Accuracy of yellow fever case definition of epidemiologic surveillance, São Paulo, 2018

ABSTRACT OBJECTIVE To evaluate the accuracy of yellow fever (YF) suspected case definitions from the Brazilian Ministry of Health (BMH) and World Health Organization (WHO), as well as propose and evaluate new definitions of suspected cases, considering confirmed and discarded cases. METHODS The retrospective study was conducted at the Instituto de Infectologia Emílio Ribas (IIER), using the Epidemiologic Surveillance Form of YF cases. From the confirmed and discarded cases of YF, a logistic regression model was developed. The independent variables were used in a proposed definition of a suspected case of YF and its accuracy was evaluated. RESULTS In total, 113 YF suspect cases were reported, with 78 confirmed (69.0%). The definitions by BMH and WHO presented low sensitivity, 59% and 53.8%, and reduced accuracy, 53.1% and 47.8%, respectively. Predictive factors for YF were thrombocytopenia, leukopenia, and elevation of transaminases greater than twice normal. The definition including individual with acute onset of fever, followed by elevation of ALT or AST greater than twice the reference value AND leukopenia OR thrombocytopenia presented high sensitivity (88.3%), specificity (62.9%), and the best accuracy (80.4%), as proposed in the model. CONCLUSION The YF suspected case definitions of the BMH and the WHO have low sensitivity. The inclusion of nonspecific laboratory tests increases the accuracy of YF definition.

Comparación clínica y laboratorial de la fiebre amarilla severa versus dengue grave en Perú / Clinical and laboratory differences between severe yellow fever and severe dengue in emergency patients

En los centros de Emergencia con poco apoyo de laboratorio, es difícil diferenciar a los pacientes con dengue grave y fiebre amarilla severa. El objetivo fue comparar el perfil clínico y de laboratorio de los pacientes con dengue grave y fiebre amarilla severa en Urgencias. Se realizó un estudio observacional retrospectivo de pacientes con diagnóstico confirmado de dengue y fiebre amarilla en el período 2018 a 2020 atendidos en la Unidad de Emergencia del Hospital Carrión, Huancayo-Perú. Se evaluaron un total de 35 pacientes, 11 pacientes (31,4%) fueron diagnosticados con fiebre amarilla severa y 24 pacientes (68,5%) con dengue grave. La media de los resultados de laboratorio con fiebre amarilla severa fueron bilirrubina indirecta 4,7 ml/dL, aspartato transaminasa 4463 UI/L, transaminasa aminotransferasa 4329 UI/L, creatinina 4,9 mg/dl. En pacientes con dengue grave el hematocrito promedio fue 51,8, hemoglobina 17,6 g/dl, plaquetas 24 × 103/mm. En pacientes con síndrome ictérico-febril la presencia de bradicardia, bilirrubina indirecta elevada y transaminasas muy elevadas debe hacer sospechar de fiebre amarilla; mientras que los pacientes que acuden por ascitis, derrame pleural, aumento de hematocrito y deficiencia de plaquetas, se debe tratar como dengue grave sobre todo en Unidades de Emergencia con poco apoyo de laboratorio(AU)

In Emergency centers with little laboratory support, differentiating patients with dengue and yellow fever is difficult. The Aim was to compare the clinical and laboratory profile of patients with severe dengue and severe yellow fever in the Emergency unit. We conducted a retrospective observational study of patients with a confirmed diagnosis of dengue and yellow fever in the period 2018 to 2020 treated in the Emergency Unit of the Carrión hospital, Huancayo-Peru. A total of 35 patients were evaluated, 11 patients (31.4%) were diagnosed with severe yellow fever and 24 patients (68.5%) with severe dengue. The mean laboratory results in patients with severe yellow fever were indirect bilirubin 4.7 ml/dL, aspartate transaminase 4463 IU/L, transaminase aminotransferase 4329 IU/L, creatinine 4.9 mg / dl. In patients with severe dengue were hematocrit 51.8, hemoglobin 17.6 g / dl, platelets 24 × 103 / mm. In patients with syndrome jaundice and fever the presence of bradycardia, elevated indirect bilirubin, and very elevated transaminases should be suspicious for yellow fever; while in patients who come for ascites, pleural effusion, increased hematocrit and platelet deficiency, it should be treated as severe dengue especially in Emergency Units with little laboratory support(AU)

