North America

Good sanitation and clean water are available in major urban areas and most rural areas. Many vector-borne infections are found in focal areas and can pose a risk to travelers, especially adventure travelers to rural areas. In temperate areas these infections occur during the summer months. Levels of immunization are high in most areas. Poliomyelitis has been eradicated.

Vector-borne infections: Lyme disease is endemic in northeastern, north central (upper Midwest), and Pacific coastal areas of North America. West Nile fever was first documented in the United States (New York) in 1999 and has since spread throughout continental U.S. and southern Canada. Other vector-borne infections include Rocky Mountain spotted fever, murine typhus, rickettsialpox, St. Louis encephalitis, La Crosse encephalitis, Eastern equine encephalitis, Colorado tick fever, and relapsing fever. Ehrlichiosis (granulocytic and monocytic) has been reported primarily from the central and eastern thirds of the United States. Sporadic local transmission of dengue has occurred since 1995 in Florida and Texas, and the vector mosquito Aedes aegypti inhabits the southeastern United States. An outbreak of dengue in Hawaii in 2001-2002 was transmitted byAe. albopictus.

Food- and water-borne infections: Outbreaks of diarrhea caused by enterohemorrhagic Escherichia coli O157:H7 have occurred in many areas and have increased in the past decade. Campylobacter and Salmonella are the most common causes of acute bacterial diarrhea. Giardiasis and cryptosporidiosis occur sporadically and in outbreaks. Outbreaks of diarrhea due to norovirus are increasingly being reported in the United States and Canada.

Airborne and person-to-person transmission: Outbreaks and cases of pertussis have been increasing for more than a decade. The incidence of tuberculosis is low (about 5/100,000 population). Numbers of measles cases have declined in the United States and Canada, and most of these cases are imported or linked to imported cases.

Sexually transmitted and blood-borne infections: The HIV prevalence in adults aged 15-49 years is estimated to be 0.5% -<1.0% in US, and is 0.1%-<0.5% in Canada.

Zoonotic infections: Rabies is enzootic in bats, raccoons, foxes, and other wild animals. Human cases are rare. Cases of hantavirus pulmonary syndrome have been widely distributed in North America, with the greatest concentration in the western and southwestern United States. Tularemia* is found in wide areas of the United States, including Alaska, and Canada, with the greatest number of cases in the central states (Missouri and neighboring states). Outbreaks have occurred on Martha’s Vineyard (Massachusetts). Q fever* cases occur sporadically, especially in persons having contact with livestock in the western part of the region; a number of outbreaks have been documented in the Maritime provinces, eastern Canada. Plague* is enzootic in the western United States, and rare human cases occur, almost 90% from New Mexico, Colorado, Arizona and California, often associated with prairie dogs. Many outbreaks of anthrax in animals were reported in agricultural regions of the US and Canada in 2006; infection in humans is rare.

Soil- and water-associated infections: Coccidioidomycosis is endemic in the southwestern United States and can occur in visitors to the area. Its incidence has increased in Arizona and California in recent years. Histoplasmosis is highly endemic, especially in the Mississippi, Ohio, and St. Lawrence River valleys. Sporadic cases and large outbreaks occur. Hawaii has the highest incidence rate of leptospirosis* in the United States, although sporadic cases and outbreaks have occurred elsewhere, primarily in warmer regions or in summer months. Leptospirosis is often associated with water recreational activities. Nonhuman schistosomes that cause cercarial dermatitis are widely distributed in freshwater and seawater along the Atlantic, Pacific, and Gulf coasts, and inland lakes.

Other hazards: Violent injury and death related to guns; rates are higher in the United States than in most industrialized countries. Nineteen species of venomous snakes inhabit North America; the highest bite rates are found in southern states and southwestern desert states. Tick paralysis is most often reported from western Canada and the northwestern United States.

List of Countries

Mexico and Central America

Vector-borne infections have focal distributions, and some are seasonal. Access to clean water and sanitary disposal of waste remain limited in many areas, so infections related to fecal contamination of food and water remain common. Levels of vaccine coverage are generally good and improving.

More common infections in travelers to the area include gastrointestinal infections, dengue fever, and myiasis. The risk of malaria is low in most countries; more than half of the cases of malaria in travelers to this region are caused by P. vivax. Chronic or latent infections with late sequelae in immigrants (and long-term residents) include cysticercosis, tuberculosis, Chagas’ disease, leishmaniasis, and strongyloidiasis.

