Shiloh
Editor, Senior Moderator
Source: http://www.nejm.org/doi/full/10.1056/NEJMp1702172?query=featured_home&
Perspective
Yellow Fever ? Once Again on the Radar Screen in the Americas
Catharine I. Paules, M.D., and Anthony S. Fauci, M.D.
March 8, 2017DOI: 10.1056/NEJMp1702172
Four arthropod-borne viruses (arboviruses) have recently emerged or reemerged in the Americas, spreading rapidly through populations that had not previously been exposed to them and causing substantial morbidity and mortality.1 The first was dengue, which reemerged to cause widespread disease predominantly in South America and the Caribbean in the 1990s. This epidemic was followed by West Nile virus in 1999, which has since become endemic in the continental United States, and chikungunya in 2013, which continues to cause disease, predominantly in the Caribbean and South America. Most recently, Zika virus emerged in Brazil in 2015 and spread through infected travelers to more than 60 countries and territories in the Americas, including the United States.
Over the past several weeks, a fifth arbovirus, yellow fever virus, has broken out in Brazil, with the majority of the infections occurring in rural areas of the country. These are referred to as sylvatic, or jungle, cases, since the typical transmission cycle occurs between forest mosquitoes and forest-dwelling nonhuman primates, with humans serving only as incidental hosts. In this ongoing outbreak, health authorities have reported 234 confirmed infections and 80 confirmed deaths as of February 2017.2 Confirmed infections have occurred in the Brazilian states of Minas Gerais, Esp?rito Santo, and S?o Paulo (see mapConfirmed Cases of Yellow Fever in the Current Outbreak.), and hundreds of additional cases remain under investigation. The high number of cases is out of proportion to the number reported in a typical year in these areas.
Although there is currently no evidence that human-to-human transmission through Aedes aegypti mosquitoes (urban transmission) has occurred, the outbreak is affecting areas in close proximity to major urban centers where yellow fever vaccine is not routinely administered. This proximity raises concern that, for the first time in decades, urban transmission of yellow fever will occur in Brazil...
Perspective
Yellow Fever ? Once Again on the Radar Screen in the Americas
Catharine I. Paules, M.D., and Anthony S. Fauci, M.D.
March 8, 2017DOI: 10.1056/NEJMp1702172
Four arthropod-borne viruses (arboviruses) have recently emerged or reemerged in the Americas, spreading rapidly through populations that had not previously been exposed to them and causing substantial morbidity and mortality.1 The first was dengue, which reemerged to cause widespread disease predominantly in South America and the Caribbean in the 1990s. This epidemic was followed by West Nile virus in 1999, which has since become endemic in the continental United States, and chikungunya in 2013, which continues to cause disease, predominantly in the Caribbean and South America. Most recently, Zika virus emerged in Brazil in 2015 and spread through infected travelers to more than 60 countries and territories in the Americas, including the United States.
Over the past several weeks, a fifth arbovirus, yellow fever virus, has broken out in Brazil, with the majority of the infections occurring in rural areas of the country. These are referred to as sylvatic, or jungle, cases, since the typical transmission cycle occurs between forest mosquitoes and forest-dwelling nonhuman primates, with humans serving only as incidental hosts. In this ongoing outbreak, health authorities have reported 234 confirmed infections and 80 confirmed deaths as of February 2017.2 Confirmed infections have occurred in the Brazilian states of Minas Gerais, Esp?rito Santo, and S?o Paulo (see mapConfirmed Cases of Yellow Fever in the Current Outbreak.), and hundreds of additional cases remain under investigation. The high number of cases is out of proportion to the number reported in a typical year in these areas.
Although there is currently no evidence that human-to-human transmission through Aedes aegypti mosquitoes (urban transmission) has occurred, the outbreak is affecting areas in close proximity to major urban centers where yellow fever vaccine is not routinely administered. This proximity raises concern that, for the first time in decades, urban transmission of yellow fever will occur in Brazil...