Paraguay: Selective Vaccinations



Rabies is a viral infection caused by viruses belonging to the Lyssavirus genus. It is a zoonosis – an animal disease that can spread to humans – transmitted by saliva through bites and scratches of infected mammals. The infection primarily circulates among domestic, feral, and wild animals such as dogs, cats, monkeys, foxes, bats, raccoons, and skunks, although all mammals are at risk. The virus attacks the Central Nervous System targeting the brain and the spinal cord, and if untreated is fatal.


Rabies is present on all continents except Antarctica. The majority of human infections occur in Asia and Africa. Travellers coming into close contact with domestic animals or wildlife on ecotourism trips, or those undertaking outdoor activities like cave exploring, camping, trekking, and visiting farms or rural areas are at higher risk. Rabies is also an occupational hazard for veterinarians and wildlife researchers. Children are especially vulnerable since they may not report scratches or bites. They should be cautioned not to pet dogs, cats, monkeys, or other mammals.


Usually symptoms appear 1 to 3 months, although they can appear as early as a few days after exposure to the virus. The illness is characterized by fever and pain or a tingling sensation at the wound site. As a result of inflammation to the brain and spinal cord, some patients present with anxiety, hyperactivity, convulsions, delirium, and have a fear of swallowing or drinking liquids, as well as a fear of moving air or drafts. In other patients, muscles become paralysed followed by a coma. Once symptoms are present, most patients die within 1 or 2 weeks.


Avoid contact with feral animals or wildlife. Try to anticipate an animal’s actions and always be careful not to make sudden moves or surprise them. If you’ve been bitten or scratched by a mammal, wash the wound repeatedly and thoroughly with copious amounts of soap and water, and irrigate with an antiseptic. Seek medical attention immediately.


A series of 3 pre-exposure rabies vaccination shots is advised for persons planning an extended stay or on work assignments in remote and rural areas, particularly in Africa, Asia, Central and South America. The pre-exposure series simplifies medical care if the person has been bitten by a rabid animal and gives enough time to travel from a remote area to seek medical attention. Although this provides adequate initial protection, you will require 2 additional post-exposure doses if you were exposed to the virus. The preferred vaccines for rabies pre-exposure vaccination and post-exposure therapy are HDCV (Human Diploid Cell Rabies Vaccine) and PCECV (Purified Chick Embryo Cell Vaccine). These two vaccines are interchangeable.

Be aware that if you are in a remote area and are offered daily rabies treatment injections lasting 14 to 21 days, it may be one of the older animal brain-derived vaccines. We recommend that you do not take them due to serious side effects.

Note: Travellers who have not received the pre-exposure series need 4 to 5 shots of the rabies vaccine (depending on your health status) and the Human Rabies Immune Globulin (HRIG) which is calculated as 20 IU (International Units) per kilo of body weight. The full dose of HRIG should be injected into and around the bite site and if there is any remaining, it is given intramuscularly in another part of the body away from the wound. In some countries purified Equine Rabies Immune Globulin (ERIG) is used for post-exposure therapy when HRIG is not available. Note that HRIG is in short supply worldwide and is often not available in rural and remote settings, including urban areas.

Rabies virus images, life cycle, and distribution maps: Infection Landscapes

Information last updated: February 23, 2021. 

  • Warrell MJ, Warrell DA. Rabies and Related Viruses. In: McGill, A; Ryan, E; Hill, D; Solomon, T, eds. Hunter's Tropical Medicine and Emerging Infectious Diseases. 9th ed. New York: Saunders Elsevier; 2013: 344-348.
  • Centres for Disease Control and Prevention: Yellow Book, Rabies
  • Public Health Agency of Canada: Canadian Immunization Guide, Rabies Vaccine
  • World Health Organization: International Travel and Health, Vaccine Preventable Diseases and Vaccines