Mother Nature seems mad at us. Or perhaps, rather, this is what happens when we dismantle public health systems. Diseases thrive when humans are most vulnerable, and now we have two diseases of high consequence in the news: hantavirus and Ebola.

That’s on top of tick season peaking and heat-related illnesses entering the picture. I end with some good news and a poll.

Here’s what’s going on and what it means for you and your health.

In case you missed it: NYT op ed

Last week, I wrote for the Times and, to my surprise, didn’t combust from nervousness.

It’s time to stop playing games and speak truth to power. The public deserves stronger, better systems. That’s not created by performative headlines or destruction alone; it also means not going back to 2019.

Here’s a gift link.

Disease weather report

Hantavirus update

The outbreak remains contained, and 41 people are being actively monitored in the U.S. Risk remains low for reasons previously covered.

A few updates:

1. People shuffling. The three people in biocontainment units (hospital-level setting) were moved to the Nebraska quarantine center (more like an isolated dorm room). All three tested negative, even the doctor who had a “mild positive.” It’s a telling sign of just how hard it is for this virus to spread; the doctor was treating infected patients on the cruise ship with very little PPE.
2. Are those in Nebraska able to go home? The federal government is forcing them to stay until the end of the month, even though some want to quarantine at home. This is pretty darn hypocritical given the administration’s medical freedom movement.

Countdown to mid-June. We’re in a waiting game to see if the outbreak grows. The 42-day quarantine clock starts from last exposure and CDC is assuming that was the day passengers arrived in Nebraska. The median infection window is 18 days, which is an intermediate target for good news.

What this means for you: Unless you’re a passenger or were alerted by health officials of a contact, your risk is essentially zero.

Ticks still ticking, but did they peak?

We are in peak tick season, especially in the Midwest and Northeast, where ~110 per 100,000 people visit emergency departments for tick bites.

But we may have already peaked, which is 5 weeks earlier than previous years. Whether this season is just early or will stretch on unusually long, time will tell.

Heat: Introducing a new section

Heat risk peaks today across Texas and the Northeast, then eases later in the week.

Heat sends more people to the ER with heat stroke, asthma attacks, dehydration, and heart problems. While relatively rare, it can also lead to death, which has increased over the past decade with more extreme heat. An increase in deaths outside largely drives this pattern. Indoor deaths are mostly among those without a working AC.

The real danger is heat imbalance. That’s when your body produces more heat than it can release. Normally, sweat helps cool us down. But when it’s hot and humid, sweat doesn’t evaporate as easily. The air is already saturated with moisture, making it harder for your body to cool itself and increasing the risk of illness.

Some federal tools were dismantled in 2025, but the NOAA-CDC HeatRisk tool remains active. This tool:

• Offers hyperlocal risk forecasts up to 7 days ahead.
• Rates conditions from “No Risk” to “Extreme” by considering temperatures, humidity, and other factors.
• Provides an action: what you and your family can do to be protected.

What this means for you: Over the summer, be sure to check the HeatRisk tool.* A red day isn’t the best day for that soccer game for a kid with asthma, and a stretch of orange days is a great time to check on your elderly neighbor.

*Disclosure: I helped build this tool as a Senior Advisor to CDC.

Spotlight: Ebola outbreak

A concerning Ebola outbreak is unfolding in Central Africa. This remains a very low risk to those in the U.S., but the WHO just declared it a public health emergency of international concern. Over 340 suspected cases and 100 deaths have been reported, and now there is a travel ban from three countries.

I called my friend Dr. Craig Spencer, a physician and Ebola survivor who worked in this region, to fill you in. Craig, take it away…

What is Ebola? It’s a virus you don’t want to mess with. It was first discovered in 1976 near the Ebola river (hence the name). It’s severe (25-90% case fatality rate). Symptoms include fever, severe headache, vomiting, and in serious cases, internal and external bleeding.

How did this start? We don’t know yet, but typically when a human comes in contact with an infected animal, usually fruit bats. From there, the virus spreads person-to-person. The people who take care of patients when they’re very sick—especially close family members and health care workers—are the most at risk. It spreads through direct contact with bodily fluids.