Vector-borne infections: Malaria is present in focal areas of all these countries; it remains sensitive to chloroquine in all areas except for parts of Panama. Risk for travelers is low in most areas. Dengue epidemics have affected most of these countries in the past 5 years. Other vector-borne infections include rickettsial infections (spotted fever and murine typhus) and relapsing fever (tick borne). Foci of active transmission of leishmaniasis (predominantly cutaneous) are present in all countries. West Nile virus has been found in Mexico and may spread in Central America. Localized foci of transmission of Chagas disease exist in rural areas. Risk to the usual traveler is low. Onchocerciasis is endemic in focal areas of Mexico (Oaxaca, Chiapas) and Guatemala; eradication efforts are in progress. Myiasis (primarily botfly) is endemic in Central America.

Food- and water-borne infections: Diarrhea in travelers is common and may be caused by bacteria, viruses, and parasites. Diarrhea caused by enterotoxigenic E. coli predominates, but other bacteria and protozoa (including Giardia, Cryptosporidia, and Entamoeba histolytica) can also cause diarrhea. Risk of hepatitis A is high in many areas; epidemics of hepatitis E have occurred in Mexico. Other infections include brucellosis, typhoid fever, and amebic liver abscess. Nicaragua and Guatemala reported cholera in 2002-2003; however, risk for travelers is low. Gnathostomiasis has increased in Mexico, with many cases being reported from the Acapulco area; infection has been reported in travelers. Intestinal helminth infections are common in some local populations but are rare in visitors to the area. Central nervous system cysticercosis is a common cause of seizures in local residents.

Airborne and person-to-person transmission: The estimated annual incidence rate of tuberculosis per 100,000 population is 25-50 in most of the area, but 50-100 in Guatemala, Nicaragua, and Honduras.

Sexually transmitted and blood-borne infections: The estimated prevalence of HIV in adults is 0.1% - <1%. Incidence of cervical cancer (due to human papillomavirus) is as high as 33/100,000 women.

Zoonotic infections: Rabies is found throughout the region. Anthrax* is enzootic throughout the region and can infect humans; this disease is most common in El Salvador, Guatemala, Honduras, and Nicaragua. Cases of hantavirus pulmonary syndrome have been reported from Panama.

Soil- and water-associated infections: Outbreaks of leptospirosis have occurred in travelers to the area (including whitewater rafters in Costa Rica and U.S. troops training in Panama); hemorrhagic pulmonary leptospirosis* has occurred in Nicaragua. Sporadic cases and outbreaks of coccidioidomycosis and histoplasmosis have occurred in travelers to area. Risky activities include disturbing soil and entering caves and abandoned mines. Paracoccidioidomycosis is endemic in parts of Mexico and Central America. Hookworm infections are common in some local populations but rare in travelers. Cutaneous larva migrans occurs in visitors, especially those visiting beaches.

Other hazards: Scorpion and snake bites and motor vehicle accidents occur. Screening of blood before transfusion is inadequate in many hospitals.

The Caribbean

Access to clean water and levels of sanitation are highly variable in the region.

More common infections in travelers include gastrointestinal infections; dengue fever is reported during periods of epidemic activity.

Vector-borne infections: Malaria is endemic in Haiti and is found in focal areas in the Dominican Republic. In 2006, malaria (falciparum) was confirmed in travelers to Great Exuma, Bahamas, and Kingston, Jamaica, areas where malaria transmission typically does not occur. Dengue epidemics have occurred on many of the islands. Most islands are infested with Aedes aegypti, so these places are at risk for introduction of dengue. Lymphatic filariasis has a high prevalence in parts of Haiti; it is endemic in 9 of 13 municipalities in the Dominican Republic and Haiti. Spotted fever due to Rickettsia africae has been acquired in Guadeloupe. Transmission of cutaneous leishmaniasis occurs in the Dominican Republic.

Food- and waterborne infections: Risk of diarrheal illness varies greatly by island. Risk of diarrhea and hepatitis A is high, especially on the island of Hispaniola, where an outbreak of typhoid fever occurred in 2003. An outbreak of eosinophilic meningitis caused by Angiostrongylus cantonensis occurred in travelers to Jamaica. Intestinal helminths are common in local populations on some islands but are rare in short-term travelers.

Airborne and person-to-person transmission: The annual incidence of tuberculosis is estimated to exceed 300 per 100,000 population in Haiti and is 50-100 per 100,000 population in the Dominican Republic. The rates are substantially lower on other islands.

Sexually transmitted and blood-borne infections: The prevalence of HIV infection is estimated to be 4.5% in Haiti (1.8%-7% in pregnant women) and greater than 2% in the Dominican Republic. The prevalence of chronic infection with hepatitis B is moderate (2%-7%) in Haiti and Dominican Republic, but <2% on most of the islands. Seroprevalence of HTLV-I/II is reported to be as high as 5%-14% on some is-lands.

