While the likelihood of yellow fever outbreaks in the USA is low, "travel-related cases of yellow fever could occur, with brief periods of local transmission in warmer regions such as the Gulf Coast states", wrote Dr. Anthony Fauci, director of National Institute of Allergy and Infectious Diseases and colleague Dr. Catharine Paules.
The Health Ministry has confirmed more than 300 cases of yellow fever so far during Brazil's summer rainy season.
"This proximity raises concern that, for the first time in decades, urban transmission of yellow fever will occur in Brazil", wrote Fauci and Catharine Paules, a colleague at NIAID. Ss with Zika, however, travel-related cases could seed the virus to Aedes aegypti populations and result in brief local transmission in warmer regions such as the Gulf Coast, where the mosquitos are found.
Yellow fever is spread by the Aedes aegypti mosquito, which circulates in parts of the southern United States. The Pan American Health Organization listed a 33% fatality rate for confirmed cases. according to the CNN.
But they said identifying suspected yellow fever cases early might be hard in countries like the United States, where many doctors have never seen a case and know little about the symptom profile and the course of the illness, which plays out in three stages: infection, remission, and intoxication. But millions of Brazilians have since been vaccinated this year as health authorities scramble to prevent the outbreak from turning into an epidemic.
The entire state of Espirito Santo is now considered at risk for transmission of the virus, the World Health Organization (WHO) claims.
"In an era of frequent global travel, any marked increase in domestic cases in Brazil raises the possibility of travel-related cases", they wrote.
Vaccine for yellow fever was developed in 1937 but the stockpile was so low that only 20 percent of the standard dose per person was administered in Angola and Congo when outbreaks occurred two years ago.
Rio state was not in that at-risk area for this outbreak and it has not had any cases.
"The concern now is that there are a considerable number of these jungle cases, and there's always the possibility - although it's very unlikely - that some of these infected people in the jungle" will travel to an urban area and spread the infection to the city-dwelling Aedes aegypti mosquitoes, Fauci said in an interview Wednesday, rather than the jungle-dwelling species that are transmitting it now.
Top infectious disease specialists are warning that a yellow fever outbreak in the jungles of Brazil could bring the disease to the United States.
"It's a public health heads-up". Early symptoms include a fever that can mimic flu, followed by a period of remission, and then a stage called "intoxication" - high fever, liver dysfunction and jaundice, and even kidney failure, heart and nervous system dysfunction, and shock.
Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, acknowledged that while it was too early to panic, the prospect of "urbanized" yellow fever was one that strikes fear in the hearts of public health officials.
Researchers for the US Centers for Disease Control and Prevention compared birth outcomes prior to the Zika epidemic's outbreak in 2015 - using data from three US state registries - to those of mothers infected by the virus in 2016.