Reports of people contracting and dying from the brain-eating amoeba typically crop up in the summer. When they do, headlines and news tickers evoke a new hidden killer lurking in our midst. This summer in the U.S.: A 12-year-old boy from Florida contracted a fatal case in June and a 9-year-old girl died in Kansas last week. Not that the threat is actually new — or even necessarily growing worse. Since the early '60s, the CDC in Atlanta has confirmed 132 cases in the U.S. — though CDC epidemiologists suspect that as many as double the number of cases have gone unreported. Many victims were young boys. Most lived in Florida, Texas, or one of the southern states. They had gone swimming in improperly chlorinated pools, in lakes, or in rivers. Two boys dunked their heads in bathwater. In adults, the disease is often linked to rinsing the nasal passages out with water with a neti pot or during ritual ablutions. No one is really certain how rare a disease it is.

The amoebas themselves are not rare; it seems they are everywhere. Surveys in the 1970s found Naegleria fowleri in close to half the lakes in Florida. By 2010, the amoeba climbed as far north as Minnesota, and, with global warming, some scientists expect the heat-loving organisms to spread. In 2011, two Australian researchers reviewed data from 18 countries in North America, Europe, and Asia and found overwhelming evidence that water towers and drinking-water systems were colonized with enough amoebas to be a health concern.

We live in a country, and an age, with extraordinarily safe water. But even in water coming out of ours taps, millions of microorganisms we cannot see — and perhaps do not want to know about — survive. The increasing awareness of the brain-eating amoeba exposes a subtle crack in the nation’s hygienic vigilance and a much larger flaw in our perception. Here was a potential pathogen that could not feasibly be eradicated, that lived in warm freshwater and crawled around lakes and reservoirs — and potentially home plumbing.

The same week Kali fell ill, the CDC’s Free-Living Ameba Laboratory in Atlanta received a drug called miltefosine that is made in Germany and is not distributed in the U.S. (The drug was originally developed to treat breast cancer and, despite some promising evidence, there simply wasn’t enough data to approve its “off-label” treatment of parasitic meningitis.) Before 2013, says Dr. Michael Beach, a CDC epidemiologist who oversees the amoeba laboratory, the agency had never been able to fly the drug in fast enough from Europe. “Patients would essentially be dead before we could get it.”

That Saturday, the day after Kali's hospitalization, the first shipment left Atlanta for Little Rock. “First they said, ‘It’s on its way,’" says Traci. "Then they came back in and said, ‘We’ve got bad news. Delta lost it.’ It was lost in baggage control, so the head doctor, he went out to airport instead of having it delivered. He didn’t want it to get lost again.” On Sunday, doctors added miltefosine to Kali’s regimen of antibiotic drugs. (One of them, Amphotericin B, is considered a drug of last resort because it can cause liver and kidney failure.)

On Monday, doctors lowered Kali’s body temperature to 93℉ using a machine that circulates chilled water in gel pads placed against her skin — a procedure common in traumatic brain injury. Dr. Mark Heulitt, one of her doctors, later explains, “The way God designed this, there’s holes in the bottom of your skull, where all your nerves go. When pressure builds up and pushes the brain through those holes, it acts like a plug and cuts off blood supply to the brain. Once you cut off blood supply to the brain, the brain dies very quickly. There’s no way to reverse that. It’s called herniation ... We just don’t see survivors. It just doesn’t happen.”

That Tuesday, four days after her daughter had fallen ill, Traci taped a segment for the 9 o'clock news. “If your child has been swimming anywhere and they start complaining — their head hurting and running a fever or just not acting normal — go to the doctor.” She didn’t mention the beach or the pool or the water park. But the amoeba lived in water and as far as the public knew, it could be anywhere. That weekend the hospital saw a modest spike in emergency room visits, about 20 more than the average for July.

That night, Traci slept in the conference room of the ICU and scrolled through old photos on her phone. She didn’t care if they lost the house and everything the family owned — she just wanted Kali back again. Her cousin, Doug Beck, set up a prayer page on Facebook, one that would come to have 30,000 likes. On Thursday, July 25, now a full week into the ordeal, she sent an update: Kali is still in the induced coma. She still has a long fight ahead. Doctors are monitoring everything closely and checking her responses to see what progress has been made. Thank you all for the prayers and for sharing her story with others.

The hospital had private rooms with lockers and showers for parents on a separate floor. To the Hardigs, these rooms felt galaxies away from their daughter. “It was,” as Joseph puts it, “as if there was no one else in the world. The whole world just faded away.”