No - See - Ums

Lurking on the beaches of many favorite dive resorts is a disease that can do more than ruin your vacation. It’s a disease that can haunt you months after you return home, and even, in the words of one subscriber, “seriously ruin your life.” Though it’s not as widely known as malaria, it can be every bit as painful, tenacious, and dangerous, as some of your fellow Undercurrent readers have told us. Worse yet, the source of the infection is nearly invisible — the ubiquitous no-see-um.

Like most divers, when Undercurrent reader Barry Lipman (Brookfield CT) and his wife, Dr. Ingrid Pruss, ventured to Guanaja a couple years ago, they expected a fun-filled week of diving and relaxing on the beach. Instead, they found Guanaja’s no-see-ums an allnight, all-day plague. No-see-ums ruined a lunch-time beach picnic where Lipman received several hundred bites and finally evacuated to the water to escape the pests. That night he developed a 102° fever and discovered that he was covered with little itching bumps. A six-day course of prednisone alleviated his symptoms and allowed him to continue diving, but other guests were not as lucky. One young girl developed a 105° fever after spending the day as a no-seeum smorgasbord. But generally, given that the voraciousness of Honduras’ hordes of no-see-ums is infamous, the Lipmans tried to take it in stride. Once they got home, they figured their problems with no-see-ums would be over.

They were wrong. About four months after they returned, Pruss developed small, reddish blemishes on her face at exactly the locations of some of the no-seeum bites. They consulted a dermatologist and mentioned the recent assault by no-see-ums in Honduras. He listened and made a diagnosis: cystic acne. The blemishes grew into ulcerated lesions. It took a trip to Curaçao and visits to specialists there before the Lipmans got an accurate diagnosis. Ingrid Pruss had leishmaniasis.

If you’ve never heard of leishmaniasis, you’re hardly alone. Neither had the Lipmans, but they were quick studies. They learned that the culprits were indeed what are commonly referred to as no-see-ums, minute insects of the genuses Phlebotomus or Lutzomya also often called “sand fleas” or, in the medical literature, “sand flies.” Like mosquitoes, gestating female nosee- ums hungry for protein search for a “blood meal,” and in the process transmit one of the twenty-plus species of protozoan parasites responsible for the disease. Lipman says he also was told that the fever and rash he developed in Honduras the night after receiving hundreds of nosee- um bites were not the result of leishmaniasis but a reaction to the toxins he received from the bites themselves, and that “multiple nosee- um bites can cause death by kidney failure from their toxins alone, without any other infectious agent involved.”

While leishmaniasis affects 12 million people in 88 countries (with 2.5 million new infections annually), most of the high-risk areas are not dive destinations. However, leishmania is now well-entrenched in Honduras, Belize, and other areas in Central America and appears to be spreading to islands in the Caribbean, including Hispaniola and Trinidad. Old World strongholds include Thailand and Egypt. It is considered a dynamic disease whose range is spreading, and it garnered some attention in the U.S. in recent years when several Gulf War vets brought it back as a souvenir of Operation Desert Storm.

In its cutaneous form, leishmaniasis is characterized by a skin sore or sores that develop weeks or months after transmission. Sores typically leave scars, and some forms can be severely disfiguring. Though Pruss says chemotherapy has gotten her leishmaniasis itself under control, the lesions they left behind are another story. One sore refused to heal, and after the tissue became ischemic due to restricted blood circulation, she required hyperbaric chamber treatment to close the wound. She says she is currently “having a hard time finding a plastic surgeon who will be willing to repair the disfigurement of the wound since...they worry about any potential of reactivating the disease.”

Visceral leishmaniasis, traditionally known as kala-azar (Hindi for “black sickness” because of victims’ darkening skin), may take months and even years to develop and is fatal if untreated. Symptoms include fever, weight loss, cough, diarrhea, lethargy, enlargement of the spleen and liver, and anemia. Both forms require a biopsy for diagnosis.

Though leishmaniasis accounts for less than 5% of the tropical infections American travelers return with each year, unless the victim consults a physician specializing in tropical medicine, diagnosis is often inaccurate. The disease itself is difficult to cure and victims are prone to recurrences. For decades antimony (sodium stibogluconate) has been considered the most effective treatment, but the three-week intravenous regimen is toxic in itself, and the parasite is reportedly becoming antimony-resistant in some areas. Other treatments are available, but no cure is 100% effective, and there are currently no preventative medications or vaccines. (A vaccine is being tested, but, since it involves infecting patients with a minute quantity of live protozoa, there is some concern that patients might contract the disease through vaccination.) Pruss tried several treatments before her infection was brought under control, and there is no guarantee that it will not recur.

With no certain cure, an ounce of prevention is definitely the key. No-see-um infestations tend to be cyclic, and the bugs are usually more of a problem at night and when the wind dies down on the beach. The first line of defense is generally dousing yourself with insect repellents containing DEET, although some divers report success with Avon’s Skin-So-Soft or cactus juice. If possible, longsleeved shirts, long pants, and socks should be worn. Reader Mike de la Chapelle (Bellevue WA) describes guests’ efforts to avoid bites during a sand-flea-invested trip to Belize’s Jaguar Reef Lodge: “After the first night of carnage, we quickly learned how to survive.... It was hilarious to see guests show up for meals either wrapped up like mummies or glistening with a thick coat of DEET.” Impregnating clothing and fine-mesh screens and bed nets with permethrin will provide added protection. (Items should be sprayed and allowed to dry before use.) Aerosol insecticides can also be used in rooms to clear them of pests. Concerned travelers who know that no-see-ums “love them” should either take more aggressive steps, including using DEET, or try a live-aboard trip, thus bypassing no-see-ums altogether. If you develop persistent sores you fear may be indicative of leishmaniasis, ask for a referral to a tropical medicine specialist or contact the Center for Disease Control (www.cdc.gov), which can help clinicians with biopsies and cultures as well as recommending and furnishing medication.

While the odds of bringing home leishmaniasis as a dive trip souvenir are probably too small to allow leishmania to influence dive travel plans, the consequences of infection are unpleasant enough that it only makes sense to take aggressive steps to avoid becoming the main course for a hoard of hungry no-see-ums.

— J. Q.