Portal de Periódicos da CAPES

Practical Lessons From a Family Sojourn to Equatorial South America

2001; Lippincott Williams & Wilkins; Volume: 10; Issue: 6 Linguagem: Inglês

10.1097/00019048-200108000-00003

1536-9943

Gonzalo Ballon-Landa,

Malaria Research and Control

I AM OFTEN LULLED into daydreaming by the itineraries for which the patients in my traveler’s clinic prepare, so it was with great pleasure and anticipation that I began to plan a 4-week trip through equatorial South America with family and friends. This continent is full of beautiful history, colonial cities, ruins, cultures, and jungles, and judging from the volume of travelers we see who go there, it holds a special appeal. Many of the travelers are physicians, and it is for their benefit and aid in planning a similar trip that the experiences gained in this sojourn are recounted. Preparations Our group comprised 16 San Diegans from five families, including five teenagers and 11 adults. Part of the time we planned to visit friends or family, which means we would be at a higher risk of acquiring enteric illnesses. This trip would be a “comfortable adventure,” which included visiting both popular and remote tourist attractions, with the aid of local tour operators. We did not backpack, camp, or trek; moreover, being “city slickers,” we made reservations through a Peruvian travel agency and stayed in excellent, first-class hotels. The trip included vibrant metropolises like Lima and Sao Paulo, colonial cities such as Arequipa, La Paz, the former Inca capital, Cuzco, the port city of Puno on Lake Titicaca, and the once world rubber export center city in the Amazon basin, Manaus, Brazil (Fig. 1). One is not at risk of tropical diseases in these cities (except in Manaus), only traveler’s diarrhea. In the immediate jungle surroundings of Manaus, however, there is chloroquine-resistant falciparum malaria and dengue fever, which is most prevalent in the rainy season, from November through April.FIGURE 1.: Points in the itinerary.The weather and activities in South America were as varied as the clothes we needed: from light trekking clothes and shorts to tuxedos, dresses, and winter coats. We froze and sweltered, hiked and ballroom danced. Available at adventure stores are shirts, trousers, shorts, and other paraphernalia made of lightweight, high-tech, fast-drying material, which we found comfortable and practical in the jungle cruise. They were easy to wash in the river (sometimes we washed them as we swam in them) and dried in an hour when we hung them on the boat deck. The night temperatures in the Amazon averaged about 85°F, but 35°F was expected in Lake Titicaca, which is the highest navigable lake in the world. The group had to think about preventing altitude sickness as well, considering that we landed at the following high altitude airports: Arequipa (7250 ft.), Cuzco (10,400 ft.), Juliaca (12,600 ft.), and La Paz (13,000 ft.). To allow our bodies to acclimatize to the heights and minimize the risk of altitude sickness or “soroche” in local parlance, we flew into these airports in just that order [1]. Only one person took acetazolamide (Diamox®) prophylactically, and besides a minimal headache that resolved with aspirin or locally acquired “soroche pills” (aspirin 160 mg, salofene 160 mg, and caffeine 15 mg) and the awareness that one gets more dyspneic walking upstairs at 10,000 ft., we experienced no untoward effects. The usual recommendation for Diamox is 500 mg tid starting 2 days before arrival at a high altitude. The planned gradual ascent brought the group first to Arequipa, at 7250 ft. This colonial city is built of white lava stone from its three surrounding majestic volcanoes and has excellent hotels, attractions, and facilities. A one-night excursion from this city to the Colca Valley (10,400 ft.) affords one the opportunity to see Andean condors in the wild soaring in one of the deepest canyons in the world. Back from Arequipa, we flew to Cuzco, from which trips to Macchu-Picchu, Pisac, and Urubamba were taken. The next leg of the trip was to Lake Titicaca (12,600 ft.), served by the Juliaca airport and the port city of Puno. The extraordinary sunrise over the water viewed from a promontory outside the Hotel Isla Estevez in this city was one of the unexpected highlights of this trip. Outside the relative safety of the cities, the group visited Macchu Picchu (the lost city of the Incas, discovered by Hiram Bingham in 1918), the Sacred Valley of the Incas, and the market of Pisac (valley of the Urubamba River), Lake Titicaca and environs, the magical Colca Valley, the ruins of Tiahuanacu, and an 8-day Amazon River boat adventure. This double-decked, shallow-keeled boat measuring some 80 ft. in length was the property of a renowned Amazon guide and captain who was a friend of one of the members of the excursion. Our temporary home came complete with a brazil-wood-paneled dining room, comfortable cabins with private, if small, baths for 16 people and eight staff, including the captain-owner. After the itinerary was set and the possible microbial threats in the trip were identified, the strategies to avoid illness were developed: vaccines, chemoprophylaxis, other preventive measures and treatment (Table 1).TABLE 1: Medical preparations for a trip to equatorial South AmericaThe only area in the itinerary possessing a risk of yellow fever was outside Manaus, Brazil. There is no risk in Macchu Picchu, Cuzco, Colca, or Lake Titicaca, which are up in the Andes, or in any of the cities. Although spottily and unpredictably enforced, South American countries require a yellow fever vaccine certificate from any tourist who has visited a country where this disease exists; therefore, when entering Bolivia, Ecuador, or