Experimental yellow fever virus infection in the squirrel monkey (Saimiri spp. ) I: gross anatomical and histopathological findings in organs at necropsy

BACKGROUND Non-human primates contribute to the spread of the yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas. OBJECTIVE To describe the severe histopathological aspects of YFV infection, 10 squirrel monkeys were infected with YFV and blood, brain, liver, kidney, spleen, heart, lung, lymph node and stomach were collected at 1-7, 10, 20 and 30 days post-infection (dpi). METHODS Histopathological analysis and detection of the genome and viral antigens and neutralising antibodies were performed by RT-PCR, immunohistochemistry and neutralisation test, respectively. FINDINGS Only one animal died from the experimental infection. The genome and viral antigens were detected in all investigated organs (1-30 dpi) and the neutralising antibodies from seven to 30 dpi. The brain contained perivascular haemorrhage (6 dpi); in the liver, midzonal haemorrhage and lytic necrosis (6 dpi) were observed. The kidney had bleeding in the Bowman's capsule and tubular necrosis (6 dpi). Pyknotic lymphocytes were observed in the spleen (1-20 dpi), the lung had haemorrhage (2-6 dpi), in the endocardium it contained nuclear pyknosis and necrosis (2-3 dpi) and the stomach contained blood in the lumen (6 dpi). MAIN FINDINGS Squirrel monkeys reliably reproduced the responses observed in human cases of yellow fever and, therefore, constitute an excellent experimental model for studies on the pathophysiology of the disease.

Fiebre amarilla selvática con serología positiva para leptospira en un varon joven peruano / Jungle yellow fever with positive serology for leptospira in a young peruvian male

RESUMEN Fiebre amarilla (FA) y leptospirosis son zoonosis endémicas subdiagnosticadas de las regiones tropicales de África y Sudamérica. Ambas, pueden ser clínicamente indistinguibles y presentarse como síndrome febril icterohemorrágico agudo. Reportamos el caso de un varón de 20 años, procedente del departamento de Amazonas que se presentó con nueve días de enfermedad caracterizada por falla multiorgánica (compromiso neurológico, renal, hepático, respiratorio, y hematológico). Recibió tratamiento antibiótico, soporte transfusional, dialítico, hemodinámico, y ventilatorio; y a pesar de la gravedad del cuadro clínico, evolucionó favorablemente. Se confirmó FA por Rt-PCR y se obtuvo serología positiva para leptospira por ELISA y microaglutinación. Sin embargo, no se pudo demostrar, desde el punto de vista laboratorial, coinfección real por FA y leptospira. Este caso de FA severa con desenlace no fatal enfatiza la importancia del diagnóstico sindrómico adecuado, y un tratamiento de soporte precoz y agresivo que puede salvar la vida del paciente.

ABSTRACT Yellow fever (YF) and leptospirosis are under-diagnosed endemic zoonoses of the tropical regions of Africa and South America. Both may be clinically indistinguishable and present as an acute icterohemorrhagic febrile syndrome. We report the case of a 20-year-old male from the department of Amazonas who presented with nine days of disease characterized by multiorgan failure (neurological, renal, hepatic, respiratory, and hematological involvement). He received antibiotic treatment, as well as, transfusion, dialysis, hemodynamic, and ventilatory support. Despite the severity of the clinical condition, he evolved favorably. YF was confirmed by Rt-PCR and positive serology was obtained for leptospira by ELISA and microagglutination. However, from a laboratory point of view, real co-infection by yellow fever and leptospira could not be demonstrated. This case of severe YF with non-fatal outcome emphasizes the importance of adequate syndromic diagnosis, and early and aggressive supportive treatment that can save a patient's life.