Why is this concerning? Four reasons:

1. This is not your normal Ebola. Ebola has six known strains. (The technical term is “species.”) Most outbreaks have been of the Zaire strain, and that’s the one we have vaccines and treatments for. But this outbreak is due to the Bundibugyo strain. This has caused a few small outbreaks in the past, but unlike the Zaire strain, there is no vaccine or treatment for this strain.
2. This outbreak is already big. Health officials learned about this outbreak long after it had already been spreading. This makes it really hard to find contacts and all the cases. Most outbreaks don’t get this big by the time they’re over, let alone this big by the time we even recognize them.
3. The location is exceptionally difficult. The outbreak is centered in eastern DR Congo, an area with significant conflict, cross-border traffic, and instability. There are also cases in the big cities here, which means a greater, faster spread due to the urban environment. I’ve worked up here; it’s a tough spot to get to and work in, due to transport and conflict. There was an Ebola outbreak here in 2018-2019 that grew to over 3,000 cases.
4. It’s on a few borders. This outbreak is close to the borders of Uganda and South Sudan. Uganda has extensive experience with Ebola outbreaks; South Sudan has less. We already know of two cases across the border in Kampala, the largest city in Uganda. And it’s possible there have already been cross-border cases into South Sudan and Rwanda, given the size of the outbreak. WHO and countries will be stepping up surveillance, but again, this is a place with a lot of conflict and instability.

This suggests the “true” outbreak is much larger, and that it will be tough to contain.

What triggers the declaration of a public health emergency of international concern (PHEIC)? WHO makes the PHEIC declaration based on three criteria:

1. It is unusual and unexpected.
2. There is the potential for cross-border spread.
3. It requires a coordinated, international response.

This is the ninth time it’s happened in history. But what is unique is that this is typically determined by committee. The director general declared PHEIC without convening the committee, hinting at the outbreak’s urgency. The outbreak was first announced on Friday, and a public health emergency was declared the next day.

This designation helps with emergency funding and signals to the world the urgency of the outbreak.

This has been spreading for awhile, without detection. Is this because of the cuts to USAID and global health efforts? They almost certainly played a role. U.S. funding once built strong surveillance systems around the world; without it, many of those programs are now shuttered. For example,

• USAID helped train communities on safer burial practices during the last Ebola outbreak and set up airport screening to prevent symptomatic travelers from boarding planes.
• CDC worked alongside affected countries and WHO to expand testing and coordinate the early response.

But the biggest loss was trust. Outbreak detection depends as much on relationships as technology. When we pulled our funding and support, we didn’t just lose the programs. We lost the credibility and the contact that made early warning possible. That’s almost impossible to rebuild quickly once an outbreak has already begun.

Does the travel ban work? Travel bans may seem like a necessary step, but they do not work unless you stop all travel from every country worldwide. Travel bans are often a political move; a tool to show the public that the government is responding. Travel bans can do a lot of damage in the meantime, like perpetuating disease-related stigma, reducing access to medical supplies, and more.

What this means for you: If you had travel plans to this region, it’s time to cancel them. This is a high-risk situation in Central Africa and CDC released a Level 4 Travel Advisory (i.e., the highest warning level.)

One American, a physician who was working in DRC on a mission, has tested positive. His family also had high-risk exposure. We have specialized treatment centers in the U.S. with experience taking care of Ebola patients, but the U.S. is sending them to Germany, arguing that its a shorter flight for the patient and their family.

To the general public in the U.S., your risk remains very, very low right now.

Good news

• Opioid deaths in the U.S. have declined for the third year in a row, driven by education and medical advancements. Harm reduction workers are noticing a less publicized reason: smoking is becoming more common than injecting. This shift may be saving lives because it allows people to better titrate their dose in real time, reducing the risk of a fatal overdose.

• Mifepristone was overruled by the Supreme Court. The Supreme Court blocked a Fifth Circuit ruling that would have required women to obtain Mifepristone through in-person visits, allowing telehealth and mail access to continue nationwide. This matters enormously for access: medication abortions now account for more than 60% of abortions in the U.S.

Bottom line

Public health is never boring—it can be slightly terrifying (and really sad) at times. Let this all be a reminder of why we need these systems in place, from local to state, federal, and global.

Love, YLE

Your Local Epidemiologist (YLE) is founded by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife. YLE comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. YLE reaches over 425,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below: