[cnn-photo-caption image= http://am.blogs.cnn.com/files/2009/12/lagloria31.jpg caption="Dr. Sanjay Gupta and crew found patient zero tucked away in this small mountain village in La Gloria, Mexico"]
By Danielle Dellorto, CNN
It was late April. I remember it being a somewhat quiet news day when I received the call. It was an editor on our international news desk alerting us that about 100 people had gotten very ill in Mexico City with severe flu-like symptoms.
They had no clue what was causing it at the time. The only thing health officials were telling us was that the patients had contracted a highly contagious virus that hadn’t been seen in humans before. The hunt was on: Dr. Sanjay Gupta and I hopped on the next flight out to Mexico City to track down the mystery virus that was getting so many people so sick.
Within 24 hours of arriving, the dense city of about 8 million people had literally turned into a ghost town. The mayor was urging people to stay inside; the hospitals were overcrowded; schools, public transportation, and restaurants closed their doors. At one point, I remember walking down the unusually empty streets of Mexico City in awe. It was an eerie feeling, but also a defining moment for me as a journalist. I realized that people, not just in Mexico City, were scared of this unknown killer virus. What was it? Would they be infected? What should they do? We didn't know it at the time, but H1N1 influenza was about to become a global epidemic and the world was already looking to us for answers.