It has long been predicted that climate change will have detrimental impacts on human health through issues such as heat stroke and malnutrition, but now scientists at the World Health Organization (WHO) are predicting a rise in climate-sensitive diseases such as dengue and yellow fever as temperatures gradually warm.
According to the Center for Disease Control and Prevention (CDC), yellow fever causes severe liver disease with bleeding, while severe forms of dengue causes fever, abdominal pain, vomiting, joint pain, bleeding, and difficulty breathing with a risk for death especially in young children.
“As many as 100 million people are infected [with dengue] yearly,” says the CDC. “There are not yet any vaccines to prevent infection with dengue virus.”
This figure just applies to the tropical areas, which currently confine the range of the dengue virus. WHO expects that by 2080, an additional 2 billion people will be exposed to dengue on a regular basis. A lack of vaccine means that anyone in this tropical area is at risk to contract dengue.
Though similar to dengue, yellow fever does have a vaccine, which means that the expansion of the yellow fever range poses a much lower risk to the general population as immunizations against this disease become more prevalent.
The organism responsible for spreading dengue and yellow fever is the mosquito Aedes aegypti. The insect is dark and has small white spots decorating its legs and body.
The effects of climate change have already been seen on the range of this insect, which means that dengue and yellow fever are not far behind. According to Aljazeera America in an article written by Patricia Sagastume, “For nearly 60 years, dengue was eradicated from the United States with the onset of mosquito-control spraying and prevention campaigns. But since 2001, outbreaks in Hawaii, Texas, and Florida’s Key West have signaled its return.” And if climate models are to be believed, this is just the beginning of a new norm for American citizens.
A focus on prevention is essential to areas newly affected by dengue and yellow fever. For yellow fever, the obvious first step is to get vaccinated against yellow fever, but solving the problem posed by dengue is not as simple because there is no vaccine currently available.
According to the CDC, “When infected [with dengue], early recognition and prompt supportive treatment can substantially lower the risk of developing severe disease.”
Obviously, the best prevention is not getting bitten in the first place, which will undoubtedly lead many municipalities to try and eliminate the mosquito population in the area, but it may not be that simple. Aedes aegypti is a highly resistant mosquito which can easily recover after human interventions.
The CDC states, “If we were to eliminate all larvae, pupae, and adult Ae. aegypti at once from a site, its population could recover two weeks later as a result of egg hatching following rainfall or the addition to containers harboring eggs.”
This means that American cities everywhere will have to begin thinking of strategies to control mosquito populations in order to keep the public safe, but one thing is for sure: it won’t be easy.