The following is a letter from Dr. Jonathan E. Fielding, director of the Los Angeles County Department of Public Health, to his staff, dated March 26:

I have been very privileged to have been your colleague over the past 16 years. After considerable thought, I have decided to leave county service when a successor, whom I understand will be identified through a nationwide executive search, is ready to assume the post. I plan to return to UCLA to help train future public health leaders and do research on how we can be even more effective.

Jonathan Fielding, M.D.

It has been a great pleasure to work with each and every one of you over the years. With your assistance as Public Health Ambassadors, together we have changed the capacity and face of public health in the most populous county in the nation. Due to your commitment to mission, drive and hard work to improve health in our county, your department is viewed as one of the best local health departments in the nation.

Here are some of the many events and accomplishments that have contributed to our high standing:

* Established as a separate county department;

* Became a respected source of accurate information on many diseases and environmental threats;

* Greatly increased emergency preparedness;

* Mounted the largest immunization activity in the history of the county in our H1N1 response;

* Built a state-of-the-art public health laboratory and the first of a new generation of public health centers;

* Implemented the widely used L.A. Public Health Survey;

* Reduced food-borne illness through an immensely popular and widely imitated restaurant grading system;

* Established effective programs to reduce tobacco use and increase physical activity;

* Helped to stop the increase in childhood obesity;

* Increased the accountability of our many contractors who provide essential services to county residents;

* Increased our response to both old and new environmental threats;

* Secured a court judgment of over $600 million to reduce the threat of lead poisoning in low-income county residences;

* Authored a 37-chapter book on what works in public health based on our wide-ranging experiences.

This list is only a small sample of the highlights of our work together. Each program and office could add important advances in our ability to tackle public health problems in our county. I salute you – your dedication to public health, and your commitment to fulfill our mission – Healthy People in Healthy Communities.

With your help I am confident that our department will continue to make a difference in the lives of every resident of our great county.