For Rosario, listening to people and involving them in the initiatives that they identify as important is a given when you see people as the key agents of change in their own lives. This is something she learned to do many years ago.

April 7 is World Health Day, a celebration of the founding of the World Health Organization (WHO). Sometimes in our day-to-day public health work, the way we deliver messages can create more obstacles than we realize. Changing behaviour does not come easily to anyone and a behaviour change project requires great insight into people's lives to understand the barriers to change.

My project has its roots with my colleagues at the Guatemalan Ministry of Health who, after the initial success in the roll-out of the zinc and oral rehydration salts (ORS) treatment program for diarrhea, started thinking of ways to improve the program and its potential impact. They had the initial idea for what's become the cajita salvavida or "Life-saving Box."

Recent advances in micronutrient nutrition have given hope in the management of diarrhea. Using zinc, along ORS, not only helps children get better faster, it can prevent future episodes and even save their lives. This combined treatment costs as little at 50 cents per episode.