Chapter 2 The Pre-Travel Consultation Counseling & Advice for Travelers
HUMAN INTERACTION WITH ANIMALS: A RISK FACTOR FOR INJURY AND ILLNESS
Animals, even those in close association with humans, such as dogs, can attack if they perceive threat, are protecting their young or territory, or are injured or ill. Although attacks by wild animals are more dramatic, attacks by domestic animals are far more common, and secondary infections of wounds may result in serious systemic disease. This section will cover the most common routes of transmission of illness and injury from animals and insects. However, most animals can transmit disease by more than one route. This section provides examples of high-priority diseases and injuries from animals and refers the reader to other sections for more detailed descriptions of the specific diseases.
BITES AND SCRATCHES
Bites from certain mammals, such as monkeys, dogs, bats, and rodents, present a risk for rabies, tetanus, pasteurellosis, bartonellosis, and other infections. These animals’ saliva can be so heavily contaminated with bacteria that a bite may not even be necessary to cause infection if the animal licks a preexisting cut or scratch. Young children are more likely to be bitten by animals and to sustain more severe injuries from animal bites.
Before departure, travelers should have a current tetanus vaccination or documentation of a booster vaccination in the previous 5–10 years. Travel health providers should assess a traveler’s need for preexposure rabies immunization (see Chapter 3, Rabies). While traveling, people should never try to pet, handle, or feed unfamiliar animals (whether domestic or wild, even in captive settings such as game ranches or petting zoos), particularly in areas where rabies is endemic. Travelers should never attempt to feed, pet, or handle any animal such as monkeys, bats, or rodents while traveling. To mitigate the risk of exposure to rabies, stray dogs should be avoided, and travelers should avoid the temptation to adopt a stray dog from abroad.
To prevent infection, all bite and scratch wounds should be promptly cleaned with soap and water, and the wound should be promptly debrided if necrotic tissue, dirt, or other foreign materials are present. Often times, a course of antibiotics is appropriate after dog or cat bites or scratches as these can lead to local or systemic infections. Wound care is especially important for tetanus- or rabies-prone wounds (see the Rabies and Tetanus sections in Chapter 3). Travelers who might have been exposed to rabies should contact a health care provider as soon as possible for advice about rabies postexposure prophylaxis (PEP). Travelers who received their most recent tetanus toxoid–containing vaccine >5 years previously, or who have not received ≥3 doses of tetanus toxoid–containing vaccines, may require a dose of tetanus toxoid–containing vaccine (Tdap, Td, or DTaP).
If a bite occurs or if infectious material (such as saliva) from a bat gets into the eyes, nose, mouth, or a wound, the traveler should wash the affected area thoroughly and seek medical advice immediately. Any suspected or documented bite or scratch from a bat anywhere in the world should be considered a risk, and the traveler should be evaluated for rabies PEP. It is not possible to tell if a bat has rabies without laboratory confirmation; however, any bat that is active by day, is found where bats are not usually seen (for example, indoors or outdoors in areas near humans), or is unable to fly is far more likely to be rabid. People usually know when they have been bitten by a bat, but bats have tiny teeth, and not all wounds may be apparent. Travelers should seek medical advice even in the absence of an obvious bite wound if they wake up to find a bat in the room or see a bat in the room of an unattended child.
After a monkey bite or scratch, travelers should be advised to thoroughly clean the wound and seek medical care immediately to be evaluated for possible rabies and herpes B PEP. Macaque bites can transmit herpes B virus, a virus related to the herpes simplex viruses (see Chapter 3, B virus). Additional information and photos of macaques can be found at the website for the National B Virus Resource Center at the Georgia State University Viral Immunology Center (www2.gsu.edu/~wwwvir).
Wild rodents are unlikely to have rabies; however, each exposure needs to be evaluated. If the bite was provoked (such as through feeding, petting, or playing with the animal) and the animal appeared healthy, the animal was probably not rabid at the time of the bite. Most experts would not recommend postexposure prophylaxis in this situation. If the bite was unprovoked or the animal appeared unhealthy and is unavailable for testing, rabies PEP should be considered.
STINGS AND ENVENOMATIONS
Poisonous snakes are hazards in many locations, although deaths from snakebites are rare. Snakebites usually occur in areas where dense human populations coexist with dense snake populations, such as Southeast Asia, sub-Saharan Africa, and tropical areas in the Americas.
Common sense is the best precaution. Most snakebites result from startling, handling, or harassing snakes. Therefore, all snakes should be left alone. Travelers should be aware of their surroundings, especially at night and during warm weather when snakes tend to be more active. For extra precaution, when practical, travelers should wear heavy, ankle-high or higher boots and long pants when walking outdoors in areas possibly inhabited by venomous snakes.
Travelers should be advised to seek immediate medical attention any time a bite wound breaks the skin or when snake venom is ejected into their eyes or mucous membranes. Immobilization of the affected limb and application of a pressure bandage that does not restrict blood flow are recommended first aid measures while the victim is moved as quickly as possible to a medical facility. Incision of the bite site and tourniquets that restrict blood flow to the affected limb are not recommended. Specific therapy for snakebites is controversial and should be left to the judgment of local emergency medical personnel. Specific antivenoms are available for some snakes in some areas, so trying to ascertain the species of snake that bit the victim may be critical.
Insects and other Arthropods
Bites and stings from spiders and scorpions can be painful and can result in illness and death, particularly among infants and children. Other insects and arthropods, such as mosquitoes and ticks, can transmit infections. See the Protection against Mosquitoes, Ticks, & Other Arthropods section earlier in this chapter.