Brazil from Peru, one has to show it. The reader is well advised to receive the needed vaccines at home, for, as a student in 1970, once lacking a certificate of smallpox vaccination necessary for entry into Peru, I had to be inoculated right there by a medic at the Lima airport! Beware, however, that Brazil, which actually requires Americans to have a tourist visa (costing $45.00) secured in the United States, will not issue the visa to tourists planning a stay in Peru without proof of vaccination. For those not able to go to the consulate, there is a courier service available. Food-Borne Illnesses The prevention of diarrhea rests primarily on choosing food wisely and avoiding contaminated water and ice. Everyone received instructions and pamphlets regarding these precautions [2]. Soon after arrival, it became apparent that keeping the dietary restraints in the real world is very difficult for travelers [3]. One of Peru’s typical dishes is ceviche, raw fish “cooked” in lime juice, usually accompanied by lettuce. One of the teenagers fell prey to this delicacy’s temptation and subsequently developed diarrhea and nausea, despite taking bismuth subsalicylate prophylaxis recommended by his physician father (this author does not subscribe to this recommendation). He was treated with ciprofloxacin and recovered quickly. A 5-day supply of this quinolone had been given to all travelers to have on hand for self-treatment of moderate-to-severe diarrhea. Instructions were included in the pamphlet. Because of warnings about the use of quinolones for children in the Physicians Desk Reference, these drugs are not routinely recommended for children. However, there is growing evidence, consensus, and experience [4] with ciprofloxacin, and many pediatric infectious diseases doctors recommend this for traveler’s diarrhea. The parents of the teenagers on the trip were given an explanation of the risk and benefit, and they accepted it. There was an outbreak of diarrhea in the group, which occurred in Brazil after a special feast with fish barbeque prepared and eaten on a beach on the Rio Negro. It has been a personal observation that it is after these family feasts that many outbreaks of diarrhea occur, presumably because of the breakdown in the usual careful mode of food preparation. The chefs were the same as on the boat, where precautions were observed, but in the busy anticipation of this special occasion, rules probably were broken. Everyone who partook of this feast fell ill, except the one child who slept through it. There were varying degrees of severity: two people had fever, nausea, myalgias, headache, vomiting, and diarrhea, whereas others were less ill and had only mild diarrhea. One of the more severely affected could not keep his pills down, and no one in the group was in possession of any antiemetics, which were not available in Manaus! Additionally, as his original presentation, he had no diarrhea, so the author, whose assistance was sought, for a few hours considered a diagnosis of dengue. Malaria, even after the diarrhea was manifest, was also not out of the question, but made much less likely by the fact that the traveler was taking weekly mefloquine. However, 15.6% of imported malaria cases into the United States have taken CDC-recommended prophylaxis [5], and a study of falciparum malaria in children in Manaus reports a 34.4% incidence of diarrhea in these patients [6]. Swimming The high temperature and humidity of the days cast an inviting hue to the river waters upon which we navigated. There were dangers to swimming, the least of which were the “seven plagues of the Amazon.” The piranhas do not attack when the river waters are high because there is plenty of better food; in fact, some of the passengers fished piranhas out of one side of the boat while the children swam on the other! The alligators, of which we saw many nightly in our canoe incursions into the forest, are too small in many parts of the river, but it is recommendable that one stay away from the larger ones in the surrounding lagoons. The anacondas (“sirapiju” in local dialect) inhabit mostly other rivers, and the giant catfish (“piraiba”), stingrays, and electric eels were nowhere to be seen. The greatest danger in the river was not from these fabled predators, but from the microbes, including enteric pathogens, leptospirae, and arthropod-borne viruses. All in all, however, the fun of jumping into the river proved irresistible to the children and adults alike. Luckily, no illnesses resulted from these activities, probably because of the knowledge of the captain, who impressed upon everyone which specific places were safe for swimming. Mosquito-Borne Diseases August is the dry season in the areas the group visited, and with exception of low clouds in the coastal cities of Lima and Sao Paulo and a squall here and there in the Amazon jungle, sunny days were the rule. However, the local inhabitants of this vast rain forest joke that there are only two seasons there: the rainy season and the very rainy season, so one must be prepared. Because of the dry weather elsewhere, we only encountered mosquitoes at the Amazon River and to a much lesser degree, because of its acid waters, at the Rio Negro. This must not lull one into complacency. A chance encounter with a Brazilian Public Health official at a remote lonely beach revealed the local malaria risk. In his bailiwick, he had found in January that 80 of 300 blood smears were positive, gradually decreasing such that as of July, there were only seven, but the natives do not take malaria prophylaxis and largely do not sleep in mosquito nets. A doctor travels by water once a month from Manaus, 22 km away, to offer care. There are now almost half a million cases of