Effective global response to emerging infectious diseases.

To discuss the global efforts needed to detect and control emerging infections, I will begin with a personal experience. In 1987, a large epidemic of meningococcal meningitis occurred during the haj, the annual pilgrimage of Moslems to Mecca. The Centers for Disease Control and Prevention (CDC) sent a team of epidemiologists and laboratorians to Kennedy Airport to meet the thousands of pilgrims returning to the United States. Returning pilgrims were given chemopro-phylaxis; nasopharyngeal cultures showed that 11% of the pilgrims carried the epidemic strain of group A Neisseria meningitidis, the causative agent. Only 25% of the returning pilgrims were intercepted and treated; thousands of others dispersed throughout the country (presumably with the same 11% carriage rate of this highly virulent strain). Were U.S. surveillance systems adequate to rapidly detect any subsequent outbreaks? We were completely dependent on local physicians to diagnose cases, on laboratories to isolate and serotype the organism, on the notification systems to inform the state and federal agencies. In this instance, the United States was fortunate and did not see any secondary outbreaks. Other countries were not so fortunate; large epidemics occurred in Chad, Kenya, and Tanzania as a result of the same virulent clone of N. meningitidis. The importation of this epidemic clone illustrates the central importance of local capacity to diagnose, report, and control emerging infectious diseases. A more recent example is the 1997 influenza H5N1 outbreak in Hong Kong: the outbreak illustrates what systems are needed to detect a new organism and to respond appropriately. First, the Hong Kong public health system had to have the capacity to isolate the organism and to recognize that it was not an ordinary influenza strain. Because infections emerge at the local level, the capacity to detect new threats when they arise should be available throughout the world. Secondly, the specialized diagnostic reagents had to be available and the reference laboratories had to be able to make a definitive identification, not just of that initial strain, but of the hundreds of other strains evaluated. In this case, H5 reagents (the result of National Institutes of Health [NIH] research) had been distributed (by CDC) to reference laboratories internationally. The capacity to respond to potential outbreaks with expert epidemiologic investigation also had to be in place. The team that went to Hong Kong consisted of epidemiolo-gists, laboratorians, a public affairs specialist, and an expert in animal influenza. The team worked …