Avoid real World Cup fever: Prevention of vector-borne disease during travel to Brazil

March 18th, 2015

The 2014 FIFA World Cup taking place in Brazil will be followed by the 2016 Summer Olympics, with each event attracting 600,000 international visitors. While many gains have been made in the reduction of communicable diseases in this Latin American country, infectious diseases still pose a great challenge in many areas of Brazil, we report in the July 2014 issue of Infectious Disease Alert.

Malaria cases have decreased overall, but the annual incidence of dengue has increased over the last two decades, and transmission areas of yellow fever also have grown larger. Much of the morbidity and even mortality due to the infectious diseases found in Brazil are either vaccine-preventable or reduced by avoidance of mosquitoes, use of insect repellent, and/or the use of prophylactic medication.

The Boston Area Travel Medicine Network (BATMN), consisting of five travel clinics in the Boston area, reviewed 599 travelers who had destinations that included Brazil.¹ A total of 85% received prescriptions for self-treatment of traveler’s diarrhea, and 39% received anti-malarial prophylaxis. Yellow fever and typhoid were the most commonly administered pre-travel vaccinations at 71% and 58% respectively. A total of 50% of travelers received Hepatitis A vaccination (and another 39% had previously received this vaccine) with 14% receiving influenza vaccination and 11% obtaining Hepatitis B pre-travel immunization. The most common risk prevention topics included vector-borne disease avoidance and fresh water exposure at 98% and 96%.

Brazil is a country with several vector-borne infection transmission zones, making initial pre-travel guidance difficult. Malaria -- especially Plasmodium vivax but also some P. falciparum -- is a disease with continued prevalence in Brazil, particularly in the Amazon region. However, most of the common areas of travel are without significant risk of transmission. Chemoprophylaxis is indicated for travelers whose itineraries include malaria-endemic parts of the country. Brazil has large regions that are yellow-fever endemic and pre-travel vaccination is indicated for all visitors except those visiting only eastern coast areas. Dengue fever is transmitted year-round via the vector mosquitoes Aedes aegypti and Aedes alboptictus and precautions should be taken against mosquitoes, including avoidance and the use of insect repellants. Furthermore, typhoid fever is present but much less common in Brazil and immunization may be indicated. While influenza remains the most common vaccine-preventable disease in travelers, most of the visitors to Brazil did not obtain the vaccine.

-- Philip R Fischer, MD, DTM&H, Professor of Pediatrics, Department of Pediatric and Adolescent, Medicine, Mayo Clinic; and Peter J. Holmberg, MD, pediatric resident at the Mayo Clinic in Rochester, MN

Reference

1. Iliaki E, et al. Travel to Brazil: Analysis of Date from the Boston Area Travel Medicine Network (BATMN) and Relevance to Travelers Attending World Cup and Olympics. J Travel Med 2014;21(3):214-217