Emergence of Madariaga virus as a cause of acute febrile illness in children, Haiti, 2015-2016

Madariaga virus (MADV), also known as South American eastern equine encephalitis virus, has been identified in animals and humans in South and Central America, but not previously in Hispaniola or the northern Caribbean. MADV was isolated from virus cultures of plasma from an 8-year-old child in a school cohort in the Gressier/Leogane region of Haiti, who was seen in April, 2015, with acute febrile illness (AFI). The virus was subsequently cultured from an additional seven AFI case patients from this same cohort in February, April, and May 2016. Symptoms most closely resembled those seen with confirmed dengue virus infection. Sequence data were available for four isolates: all were within the same clade, with phylogenetic and molecular clock data suggesting recent introduction of the virus into Haiti from Panama sometime in the period from October 2012-January 2015. Our data document the movement of MADV into Haiti, and raise questions about the potential for further spread in the Caribbean or North America.

马答里亚加病毒（Madariaga virus, MADV），又称南美东部马脑炎病毒（South American eastern equine encephalitis virus），此前仅在中南美洲的动物与人体中被检出，从未在伊斯帕尼奥拉岛及加勒比海北部地区发现该病毒。2015年4月，研究人员在海地格雷西耶/莱奥甘地区的某学校队列中，从一名因急性发热性疾病（acute febrile illness, AFI）就医的8岁儿童的血浆病毒培养物中分离出MADV。随后，研究人员又于2016年2月、4月及5月，从该队列中另外7名急性发热性疾病患者的样本中分离出该病毒。该病毒感染所致临床症状与确诊登革病毒感染者的症状高度相似。研究人员对4株分离毒株完成了测序分析，结果显示所有毒株均隶属于同一进化分支（clade）；系统发育（phylogenetic）与分子钟（molecular clock）分析数据表明，该病毒于2012年10月至2015年1月期间的某一时间点从巴拿马传入海地，属于近期引入事件。本研究证实了马答里亚加病毒传入海地的事件，并引发了关于该病毒在加勒比地区或北美进一步传播潜力的诸多疑问。