Dateline has covered several cases of crime and betrayal. Yet some stories sent shockwaves like The Prussian Blue Mystery. This episode examines the horrifying poisoning of Brigida Uto.A young mother from San Diego who nearly lost her life. Her own spouse slowly fed her a deadly poison. He was a Navy sailor during that time. The substance he used was once found in a rat-killing substance. For many months, nobody knew what was going on. Brigida's system was shutting down. Doctors fought against time to solve this medical chaos.The case evolved into a criminal investigation, revealing a sinister plot that shocked the entire nation. Medical professionals worked very hard to comprehend the source of her mysterious illness.1) Brigida Uto's terrifying and mysterious symptoms according to DatelineWhen Brigida came to Kaiser Permanente in March 2013, she was barely clinging to life. She was only 28 years old. Her symptoms confused the medical residents immediately.Brigida was losing her vision very fast. She could not feel her hands or feet at last. Her extremities had gone completely senseless. Laura Comstock was the triage nurse who first witnessed her tragic state.She told Dateline something alarming. Brigida couldn't even see the water being offered to her. These were not typical symptoms of normal illness. Something lethal was destroying her nervous system. Her body was failing in several ways at once. Doctors knew they were encountering something unusual. They had to act quickly. The young mother's condition continued to deteriorate. Each moment counted in saving her life.2) The Medical investigation that uncovered the poisonThe medical team started an intense investigation. They ran several tests on Brigida. Additionally, standard poising panels displayed nothing. This was not a common toxic element. The Prussian Blue Mystery title refers to the treatment doctors eventually used. But first they needed to identify the poison.One doctor made a crucial decision in the beginning. He told investigators he was treating this as intentional poisoning. Brigida's symptoms pointed to something deliberate. Her condition was accidental or natural. The pattern suggested ongoing exposure to a toxic agent. The medical staff worked with federal investigators. Together, they finally identified the culprit. It was Thallium. This discovery would prove crucial to saving her life.3) Understanding Thallium and its deadly natureThallium is a highly toxic heavy poison. It was once commonly utilized in rat poison. Assassins have used it as a weapon throughout the course of history.Former spies were targeted with this substance. The U.S. government classifies it as a weapon of enormous destruction. The classification clearly illustrates its toxicity and lethality.Thallium poisoning causes terrible symptoms. It initially attacks the nervous system, and victims lose sensation in their limbs. Their vision deteriorates fast. Hair loss often takes over. The poison accumulates slowly in the body. Small doses over time can be just as toxic as one large dose. This makes it particularly insidious for deliberate poisoning. The substance works ruthlessly and silently.4) The Shocking truth behind Brigida's poisoningThe FBI launched an immediate criminal investigation. Dateline revealed the shocking truth. Brigida's own husband was poisoning her slowly. He was serving as a Navy sailor. For months, he had been adding Thallium to her drinks and food.No one suspected him at first. He appeared to be a concerned husband. But the evidence mounted against him. Investigators eventually found the poison at their house. They found his method of administration. He had been slowly poisoning his young wife.The betrayal was unbelievable. He had used a substance classified as a weapon of mass destruction. His actions were calculated and ongoing. The family members who spoke on Dateline expressed their disbelief and horror.Also See: Dateline: The Box - 5 harrowing details about Bill Stout's murder, revealed 5) The lifesaving Prussian Blue treatmentOnce the doctors discovered Thallium, they knew what to do. The treatment is termed Prussian Blue. The medication binds to Thallium in the body. It helps remove the poison through the digestive route.The Prussian Blue Mystery gets its name from this lifesaving treatment.The medical team on Dateline explained their urgency. Time was running out for Brigida. The Prussian Blue treatment started immediately. Her condition stabilized eventually. She started recovering from the brink of death.Brigida's family spoke about their horror and relief. They could not believe what had happened to their beloved one. The case stands as a testament to medical perseverance and detective work.Dateline exposed a terrifying betrayal that nearly ended one woman's life through systematic and purposeful poisoning.Also See: Dateline: The Prussian Blue Mystery - Who is Race Remington Uto and what do we know about his crimes? Disturbing details explored