Febre Amarela / Yellow Fever

A Febre Amarela é uma doença infecciosa aguda, caracterizada por febre. Não é transmissível e tem duração de no máximo 12 dias. As manifestações clínicas revelam as fases evolutivas da doença. Este trabalho consiste em um artigo de atualização, no qual foi realizado um estudo bibliográfico interpretativo e descritivo baseado na literatura atual sobre a Febre Amarela no Brasil. Esta doença é causada por um arbovírus que pertence à família Flaviviridae. A expansão da área de vacinação é muito discutida atualmente. Segundo o Ministério da Saúde, em 2016, foram confirmados seis casos de Febre Amarela no Brasil. Conforme a Sociedade Brasileira de Infectologia, a fisiopatologia desta doença é a mesma no ciclo urbano e no silvestre. O seu diagnóstico pode ser dividido em clínico e laboratorial, pois são as duas formas de confirmar a doença em indivíduos. As medidas preventivas consistem, principalmente, na imunização, medidas de proteção e no controle do vetor. Esta pesquisa fornece dados atuais em bases confiáveis, podendo ser utilizada para futuros trabalhos.

Yellow Fever is an acute infectious disease, characterized by fever. It is not transferable and lasts for a maximum of 12 days. The clinical manifestations reveal the evolutionary phases of the disease. This work consists of an update article, where an interpretative and descriptive bibliographic study was carried out based on the current literature on Yellow Fever in Brazil. This disease is caused by an arbovirus belonging to the family Flaviviridae. The expansion of the vaccination area is much discussed today. According to the Ministry of Health, in 2016, six cases of yellow fever were confirmed in Brazil. According to the Brazilian Society of Infectology, the pathophysiology of Yellow Fever is the same in the urban and wild cycle. The diagnosis of yellow fever can be divided into clinical and laboratory, as they are the two ways to confirm the disease in individuals. Preventive measures consist mainly of immunization, protective measures and vector control. This research provides current data on a reliable basis and can be used for future work

Yellow fever

Summary The yellow fever (YF) virus is a Flavivirus, transmitted by Haemagogus, Sabethes or Aedes aegypti mosquitoes. The disease is endemic in forest areas in Africa and Latin America leading to epizootics in monkeys that constitute the reservoir of the disease. There are two forms of YF: sylvatic, transmitted accidentally when approaching the forests, and urban, which can be perpetuated by Aedes aegypti. In Brazil, the last case of urban YF occurred in 1942. Since then, there has been an expansion of transmission areas from the North and Midwest regions to the South and Southeast. In 2017, the country faced an important outbreak of the disease mainly in the states of Minas Gerais, Espírito Santo and Rio de Janeiro. In 2018, its reach extended from Minas Gerais toward São Paulo. Yellow fever has an incubation period of 3 to 6 days and sudden onset of symptoms with high fever, myalgia, headache, nausea/vomiting and increased transaminases. The disease ranges from asymptomatic to severe forms. The most serious forms occur in around 15% of those infected, with high lethality rates. These forms lead to renal, hepatic and neurological impairment, and bleeding episodes. Treatment of mild and moderate forms is symptomatic, while severe and malignant forms depend on intensive care. Prevention is achieved by administering the vaccine, which is an effective (immunogenicity at 90-98%) and safe (0.4 severe events per 100,000 doses) measure. In 2018, the first transplants in the world due to YF were performed. There is also an attempt to evaluate the use of active drugs against the virus in order to reduce disease severity.

Metagenomic analysis reveals Hepatitis A virus in suspected yellow fever cases in Brazil

Using a metagenomic approach, we identified hepatitis A virus among cases of acute febrile illnesses that occurred in 2008-2012 in Brazil suspected as yellow fever. These findings reinforce the challenge facing routine clinical diagnosis in complex epidemiological scenarios.

