Why cutaneous leishmaniasis could not be prevented completely? An open discussion

Sir,

Leishmaniasis is endemic in 88 countries throughout Africa, Asia, Europe, and North and South America. ^[1] There are an estimated 12 million cases worldwide, with 1.5-2 million new cases reporting each year. Leishmaniasis is a disease associated with travel to an endemic area and social-economical factors. But it has been seen in Old and New World too. It has to be said that in World War II, there was a high incidence of leishmaniasis and sand fly fever in troops deployed to the Persian Gulf region. However, with consideration of a few health measures, the disease was controlled. However, 150 cases of leishmaniasis have been reported among the US soldiers serving in Iraq in 2003 and possibly the year after. In addition, the disease has been detected in foreign travelers in Afghanistan, Kuwait, and other areas in Southwest Asia or Central Asian countries. The Leishmania protozoan was first described in 1903. ^[2] Since then, this organism has been found to be a complex grouping of species, causing infections in humans. Some species cause visceral leishmaniasis, some cause cutaneous disease, and some cause both. This article focuses on cutaneous leishmaniasis and its prevention. Cutaneous leishmaniasis occurs in many parts of the world. In the Old World, the disease is primarily caused by Leishmania tropica in urban areas and Leishmania major in dry desert areas. ^[3] The incubation period is short, i.e., about 2-8 weeks, although longer periods (6-12 months) have been reported too. The disease begins as an erythematous papule at the site of the sand fly bite on exposed parts of the body. The papule increases in size and becomes a nodule. It may ulcerate and become infective with an accompanying bacterial infection. There may be multiple lesions, sometimes with 32 ulcers counted. Cutaneous leishmaniasis can become disseminated (diffuse cutaneous leishmaniasis), especially in immunosuppressed individuals, particularly in HIV/AIDS patients. ^[4] These conditions occur in developed as well as developing countries. When patient can be visited by physicians, the cutaneous scraping is the simplest and most common test with 70-75% sensitivity. The slides should be made. They are fixed with methanol, stained with Giemsa, and examined under oil immersion. Amastigotes are seen in monocytes or extracellularly. By immunologic tests, the antibodies are detected most consistently in mucosal disease. The molecular test, i.e., polymerase chain reaction test is highly sensitive. ^[5] At the present time, only a few heath measures could be effective for preventing the disease and they are listed as follows:

1. Vaccine development is under way. The combination of killed promastigotes plus Bacillus Calmette-Guérin vaccine is being tested in Iran, Sudan, and Ecuador. ^[6],[7]
2. Leishmanization well applied in order to prevent the infection in a large population.
3. Avoiding sand flies is important but difficult because they have adapted to urban environments.
4. The use of insecticides, especially in endemic areas, is important for travelers. House and space spraying has reduced sand fly populations in different part of the world.
5. Destruction of rodent reservoirs by pumping insecticides into rodent burrows has had limited success.
6. Personal hygiene in order to avoid visiting an endemic area and consideration of protective measures could be effective.
7. Use of repellents could be effective when used overnight.
8. Health education to travelers and immigrants could be effective too.

In conclusion; the disease is endemic in many parts of the world. At the present time, there is no effective available vaccine in order to prevent the risk. Only the prevention measures could be effective ^{[3],[8],[9],[10],[11],[12],[13],[14]} and perhaps new vaccines might be expected in the future ^[14].

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/1755-6783.80539