Dr. Claire Panosian Dunavan
Posted: 06/30/2010 07:15:04 PM PDT
Last month, roughly 2,000 people in several eastern states and Washington, D.C., got a nasty jolt when they opened their mail. All received letters urging immediate testing for the blood-borne virus Hepatitis B.
The reason? They were either patients or volunteers at a free dental fair now known to have spawned at least five Hepatitis B infections.
Of the first wave of victims, four had viruses with identical molecular fingerprints (thus implicating a common source); the fifth refused confirmatory testing.
This medical news story got me thinking about several things. No.1: The alphabet soup of hepatitis viruses that still befuddles many people. No2: the fact that - despite vaccination - the U.S. still has its share of Hepatitis B carriers. And, finally, the importance of meticulous protocols to prevent dental transmission of any blood-borne virus.
In a moment, I'll elaborate on all of the above. But first let me to step back in time.
In May 1999, I traveled to Asia to co-produce a medical film about Hepatitis B. At that time, more than 1 in 20 residents of the countries I visited were Hepatitis B carriers often infected at birth. Years later, as adults, the patients I interviewed - many of whom were still uninformed about Hepatitis B - were paying the ultimate price for their longtime invader.
Norma, a mother in Manila, noticed her stomach swelling. She thought she was pregnant again. Ong-Pin, a janitor in Hong Kong, turned yellow and lost weight.
Hyo-Jin, a student in Seoul, couldn't say when he became ill. He simply recalled that - at age 14 - surgeons operated on his liver, carving out a tumor the size and shape of a baby's fist.
Before my trip, I could cite numbers and facts. Worldwide, yearly deaths due to Hepatitis B were then 600,000 - placing the disease in the top 10 causes of death. One in four people who became chronically infected during childhood and one in seven who become chronically infected later in life died from cirrhosis or liver cancer. Among Asian-born men, hepatocellular carcinoma (hepatoma for short) was the second leading malignancy after lung cancer.
But, for me, it was people like Norma, Ong-Pin, and Hyo-Jin who put a human face on the ancient virus that some people clear and others carry like a ticking bomb to their grave.
OK, now let's return to that fateful West Virginia dental clinic, circa 2009. Did its organizers ever dream that their well-intentioned outreach might propagate Hepatitis B? I doubt it.
After all, the U.S. was one of the lucky ones. Yes, during the 1970s, we saw plenty of Hepatitis B contracted from dirty needles, tainted blood, unprotected sex and the like, but overall our disease burden was low compared to most other countries. Then came the Hepatitis B vaccine. With its uptake, U.S. rates dropped even further in children and younger adults.
But not in everyone.
As reported in the upcoming July 15 issue of the Journal of Infectious Diseases, over the past two decades, the burden of Hepatitis B hasn't budged in Americans over 50, especially foreign-born.
The current estimated reservoir of chronically infected? 730,000.
To be honest, within our borders, Hepatitis B has long been overshadowed by Hepatitis C, another blood-borne virus which afflicts fewer people worldwide but currently numbers an estimated 3.2 million U.S. victims. Hepatitis C (for which we have no vaccine) is now the leading cause of liver transplantation in this country.
Hepatitis A, on the other hand, is a ubiquitous global virus which causes serious, but self-limited, illness. Like many doctors of my generation, I still remember giving hefty gamma globulin shots to protect overseas travelers against Hepatitis A. Since the 1990s, however, a true Hepatitis A vaccine has largely replaced gamma globulin.
Ready for two more?
Hepatitis D is an incomplete blood-borne virus which survives by hitching a ride on Hepatitis B. Hepatitis E on the other hand, like Hepatitis A, is fecal-oral in its transmission. Large outbreaks usually occur when sewage contaminates drinking water following floods or monsoons, but sporadic cases have also been seen in U.S. travelers.
So that completes the hepatitis primer. As for dodging dental transmission, surprise, surprise: it all comes down to office practice. Clean gloves, autoclaved instruments, and proper handling of blood- and saliva-tinged objects are key aspects easily observed by patients.
If dental office hygiene doesn't meet your standards, move on. After all, you never know what blood-borne and other viruses might be lurking in the person who previously warmed your padded chaise. In some cases, sad to say, your predecessor and your dentist might not know either.
Dr. Claire Panosian Dunavan is an infectious disease specialist and a professor of medicine at the David Geffen School of Medicine at UCLA and a resident of Pasadena. She can be reached at drclaired@earthlink.net
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