Yellow fever outbreak in Brazil: the puzzle of rapid viral spread and challenges for immunisation

We discuss the complex eco-social factors involved in the puzzle of the unexpected rapid viral spread in the ongoing Brazilian yellow fever (YF) outbreak, which has increased the reurbanisation risk of a disease without urban cases in Brazil since 1942. Indeed, this rapid spatial viral dissemination to the Southeast and South regions, now circulating in the Atlantic Forest fragments close to peri-urban areas of the main Brazilian megalopolises (São Paulo and Rio de Janeiro) has led to an exponential increase in the number of yellow fever cases. In less than 18 months, 1,833 confirmed cases and 578 deaths were recorded most of them reported in the Southeast region (99,9%). Large epizooties in monkeys and other non-human primates (NHPs) were communicated in the country with 732 YF virus (YFV) laboratory confirmed events only in the 2017/2018 monitoring period. We also discuss the peculiarities and similarities of the current outbreak when compared with previous great epidemics, examining several hypotheses to explain the recent unexpected acceleration of epizootic waves in the sylvatic cycle of the YFV together with the role of human, NHPs and mosquito mobility with respect to viral spread. We conclude that the most feasible hypothesis to explain this rapidity would be related to human behavior combined with ecological changes that promoted a significant increase in mosquito and NHP densities and their contacts with humans. We emphasize the urgent need for an adequate response to this outbreak such as extending immunisation coverage to the whole Brazilian population and developing novel strategies for immunisation of NHPs confined in selected reserve areas and zoos. Finally, we stress the urgent need to improve the quality of response in order to prevent future outbreaks and a catastrophic reurbanisation of the disease in Brazil and other South American countries. Continuous monitoring of YFV receptivity and vulnerability conditions with effective control of the urban vector Aedes aegypti and significant investments in YF vaccine production capacity and research and development for reduction of adverse effects are of the highest priority.

Improvement of a RT-PCR assay for Yellow Fever virus genome detection

The aim of the present study was to describe an improved protocol of reverse transcription polymerase chain reaction (RT-PCR) for Yellow Fever virus genome detection. A strain of ribonucleic acid of Yellow Fever virus was submitted to the improved protocol of RT-PCR and the amplicons were visualized under ultraviolet transilluminator, purifed and sequenced. The nucleotide sequence obtained was compared with sequences available in GenBank using the tblastx tool. The amplicons produced by the strain of ribonucleic acid of Yellow Fever virus exhibited fragments of 400 and 800 base pairs and the consensus sequence exhibited a similarity of 100% with Yellow Fever virus sequences recorded in GenBank. The improved protocol described in this study allowed Yellow Fever virus genome detection and enabled the elimination of the nested-PCR step, which has been frequently associated with contamination. In addition, it reduced the time of reaction, the cost of reagents and the possibility of sample contamination. New methods of investigating these infections must be elaborated and a continuous vigilance of these viruses in their different vectors and hosts is required to avoid negative impacts on human health, tourism and trade.(AU)

First report of yellow fever virus in non-human primates in the State of Parana, Brazil

Sylvatic yellow fever is a zoonosis associated mainly with wild animals, especially those in the genus Alouatta, that act as the source of infection. Once infected, these animals pass the disease on to humans by way of an infected mosquito belonging to the genera Aedes, Haemagogus, or Sabethes. The present study is the first report of a case of yellow fever in non-human primates (NHP) in the State of Paraná, Brazil. After the case was diagnosed, several prophylactic measures were adopted to prevent outbreaks of the disease in humans.

Fiebre amarilla / Yellow fever

La fiebre amarilla representa a una de las fiebres hemorrágicas que adquieren en Venezuela y a una de las cuatro arbovirosis endémicas que tenemos. Revisando la literatura médica nacional e internacional, se actualizan aspectos relevantes de esta endemia rural. Se mencionan en la etiología las características del agente viral, que tiene ARN como componente primordial de su genoma. En la epidemiología, se menciona su prevalencia en el continente americano y africano y se evalúa su modo de transmisión. En la patogenia y la anatomía patológica se describe al hígado como órgano blanco de la infección. Se destacan en las manifestaciones clínicas los trastornos hemorrágicos y de la coagulación sanguínea. El diagnóstico como en Medicina Tropical, corresponde a un diagnóstico integral: la clínica, en primer lugar, asociada a la epidemiología y a la etiología de la enfermedad. Se establece diagnóstico diferencial con otras entidades relacionadas. El tratamiento es de soporte y en terapia intensiva. Se concluye con la profilaxis, evaluando la utilidad que sigue teniendo la vacunación.

