A New Malaria Drug

In countries we visit to dive -- the Solomons, Papua New Guinea, even Belize and Honduras -- we’re at risk for malaria. Of roughly 7,000,000 Americans traveling to regions with malaria, about 1,000 get infected. On the other hand, more than 1,000,000 people a year die of malaria, largely because they can’t afford a prophylaxis.

The malaria parasite, carried by an Anopheles mosquito, has gradually grown immune to the basic treatment, chloroquine, requiring other drugs to be developed. The latest was mefloquine (sold as Larium), but in some divers, its side effects has mimicked the bends, leading to evacuations and treatment that proved to be unnecessary.

In July, the US Food and Drug Administration approved a new antimalarial drug, Malarone, manufactured by Glaxo Wellcome. A combination of the antimalarial agents atovaquone and proguanil, Malarone has been available overseas, but the typically conservative FDA waited for 12 clinical trials. In the most recent, only two of 279 people in Africa who used Malarone for three months contracted malaria, compared to 92 out of 297 who took a placebo. Malarone’s side effects, which appeared in about 10 percent of people, included vomiting, abdominal pain and headaches.

One begins taking Malarone two days before entering a malarial region, continues daily, and stops seven days after departure. Should malaria set in, one should take four tablets in single doses daily for three days. It is available only by prescription.

So, now that we’re better protected against malaria, what about being better protected against those annoying bites? The sand flies of the Bahamas and the no-see-ums of Honduras, just to name a couple of destinations, constantly destroy the vacations of unprotected divers. In fact, as we reported in January 2000, sand fly bites can inflict leishmaniasis, a particularly nasty disease, as more than one Undercurrent reader has reported.

Reader Aurora Pan (Castro Valley, CA) reported on a July trip to Lighthouse Reef Resort in Belize: “Wish we’d known about the no-see-ums and that nothing deters them. We experienced a lightning strike on the atoll and with the shut down of the air conditioner, the no-see-ums were unbearable. Nothing deterred them. For some of us, nothing alleviated the resultant itching. Unfortunately, the dining room at Lighthouse Reef is open to the elements and on those days when the wind doesn’t blow, it’s open season for the bugs.”

So, what’s the best protection? Consumer Reports recently tested 13 bug repellants, most of which rely on 7 to 100 percent of N,N-diethylmeta- toluamide, called Deet. Deet’s vapors discourage bugs from landing. Generally, the higher the percentage of Deet, the longer it lasts.

CR’s tests pitted the repellents against three species of mosquitoes —including the Anopheles — exposing the arms of human testers to 200 mosquitoes. Researchers counted the number of bugs that bit during three minutes, then exposed the testers every half hour until at least one mosquito bit during two successive exposures. Interestingly, the Anopheles bit no matter what repellent they used — a reason not to rely on repellent alone in malaria infested areas.

The two most effective repellents were Amway HourGuardl2, a cream that’s 33 percent Deet, and Off Deep Woods for Sportsmen, a pump spray that’s 100 percent Deet. They kept mosquitoes from biting for 11-12 hours.

Amway Hour Guard 12 is no longer available; it is now sold as 3M Ultrathon by Travel Medicine (you can order by phone: 800-872- 8633, or on the web; www.ultrathon.com). The 3M formulation has been the standard repellent of the U.S. armed forces for more than a decade.

BugOut, an aerosol with 15 percent Deet, worked for at least 4 hours against mosquitoes. Avon Skin So Soft Bugout Plus, a product with something called IR3535, protected against mosquitoes for 0 to 2 hours.

CR also tested several products that use plant oils instead of Deet. While Natrapel did little to protect the testers, Skin So Soft with citronella did nothing: mosquitoes bit their arms at the earliest opportunity. Bite Blocker contains soybean, coconut and geranium oils; the soybean oil of Bite Blocker offered protection for 1 to 4 hours.

My own experience is that Skin So Soft works for people who would not normally attract mosquitoes anyhow. For guys like me, who they love, it’s useless. Still, many people don’t use Deet products because they fear it’s unsafe. But the Environmental Protection Administration doesn’t think so. After a comprehensive assessment in 1998, they concluded that “as long as consumers follow label directions and take proper precautions, insect repellents containing Deet do not present a health concern.”

Finally, if you want to wrap yourself in clothes and get real protection consider permanone, a synthetic version of an insecticide derived from chrysanthemums. It actually kills mosquitoes. You spray it on your clothes and it lasts through at least one laundering, perhaps as long as two weeks.

CR found that the spray Repel Permanone, with .5 percent permanone, kept mosquitoes at bay for 24 hours. A 6-ounce can of Repel Permanone, priced at $5.50, is enough to treat two sets of clothes. It’s available in most outdoor stores.

So, the upshot is if you’re headed to malaria country, get a prescription for Malarone. Don’t rely on Deet to protect you. If you’re headed to bughavens like Honduras, Belize, or the Bahamas, don’t rely on Skin So Soft to protect you. Deet’s the man.

PS: The International Association of Medical Assistance to Travelers annually publishes a world malaria risk chart loaded with information about at-risk countries. It also produces other material, including a world immunization chart indicating recommended immunizations for any country in the world, and a country by country list of English speaking doctors. While they’ll send you information for free, they survive by donations so send them a few bucks. IAMATA, 417 Center St., Lewiston NY 14092-3633.

-Ben Davison