Carta Acesso aberto Produção Nacional Revisado por pares

WEST NILE FEVER IN BRAZIL: SPORADIC CASE, SILENT ENDEMIC DISEASE OR EPIDEMIC IN ITS INITIAL STAGES?

2015; UNIVERSIDADE DE SÃO PAULO; Volume: 57; Issue: 3 Linguagem: Inglês

10.1590/s0036-46652015000300017

ISSN

1678-9946

Autores

Marcelo A. Cunha e Silva VIEIRA, Aline de Almeida Xavier Aguiar, Amaríles de Souza Borba, Herlon Clístenes Lima Guimarães, Kelsen Dantas Eulálio, Linduarte Leitão de ALBUQUERQUE-NETO, Maria do Amparo Salmito, Oriana Bezerra Lima,

Tópico(s)

Viral Infections and Vectors

Resumo

During the initial reports in some countries of Africa and Asia and until the 1990s, West Nile fever (WNF) was only considered a "minor" public health problem.The disease gained awareness after outbreaks occurred in Israel, Australia and European countries and, in particular, due to the large number of people and animals affected in the United States of America between the end of the 1990s and the beginning of the new century.Thereafter, signs of West Nile virus (WNV) circulation were detected in the Cayman Islands, El Salvador, Guatemala, Belize, Colombia, Venezuela, and Argentina.However, viral isolation was rarely achieved, and records of human, equine and avian morbidity in Latin America are lacking.Moreover, for unclear reasons, there was no correspondence between the expansion of the geographic range of viral circulation and the occurrence of significant animal or human morbidity by WNF in these regions 7 .Given the evidence of WNV circulation in South American countries beginning in 2003, the Brazilian Ministry of Health adopted the reporting of suspected human cases of WNF 7 .In parallel with the implementation of surveillance strategies for monitoring the introduction of the virus into the country, Brazilian researchers posed the question: "West Nile Encephalitis: our next epidemic?" 3.Between 2002 and 2013, serological evidence of viral circulation was found in horses and birds in the Amazon and Pantanal regions 4,6,8 .Serological surveys conducted in the states of Rio Grande do Sul (2002) and Rio Grande do Norte (2003), which included a significant number of birds of various species, found no evidence of WNV circulation in the country 1 .In 2010, despite the negative results of the study "Is West Nile virus a potential cause of central nervous system infection in Brazil?", SOARES et al. 10 concluded that "With the recent activity in Argentina, it is fundamental to continue to monitor for this virus as an emerging cause of neurological disease in South America".Similarly, in early 2014 FIGUEIREDO & FIGUEIREDO 2 advised: "It is necessary to improve the surveillance of SLEV, ROCV, and WNV in Brazil.Therefore, doctors must include flaviviruses (not only dengue) and other arboviruses in their differential diagnosis of acute febrile disease and of meningoencephalitis.In fact, if the doctors do not think on these pathogens, it will perpetuate the mistaken idea that these diseases do not exist here".In August 2014, a ranch worker from a rural area of Aroeiras do Itaim municipality (Piauí State, Brazil) was admitted to the Natan Portella Institute for Tropical Diseases (Teresina, Piauí State, Brazil) with clinical symptoms of acute encephalitis.Since June 2013, a sentinel surveillance program of viral encephalitis has been instituted by the Municipal Health Department of Teresina.A research protocol established in partnership with the Evandro Chagas Institute (Ananindeua, Pará State, Brazil) enabled the shipment of blood, cerebrospinal fluid and fecal samples in an attempt to isolate and molecularly and serologically detect herpes viruses, enteroviruses and arboviruses.From the start of the program until the admission of this patient, samples from 36 patients had been examined.In the second half of November 2014, the Evandro Chagas Institute released the results of the examinations that undoubtedly confirmed that Piauí had recorded the first human case of WNF in Brazil 12 .

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