The yelow fever represents one of the hemorrhagic fever that can be acquired in Venezuela and one of the four endemic arbovirosis we have. By reviewing the national and international medical literature. Relevant aspects of this endemic rural disease have been updated. In the etiology, several characterictics of the virus are mentioned; including the RNA as a primordial component of its genome. In the epidemiology, its prevalence on the African and American continents is mentioned, and the transmission mode es evaluated. In the pathogenesis and pathological anatomy, the liver is described as the primary organ of infection. Bleeding and blood clotting disorders are the essential clinical manifestations. Like in Tropical Medicina, The corresponding integral diagnosis is required. In the first instance, the clinical aspects, associated to the epidemiology and to the etiology of the disease are analyzed a diffential diagnosis is made with other related entities. The treatment consists of support measures and Intensive Care in the Intensive Care Unit (ICU). For the prophylaxis, we discuss the advantages of vaccination.

Reemergence of yellow fever: detection of transmission in the State of São Paulo, Brazil, 2008 / Reemergência de febre amarela: detecção de transmissão no Estado de São Paulo, Brasil, 2008

INTRODUCTION: Following yellow fever virus (YFV) isolation in monkeys from the São José do Rio Preto region and two fatal human autochthonous cases from the Ribeirão Preto region, State of São Paulo, Brazil, two expeditions for entomological research and eco-epidemiological evaluation were conducted. METHODS: A total of 577 samples from humans, 108 from monkeys and 3,049 mosquitoes were analyzed by one or more methods: virus isolation, ELISA-IgM, RT-PCR, histopathology and immunohistochemical. RESULTS: Of the 577 human samples, 531 were tested by ELISA-IgM, with 3 positives, and 235 were inoculated into mice and 199 in cell culture, resulting in one virus isolation. One sample was positive by histopathology and immunohistochemical. Using RT-PCR, 25 samples were processed with 4 positive reactions. A total of 108 specimens of monkeys were examined, 108 were inoculated into mice and 45 in cell culture. Four virus strains were isolated from Alouattacaraya. A total of 931 mosquitoes were captured in Sao Jose do Rio Preto and 2,118 in Ribeirão Preto and separated into batches. A single isolation of YFV was derived from a batch of 9 mosquitoes Psorophoraferox, collected in Urupês, Ribeirão Preto region. A serological survey was conducted with 128 samples from the municipalities of São Carlos, Rincão and Ribeirão Preto and 10 samples from contacts of patients from Ribeirão Preto. All samples were negative by ELISA-IgM for YFV. CONCLUSIONS: The results confirm the circulation of yellow fever, even though sporadic, in the Sao Paulo State and reinforce the importance of vaccination against yellow fever in areas considered at risk.

