title: Zika Virus Outbreak in Rio de Janeiro, Brazil: Clinical Characterization, Epidemiological and Virological Aspects.
abstract: BACKGROUND
  In 2015, Brazil was faced with the cocirculation of three arboviruses of major public health importance. The emergence of Zika virus (ZIKV) presents new challenges to both clinicians and public health authorities. Overlapping clinical features between diseases caused by ZIKV, Dengue (DENV) and Chikungunya (CHIKV) and the lack of validated serological assays for ZIKV make accurate diagnosis difficult.
  The outpatient service for acute febrile illnesses in Fiocruz initiated a syndromic clinical observational study in 2007 to capture unusual presentations of DENV infections. In January 2015, an increase of cases with exanthematic disease was observed. Trained physicians evaluated the patients using a detailed case report form that included clinical assessment and laboratory investigations. The laboratory diagnostic algorithm included assays for detection of ZIKV, CHIKV and DENV. 364 suspected cases of Zika virus disease were identified based on clinical criteria between January and July 2015. Of these, 262 (71.9%) were tested and 119 (45.4%) were confirmed by the detection of ZIKV RNA. All of the samples with sequence information available clustered within the Asian genotype.
  This is the first report of a ZIKV outbreak in the state of Rio de Janeiro, based on a large number of suspected (n = 364) and laboratory confirmed cases (n = 119). We were able to demonstrate that ZIKV was circulating in Rio de Janeiro as early as January 2015. The peak of the outbreak was documented in May/June 2015. More than half of the patients reported headache, arthralgia, myalgia, non-purulent conjunctivitis, and lower back pain, consistent with the case definition of suspected ZIKV disease issued by the Pan American Health Organization (PAHO). However, fever, when present, was low-intensity and short-termed. In our opinion, pruritus, the second most common clinical sign presented by the confirmed cases, should be added to the PAHO case definition, while fever could be given less emphasis. The emergence of ZIKV as a new pathogen for Brazil in 2015 underscores the need for clinical vigilance and strong epidemiological and laboratory surveillance.
authors.affiliation: Acute Febrile Illnesses Laboratory, Evandro Chagas National Institute of Infectious Diseases; Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Patrícia
authors.identifier: http://orcid.org/0000-0001-9555-7976
authors.initials: P
authors.lastname: Brasil
authors.affiliation: Acute Febrile Illnesses Laboratory, Evandro Chagas National Institute of Infectious Diseases; Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Guilherme Amaral
authors.initials: GA
authors.lastname: Calvet
authors.affiliation: Acute Febrile Illnesses Laboratory, Evandro Chagas National Institute of Infectious Diseases; Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: André Machado
authors.initials: AM
authors.lastname: Siqueira
authors.affiliation: Acute Febrile Illnesses Laboratory, Evandro Chagas National Institute of Infectious Diseases; Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Wakimoto
authors.affiliation: Flavivirus Laboratory, Oswaldo Cruz Institute/ Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Patrícia Carvalho
authors.initials: PC
authors.lastname: de Sequeira
authors.affiliation: Scientific Computation Program, Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Aline
authors.initials: A
authors.lastname: Nobre
authors.affiliation: Clinical Research Platform, Evandro Chagas National Institute of Infectious Diseases; Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Marcel de Souza Borges
authors.initials: Mde S
authors.lastname: Quintana
authors.affiliation: Flavivirus Laboratory, Oswaldo Cruz Institute/ Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Marco Cesar Lima de
authors.initials: MC
authors.lastname: Mendonça
authors.affiliation: Acute Febrile Illnesses Laboratory, Evandro Chagas National Institute of Infectious Diseases; Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Otilia
authors.initials: O
authors.lastname: Lupi
authors.affiliation: Acute Febrile Illnesses Laboratory, Evandro Chagas National Institute of Infectious Diseases; Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Rogerio Valls
authors.initials: RV
authors.lastname: de Souza
authors.affiliation: Acute Febrile Illnesses Laboratory, Evandro Chagas National Institute of Infectious Diseases; Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Carolina
authors.initials: C
authors.lastname: Romero
authors.affiliation: Acute Febrile Illnesses Laboratory, Evandro Chagas National Institute of Infectious Diseases; Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Heruza
authors.initials: H
authors.lastname: Zogbi
authors.affiliation: Acute Febrile Illnesses Laboratory, Evandro Chagas National Institute of Infectious Diseases; Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Clarisse da Silveira
authors.initials: Cda S
authors.lastname: Bressan
authors.affiliation: Flavivirus Laboratory, Oswaldo Cruz Institute/ Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Simone Sampaio
authors.initials: SS
authors.lastname: Alves
authors.affiliation: Mosquito Transmitters of Hematozoans Laboratory, Oswaldo Cruz Institute/ Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Lourenço-de-Oliveira
authors.affiliation: Flavivirus Laboratory, Oswaldo Cruz Institute/ Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Rita Maria Ribeiro
authors.initials: RM
authors.lastname: Nogueira
authors.affiliation: Scientific Computation Program, Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Marilia Sá
authors.initials: MS
authors.lastname: Carvalho
authors.affiliation: Flavivirus Laboratory, Oswaldo Cruz Institute/ Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil.
authors.forename: Ana Maria Bispo
authors.initials: AM
authors.lastname: de Filippis
authors.affiliation: Section Clinical Tropical Medicine, Department of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany & German Center for Infectious Disease Research, Heidelberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jaenisch
mesh_terms: D000293:Adolescent; D000328:Adult; D001938:Brazil / Q000453:epidemiology; D002648:Child; D016000:Cluster Analysis; D004196:Disease Outbreaks; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014759:Viral Envelope Proteins / Q000235:genetics; D055815:Young Adult; D000071244:Zika Virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D000071243:Zika Virus Infection / Q000453:epidemiology* / Q000473:pathology* / Q000821:virology
chemical_list: D012367:RNA, Viral; D014759:Viral Envelope Proteins