Animals in general tend to avoid human beings, but they 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 (1,2). Animals cause injury through bites, kicks, or blunt trauma, or by the use of horns or claws. Further damage can occur if injuries become secondarily infected, as these infections may result in serious systemic disease. In addition, animals can transmit zoonotic infections. A recent 10-year retrospective review of dog bites showed that 75% of the bites were preventable because the person intentionally interacted with the dog (3). Travelers should never try to pet, handle, or feed unfamiliar animals, domestic or wild, particularly in areas of endemic rabies. Young children are more likely to be bitten by animals and sustain more severe injuries from animal bites. They are also less likely to report having been bitten and thus should be closely supervised while around wild or domestic animals, especially those not known to have been properly vaccinated against rabies (3-5). All bite wounds should receive prompt attention and cleansing to reduce the risk of infection (see Chapter 4.) CDC also recommends that travelers be up to date on tetanus vaccination; adults should have a booster before departure, if they have not had one within the last 5 to 10 years.
Macaques, a type of monkey, pose an additional threat as potential sources of herpes B virus (6). Herpes B virus is related to the herpes simplex viruses, which cause oral and genital ulcers. Herpes B infection is rare in humans, and most documented cases have resulted from occupational exposures. No case of herpes B infection has occurred in travelers or others exposed to monkeys in the wild. However, travelers to areas where free-ranging macaques exist (essentially in most of the world, except for the Americas, although macaques may be found in parts of the Caribbean) should be aware of the potential risk. An infected monkey may appear completely healthy, and herpes B infection rates may be high in some populations. Documented routes of infection include animal bites and scratches, exposure to infected tissue or body fluids (through splashes), cage scratches, and human-to-human spread. Some exposures resulting in human infection were considered trivial at the time they occurred. Disease may start as an influenza-like illness within 1 month after exposure, although the incubation period may be less than 1 week. Neurologic symptoms develop as the virus infects the central nervous system and may lead to ascending paralysis and respiratory failure. Untreated disease has a mortality rate of 80%, whereas the mortality rate for treated disease is 20%. First aid in terms of cleaning a wound and monitoring the person both clinically and serologically are keys to management. Recent guidelines have been published for the prevention of herpes B infection after exposure and for the treatment of established infection (7). Travelers should never attempt to feed, pet, or otherwise handle any monkeys.
Poisonous snakes are hazards in many locations, although deaths from snakebites are relatively rare. Snakebites usually occur in areas where dense human populations coexist with dense snake populations (e.g., Southeast Asia, sub-Saharan Africa, and tropical America) (8). The Australian brown snake; Russell’s viper and cobras in southern Asia; carpet vipers in the Middle East; and coral snakes and rattlesnakes in the Americas are particularly dangerous. Most snakebites are the direct result of startling, handling, or harassing snakes. Because snakes tend to be active at night and in warm weather travelers should wear boots and long pants as a precaution when walking outdoors at night in areas possibly inhabited by venomous snakes. Attempts to kill snakes are dangerous. The venom of a small or immature snake can be even more concentrated than that of larger ones; therefore, all snakes should be left alone. Fewer than half of all snakebite wounds actually contain venom, but travelers should be advised to seek immediate medical attention any time a bite wound breaks the skin. 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 (9). 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.
The bites and stings of some arthropods may cause unpleasant reactions. Travelers should be advised to seek medical attention if an insect bite or sting causes redness, swelling, bruising, or persistent pain. Those who have a history of severe allergic reactions to insect bites or stings should also consider carrying an epinephrine autoinjector (EpiPen) in case of recurrence. Many insects can transmit communicable diseases, even without the traveler’s being aware of the bite. This is particularly true when camping or staying in rustic accommodations. Travelers to many parts of the world should be advised to use insect repellents containing DEET, protective clothing, and mosquito netting (see Chapter 2). Bites and stings from spiders and scorpions can be painful and can result in significant morbidity and mortality, particularly among infants and children. In general, exposure to scorpion envenomations can be avoided by wearing long sleeves and pants while hiking, sleeping under mosquito nets, and by shaking clothing and shoes before putting them on (10).
When traveling in an area that is experiencing an outbreak of avian influenza, (http://www.cdc.gov/flu/avian/outbreaks/current.htm) travelers should avoid all contact with poultry (e.g., chickens, ducks, geese, pigeons, turkeys, and quail) or any wild birds, and avoid settings where 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 made with uncooked poultry blood.