INTRODUÇÃO: A partir do isolamento do vírus febre amarela (VFA), de macacos, da região de São José do Rio Preto e de dois casos humanos autóctones fatais, da região de Ribeirão Preto, Estado de São Paulo, foram realizadas duas expedições para pesquisa entomológica e avaliação ecoepidemiológica. MÉTODOS: Um total de 577 amostras de humanos, 108 de macacos e 3.049 mosquitos foram analisados por um ou mais métodos: isolamento viral, ELISA-IgM, RT-PCR, histopatologia e imunohistoquímica. RESULTADOS: De 577 amostras humanas, 531 foram testadas por ELISA-IgM, sendo 3 positivas, 235 foram inoculadas em camundongos, 199 em cultura de células, obtendo-se 1 isolamento viral. Uma amostra foi positiva por histopatologia e imunohistoquímica. Por RT-PCR foram processadas 25 amostras com 4 reações positivas. Os 108 espécimes de macacos foram inoculados em camundongos, 45 em cultura de células, obtendo-se 4 isolamentos de VFA, de Alouatta caraya. Um total de 931 mosquitos foram capturados em São José do Rio Preto e 2.118 em Ribeirão Preto e separados em lotes. Um único isolamento de VFA foi derivado de um lote de 9 mosquitos Psorophora ferox, coletados em Urupês, região de Ribeirão Preto. Um inquérito sorológico foi realizado com 128 amostras dos municípios de São Carlos, Rincão e Ribeirão Preto e mais 10 amostras de contactantes de pacientes de Ribeirão Preto. Todas as amostras foram negativas por ELISA-IgM para VFA. CONCLUSÕES: Os resultados confirmam a circulação, mesmo que esporádica, do VFA no Estado de São Paulo e reforça a importância da vacinação antiamarílica nas áreas consideradas de risco.

Suspected YF case in south Sudan

Following the Yellow fever [YF] outbreak in northern Uganda and the threat of spreading it to south Sudan [Please see Weekly Epidemiological Monitor; vol-4; issue- 1] an active case finding was carried out in the bordering towns of south Sudan in December and January 2011. During this period, 45 cases meeting the case definition of suspected YF were identified. Of these suspected cases, 14 were reported from Eastern Equatoria state and the remaining 31 cases were from Central Equatoria state of south Sudan. However, only one blood specimen collected from one suspected case in Magwi town of Central Equatoria state was tested positive for YF on 3 March by ELISA IgM test. The sample was also weakly positive for dengue fever. The test was performed at the CDC laboratory at Kenya

Circulation of antibodies against yellow fever virus in a simian population in the area of Porto Primavera Hydroelectric Plant, São Paulo, Brazil / Circulação de anticorpos contra o vírus amarílico em população simiana da região da usina hidrelétrica de Porto Primavera, São Paulo, Brasil

Yellow fever (YF) is an acute viral infectious disease transmitted by mosquitoes which occurs in two distinct epidemiological cycles: sylvatic and urban. In the sylvatic cycle, the virus is maintained by monkey's infection and transovarian transmission in vectors. Surveillance of non-human primates is required for the detection of viral circulation during epizootics, and for the identification of unaffected or transition areas. An ELISA (enzyme-linked immunosorbent assay) was standardized for estimation of the prevalence of IgG antibodies against yellow fever virus in monkey sera (Alouatta caraya) from the reservoir area of Porto Primavera Hydroelectric Plant, in the state of São Paulo, Brazil. A total of 570 monkey sera samples were tested and none was reactive to antibodies against yellow fever virus. The results corroborate the epidemiology of yellow fever in the area. Even though it is considered a transition area, there were no reports to date of epizootics or yellow fever outbreaks in humans. Also, entomological investigations did not detect the presence of vectors of this arbovirus infection. ELISA proved to be fast, sensitive, an adequate assay, and an instrument for active search in the epidemiological surveillance of yellow fever allowing the implementation of prevention actions, even before the occurrence of epizootics.

A febre amarela (FA) é doença infecciosa aguda de origem viral transmitida por mosquitos. No ciclo silvestre, o vírus é mantido por meio da infecção de macacos e da transmissão transovariana nos vetores. A vigilância sobre populações de primatas não humanos torna-se necessária para detectar a circulação viral, quando ainda está restrito a epizootias, e para determinar sua presença em regiões indenes ou de transição para a doença. Padronizou-se a técnica ELISA (Enzyme Linked Immunosorbent Assay) para determinar a prevalência de anticorpos da classe IgG contra o vírus da FA em soros de bugios (Alouatta caraya) da região do reservatório da Usina Hidrelétrica de Porto Primavera, SP. Foram testados soros de 570 macacos sendo que nenhuma amostra mostrou-se reativa para a presença de anticorpos contra o vírus da FA. Os resultados são coerentes com a epidemiologia da FA na região. Mesmo sendo área de transição, não se conhece, até o momento, ocorrência de epizootia ou surto de FA em humanos e investigações entomológicas não apontaram a presença de vetores para esta arbovirose. A técnica mostrou-se sensível, rápida e útil à vigilância epidemiológica como instrumento de busca ativa permitindo desencadear ações preventivas, como vacinação, antes mesmo do surgimento de epizootias.

