Leishmaniasis

General Information
Leishmaniasis is an infection primarily involving the skin, mucous membranes, and certain internal organs.  It is transmitted (in most cases) by sandflies and occurs in tropical and subtropical areas of the world.  The vector sandflies are abundant in the drier areas of the tropics and subtropics but may also be found in humid areas.  The transmitting female sandfly (only female sandflies take blood) most frequently bites at night and shelters in dark corners during the day. 

Occurrence
The dog is the principal animal reservoir for leishmaniasis, but rodents, horses, cattle and sheep have also been found to play a role in transmitting the infection to humans.  It should be noted that humans can also act as a reservoir.  The sandfly bites an infected individual or animal and ingests the causative parasite.  The parasites increase in number inside the insect and are later transmitted through the insect's bite.  When humans are infected, a variety of symptoms occur and these symptoms are classified into three major types of leishmaniasis. 

Types of Infection
Cutaneous leishmaniasis (Aleppo boil, Aleppo button, Baghdad boil, Baure ulcer, Delhi boil, Oriental sore, Tropical sore) is found in central Asia, India, the Mediterranean coastal plain and West Africa. The single or multiple lesions commonly occur on the fact, arms and legs.  The lesions appear 2 to 8 weeks after the sandfly bites and begin as small areas of skin elevation and inflammation.  The elevated skin areas enlarge slowly, and within a few months, can develop into ulcers that remain for up to 2 years, followed by slow healing.

Mucocutaneous leishmaniasis (Amerian leishmaniasis, Chiclero ulcer, Espundia, Forest yaws, Uta) is found in Central and South America.  The ulcers may spread to the mucous membranes of the nose and mouth and invade the nasal septum resulting in severe facial lesions with extensive deformity.

Visceral leishmaniasis (Dumdum fever, Kala azar) is found in parts of China, the Indian subcontinent, the Mediterranean coastal plain, East Africa and South America).  Visceral leishmaniasis is primarily transmitted through the bite of sandflies but is also transmitted by blood transfusions and sexual contact.  The causative parasite invades the spleen, liver, bone marrow, lymph nodes and skin.  After an incubation period of 2-6 months, symptoms appear with fever, dizziness, weakness and weight loss.  If left untreated, this infection can become chronic and result in complications and infections such as pneumonia and can lead to death. 

Prevention and Treatment
The use of insecticides and repellents, proper sanitation and avoidance of sandfly breeding habitats are important preventive measures.  Medical consultation is necessary when the possibility of leishmaniasis is suspected.  Laboratory tests are necessary for a definite diagnosis and drugs are available for treatment. 

Make your appointment at the SHS Travel Clinic by calling (858) 534-8089.

Last Updated: 05/27/03