Contributing columnist

Ronald A. Klain, a Post contributing columnist, was White House Ebola response coordinator from 2014 to 2015 and a senior adviser to Hillary Clinton’s 2016 campaign.

Summer is coming. And if you think a warm-weather surge of mosquitoes and ticks is not as frightening as the fictional winter’s White Walkers from “Game of Thrones,” you haven’t read this last week’s report by the Centers for Disease Control and Prevention on the rapidly escalating danger of infectious diseases spread by insects.

The CDC’s key findings: The number of Americans infected with such diseases, including Zika, West Nile and Lyme, has more than tripled in a decade, jumping from about 30,000 cases a year in 2006 to almost 100,000 in 2016. This total includes nine types of infections never before seen in the United States, including Zika and chikungunya. Looking ahead, 80 percent of state and local health departments are not ready for the insect-borne threat we are facing in just a few weeks.

Why the surge? Global travel is a major cause; as commerce, culture and tourism spread rapidly, so do diseases. Scientists also identify more infections, thanks to new research tools. But there’s another factor slipped into the CDC report: Certain mosquitoes and ticks are “moving into new areas.” This anodyne language refers to the fact that, as temperatures and moisture rise across the United States, disease-bearing insects expand their reach. Thus, we face another risk posed by the threat that Trump administration officials dare not speak aloud: climate change.

Coincidentally, the day before the CDC’s report, a man who has worked mightily to save millions from disease threats — Bill Gates — went public with a recent conversation he had with President Trump. Gates told Stat News that they had discussed Gates’s work to try to find a universal flu vaccine; his foundation has offered a $12 million prize for development of a vaccine in hopes of taming a pandemic flu threat that could take more than 30 million lives in a single year.

As generous as Gates is, however, no single individual has the resources to protect us from the growing array of infectious diseases confronting us: Only government action has that scope.

And although Gates said Trump was enthusiastic about the universal flu vaccine project, there are reasons to be skeptical that this president’s administration is up to the broader challenge. As Gates reminded the president, nearly a year and a half into his tenure, Trump still does not have a science adviser. John Bolton’s purge at the National Security Council pushed out the official there overseeing pandemic preparation, Tom Bossert. Trump’s controversial CDC director, Robert Redfield, has been busy explaining why he will, or won’t, get paid double what his predecessors made.

But the biggest challenge is Trump himself. When the United States faced the West African Ebola epidemic in 2014, Trump attacked science-based responses to the threat and essentially argued that President Barack Obama should leave American health-care workers in Africa to die when they were sickened while fighting the disease. (Obama didn’t, and they were saved.) Trump has “energized” the anti-vaccine movement that imperils all that Gates and his allies are trying to achieve. He has proposed an 80 percent reduction in programs designed to stop dangerous diseases overseas before they come to the United States.

The xenophobia that Trump preached during the 2016 campaign contributed to congressional delay as reports emerged about a Zika outbreak arriving here. Trump’s anti-immigration followers said that tougher immigration laws — not public-health measures — were the way to stop Zika. While Congress dithered, Zika took root in parts of Florida and Texas, and — for the first time in history — the CDC had to issue an advisory against travel to parts of the continental United States.

It doesn’t have to be this way. The solutions are well known: Empowered leadership at the White House. A public-health emergency fund that a president can quickly deploy before Congress acts. More investments in research, epidemic prevention, and well-equipped and trained teams at regional hospitals. Increased support for state and local ­public-health departments, our front-line defense. More research on vaccines and therapeutics, and clearer policies on their rapid approval and deployment. And most important: robust investment in global health security to help other countries identify, isolate and respond to outbreaks before they become global epidemics.

These ideas all have bipartisan origins and have had (at least until recent years) bipartisan support. But they require investing more money overseas in the face of a powerful isolationist headwind.

Later this month, the Smithsonian will open an exhibit called “Outbreak,” commemorating the 100th anniversary of the Spanish flu epidemic that killed more Americans than both world wars combined. We are far from prepared for the sort of threats that the exhibit highlights, and retreating from the world is no answer: There is no wall high enough to keep America safe from infectious diseases in today’s connected world. And summer is coming.