Gestão em ciência e tecnologia: desafio para os laboratórios de Saúde Pública no Brasil / Science and Tecnology Management: a Challenge for Public Health Laboratories in Brazil

A partir da percepção dos pesquisadores, objetivou-se inferir as condições para realização de pesquisas científicas em todos os laboratórios de Saúde Pública que, no Brasil, são referência para o diagnóstico de dengue, febre amarela e febre maculosa. Um questionário foi enviado aos pesquisadores, contemplando conceitos e temas sobre a gestão de projetos científicos e o ambiente para a produção científica. Cada item investigado apresentava alternativas de resposta segundo a escala de atitudes de Likert, de modo a captar o ponto de vista do pesquisador sobre a situação atual e a situação desejável, em seu próprio laboratório. Os resultados foram lançados em gráficos e avaliados pelo exame de consistência interna, de acordo com o alfa de Cronbach. Concluiu-se que os laboratórios de referência para dengue, febre amarela e febre maculosa no Brasil dispõem de condições para a execução de pesquisas científicas mas enfrentam dificuldades relacionadas, principalmente, ao planejamento e gestão em ciência e tecnologia.

This study had the objective to understand the perception of researchers about the conditions for scientific research production available in Brazilian reference laboratories for the diagnosis of dengue; yellow fever and spot fever. A questionnaire was sent to researchers with questions related to concepts and themes on scientific projects management and the environment for scientific production. It was a Likert type questionnaire with multiple response options. Thepurpose was to know the point of view of each researcher about the present situation and the desirable situation intheir laboratory of origin. Results were plotted in graphs and their internal consistency was checked using Cronbach's alpha. This study has concluded that those reference laboratories are able to undertake scientific projects, although they have difficulties related mainly to scientific and technology planning and management.

Febre amarela / Yellow fever

No presente artigo os autores enfatizam os aspectos mais importantes da febre amarela - epidemiológicos, etiológicos, imunopatológicos, clínicos, terapêuticos, preventivos e de controle -, enfermidade causada por um vírus da família Flaviviridae e transmitida por insetos dos gêneros Aedes, Sabethes e Haemagogus.

Evaluación retrospectiva de fiebre amarilla selvática en Venezuela período 2003-2005 / Retrospective evaluation of jungle yellow fever in Venezuela during the years 2003-2005

La fiebre amarilla es una enfermedad viral, propia de algunas regiones tropicales de América del Sur y Africa, causando numerosas epidemias con elevadas tasas de mortalidad. Con el objetivo de caracterizar retrospectivamente el brote de fiebre amarilla selvática en Venezuela en el año 2003, a través de la determinación del número de casos confirmados y defunciones en los estados afectados, según grupos etarios, sexo, ocupación y procedencia y la identificación de factores desencadenantes del brote, así como también el estudio de los casos reportados en los años 2004 y 2005, se estudiaron los casos registrados oficialmente en el estado Zulia, durante el periodo de estudio. El Zulia fue el estado más afectado en el período evaluado con 25 casos (p<0,001), reportando mayor tasa de ataque durante el año 2003, Mérida y Monagas en el año 2004, y Portuguesa en el 2005. El grupo etario más afectado fue 25-44 años, predominando el sexo masculino, afectando mayormente al trabajador agrícola. Los resultados evidencian la alta letalidad de la fiebre amarilla al arrojar un 46,51 por ciento en el año 2003, 60 por ciento en el 2004 y 66,67 por ciento en el 2005. Se recomienda la implementación de medidas que permitan establecer una vigilancia mínima en las zonas con actividad demostradas.

