Improved surveillance, response needed to contain emerging diseases

May 2007

Since the first reported case of West Nile Virus in the United States during the summer of 1999, more than 17,000 cases of this emerging disease have been reported to the CDC. However, researchers are hopeful that better surveillance and testing methods will help track this illness and other emerging diseases as they continue their trek across the United States.

“We need to improve our surveillance and response so that there is increasing efforts for rapid clinical diagnosis and rapid containment. The roles of the World Health Organization, the CDC and local health departments are important in developing effective surveillance and response,” Stanford T. Shulman, MD, a professor of pediatrics of Northwestern University, said at Miami Children’s Hospital 42nd Annual Pediatric Postgraduate Course: “Perspectives in Pediatrics.”

Shulman, who is also a member of the Infectious Diseases in Children Editorial Board, discussed West Nile virus and other emerging diseases at the meeting.

Types of emerging diseases

There are essentially three categories of emerging diseases, which include newly emerging/newly recognized, re-emerging and deliberately emerging.

Some of these emerging diseases are actually brand new agents, whereas others are not brand new, but are newly recognized because of new and improved technology, according to Shulman.

Re-emerging diseases are those that have been around for a long time, such as tuberculosis, group A streptococcus and polio, which have all come back for a variety of reasons. The deliberately emerging type consists of bioterrorism agents, such as anthrax, he said.

There are many pathogen, host and environmental factors that have contributed to the emergence of infectious diseases, according to Shulman.

“Changes in ecosystems were related to the spread of West Nile, which was an unknown infection on this continent until about five or six years ago when it emerged on the East Coast and then changed reservoir hosts and spread across the United States,” he said.

Other factors involved in emerging infections include international travel and commerce, technology and industry, poverty and social inequality, war and famine and the intent to harm, such as bioterrorism.

Meeting the challenges

Tracking the presence of the virus is important in planning the prevention and control of West Nile Virus infections from mosquitoes to humans, according to a media fact sheet from the CDC.

West Nile has slowly made its way across the United States and, as of April 3, 2007, human cases of the virus have been reported in 45 states, according to the CDC.

Research efforts are ongoing and are being designed to “develop better surveillance tools, better diagnostics, vaccine development and therapies,” Shulman said. “Our local fire, health and police departments also need better diagnostic measures so when a white dust or powder [anthrax] is found, they will be able to use rapid tests to find out what the substance is.

“We need to also take advantage of new technology to help us in all of these ways through the use of genomics, proteomics and nanotechnology, which are all being utilized to try to meet the challenges of emerging infectious diseases.”

For more information:

• Shulman S. Emergent infectious diseases of children. Presented at: Miami Children’s Hospital’s 42nd Annual Pediatric Postgraduate Course: “Perspectives in Pediatrics;” March 19-22, 2007; Miami.