Last night I watched a Scientific American TV program with
Alan Alda retracing Charles Darwin”s steps in the Galapagos
Islands. In Kansas, a creationist governmental body wants to
outlaw teaching evolution in the schools. In contrast, the
Governor of Minnesota calls organized religion a sham that
serves as a crutch for the weak-minded and wants to come back
as a bra! In a more recent TV interview, he says that being
weak-minded isn”t that bad! I won”t touch Jesse”s remarks; he”s
just too big for me! However, I will respond to the wishes of one
of my readers to talk about evolution; actually, about one of
today”s major evolutionary challenges which threatens mankind.
The challenge is the rapid evolution taking place in the world of
bacteria and viruses harmful to Homo sapiens. We”re all familiar
with AIDS and the ability of the HIV virus to evolve in response
to different drug treatments. In our area of New Jersey, we”ve
had family members with Lyme disease, which may not be an
evolving bug but one that”s been around for a long time. Now,
however, today”s frost is welcomed in many areas of New York,
New Jersey and Connecticut because it kills mosquitoes carrying
the new West Nile-like encephalitis. Just this morning I heard
that DNA studies have shown that this is a form of encephalitis
never been seen before. When my wife had surgery recently, I
was more confident in the outcome of the surgery in the hands of
a capable surgeon than I was that she would not pick up a drug-
resistant staph infection. These “superbugs” are demonstrating
evolution in a devastating fashion.
What really caught my attention was last week”s “60 Minutes”
segment on the evolution of drug-resistant forms of tuberculosis.
For those who missed the episode, it focused on the situation in
Russian prisons, notably in Siberia. Drug-resistant TB (DR-TB)
is running rampant in these prisons. One case cited was a prison
of 230 inmates, all of whom had DR-TB! Last year, some
20,000 prisoners contracted DR-TB and those who were released
after serving their terms infected some 15,000 Russian civilians.
To make matters worse, TB bacteria can be airborne and infect
you even after only casual contact with someone carrying the
disease. You may think, “Oh well, the problem is in Russia and
doesn”t concern me.” Hey, if you”ve followed these columns, you
know that I just came back from St. Petersburg in June. What”s
more, thousands of your fellow countrymen (or women) visit
Russia on cruise ships and other tours every week. Chances are
pretty good that you”ve been within a few yards of one of these
intrepid travelers yourself recently if you get out much.
Steve Croft interviewed Dr. Lee Reichman on the “60 Minutes”
show. Dr. Reichman is executive director of the New Jersey
Medical School National TB Center and lectures at the
University of Medicine and Dentistry of New Jersey (UMDNJ)
to visiting Russian physicians on the epidemiology and treatment
of TB. A big problem is that the proper treatment of DR-TB is
not simple and is not known to most physicians who encounter
TB patients. I”m an adjunct associate professor in the department
of surgery at UMDNJ-Robert Wood Johnson Medical School
and some of the information conveyed herein is from an article in
the Fall 1999 issue of the UMDNJ publication “Health State”.
Incidentally, just because I”m in the department of surgery, don”t
ask me to assist in your hernia operation. I”d faint dead away at
the first cut!
Back to DR-TB, why is it such a worrisome problem? In the
1950s, antibiotic therapy was shown to cure TB and it virtually
ceased to be a significant problem in the developed nations.
Then, the HIV virus made its appearance and, with lowered
immunities and increased immigration from the less-developed
countries, fueled a new wave of TB. Human nature began to
play an important role. How many times have you been
prescribed a certain medicine and told to take it until you”ve used
up all the pills in the bottle? Or, maybe the doctor failed to tell
you? Have you ever felt much better after a few days and
stopped taking the pills? If so, shame on you! You may have
unknowingly contributed to the development of a drug-resistant
strain of virus or bacterium. The reason is that, by stopping the
treatment early, the bacteria or viruses that remain behind are the
forms more resistant to the medication. They normally are
present in relatively small numbers, but thanks to your
negligence, are now the dominant species in your body. This
doesn”t even consider mutations of the normal viruses or bacteria
that might evolve to resist the drug. Sorry to beat up on you like
this, but I now take all the medication prescribed, regardless of
how I feel. However, I admit that in the past I may have done
my share to advance the cause of those superbugs.