Zoonotic infections: Anthrax* is hyperendemic in Haiti but has not been reported on most of the other islands.

Soil- and water-associated infections: Cutaneous larva migrans is a risk for travelers with exposures on beaches. Endemic foci of histoplasmosis are found on many islands, and outbreaks have occurred in travelers. Leptospirosis* is common in many areas and poses a risk to travelers engaged in recreational freshwater activities. Foci of schistosomiasis have been active in the past in the Dominican Republic, Puerto Rico, and other islands, but pose little risk to travelers.

Other hazards: Outbreaks of ciguatera poisoning, which results from eating toxin-containing reef fish have occurred on many islands. Injury from motor vehicle accidents (including from motorized scooters) is a risk for travelers. Screening of blood before transfusion is inadequate in hospitals on many islands.

MAP 3-02 Regions - North America, Mexico and Central America, and the Caribbean

Temperate South America

The overall risk for infections is low for most travelers to the area. Gastrointestinal infections are a risk, especially in rural areas. Chronic and latent infections in immigrants (and long-term residents) include cysticercosis, Chagas’ (from remote acquisition), echinococcosis, soil-associated fungal infections (see below), and intestinal helminth infections.

Vector-borne infections: Limited areas of malaria risk are found in Argentina. Dengue outbreaks have occurred in Argentina since 1997, and Aedes aegypti infests the country as far south as Buenos Aires. An outbreak occurred on Easter Island (Chile) in 2002. Other vector-borne infections include bartonellosis (limited to the slopes of the Andes in Chile), tick-borne relapsing fever (reported from northern Argentina and Chile), murine typhus, and spotted fever due to Rickettsia rickettsii (reported from Argentina). Leishmaniasis (both cutaneous and mucocutaneous) is endemic in northern Argentina and may be present in Uruguay. Programs to eradicate American trypanosomiasis (Chagas’ disease) have reduced or interrupted active transmission in many areas.

Food- and water-borne infections: Risk of hepatitis A is moderate to high in parts of the region. Diarrhea in travelers is caused by bacteria, viruses, and parasites. Typhoid fever outbreaks have occurred in Chile in the past, and sporadic infections occur in the region. Typhoid fever, amebic abscesses, and brucellosis can be acquired by travelers. Fascioliasis occurs sporadically, but travelers are at low risk.

Airborne and person-to-person transmission: The annual incidence of tuberculosis is estimated to be 25-50 per 100,000 population in most of region, but lower in Chile. Influenza outbreaks peak in May-August.

Sexually transmitted and blood-borne infections: The estimated prevalence of HIV infection in adults is low (0.1%-<1%). Foci of high endemicity of HTLV-I are found in Argentina and Chile.

Zoonotic infections: Q fever* (airborne spread) is common in areas where livestock are raised; frequent outbreaks have been noted in Uruguay. Rabies is present in the region. Anthrax* is enzootic in Argentina. Sporadic cases of hantavirus pulmonary syndrome (Andes virus; rodent reservoir host) have been reported from Argentina and Chile. Argentine hemorrhagic fever caused by Junin virus (rodent reservoir) is found in an agricultural area of Argentina. Risk to travelers is low.

Soil- and water-associated infections: Histoplasmosis is endemic in Uruguay and parts of Venezuela. Coccidioidomycosis is found in focal areas of Argentina and Chile; paracoccidioidomycosis is highly endemic in Uruguay and in parts of Argentina and sporadic elsewhere. Sporotrichosis is highly endemic in Uruguay and sporadic elsewhere. Hookworm infections are endemic in warm, wet areas but are rare in travelers. Leptospirosis* is a risk in warmer months.

Other hazards: Screening of blood prior to transfusion is inadequate in many hospitals.

Tropical South America

More common infections in travelers include dengue, gastrointestinal infections, and malaria. Chronic or latent infections in immigrants (and long-term residents) include tuberculosis, schistosomiasis, leishmaniasis, Chagas’ disease, cysticercosis, and intestinal helminth infections, including strongyloidiasis.

