Epidemiology
Leishmaniases are diseases caused by protozoans of the genus Leishmania.
They are transmitted by the bites of female phlebotomine sandflies, a type of small hairy fly 2 to 4 mm in length. The female bites at dusk, and the bite is painful.
Phlebotomus are found throughout the year in tropical zones, and have been found in temperate regions. Leishmaniases are extremely widespread in the world, present mainly in India, China, South America, Africa and Southern Europe.
They infect approximately 12 million people per year, and the incidence is on the rise with 1 to 1.5 million new cases per year. This increase is due to new cradles of infection (Algeria, Tunisia) and emerging coinfection of leishmaniasis and AIDS, particularly in meridional Europe (Spain, France, Italy, Portugal), as well as in the Horn of Africa, which increases the human reservoir.
Symptoms
There are 3 distinct forms of leishmaniasis: visceral, cutaneous and cutaneomucous.
Visceral leishmaniasis :
This is the most serious form; humans rarely develop this form of the disease. It is observed in immunodeficient persons (AIDS).
After 3 to 6 months of incubation, it is characterised by irregular bouts of fever, weight loss, splenomegaly and anaemia. It can be spontaneously deadly. When treated early, the outcome is favourable.
Cutaneous leishmaniasis :
This form is characterised by slowly progressing skin lesions without generalised symptoms. A distinction is made between 2 clinical types:
- localised forms :
- localised cutaneous leishmaniasis: ulcerated or crusted lesions located on the face, hands, forearms and lower limbs. They are diagnosed between 1 and 4 months after the bite.
- diffuse forms :
- diffuse cutaneous leishmaniasis: non-ulcerated nodules accompanied by other types of nodules over the entire body. The appearance of the patient may resemble the contagious form of leprosy (lepromatous leprosy).
Cutaneomucous leishmaniasis :
This form arises between 1 and 40 years after the initial onset. The nasal, oral and labial mucous membranes can become the site of inflammatory processes that may progress to perforation of the nasal septum.
This form affects 1 to 3% of persons who have contracted the cutaneous form.
Treatment
The treatment of leishmaniasis includes :
- the use of pentavalent antimony derivatives (PAD) via intramuscular (IM) or intravenous (IV) injection,
- pentamine salts via IM, or more recently amphotericine B via IV.
- treatments by oral route (miltefosine),
- local treatments.
Prevention
1. Vaccination
There is no vaccine yet, but active research is underway.
2. Prevention of insect bites
Prevention is mainly based on :
- wearing ample clothing that covers the body,
- use of repellent products for the body and appropriate insecticide clothing (Moustifluid High Protection Tropical Zones and Moustifluid Lotion For Fabrics and Clothing Tropical Zones).