numerous pathogenic organisms in our environment no doubt and
some are more prolific and are noteworthy enough to be placed
on the evening news and be famed as the scourge of mankind, and
rightly so. However there is one small, seemingly insignificant
organism that crops up from time to time and captures the attention
of the public. It occurs during the summer months from June through
September when temperatures exceed 80°F. Although kept in
the shadows, this organism's claim to fame is Primary Amebic
Meningoencephalitis, or PAM for short. PAM is an infectious
disease caused by a small, thermophilic, freshwater amoeba known
as Naegleria fowleri, which occurs naturally in our environment.
known about N. fowleri but quite a bit is known about the
infection that it causes. The infection is acquired by having
the amoeba introduced, forcefully, into the nasal passage. This
is accomplished by diving into contaminated warm, natural bodies
of freshwater. There have been a few reported cases of PAM having
been documented without freshwater activity but little or no information
on these particular cases is available. Once inside the nasal
passage the amoeba, N. fowleri, invades the Central Nervous
System infecting the brain of the host causing severe hemorrhaging
and swelling of the brain leading to the death of the host.
So, who is
at risk for infection from N. fowleri? The risks of encountering
N. fowleri are high, while the risk of being infected is
low. PAM is a rare infection. It seems that young males are the
most susceptible with very few cases reported in females. However,
this could be due to the fact that young males are more aggressive
in freshwater related activities than females. There has been
no evidence of any sexual preference as related to the host. Those
with compromised immune systems are highly susceptible to the
are the symptoms of infection and what can be done? The symptoms
of PAM usually occur in less than a week. They are as follows:
- Stiff neck
- Coma and
Most of those
who are infected with N. fowleri die within 72 hrs. There
is no evidence of the infection being spread from person to person
nor is there evidence of self-infection due to the culturing and
handling of N. fowleri. For those who may be considering
culturing this amoeba, it is strongly recommended that they be
very familiar with the Material Safety Data Sheets (MSDS) for
the storage and handling of Biological Safety Level 2 organisms.
a N. fowleri infection is very slim, it is considered to
be 100% fatal, however there have been five reported cases of
the host surviving. Aggressive treatment is given using Amphotericin
B and Micronozale and other drugs or antibiotics but time is of
the greatest importance in treating the infection. At the onset
of symptoms, it has been recommended that the individual consult
a physician immediately and, if having been involved in freshwater
activities such as swimming and diving in warm freshwaters, the
physician should be notified of such activities.
fowleri can be quite prolific during the hot summer months
and can be found in such places as the shallow areas of lakes,
slow moving streams and rivers, ponds, and poorly treated swimming
pools and spas. Children's small backyard pools, the kind used
to splash around in, should not be left standing more than a day,
since they can heat rapidly. PAM infections are not uncommon in
the United States.
previously, Primary Amoebic Meningoencephalitis is a rare infection
and is something to be aware of during the summer months but not
to be alarmed over. There have been only about 300 cases of PAM
reported worldwide. For more information on PAM and Naegleria
consult your local health department or contact the Center for
Disease Control (CDC).
At this time
I would like to recognize my resources of information concerning
PAM and N. fowleri:
of Laboratory Security, Health Canada
fowleri: A New Hazard to Recreational Swimmers.
Kelly A. Reynolds, Ph. D. Source: Dept. of Human Services, Public
Health Division, Gov. of Victoria, Australia.
for Disease Control, United States of America (www.dpd.cdc.gov
Meningoencephalitis, Robert W. Tolan, Jr, MD, Chief of Pediatric
Infectious Diseases, Medical Director of the Pediatric Emergency
and Hospitalist Programs, Capital Health System; Clinical Associate
Professor of Pediatrics, Drexel University College of Medicine.
is a retired U.S. Navy, Petty Officer. He now calls Western North
Carolina home, the city of Rutherfordton, after 21 yrs. of naval
service. Although his new home has not a "flight deck"
or aircraft landing overhead while he is trying to sleep, he is
coping fine. His interests lie in the study of Nature and Microorganisms,
chiefly Protozoa and as an amateur, is currently researching infectious
diseases associated with Protozoa. Leisure activities include
fly tying and fly fishing for trout in the mountain streams of
Western North Carolina and wilderness hiking.