Description

Leishmaniasis is a parasitic disease transmitted by the bite of some species of sanDescription

Leishmaniasis is a parasitic disease transmitted by the bite of some species of sand flies. The disease most commonly manifests either in a cutaneous (skin) form or in a visceral (internal organ) form. Cutaneous leishmaniasis is characterized by one or more skin sores (either open or closed) that develop weeks to months after a person is bitten by infected sand flies. The manifestations of visceral leishmaniasis, such as fever, enlargement of the spleen and liver, and anemia, typically develop months, but sometimes years, after a person becomes infected.

Occurrence

Leishmaniasis is found in approximately 90 tropical and subtropical countries around the world. More than 90% of the world's cases of visceral leishmaniasis occur in Bangladesh, Brazil, India, Nepal, and Sudan. It also occurs in some of the following regions: the Americas (from northern Argentina to southern Texas in the United States); northern Asia; the Middle East; and Africa (particularly east and north Africa). Leishmaniasis is not found in Australia or Oceania (that is, the Pacific islands, including Melanesia, Micronesia, and Polynesia).

Risk for Travelers

People of all ages are at risk for leishmaniasis if they live or travel where leishmaniasis is found. Leishmaniasis usually is more common in rural than urban areas, but it is found in the outskirts of some cities. Risk is highest for people who are outdoors in leishmaniasis-endemic areas between dusk and dawn. Adventure travelers, Peace Corps volunteers, missionaries, ornithologists, other people who do research outdoors at night, and soldiers are examples of people who might have an increased risk for leishmaniasis (especially cutaneous leishmaniasis).

Preventive Measures

Vaccines and drugs for preventing infections are not currently available. Preventive measures for the individual traveler are aimed at reducing contact with sand flies. Travelers should be advised to avoid outdoor activities when sand flies are most active (dusk to dawn). Although sand flies are primarily nighttime biters, infection can be acquired during the daytime if resting sand flies are disturbed. Sand fly activity in an area can easily be underestimated because sand flies are noiseless fliers, and rare bites might not be noticed.

Travelers should be advised to use protective clothing and insect repellent for supplementary protection. Clothing should cover as much of the body as possible and tolerable in the climate. Repellent with N,N-diethylmetatoluamide (DEET) should be applied to exposed skin and under the edges of clothing, such as under the ends of sleeves and pant legs. It should be applied according to the manufacturer's instructions; repeated applications may be necessary under conditions of excessive perspiration, wiping, and washing (see Insect Protection). Although impregnation of clothing with permethrin can provide additional protection, it does not eliminate the need for repellent on exposed skin and should be repeated after every five washings.

Using bed nets and screening on doors and windows can reduce contact with sand flies. Fine-mesh netting (at least 18 holes to the linear inch; some sources advise even finer) is required for an effective barrier against sand flies, which are about one-third the size of mosquitoes. However, such closely woven bed nets might be difficult to tolerate in hot climates. Impregnating bed nets and window screens with permethrin aerosol can provide some protection, as can spraying dwellings with insecticides.

Treatment

Specific treatment is available and travelers should be advised to consult with an infectious disease or tropical medicine specialist.
d flies. The disease most commonly manifests either in a cutaneous (skin) form or in a visceral (internal organ) form. Cutaneous leishmaniasis is characterized by one or more skin sores (either open or closed) that develop weeks to months after a person is bitten by infected sand flies. The manifestations of visceral leishmaniasis, such as fever, enlargement of the spleen and liver, and anemia, typically develop months, but sometimes years, after a person becomes infected.

Occurrence

Leishmaniasis is found in approximately 90 tropical and subtropical countries around the world. More than 90% of the world's cases of visceral leishmaniasis occur in Bangladesh, Brazil, India, Nepal, and Sudan. It also occurs in some of the following regions: the Americas (from northern Argentina to southern Texas in the United States); northern Asia; the Middle East; and Africa (particularly east and north Africa). Leishmaniasis is not found in Australia or Oceania (that is, the Pacific islands, including Melanesia, Micronesia, and Polynesia).

Risk for Travelers

People of all ages are at risk for leishmaniasis if they live or travel where leishmaniasis is found. Leishmaniasis usually is more common in rural than urban areas, but it is found in the outskirts of some cities. Risk is highest for people who are outdoors in leishmaniasis-endemic areas between dusk and dawn. Adventure travelers, Peace Corps volunteers, missionaries, ornithologists, other people who do research outdoors at night, and soldiers are examples of people who might have an increased risk for leishmaniasis (especially cutaneous leishmaniasis).

Preventive Measures

Vaccines and drugs for preventing infections are not currently available. Preventive measures for the individual traveler are aimed at reducing contact with sand flies. Travelers should be advised to avoid outdoor activities when sand flies are most active (dusk to dawn). Although sand flies are primarily nighttime biters, infection can be acquired during the daytime if resting sand flies are disturbed. Sand fly activity in an area can easily be underestimated because sand flies are noiseless fliers, and rare bites might not be noticed.

Travelers should be advised to use protective clothing and insect repellent for supplementary protection. Clothing should cover as much of the body as possible and tolerable in the climate. Repellent with N,N-diethylmetatoluamide (DEET) should be applied to exposed skin and under the edges of clothing, such as under the ends of sleeves and pant legs. It should be applied according to the manufacturer's instructions; repeated applications may be necessary under conditions of excessive perspiration, wiping, and washing (see Insect Protection). Although impregnation of clothing with permethrin can provide additional protection, it does not eliminate the need for repellent on exposed skin and should be repeated after every five washings.

Using bed nets and screening on doors and windows can reduce contact with sand flies. Fine-mesh netting (at least 18 holes to the linear inch; some sources advise even finer) is required for an effective barrier against sand flies, which are about one-third the size of mosquitoes. However, such closely woven bed nets might be difficult to tolerate in hot climates. Impregnating bed nets and window screens with permethrin aerosol can provide some protection, as can spraying dwellings with insecticides.

Treatment

Specific treatment is available and travelers should be advised to consult with an infectious disease or tropical medicine specialist.

© Center for Disease Control

Credits: National Center for Infectious Diseases