Leishmaniose

The leishmanioses are skin troubles or visceral due to whipped Protozoaire S pertaining to the kind Leishmania of the family of the Trypanosomidae and transmitted by the puncture of certain species of Phlébotome S, including/understanding the flies of the kind Lutzomyia in the new world and Phlébotome in the old world.

History

The disease was identified in 1901 by the Scottish Anatomopathologiste William Boog Leishman.

It is also known under the name of leichmaniose, leishmaniose and was formerly named button of the East , Clou of Biskra , Bouton of Alep , kala azar , black fever , fever with phlebotomus , fever Dum-Dum or espundia .

Parasite

The majority of the forms of the disease are transmissible only with the animals (Zoonose), but some can be transmitted to the human ones. The human infection is caused by approximately 21 of the 30 species which infect the mammals. Among those one gathers the complex of L. donovani with three species ( L. donovani , L. infantum and L. chagasi ); the complex of L. mexicana with 3 principal species ( L. mexicana , L. amazonensis and L. venezuelensis ); L. Tropica ; L. major ; L. aethiopica ; and the sub-genus Viannia with four principal species ( L. (V.) braziliensis , L. (V.) guyanensis , L. (V.) panamensis , L. (V.) peruviana . The various species are morphologiquement impossible to distinguish, but they can be differentiated by analysis from the Isoenzyme S, analyzes sequences monoclonal DNA, or antibodies.

The visceral Leishmaniose is a severe form in which the parasites migrated in the vital bodies.

Geographical distribution and epidemiology

The leishmaniose can be contracted in many tropical and subtropical countries, and one approximately finds it in areas concerned with 88 countries. Roughly 350 million people lives in the zones of endémie. The climatic conditions compatible with the development of the leishmaniose are very broad, energy of the tropical forests of Central America and South America to the deserts of Occidental Asia. More than 90 percent of the world cases of Leishmaniose visceral meets in India, with the Bangladesh, the Nepal, the Sudan and the Brésil.

The leishmaniose is also found with the Mexico, in Central America, and South America, the north of Argentina in the south of Texas (except in Uruguay or with the Chile), southernmost Europe (the leishmaniose is not widespread at the travellers bound for southernmost Europe), the Asia (except the South-East Asia), the Middle East, and Africa (particularly East and North Africa, with some cases elsewhere). The disease does not exist in Australia or Oceania.

The leishmaniose is present in Iraq and was contracted by a certain number of soldiers of the troops implied in the invasion of this country in 2003 and in its occupation. The soldiers called the disease the furoncle of Baghdad . One reported to the Agence France-Press that more than 650 soldiers of the United States would have contracted the disease between the beginning of the invasion in March 2003 and fine 2004.

In 2004, one calculated that approximately 3400 troops of the army Colombia, operative in the jungle of the south of the country (in particular around the departments of Meta and Guaviare), were reached by the leishmaniose. Apparently, one of the reasons which contributed to this epidemic was the fact that several of the soldiers reached had not used the product Répulsif, placed at their disposal because of an allegedly unpleasant odor. It is estimated that nearly 13.000 cases of the disease were recorded in the whole of Colombia throughout the year 2004, and approximately 360 new cases among soldiers had been listed in February 2005.

In September 2005 the disease was contracted by at least four marine S Dutch which stationed with Mazari Sharif, in Afghanistan and were repatriated for treatment.

Parasitic cycle

The leishmaniose is transmitted by the puncture of the phlebotomi females. The phlebotomi inject the larva at the infectious stage, of promastigotes metacyclic , during the meal of blood (1). The metacyclic promastigotes which reach the wound of puncture are phagocytées by the macrophages (2) and are transformed into amastigotes (3). The amastigotes multiply in the infected cells and reach various fabrics, following (at least partly) the species of Leishmania which is implied (4). These different tissue specificities of attack are the cause of the clinical demonstrations which different in the various forms from leishmaniose. The Phlebotomi infect themselves during the meals of blood on an infected host when they introduce macrophages carrying amastigotes (5.6). In the intestine of the phlebotomus, the parasites are different in promastigotes (7), which multiply and are different in promastigotes metacyclic and migrate in the horn of the Phlébotome (8).

Clinical signs

The symptoms of the leishmaniose are cutaneous wounds which appear weeks or months after the infected person was pricked by the phlebotomus. Among the other consequences, which can become manifest any time as from a few months until several years after infection, one counts the fever, the attack of the Rate and the Foie, and the Anémie. On the medical level, the leishmaniose is one of the causes known of splénomégalie (increase in volume of spleen), which can even become larger as the liver. There are four principal forms of leishmaniose:
  • the visceral Leishmaniose - the most serious form and potentially mortal in the absence of treatment.
  • the cutaneous Leishmaniose - the most widespread form which causes many wounds on the body, which cures in a few months leaving the particularly unaesthetic scars.
  • the cutaneous Leishmaniose diffuses - this form produced of the wide cutaneous lesions which resemble those of leprosy and are particularly difficult to treat.
  • the Leishmaniose cutaneo-mucous membrane - begins with cutaneous ulcerations which extend and damage certain fabrics (in particular nose and the mouth).