Yellow fever is a viral disease, typical of some tropical regions in South America and Africa, causing numerous epidemics with high mortality rates. In order to characterize retrospectively the jungle yellow fever outbreak in Venezuela in the year 2003, by determining the number of cases and deaths confirmed in the affected states according to age, sex, occupation and origin and by identifying factors that triggered the outbreak, as well as the study of cases reported in 2004 and 2005, cases officially registered in the State of Zulia were studied for the period in question. Zulia was the state most affected during the period evaluated, with 25 cases (p <0.001), reporting the highest attack rate during 2003; Merida and Monagas had the highest rates in 2004, Portuguesa in 2005. The most affected age group was 25-44 years, predominantly male farm workers. Results showed the high lethality of yellow fever: 46.51 percent in 2003, 60 percent in 2004 and 66.67 percent in 2005. The implementation of measures to establish a minimum surveillance in areas with proven activity is recommended.

Fiebre amarilla ayer y hoy / Yellow fever yesterday and today

En el siguiente artículo, la autora realiza una exhaustiva descripción de la Fiebre Amarilla, explicando su patogenia, síntomas, tratamiento y prevención. Se refiere también a la historia de la enfermedad en América y su situación actual.

Dengue-yellow fever sera cross-reactivity; challenges for diagnosis / Reacción cruzada en sueros de Fiebre Amarilla y Dengue: desafíos para el diagnóstico

Objective The Flavivirus genera share epitopes inducing cross-reactive antibodies leading to great difficulty in differentially diagnosing flaviviral infections. This work was aimed at evaluating the complexity of dengue and yellow fever serological differential diagnosis. Material and methods Dengue antibody capture ELISA and a yellow fever neutralisation test were carried out on 13 serum samples obtained from yellow fever patients, 20 acute serum samples from dengue patients and 19 voluntan/ serum samples pre- and post-vaccination with YF vaccine. Results Dengue ELISA revealed IgM reactivity in 46,2 percent of yellow fever patients and 42 percent of vaccinees. Sixteen out of 20 dengue patients (80 percent) had high YF virus neutralisation titres. Conclusions . Such very high cross-reactivity data challenged differential laboratory diagnosis of dengue and yellow fever in áreas where both flaviviruses co-circulate. New laboratory strategies are thus needed for improving the tests and providing a specific laboratory diagnosis. Cross-reactivity between Flaviviruses represents a great difficulty for epidemiological surveillance and preventing dengue, both of which demand urgent attention.

Objetivo Los miembros del genero Flavivirus poseen epítopes inductores de anticuerpos de reactividad cruzada, lo que representa una gran dificultad en el diagnostico diferencial. En este trabajo nos propusimos evaluar la complejidad del diagnostico diferencial entre dengue y fiebre amarilla. Materiales y métodos Ensayos de ELISA de captura para dengue y de neutralización para fiebre amarilla fueron realizados en 13 muestras de suero de pacientes con fiebre amarilla, 20 muestras de pacientes con dengue en fase aguda y 19 voluntarios sanos antes y después de ser vacunados para la fiebre amarilla. Resultados Los ensayos de ELISA para IgM contra dengue mostraron reactividad cruzada en el 46,2 por ciento de los pacientes con fiebre amarilla y 42 por ciento de los vacunados. Dieciséis de los 20 pacientes con Dengue (80 por ciento) tuvieron altos títulos de anticuerpos neutralizantes para fiebre amarilla. Conclusión La alta reactividad cruzada que se encontró, representa un desafío para el diagnostico diferencial del dengue y fiebre amarilla en áreas donde co-circulan estos Flavivirus. Nuevas estrategias de diagnóstico de laboratorio son necesarias para suministrar un diagnóstico especifico. La reactividad cruzada entre Flavivirus representa un gran problema para la vigilancia epidemiológica, control y prevención del dengue, el cual debe ser solucionado.