Most marine animals are generally harmless unless threatened. Most injuries are the result of chance encounters or defensive maneuvers. Resulting wounds have many common characteristics: bacterial contamination, foreign bodies, and occasionally venom. Venomous injuries from marine fish and invertebrates are increasing with the popularity of surfing, scuba diving, and snorkeling. Most species responsible for human injuries, including stingrays, jellyfish, stonefish, sea urchins, and scorpionfish, live in tropical coastal waters.
Travelers should be advised to maintain vigilance while engaging in recreational water activities. Prevention is the best defense:
- Avoid contact. This may be difficult in conditions of poor visibility, rough water, currents, and confined areas.
- Do not attempt to feed, handle, tease, or annoy marine animals.
- Wear protective clothing, such as protective footwear.
- Make an effort to find out which animals may be encountered at the destination and learn about their characteristics and habitats before engaging in recreational water activities.
In case of injury, identifying the species involved can help determine the best course of treatment. Signs and symptoms may not appear for hours after contact, or the animal may not have been seen or recognized at the time of injury. In such cases, treatment is based on the injury. Symptoms of venomous injuries can range from mild swelling and redness at the site to more severe symptoms, such as difficulty breathing or swallowing, chest pain, or intense pain at the site of the sting, for which immediate medical treatment should be sought. Management will vary according to the severity of symptoms and can include medications, such as diphenhydramine, steroids, pain medication, and antibiotics.
Viral infections such as rabies and viral hemorrhagic fevers can be transmitted from bats to people. A recent example of an indirect exposure is an imported case of Marburg fever in a tourist who had visited a “python cave” inhabited by bats in western Uganda. This case illustrates the risk of acquiring diseases from indirect contact with cave-dwelling bats. This same cave was the source of a fatal case of Marburg hemorrhagic fever in a Dutch tourist in 2008. Exposure to bats can occur during adventure activities, such as caving or spelunking, and can include bites, scratches, and mucosal or cutaneous exposure to bat saliva. Like any other wild animal, bats, whether sick or healthy, will bite in self-defense if handled.
Bats should never be handled. Travelers should be discouraged from going into caves or mines that have large bat infestations. Depending on the country being visited, rabies vaccination may be recommended for people engaged in activities such as caving.
Rodents carry a variety of viral, bacterial, and parasitic agents that may pose a threat to human health. Human exposure can occur directly by a bite or scratch, or indirectly by exposure to surfaces or water contaminated with urine or feces.
Rodents should never be handled. Travelers should avoid places that have evidence of infestation with rodents and should avoid contact with rodent feces. Travelers should not eat or drink anything that is suspected to be contaminated by rodent feces or urine.
Travelers who were exposed to rodents and who develop febrile illness shortly thereafter should be evaluated by a clinician. Depending on the history and symptoms, diseases such as yersiniosis, plague, leptospirosis, hantavirus, rickettsial infections, Lyme disease, Lassa fever, tickborne encephalitis, poxvirus, and bartonellosis (all discussed in further detail in Chapter 3) should be included in the list of possible diagnoses.
Ill and asymptomatic birds have been associated with cases of highly pathogenic avian influenza in humans. When traveling in an area where outbreaks of avian influenza have been reported, travelers should avoid contact with live poultry (such as chickens, ducks, geese, pigeons, turkeys, and quail) or any wild birds and should avoid settings where avian influenza A (H5N1)–infected poultry may be present, such as commercial or backyard poultry farms and live poultry markets. Travelers should not eat uncooked or undercooked poultry or poultry products, including dishes that contain uncooked eggs or poultry blood. Other pathogens from birds may infect humans through infected feces or by aerosol. These cause diseases such as histoplasmosis (see Chapter 3, Histoplasmosis), salmonellosis (see Chapter 3, Salmonellosis [Nontyphoidal]), psittacosis, and avian mycobacteriosis. Travelers should wash their hands if they come in contact with bird feces.
- Callahan M. Bites, stings and envenoming injuries. In: Keystone JS, Freedman DO, Kozarsky PE, Connor BA, Nothdurft HD, editors. Travel Medicine. 3rd ed. Philadelphia: Saunders Elsevier; 2013. p. 413–24.
- Cohen JI, Davenport DS, Stewart JA, Deitchman S, Hilliard JK, Chapman LE. Recommendations for prevention of and therapy for exposure to B virus (cercopithecine herpesvirus 1). Clin Infect Dis. 2002 Nov 15;35(10):1191–203.
- Diaz JH. The global epidemiology, syndromic classification, management, and prevention of spider bites. Am J Trop Med Hyg. 2004 Aug;71(2):239–50.
- Gibbons RV. Cryptogenic rabies, bats, and the question of aerosol transmission. Ann Emerg Med. 2002 May;39(5):528–36.
- Gold BS, Dart RC, Barish RA. Bites of venomous snakes. N Engl J Med. 2002 Aug 1;347(5):347–56.
- Lankau EW, Cohen NJ, Jentes ES, Adams LE, Bell TR, Blanton JD, et al. Prevention and control of rabies in an age of global travel: a review of travel- and trade-associated rabies events—United States, 1986–2012. Zoonoses Public Health. 2014 Aug;61(5):305–16.
- Meerburg BG, Singleton GR, Kijlstra A. Rodent-borne diseases and their risks for public health. Crit Rev Microbiol. 2009;35(3):221–70.
- Pan American Health Organization. Rabies. In: Acha PN, Szyfres B, editors. Zoonoses and Communicable Diseases Common to Man and Animals. 3rd ed. Washington, DC: Pan American Health Organization; 2003. p. 246–76.
- World Health Organization. WHO Expert Consultation on rabies. World Health Organ Tech Rep Ser. 2005;931:1–88.
- Page created: July 10, 2015
- Page last updated: July 10, 2015
- Page last reviewed: July 10, 2015
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