Leishmaniasis

Is found near the Mediterranean, Africa, China and Central and South America. Female Sandflies transmit this protozoa infection to humans from dogs or rodents. Other ways to catch it are from blood transfusions, sexual intercourse or from mother to child.

Sandflies bite at night. They only fly at lowr altitudes above ground so being bitten can be avoided by sleeping above ground (hammock or second story of a house). They may be small enough to slip between mosquito nets, but if the nets are treated with permethrin they will deter flies.
Sand flies are tiny flies that breed in moist debris, like humid places, or damp soil rich in humus. They are also linked to poor housing conditions or forest/rain forest ecosystems where they like to breed in rotting leaves between the buttresses of tree trunks. Usually a sandfly bite has a non- swollen circle around it. Sometimes biting midges, near beach resorts, are referred to as sandflies, but are in fact not.

Leishmaniasis is grouped into 3 types:

1. Cutaneous (Aleppo boil or button, Baghdad boil, Baune ulcer, Delhi boil, oriental sore, tropical sore). The Sandflies bite first appears as red patches that gradually enlarge and ulcerate. Next nodules form that are itchy, firm, yet painless. Without treatment these heal slowly, often with scarring. Cutaneous Leishmaniasis is diagnosed by biopsy. Intravenous medication is needed to treat this.

2. Visceral Leishmaniasis (dumdum fever, Kala-azar). Most cases of this type are in India, Bangladesh, Nepal, Sudan, and at the Mediterranean. 'Kala-azar' is Hindu for black sickness as the disease causes darkening of the face, limbs and abdomen. They tend to affect young people and the incubation period can last months to years. Symptoms may start during incubation period, which can last months to years. Initially a mild fever with bouts of extreme sweating. With progression - weight loss, fatigue, anorexia, nausea, abdominal pain and diarrhea develop. Enlargement of the spleen, liver and lymph nodes occur. Untreated disease is fatal. Diagnosis is confirmed with blood tests. Intravenous drugs teat this disease.

3. Mucocutaneous Leishmaniasis (American Leishmaniasis, Chiclero ulcer, Espundia, Forest yaws, Uta). Present in South and Central America. Initially painful, itchy nodules occur, which heal within a few months. Years late 40% of these develop ulcers at face and mouth, which cause disfigurement. Diagnosis may be made from biopsy or blood tests. Medication and surgery are often unsatisfactory.

Leishmaniasis is acquired through the bite of the female sandfly, which generally bite at night. They are inactive during the day and like to breed in moist dark areas. Bites can be prevented through protective clothing at evening and night, elevation of bedding so it is not on the ground and DEET.

Cutaneous Leishmaniasis involves skin infection and is caused by Leishmaniasis major, Leishmaniasis aethiopia, and Leishmania tropica. Leishmania minor is a rural disease affecting wild rodents. Tourists, hunters and others living in these areas are vulnerable. Skin lesions are large, wet and multiple and rarely spread.

Leishmania aethiopia is found in Ethiopia and Kenya and typically infects the animal reservoir, the rock hyrax. Infection by tourists is rare. Leishmania tropica is an urban disease found in the Middle East and Asia. Leishmania brazilensis (in South America) can lead to distinctive mucocutaneous lesions.

Visceral Leishmaniasis (also known as Kala-azar) is caused by Leishmania donovani. It is common in Kenya and Sudan. Transmission may be human to human but outbreaks are usually in isolated areas so tourists are not usually affected. Infected patients may present with an acute illness after 4-6 months. Symptoms include high fever and severe sweats.

Progression to splenomegaly, hepatomegaly, lymphadenopathy and wasting with anemia, but only 5% go on to more severe symptoms.

HIV infected travelers and immunocompromised people will be affected more.

Leishmaniasis links:

CDC

http://www.cdc.gov/travel/diseases/leishmaniasis.htm

WHO control of Leishmaniasis   

http://www.who.int/emc/diseases/leish/

Brown University (A scientific summary)

http://www.brown.edu/Courses/Bio_160/Projects2000/Leishmaniasis/

Leishmaniasis Slide Discussion by Dr David Humber

http://homepages.uel.ac.uk/d.p.humber/powerpoint/leishmaniasis/

Medicine sans frontiers Doctors without borders Leishmaniasis The forgotten disease

http://www.accessmed-msf.org/campaign/lsh01.shtm