Zika Virus Outbreak in Haiti in 2014: Molecular and Clinical Data.
BACKGROUND
Zika virus (ZIKV), first isolated in Uganda in 1947, is currently spreading rapidly through South America and the Caribbean. In Brazil, infection has been linked with microcephaly and other serious complications, leading to declaration of a public health emergency of international concern; however, there currently are only limited data on the virus (and its possible sources and manifestations) in the Caribbean.


METHODS
From May, 2014-February, 2015, in conjunction with studies of chikungunya (CHIKV) and dengue (DENV) virus infections, blood samples were collected from children in the Gressier/Leogane region of Haiti who presented to a school clinic with undifferentiated febrile illness. Samples were initially screened by RT-PCR for CHIKV and DENV, with samples negative in these assays further screened by viral culture.


RESULTS
Of 177 samples screened, three were positive for ZIKV, confirmed by viral sequencing; DENV-1 was also identified in culture from one of the three positive case patients. Patients were from two different schools and 3 different towns, with all three cases occurring within a single week, consistent with the occurrence of an outbreak in the region. Phylogenetic analysis of known full genome viral sequences demonstrated a close relationship with ZIKV from Brazil; additional analysis of the NS5 gene, for which more sequences are currently available, showed the Haitian strains clustering within a monophyletic clade distinct from Brazilian, Puerto Rican and Guatemalan sequences, with all part of a larger clade including isolates from Easter Island. Phylogeography also clarified that at least three major African sub-lineages exist, and confirmed that the South American epidemic is most likely to have originated from an initial ZIKV introduction from French Polynesia into Easter Island, and then to the remainder of the Americas.


CONCLUSIONS
ZIKV epidemics in South America, as well as in Africa, show complex dissemination patterns. The virus appears to have been circulating in Haiti prior to the first reported cases in Brazil. Factors contributing to transmission and the possible linkage of this early Haitian outbreak with microcephaly remain to be determined.
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America.
John
J
Lednicky
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Department of Health Services Research, Management, and Policy, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America.
Valery Madsen
VM
Beau De Rochars
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America.
Maha
M
El Badry
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America.
Julia
J
Loeb
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Christianville Foundation School Clinic, Gressier, Haiti.
Taina
T
Telisma
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Christianville Foundation School Clinic, Gressier, Haiti.
Sonese
S
Chavannes
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Christianville Foundation School Clinic, Gressier, Haiti.
Gina
G
Anilis
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Department of Pathology, Immunology, and Laboratory Sciences, College of Medicine, University of Florida, Gainesville, Florida, United States of America.|Department of Infectious Parasitic and Immunomediated Diseases, Reference Centre on Phylogeny, Molecular Epidemiology and Microbial Evolution (FEMEM)/Epidemiology Unit, Istituto Superiore di Sanita, Rome, Italy.
Eleonora
E
Cella
Department of Infectious Parasitic and Immunomediated Diseases, Reference Centre on Phylogeny, Molecular Epidemiology and Microbial Evolution (FEMEM)/Epidemiology Unit, Istituto Superiore di Sanita, Rome, Italy.
Massimo
M
Ciccozzi
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.
Mohammed
M
Rashid
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America.
Bernard
B
Okech
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Department of Pathology, Immunology, and Laboratory Sciences, College of Medicine, University of Florida, Gainesville, Florida, United States of America.
Marco
M
Salemi
Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, United States of America.
J Glenn
JG
Morris
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D004196:Disease Outbreaks; D006205:Haiti / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008969:Molecular Sequence Data; D058974:Phylogeography; D012367:RNA, Viral / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D017361:Viral Nonstructural Proteins / Q000235:genetics; D014776:Virus Cultivation; D000071244:Zika Virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D000071243:Zika Virus Infection / Q000453:epidemiology* / Q000821:virology
C096041:NS5 protein, flavivirus; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins