If divers travel abroad the risk of
malaria is a factor that should be
considered. While a few cases
appear in Central America, the
highest risk occurs in Africa, Asia
and the South Pacific where strains
have become resistant to common
preventatives like Chloroquine. In
these areas, the current substitute
is Lariam (mefloquine). If you
have followed any of our past
articles on malaria you know that
we’ve been less than pleased with
Lariam and its side effects. New
hope may be on the horizon.
A vaccine is under study by
Navy researchers. It consists of
purified genes, known as “naked
DNA,” which are injected directly
into muscle tissue. The tissue
absorbs a small amount of the DNA
and follows its instructions to
manufacture a small amount of the
protein specified by the malaria
gene. The presence of the malarial
protein, in turn, stimulates a strong
immune response in the patient
without risk of contracting the
disease itself. Navy researchers plan
to publish their study on the new
vaccine soon, but it must still
undergo massive testing before it
becomes publicly available.
Another new drug, however, is
already licensed in the United
Kingdom and may be available in
the U.S. sometime next year. The
new drug, called Malarone, is
apparently more effective than
Lariam, to which several strains of
falciparum malaria are becoming
increasingly resistant. Doctors in the
U.K. report a 98% cure rate with
Malarone, which contains two
separate compounds, proguanil and
atovaquone, each of which targets a
different stage in the protozoa’s
reproductive cycle within human
red blood cells.
Malarone, manufactured in the
U.K. by Glaxo Wellcome, has only mild
and transitory side effects and does not
cause the side effects of Lariam , which
include dizziness, insomnia, disturbing
dreams, nausea, and, in rare cases,
neuropsychological problems. It’s also
taken once a day, which is easier to
remember than Lariam’s once-a-week
dosing, and it can be stopped seven
days after departure, much sooner
than the two-to-four week post-travel
treatment Lariam now requires.
Of course, scientists have
imagined that they had the upper
hand against malaria before, most
notably when widespread DDT
usage in the 50s and 60s made the
battle seem almost over. Both
Anopheles mosquitoes and the
Plasmodia protozoa have proven
extremely resistant and adaptive.
This time, however, the parasite may
have to change the protein codes in
its DNA.
— John Q. Trigger