Kala azar, also called visceral leishmaniasis or tropical spoverosis, is a disease caused mainly by the protozoa Leishmania chagasi and Leishmania donovani, and occurs when the mosquito of the species Lutzomyia longipalpis, popularly known as a straw mosquito or birigui, is infected with one of the protozoa, bites the person and releases it into the bloodstream.
This type of leishmaniasis mainly affects children over 10 years of age and adults who have nutritional deficiencies, such as lack of iron, vitamins and proteins, and live in places with poor sanitary and hygienic conditions. Brazil’s most affected region is northeast and children are thought to be the most affected because they have more nutritional deficiencies, the immune system is not yet fully formed and they are more exposed to animals.
- After being bitten by the mosquito that transmits the disease.
- The protozoa spread through the bloodstream and the organs responsible for the formation of blood cells and body immunity.
- Such as the spleen.
- Liver.
- Lymph nodes and bone marrow.
- Causing the following symptoms:.
Visceral leishmaniasis has an incubation period of 10 days to two years, and because it is not a common disease and its symptoms appear gradually, it can be confused with other diseases such as malaria, typhoid fever, dengue or Zika, for example. Therefore, in the presence of these symptoms, it is important to consult a doctor so that the diagnosis can be made and appropriate treatment initiated.
It should be remembered that skin lesions and ulcers are caused by another type of leishmaniasis, called skin or skin. Learn what causes it and how to identify skin leishmaniasis.
The main reservoir of protozoa responsible for kala-azar are dogs and are therefore also considered the main source of mosquito infection. That is, when the mosquito bites the infected dog, it acquires the protozoa, which develops in its organism and can be transmitted to the person through the mosquito bite. Not all dogs carry Leishmania chagasi or Leishmania donovani, which is more common in dogs that are not regularly dewormed or do not receive optimal care.
When the parasite is in the mosquito’s body, it can grow easily and then travel to the salivary glands. When the infected mosquito bites the person, it passes the parasite into their salivary glands into the person’s bloodstream, easily spreading through the organs.
The diagnosis of visceral leishmaniasis is made by parasitological examination, during which a culture of bone marrow, spleen or liver is performed in order to observe one of the evolutionary forms of the protozoa. In addition, diagnosis can be made using immunological tests, such as ELISA, or immunochromatographic tests, commonly referred to as rapid tests.
The disadvantage of immunological testing is that even after treatment, there may still be a sufficient amount of antibodies, indicating infection. However, in these cases, it is important for your doctor to evaluate for symptoms, because if there are no symptoms, treatment is not indicated.
Treatment of kala-azar should be initiated as soon as possible and may be performed with the use of specific medicinal products, such as pentavalent antimonial compounds, anfoterin B and pentamidine, which should be indicated by the doctor and used as recommended by the doctor.
When starting treatment, it is also important to take certain precautions, such as evaluating and stabilizing clinical conditions, such as malnutrition and bleeding, as well as treating other infections that accompany it. It may be necessary to remain hospitalized for the use of medication in the vein, but in cases where the infection is stable and access to the hospital is easy, the doctor may recommend treatment at home and go to the hospital for follow-up.
This disease needs to be treated quickly, as it worsens within a few days and therefore the affected person may suffer life-threatening complications such as lung infection, respiratory failure, digestive bleeding, circulatory insufficiency or opportunistic infections, by viruses and bacteria. Learn more about visceral leishmaniasis treatment.