Vector-borne infections: Malaria is widely distributed, but the risk to travelers is low in most areas. Vivax malaria predominates in many areas. Dengue outbreaks have increased in the past decade, and infections occur in travelers. Yellow fever causes sporadic cases and outbreaks. Cases have been reported since 2000 from Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela. Aedes aegypti infests all these countries, including urban areas, placing them at risk for introduction of yellow fever (and dengue). Fatal yellow fever has occurred in unvaccinated travelers. Other vector-borne infections include rickettsial infections (murine typhus and spotted fever due to Rickettsia rickettsii and R. felis), relapsing fever (the tick-borne form is widely distributed; the louse-borne form occurs primarily in the highlands of Bolivia and Peru), and Venezuelan encephalitis. Oropouche fever is a common arboviral infection, especially in the Amazon ba-sin. Leishmaniasis has increased in recent years; foci of transmission of cutaneous leishmaniasis are found throughout the region; visceral leishmaniasis is found primarily in Brazil. American trypanosomiasis (Chagas’ disease) has been widespread in poor, rural areas, but transmission has been interrupted or slowed in many areas (e.g., Brazil) through eradication programs. Onchocerciasis is endemic in focal areas of Brazil, Colombia, Ecuador, and Venezuela; eradication efforts are in progress. Bartonellosis is found in the mountain valleys of Peru (largest endemic focus), Ecuador, and southwestern Colombia (at altitudes of 600-2800 meters). Lymphatic filariasis is endemic in Guyana and in focal areas of Brazil and in parts of northeastern South America. Myiasis occasionally occurs in travelers.

Food- and waterborne infections: Gastrointestinal infections in travelers are caused by bacteria, viruses, and parasites. Hepatitis A risk is widespread. Cholera was widespread in South America in the 1990s; only Brazil, Colombia, and Ecuador reported infections in 2005. Typhoid fever, brucellosis, and amebic liver abscesses are occasionally seen in travelers. Fascioliasis is highly endemic in some areas, especially in Bolivia, Ecuador, Peru, and Venezuela, but risk is low for the usual traveler. Paragonimiasis is endemic in Ecuador and Peru and occurs sporadically in other countries; infections are rare in the usual traveler.

Airborne and person-to-person transmission: The annual incidence rate of tuberculosis per 100,000 is estimated to be 100-300 in Peru, Ecuador, Bolivia, and Guyana and 50-100 or less in the rest of the region. Multidrug resistance has been a problem, especially in Peru and Ecuador, where the rate of multidrug resistance is 3%-6% among new cases (17). Leprosy is highly endemic in some focal areas (e.g., high prevalence in the Amazon and parts of the Andes). Prevalence in Brazil was 46 per 100,000 population in 2004.

Sexually transmitted and blood-borne infections: Prevalence of HIV in adults is estimated to be 0.1% -<1% in most of the region, but the prevalence is higher in Guyana and Suriname (1%-<5%). The prevalence of chronic infection with hepatitis B exceeds 8% in Peru, northern Brazil, and southern Colombia and Venezuela and is 2%-7% in the rest of the region. Hepatitis D has caused epidemics of fulminant hepatitis in the Amazon Basin. HTLV-I is found especially in areas adjacent to the Caribbean, including Colombia, Venezuela, Surinam, Guyana, and Brazil.

Zoonotic infections: Rabies is found throughout the region; vampire bats transmit infection in some areas and have been responsible for outbreaks of human rabies in Peru, Venezuela, and Brazil. Hantavirus pulmonary syndrome caused by hantaviruses with rodent reservoirs has been documented in Bolivia, Brazil, and Paraguay; these viruses may be more widely distributed. Other rodent-associated viruses include Machupo virus,* which causes sporadic infections in rural northeastern Bolivia, and Guanarito virus in Venezuela. Plague* has been reported from Bolivia, Brazil, Ecuador, and Peru since 1990 (most cases are from Peru). Echinococcosis* is endemic in cattle-grazing areas of Ecuador and other countries; the risk to travelers is low.

Soil- and water-associated infections: Endemic foci of schistosomiasis (Schistosoma mansoni) are found in Brazil, Venezuela, and Suriname. Buruli ulcer (Mycobacterium ulcerans) is endemic in French Guyana; a few cases have been reported from other countries (e.g., Peru and Suriname). Risk of leptospirosis* is widespread in tropical areas; outbreaks have followed flooding. Histoplasmosis has been reported from all countries in the region, and paracoccidioidomycosis is endemic throughout the area, with the highest transmission in Peru, Ecuador, Colombia, and Brazil. Coccidioidomycosis is more focal in distribution with endemic areas in Brazil, Colombia, Paraguay, and Venezuela.

Other hazards: Venomous snake bites, injury from motor vehicle accidents, and high altitude-related illness in the Andes occur. Screening of blood before transfusion is inadequate in many hospitals.

MAP 3-03 Regions - South America