Mosquito and tick-borne diseases are on the rise in the United States. That’s according to the Centers for Disease Control and Prevention, who has issued its monthly Vital Signs report just in time for summer 2018.

Yet despite the unsettling data, the government agency hasn't explained the real reason why. Indeed, despite compelling evidence, the CDC is politically bound from explicitly linking to the increase to climate change. Instead, its list of measures to take action include vague suggestions such as an urgency for local education and to wear “long-sleeved shirts and long pants”—rather than urging the government to invest in ways to mediate climate change.

It's another head-in-the-sand moment for a federal agency operating within an administration that is resistant to seriously tackling climate change, the most prescient existential threat of our epoch.

According to the report, the number of vector-borne diseases has nearly tripled from 2004 to 2016. Vector-borne diseases, the term used to describe diseases that derive from being bit by a mosquito, tick, or flea, include illnesses such as dengue, Zika, Lyme, or plague. The report states that nine new germs spread from mosquito bites have been discovered or introduced in the United States since 2004, too. International commerce and an increase in Americans traveling abroad could be to blame, the report states.

The report refrains from stating climate change as a likely driver. In an interview with the New York Times, the author of the study, Dr. Lyle Petersen, the agency’s director of vector-borne diseases, “repeatedly declined to connect the increase to the politically fraught issue of climate change.” Petersen reportedly told the Times he was “not under any pressure to say anything or not say anything” about climate change when asked.

Salon has contacted the CDC and has not received an immediate response.

One climate change expert told Salon this was a missed opportunity for the CDC.

“I believe the CDC missed an opportunity to highlight one of the likely drivers of the finding – climate change – but climate action won’t do much to address this specific trend in the near-term,” Jeremy Hess, Associate Professor of Emergency Medicine and Associate Professor of Environmental and Occupational Health Sciences, told Salon in an email.

“What is needed is much stronger surveillance and efforts to bring environmental information (like information on weather, land use, etc.) into our understanding of why these diseases are becoming so much more common,” he added.

It is peculiar that there is no mention of climate change in the report, considering the mounting evidence to suggest there’s a strong correlation between the two. While the other suggested factors are valid reasons as to why the U.S. is seeing an increase in such diseases, it is suspicious that climate change has not been included.

According to Kristie Ebi, Director of the Center for Health and the Global Environment (CHanGE) at the University of Washington, the rise in mosquito-borne diseases is to be expected with an intensifying climate.

“Improving monitoring, evaluation, and research can increase preparedness so that more cases of infectious disease don’t arise even as vectors enlarge their geographic range and months of disease transmission lengthen with climate change,” Ebi said.

Ebi’s suggestions support those of the CDC to some extent. The CDC, in its report, states that over 80 percent of local vector control organizations lack at least one out of five core vector control competencies, which are essentially vague solutions. The core capabilities are: Monitoring mosquitoes locally, using data to make decisions, establishing an action plan to kill mosquitos at every state of life, control vectors using “multiple types of methods,” and testing pesticide-resistance. The CDC warns that the nation is not “fully prepared” to deal with the impending epidemic.

It’s important to note the CDC has a section on its website specifically designated to climate change and the impact it can have on human health. It also lists “diseases carried by vectors” as one of its top concerns regarding public health and climate change. However, the information it states dates to 2014, and is from the Third National Climate Assessment’s Health Chapter.

According to a report from 2014 by the National Climate Assessment, North Americans have been specifically at risk for Lyme Disease, which is a tick-borne illness. According to the CDC, nearly 300,000 Americans are diagnosed with Lyme Disease each year, but only 35,000 of those cases are actually reported. The report suggests long-term studies, “to help quantify the relationships among weather variables, vector range, and vector-borne pathogen occurrence, the consequences of shifting distributions of vectors and pathogens, and the impacts on human behavior.”

Ebi said there are opportunities in which environmental information could forecast where and when outbreaks of infectious diseases could happen.

“However, limited investments are increasing risks to the health of Americans,” Ebi said. “Increasing adaptation and mitigation are critical to protecting the health of Americans as the climate continues to change.”

Limited investments appear to be the theme of the Trump Administration when it comes to studying climate change. As Politico recently reported, the administration is run by “skeptics.” According to Politico’s analysis, President Donald Trump has selected at least 20 like-minded people to serve as advisers and leaders of agencies who share his same disbelief on the issue. The war against climate change continues to become more baffling, especially as its impact begins to have a direct effect on Americans.

Unfortunately, according to Hess, the damage is likely to have already been made when it comes to mosquito-borne illnesses and climate change.

“Mitigation choices today are more likely to affect the trajectory of climate change later in the century than they are over the next few decades – impacts before 2050 are relatively ‘locked in’ based on previous emissions,” he said. “Mitigation efforts will certainly have a near-immediate impact on health by reducing particulate air pollution (from switching to cleaner fuels and renewables) and increasing physical activity (by switching to active transport), and these health co-benefits will pay for the mitigation efforts and then some, but they won’t have an immediate effect on vector-borne disease, unfortunately.”