Get the content you want anytime you want.

As the World Is Hit with Vaccine Shortages, Will This Mosquito-Borne Virus Find Its Way to Asia?

OCT 13, 2017 | KRISTI ROSA
Yellow fever—a virus transmitted through the bite of an infected mosquito—has recently made headlines in relation to the recent outbreak that sprung up in Brazil this year, an outbreak that occurred at the same time as a global vaccine shortage.

In a “Late Breakers II” symposium at ID Week 2017, Daniel Lucey, MD, MPH, from the department of Medicine/Infectious Diseases at Georgetown University Medical Center, provided insight on past yellow fever outbreaks, vaccine shortages, and what needs to be done in order to prevent future outbreaks in susceptible countries, such as those in Asia.

Dr. Lucey opened his presentation by providing a brief overview of the 2 different types of epidemiologic cycles for the virus: the urban and the sylvatic. He shared that the urban cycle “is the one we know best.” It occurs in cities where Aedes aegypti mosquitoes, or yellow fever mosquitoes, exist and spread the disease from person-to-person. In contrast, the sylvatic cycle occurs mostly in forests or jungles, involving non-Aedes aegypti mosquitoes—such as the hemophagus—and monkeys. Sometimes humans get infected as well, as can be seen in the ongoing epidemic in Brazil.

Another notable yellow fever epidemic that occurred in 2016 started in Luanda, the capital of Angola, and continued to spread throughout the country, moving north until it crossed the border into the Democratic Republic of Congo (DRC), ravaging cities and rural regions alike. It didn’t stop there; the disease continued to spread north to the DRC’s capital, Kinshasa. “Personally, I was very concerned that it was going to cross the river and go into Brazzaville, and then perhaps extend through the Republic of Congo, and eventually get to Nigeria,” Dr. Lucey admitted. Fortunately, an international response that included mass vaccination throughout Angola and consisted of dozens of millions of doses of vaccine, managed to stop the disease before it spread further.

Nevertheless, Dr. Lucey mentioned that the disease managed to reach China because 10 infected travelers brought it home with them. “For me, this is a very large red flag about what could easily happen in the near future—meaning in the coming months or years—in terms of the yellow fever virus coming to Asia where there haven’t been yellow fever epidemics,” despite the fact that Aedes aegypti mosquitoes are present in the continent and are known to transmit other infectious diseases such as dengue. You can listen to Dr. Lucey talk about this threat further in the interview clip below.

Big advances in treatment can