Leishmanioses visceral

See also: Leishmaniose visceral

Had with two subspecies of Leishmania donovani : L.D. infantum and L.D. donovani , they are described under the name of Kala-azar.

The world prevalence is about 500.000 new annual cases. They are more frequent in the countries of the Mediterranean circumference, with the Brésil, the Sudan and in the Indian peninsula.

The tanks are the Chien, the Renard and undoubtedly some rodents and the transmission is primarily carried out by the puncture of infected Phlébotome S.

The clinical picture characteristic of the disease is that of a major Splénomégalie weakening with waxy dye and Fièvre, which is constituted in a few months of evolution.

The diagnosis of certainty is affirmed by the identification of the parasite in fabrics. Several serologic methods are available with a good reliability

Leishmanioses cutaneous

See also: Leishmaniose cutaneous

In the old world, they are due to Leishmania major , L. tropica or L. aethiopica . They bear various names according to the areas:

  • Button of the East or Nail of Biskra on the Mediterranean circumference

  • Button of Alep in the Middle East

In the new world, they are due to Leishmania mexicana , L. panamensis , L. amazonensis , L. peruviana , L. braziliensis or L. guyanensis .

  • ATU in Peru

  • espundia in Brazil (tank: Lazy)
  • leishmaniasis americana (wet forest zones of South America)

They all are transmitted by the puncture of infected phlebotomi, and the tanks are various and not always well-known: certain species of rodents, dogs, etc

The button of the East is a lesion of inoculation of the parasite by the phlebotomus vector (North Africa, minor Asia, South America). After 2 weeks of incubation, appears a pruriginous papule which is ulcerated then takes the aspect of a localized furonculose. This lesion is painless and sits on the parts discovered of the body (the face for example). The parasite is found in the content of ulcerations, it must be the subject of a research under the microscope. The treatment is local, it consists of the injection of Antimoniate of méglumine (in France: Glucantime®) all around the lesion. These injections are sometimes renewed second once if the lesion is deep. They do not prevent however the constitution, several weeks, month or years after, of a visceral leishmaniose.

Treatment

There exist two molecules usually used containing Antimoine, the Antimoniate of meglumine (® Glucantim ) and the Stibogluconate of sodium (® Pentostam ). One did not completely elucidate the mechanism of action of these products against the parasite; they can disturb its mechanism of energy production or the metabolism of the Trypanothione. Unfortunately, in much of areas of the world, the parasite became resistant to antimony and for the visceral leishmaniose or cutaneo-mucous membrane. , the Amphotericine is now the treatment of choice. The failure of the AmBisome ® to treat the visceral leishmaniose ( Leishmania donovani ) were reported to Sudan, But this failure can be allotted to factors dependant on the host, the such Co-infection with the HIV or the Tuberculose more than by the resistance of the parasite.

The Miltefosine (Impavido®), is a new drug to treat the visceral leishmaniose and cutaneous. The rate of good performances for the miltefosine in phase III of the clinical trials is of 95%; Studies in Ethiopia show that it is also effective in Africa. Among immunodéprimés patients reached of the HIV and who Co-are infected by the leishmaniose, it was proven that even in the resistant shapes 2/3 of the patients react to this new treatment. Clinical trials in Colombia showed a rate of effectiveness raised for the cutaneous leishmaniose. In the forms cutaneo-mucous membranes caused by L.brasiliensis this treatment was shown more effective than other molecules. Miltefosine received the marketing authorization of the Indian authorities in 2002 and Allemandes in 2004. In 2005 it received the first authorization for the cutaneous leishmaniose in Colombie.La Miltefosine is currently evaluated also for the treatment of the leishmaniose cutaneo-mucous membrane caused by the L.braziliensis in Colombia. (More, et al. , 2003).

In October 2006 it received the statute orphan Médicament of the Food and drug administration of the USA. The molecule is tolerated generally better than of other drugs. The principal side effects are disorders of gastro-intetinaux in the 1 to the first 2 days of the treatment what does not affect its effectiveness. Since it is available for a treatment by oral way, it avoids the expenditure and the disadvantages of the hospitalization, which makes of him an interesting alternative.

The institute for world health developed the Paromomycine, whose results led to its inscription like orphan Médicament.

The initiative of the drugs for the neglected diseases also actively facilitates research for the new therapeutic ones. The leishmaniose resistant to the drugs can answer the Immunothérapie favorably (antigen inoculation of the parasite associated with a Adjuvant) who aims at stimulating the proper immune system of the patient to eliminate the parasite.

Several potential vaccines are developed, at the request of the the World Health Organization, but none is yet available in date of 2006. The team of the organic chemistry laboratory at the federal institute of Swiss technology (ETH) in Zurich tries to design a vaccine containing carbohydrates. The genome of the parasite Leishmania major was sequence. , Which make probably possible the identification of the proteins which are used by the disease-causing agent but not by the human ones; these proteins are the potential targets for medicamentous treatments.

See too

  • leishmanioses visceral (kala azar)

Random links:Abscon | Marco Pannella | Paul Pavlovitch Demidoff | Route main road 786 | Nivolelli Sangiovese untied | Crime_virtuel