malaria in Brazil annually, primarily from the northern forests, a growing problem since vector control efforts ceased, but also dengue fever has experienced a resurgence in the last two decades, and several outbreaks have been reported. In 1996, there were 180,000 cases, and recently strains that cause hemorrhagic dengue (dengue-1 and -2) are being, if rarely, isolated [7]. In neighboring Peru, there has also been a resurgence of falciparum malaria in the Amazon provinces: in 1997, there were 158,000 cases in a population of about 800,000 in the Loreto Province [8]. Older studies estimate that the risk of developing malaria for travelers to the Amazon that are not receiving prophylaxis is less than 0.01% per month, but these calculations may need updating. Fortunately, there are no mosquitoes and therefore no malaria, dengue, or yellow fever in the Andes, Cuzco, the upper Urubamba Valley, or Macchu Picchu, which are the primary tourist spots. For protection from the Amazonian insects, some had mosquito head nets, but used mostly DEET (N,N-diethylmetatoluamide), and the group experimented with several strengths and preparations. The strongest (100%) was most useful at night, when the density of insects on the Amazon River was at its highest, but it can damage some synthetic materials, such as the handles in some cameras and some items of clothing. During the day, a combination of sun block and insect repellents was useful. The insect repellents worked, and as a group, we had precious few bites. Everyone received mefloquine prophylaxis, with no side effects during the trip, although an incidence of angioneurotic edema was erroneously at first thought to be due to it. After the return, however, one of the teenagers developed a mild dysphoria that resolved in 3 months. Timing wise, it seemed to be a reaction to the drug. The group experienced no cases of mosquito-borne illnesses. Wounds It is inevitable in a month-long trip that some wounds will occur, and to avoid having to get a tetanus shot abroad, one should get one before departure. Bandages, antibiotic ointments (avoid neomycin-containing ones), and wraps should be on hand. A rabies series is recommended for backpackers or people staying for more than 4 weeks, but one must always avoid petting animals. There are lots of bats in the jungle and, considering that these can be rabies reservoirs, I cringed when the captain would approach hollow dead trees in the jungle and razz the batsto come screeching out. As they flew over our heads, I felt that I would have been much more comfortable if I had been vaccinated previously. At night, we slept in closed, air-conditioned cabins, so bats could not enter. On another night excursion, one of us caught an iguana, and although this person was not bitten, he had scrapes from the animal’s tail; the iguana was released into the forest. There was one minor wound infection in one of the youngsters who was treated and cured with amoxicillin-clavulanate. Unexpected Medical Events One day, several members of the group, lead by the captain, took an optional 2½-hour hike to some waterfalls. There, the staff made a fire and made soup for lunch while the guests frolicked and refreshed in the cascading water. On the way back, however, one of the out-of-shape adults who then admitted to also being a diabetic, ran out of water, became dehydrated, and quite fatigued. The hikers then split into two groups: the captain would lead the first and try to get back to the second with help and fluids, and I led the second with one of the staff as a guide and one of the nurses to monitor and assist our ailing companion. He was visibly diaphoretic, weak, and quickly becoming frightened at the prospect of the long return through warm, humid forests. He quickly gulped down power bars given to him by fellow hikers, and all shared their water. Eventually, we reached the river where help had arrived. His blood glucose was 130, and over the next few hours he recovered uneventfully. On a different day, after a morning visit to the Opera House and the Eiffel-designed and iron-built Manaus market, where an extraordinary variety of river fish, meats, fruits, vegetables, tapioca, coffee, and assorted market products were sold, I felt a tingling sensation in my upper lip. “Early signs of a cold sore?” Just in case, a box of valacyclovir was purchased in a nearby pharmacy ($36.00 for 20 500-mg tablets). Soon, however, my face swelled up. Obviously, I had an allergic reaction. It turned out that it was neither to the mefloquine nor to a bark mask I purchased in the market nor to the rofecoxib I had taken 2 days before. It was to the atorvastatin, which I had been taking for over a year. These angioedematous reactions continued until they suddenly ceased months later when I stopped taking this drug. Conclusions The group had a fantastic experience in South America. Traveler’s diarrhea did occur after a feast but it was controlled with quinolones. Antiemetics were not readily found and should be part of the physician traveler’s first aid kit. Common medical problems, such as dehydration and allergic reactions, unrelated to travel, can occur. Altitude sickness can be prevented by a slow ascent. First-class hotels and comforts (including ATMs and Internet cafés) are available. This region of South America is a beautiful one to visit. Acknowledgments The author thanks Mrs. Beatriz O. de Talavera from Fantasia Travel Agency, [email protected], fax (011) 51 54 21 9885, Arequipa, Peru, for the travel arrangements, “Captain” Moacir Fortes from Amazonia Expeditions Caixa Postal 703, Manaus AM, Brazil, fax (011) 55 92 671 2731, for his guidance and instruction during the Amazon River journey, and his son Eric, for reviewing the manuscript.