniasis. METHODS: A group of 13 children carrying kalazar was submitted to a duodenal perioral biopsy, with Watson\'s capsule. Nine assymptomatic children was used as control group and submitted to an endoscopic duodenal biopsy. Both groups were submitted to the parasite research, the morphometric analysis and the semi quantitative analysis of the local production of TNF-&#945;, &#948;-interferon, IL-4 e IL-10 and phenotypic analysis of the following immune cells: CD4, CD8, CD68. RESULTS: The morphometric analysis revealed that there was a limphoplasmocitary infiltrate with discrete vilositary atrophy in the cases. The presence of eosinophilus and neutrophils were not verified. The presence of leishmania was verified in all cases and was absent in the controls. The cytokine production analysis showed that both in the cases and in the controls there was a similar mean IL-10 production, with p=0.8968 (T Student test); that the IL-4 was not detected in the cases nor in the controls; that the &#948;-interferon production frequency in the controls was higher with p=0.046 (Fischer test); that the TNF-&#945; production frequency was similar in the cases and in the controls with p=0.41 (Fischer test); that there was a macrophagic infiltrate significantly higher in the cases with p=0.005757 (T Student test), that the mean CD4 in the cases was higher than in controls, Mann-Withney test with p=0,040, mediana test, p=0,019, and CD8 infiltrate was similar in the cases and in the controls with p= 0,396 respectively (T Student test). CONCLUSIONS: The duodena mucosa, being a immunetolerant environment due to the natural IL-10 production, would allow the presence and the multiplication of leishmania. That the limphoplasmocitary infiltrate composed of CD4, CD8 and CD68 cells was incapable of providing an effective immune response against the parasite, mostly because of the low &#948;-interferon local production