Not only can a bacteria be resistant to one drug, but also the real
problem now is the multiple drug-resistant TB (MDR-TB)
bacteria. For the run-of-the-mill DR-TB victim, treatment is
initiated that involves a mix of the four drugs isoniazid, rifampin,
pyrazimide and ethambutol. After two months the latter two
drugs are dropped but the isoniazid and rifampin must be
continued for 4 more months. The exact treatment will depend
on tests that may reveal certain drugs are ineffective against the
specific bacteria.
Unfortunately, the patient may feel much better after a few
weeks and the side effects of taking the 10-12 pills daily may
seem worse than the TB. Result – they stop taking the drugs.
This results in even “smarter” TB bacteria resistant to the
standard drugs. Now more toxic and more expensive drugs are
needed and the time for a cure may run up to two years, not 6
months! Furthermore, surgery may be necessary and the cost of
treating one MDR-TB patient may be about $250,000, with a
fatality rate that may be as high as 45%! It doesn”t take a
mathematical genius to figure out that the cost to solve the
Russian MDR-TB problem will be huge! That laundered
Russian money we hear about needs to be re-laundered back to
Russia! Actually, the financial giant and philanthropist George
Soros has been donating millions to help address the Russian TB
dilemma.
How are we doing in the USA? House calls, that old-fashioned
concept, seem to be one answer. Designated by a fancier term,
Directly Observed Therapy (DOT), outreach workers are
assigned to visit each infected person every single day and watch
the patient take his or her medicine. DOT was instituted in the
1970s for uncooperative patients and today there are less than
500 cases of MDR-TB in the USA, or about 2% of the total
number of TB cases. All this is cause for a bit of celebration, but
the cost of such labor-intensive programs is not cheap. Also,
immigrants remain a continuing source of infection. Of the TB
cases in this country, 40% are brought in by immigrants, who
must have X-rays showing they are free of TB to enter the
country. However, many immigrants apparently buy “clean” X-
rays or bring X-rays of friends or relatives free of the disease.
The success of the TB bacterium is in large measure due to the
complexity of its cell wall and the fact that it divides very slowly,
once a day, compared to the familiar E. coli at 3 times an hour.
When the TB bacterium enters the lung, a dutiful macrophage
engulfs it, as it would other bad guys, but thanks to the
bacterium”s resistant cell wall, the macrophage can”t penetrate
and kill the invader. Instead the TB bacterium just sits there
inside the macrophage cocoon and in about 90% of the cases
nothing ever happens. In the other 10%, the susceptible
individuals may come down with the disease within weeks or
months; the rest may not show signs of TB until much later in
their lives. There is a lot of research going on to try to figure out
how to penetrate the cell wall and to develop tests that can
determine quickly which drugs will be effective for a given form
of the TB bacterium. A more detailed technical article on this
subject can be found in the May 17th issue of Chemical &
Engineering News.
As I was writing this piece, it occurred to me why I was drawn so
strongly to the “60 Minutes” story. I owe my very existence to
TB! When my father was young, living in the Pennsylvania
Dutch country around Allentown, Pennsylvania, he developed
what his parents thought was TB. In those early days of the 20th
century, you either went to a sanatorium or you moved out West
for the cleaner, drier air. My grandparents moved to Denver,
where my Dad eventually met and married my mother, who had
moved to Denver from Princess Anne, Maryland. So, without
the TB, you wouldn”t be reading this column today. OK, you
probably wish you hadn”t!
However, after this somewhat depressing piece, Brian Trumbore
has instructed me to write next week about a happier subject,
baseball!
Allen F. Bortrum
