Visceral leishmaniasis

Visceral leishmaniasis in the Old World has two varieties - Mediterranean (childhood) visceral leishmaniasis (VL) and Indian visceral leishmaniasis (adult leishmaniasis, kala-azar).

What causes visceral leishmaniasis?

Visceral leishmaniasis is a typical zoonosis with natural foci. The reservoir of the pathogen (L. infantum) in the wild are various representatives of the dog family (Canidae) - fox, jackal, corsac fox, etc., and in populated areas - dogs. In animals, leishmaniasis develops slowly, and the source of infection can be individuals without visible external signs of the disease. In dogs, along with damage to internal organs, skin lesions are often observed (mainly on the head), which are the site of localization of leishmania and serve as a source of infection for mosquitoes. Transmission of the pathogen from sick wild animals or dogs to humans occurs through a mosquito bite. Visceral leishmaniasis mostly affects preschool children, much less often - adults.

Symptoms of visceral leishmaniasis

The incubation period of visceral leishmaniasis can be from 2 weeks to 1 year or more, but on average it is 3-5 months, so cases of the disease are registered all year round, with a predominance in the winter and spring months. Often in children under 1.5 years old, at the site of a mosquito bite, you can find a primary affect - a small pale pink nodule. Visceral leishmaniasis is characterized by the gradual development of intermittent fever. Another symptom of visceral leishmaniasis is splenomegaly: the spleen increases quickly and evenly, and the liver, as a rule, less intensely. Sometimes there is an increase in peripheral lymph nodes. Characteristic signs of visceral leishmaniasis are also: progressive anemia, leukopenia, thrombocytopenia, hyper- and dysproteinemia, increased ESR, increasing exhaustion, hemorrhagic syndrome. Complications associated with secondary infection usually occur. In young children, all clinical manifestations occur more acutely; in adults, visceral leishmaniasis often occurs chronically; the disease lasts from 3 months to 1 year, less often up to 1.5-3 years. In some infected people, mainly adults, visceral leishmaniasis has a subclinical course and can manifest itself after 2-3 years or even 10-20 years when exposed to provoking factors (HIV infection, etc.).

Visceral leishmaniasis, as an AIDS-associated invasion, has one important, fundamental difference from other opportunistic invasions (infections), namely: it is non-contagious, i.e. it is not transmitted directly from the source (animals, humans) of invasion to humans. In the countries of Southern Europe in the early 90s of the last century, 25-70% of cases of visceral leishmaniasis in adults were associated with HIV infection, and 1.5-9% of AIDS patients suffered from VL. Of the 692 registered cases of co-infection, about 60% were in Italy and France. The overwhelming majority of cases of co-infection (90%) were in men aged 20-40 years.

In Russia, the first case of VL/HIV co-infection was diagnosed in 1991.

Treatment of visceral leishmaniasis

Without specific treatment, 98-99% of patients with visceral leishmaniasis die from severe complications and additional infection. Correct diagnosis and timely treatment of visceral leishmaniasis lead to complete recovery.