leishmaniasis
Table of Contents
leishmaniasis
introduction
- leishmaniasis is a disease caused by protozoan parasites that belong to the genus Leishmania and is transmitted by the bite of certain species of sand fly.
- human infection is caused by about 21 of 30 species that infect mammals.
- affects as many as 12 million people worldwide:
- 30,000 new VL cases of and more than 1 million new CL cases each year
- > 90% of annual VL incidences occur in six countries: Bangladesh, Sudan, India, Nepal, Ethiopia, Brazil and South Sudan
- East Africa is the second largest center of VL after the Indian continent and annually adds 30,000–40,000 new cases per year
- visceral form is the second-largest parasitic killer in the world (after malaria), responsible for an estimated 500,000 cases each year worldwide
- a disease characterized by high epidemiological dynamism related to constantly changing transmission conditions depending on the environment, demography, human behavior, socio-economic status and the human immune system 1)
geography
- found in tropics and sub-tropics, in rainforests to deserts
- mainly in the developing world
- more than 90% of the world's cases of visceral leishmaniasis are in India, Bangladesh, Nepal, Sudan, and Brazil
- found across much of Asia, though not Southeast Asia
- found in Middle East including Saudi Arabia, Iraq, and Afghanistan (esp. Kabul due to poor sanitation)
- cases in Africa, particularly east and north, and spreading to southern Europe
- historically, Catania in Sicily has been an urban focus for this disease as over 80% of the urban area has the sand flies (highest numbers in Sept) of which over 10% are infected, however there seem to be only around 10 reported human infections there each year.2) The far majority of human cases in Sicily actually occur in the NW provinces of Palermo and Agrigento. Infection rates of dogs in Sicily seem to be 25-34% whilst that of cats is 12%. Rates of canine infection are 50% less in Ragusa compared to most other provinces of Sicily.
- found through much of the Americas from northern Argentina to southern Texas, though not in Uruguay or Chile.
- aka papalomoyo, papa lo moyo and ulcero de los chicleros in Latin America
- NOT found in Australia or Oceania
Prevention
- No vaccines or drugs to prevent infection are available.
- AVOID sand fly bites in endemic areas
clinical pictures
- clinical leishmaniasis is prevalently a disease of poverty and malnutrition although immunocompromise by HIV / AIDS is an increasing factor for severe disease
cutaneous leishmaniasis
- skin sores which erupt weeks to months after the person affected is bitten by sand flies
- heals in a few months to a year, leaving an unpleasant-looking scar
- can progress to the other 3 forms.
visceral leishmaniasis
- severe form in which paraistes have migrated to vital organs
- potentially fatal if untreated
- aka kala-azar, black fever, and Dumdum fever
- delayed onset of fever, weight loss, mucosal ulcers, fatigue, marked hepatosplenomegaly and anaemia
- the blackening of the skin that gave the disease its common name in India does not appear in most strains of the disease, and the other symptoms are very easy to mistake for those of malaria.
- increasing issues with co-infection with HIV / AIDS
- some time after successful treatment, generally a few months with African kala-azar, or as much as several years with the Indian strain, a secondary form of the disease may set in, called post kala-azar dermal leishmaniasis, or PKDL
diffuse cutaneous leishmaniasis
- widespread skin lesions which resemble leprosy, and is particularly difficult to treat.
mucocutaneous leishmaniasis
- starts as skin ulcers then spreads to cause tissue damage especially to mouth and nose
Treatment
leishmaniasis.txt · Last modified: 2022/08/29 07:08 by gary1