How many dentists can recognize a potential infectious epidemic? This may become a critical issue in the very near future.
"Whether naturally occurring or intentionally inflicted, microbial agents can cause illness, disability, and death in individuals while disrupting entire populations, economies, and governments. In the highly interconnected and readily traversed ‘global village’ of our time, one nation’s problem soon becomes every nation’s problem as geographical and political boundaries offer trivial impediments to such threats."1
This statement, a quote from a 2003 Institute of Medicine report, elegantly captures the essence of the threat posed by emerging, re-emerging or persistent infectious diseases.1 It noticeably contrasts with the proclamation made by 1965–1969 U.S. Surgeon General William H. Stewart, who, in 1967, declared that the war against infectious diseases had been won. Almost 40 years later, it is clear that his announcement was both erroneous and premature. Moreover, his affirmation of victory over infectious microbes probably never will be realized. Unfortunately, his confident optimism resulted in reduced funding and, as a consequence, less available financial support for, and significant decline in, scientific pursuit in the areas of research, treatment and prevention of infectious diseases. Furthermore, in the ensuing years, the public health infrastructure suffered dramatic cutbacks—funds that today are necessary to combat emerging and re-emerging diseases.
Oral health care providers have always been lauded for being in the forefront with regard to following and implementing infection control protocols, and providing care for patients with infectious diseases. However, how many dentists can recognize a potential infectious epidemic or be able to discuss and address concerns held by staff members and patients? This may become a critical issue in the very near future.
In the past 30 years, more than 40 viral infections have been diagnosed among the human population in the United States. These and other viruses have infected people in other places in the world. Some, such as the Ebola virus, are associated with a high mortality rate but rarely are encountered in humans outside specific geographic areas. Others, such as the hepatitis C virus, have infected millions of people worldwide, including approximately 1.5 percent of all Americans, but are associated with a less dramatic course.
Most emerging diseases are zoonotic in nature: they are found initially in animals and, through various modes of transmission and genetic transformations, infect and cause disease in humans. A zoonotically transmitted virus that initially attracted a lot of attention in the lay press still is causing a great deal of suffering, but it no longer is the "disease of the day" and has mostly disappeared from the front pages. Yet, this mosquito-borne virus, the West Nile virus, has in the past five years spread across the country from its original U.S. port of entry, New York City, to California and the western parts of Canada. In 2004 alone, there were 2,470 reported cases of West Nile virus infection and 88 related deaths in the United States.
Other infections, such as HIV disease, still are causing great concern. This viral infection first was brought to our attention in 1981 and has since ravaged the world, infecting more than 60 million people, including almost 1.5 million Americans. In its wake, social advances and economic growth, as well as hard-fought improvements in public health, have crumbled. This pandemic still endures almost unabated, with almost one new infection every six seconds.
A more recent example of an emerging disease is severe acute respiratory syndrome (SARS). This viral infection first was recognized in Hong Kong in the fall of 2002 and spread quickly to other countries. In an unprecedented demonstration of rapid international collaboration among public health officials, healthcare providers and researchers, transmission patterns were detected, the pathogen was identified and its entire genome was mapped. These efforts probably prevented a global pandemic. As of July 2003, 8,098 cases had been observed, with 774 fatalities. Sixty-three cases—without any deaths—were reported in the United States.
The most recent threat to global health is a potential influenza pandemic. An estimated 10 to 20 percent of U.S. residents become infected with influenza, and despite availability of vaccine for the most vulnerable populations, up to 36,000 deaths are attributed annually to this disease. The natural reservoirs of influenza A viruses are aquatic birds. However, periodical transmissions of avian influenza to other mammals and species have resulted in permanent lineages of this virus in domestic poultry, pigs, horses and humans. The passage of avian viruses through pigs is one route for human infections, but transmission directly from chickens is more common.
In 1997, the H5N1 influenza A virus was discovered in humans in Hong Kong. To stop the spread of this lethal virus, all poultry in Hong Kong were slaughtered. However, the virus continued to spread among wild birds and has again infected humans. It is assumed that human-to-human transmission also is occurring. To date, 55 human cases resulting in 42 deaths have been reported from Thailand and Vietnam. Some experts believe that if the emergent H5N1 influenza takes hold among the human population, it will put the 1918 flu pandemic to shame. The "Spanish flu" in 1918 is thought to have killed between 20 and 40 million people. H5N1 could be five times as devastating. The 1918 pandemic had a mortality rate of 2.5 percent. At present, the mortality rate of diagnosed H5N1 cases is approximately 75 percent. In this time of recent natural disasters in southeast Asia, the ability to impose strict health control measures is severely hampered by the breakdown of established public health measures.
Vigilance and establishment of different surveillance practices will be one important answer to curtail and limit the spread of these types of emerging infectious diseases. Dental care providers treat a broad range of adult, pediatric, elderly, healthy and impaired populations. As health care providers, we have a responsibility to protect the public. Maybe the time has come for dental health care providers to partake in the multidisciplinary task of disease tracking and reporting. With proper training, we would be able to shoulder a more active role in the discovery and containment of the next infectious pandemic. I believe our involvement would have a substantial impact and greatly benefit the health of all patients.
