What are the other Names for this Condition? (Also known as/Synonyms)

• Dumdum Fever
• Kala-Azar
• Systemic Leishmaniasis

What is Visceral Leishmaniasis? (Definition/Background Information)

• Leishmaniasis is a widespread, global disease that is caused by protozoa (of the Leishmania genus), which is transmitted through the bite of an infected female sandfly (a type of insect) in the tropical and subtropical regions
• There are 3 main types of Leishmaniasis that include:
  • Cutaneous Leishmaniasis, which affects the skin
  • Mucocutaneous Leishmaniasis, which affects the skin and mucous membrane
  • Visceral Leishmaniasis, which affects the entire body (systemic)
• Visceral Leishmaniasis (VL) is the most severe form of Leishmaniasis that affects the entire body and presents systemic signs and symptoms. It is mostly caused by 2 separate species of Leishmania protozoa, which are mainly found in south Asia (Indian subcontinent), east Africa, parts of north and south America, and parts of Europe
• People, who generally belong to economically weaker sections in the endemic regions, have a high risk of infection. Those who stay or travel to the rural areas are more exposed than individuals in the urban areas. But, individuals who are immunocompromised have severe signs and symptoms. In them, Visceral Leishmaniasis can be fatal
• Visceral Leishmaniasis is characterized by fever, weakness, loss of weight, anemia, and swelling of the liver and spleen. Depending upon the type of infection, the complications may include bone marrow involvement, organ failure, and severe damage to the immune system
• The treatment of Visceral Leishmaniasis involves medications and topical applications (when the skin is affected). It is based on the type and severity of the infection. Since, human infection can be caused by different species of Leishmania; the treatment also depends upon the geographical location. Treatment of underlying health conditions has to be attended to in those with poor immune system
• The prognosis depends upon the promptness in providing treatment, which can bring about a better outcome. However, in general, the prognosis of Visceral Leishmaniasis is guarded. It depends upon the health status of the individual and the severity of the signs and symptoms

Who gets Visceral Leishmaniasis? (Age and Sex Distribution)

Individuals of all ages are at risk for Visceral Leishmaniasis infection, if they are exposed to sandfly bites. There is no gender, race, or ethnicity preference noted. However, Visceral Leishmaniasis is endemic to certain regions of the world as indicated below:

• Bangladesh
• Brazil
• Ethiopia
• India
• Nepal
• Sudan

What are the Risk Factors for Visceral Leishmaniasis? (Predisposing Factors)

The risk factors for Visceral Leishmaniasis may include:

• Individuals with weak immune system owing to factors, such as HIV infection or other disabling conditions
• People living at the following geographical locations (tropics and subtropics):
  • Africa
  • Asia
  • Middle-East Asia
  • North America
  • South America
  • Southern Europe
• Traveling or visiting places where Visceral Leishmaniasis is common
• Climatic conditions and environmental changes can increase the risk of Leishmaniasis. These include deforestation, development and expansion of cities, and construction of dams
• According to the World Health Organization (WHO), certain socio-economic indicators point to a higher risk of infection. These include:
  • Poverty
  • Malnutrition
  • Famine
  • Illiteracy
  • Lack of sanitation and proper hygiene
  • Large-scale migration and settlements
• Leishmaniasis is more common in the villages and small towns (especially in the outskirts) than in the cities

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Visceral Leishmaniasis? (Etiology)

Visceral Leishmaniasis is an infectious disease caused by the bite of sandflies; small flying insects that are smaller than mosquitoes and less noisy. The sandflies transmit Leishmania organisms, which are protozoan parasites, in blood causing the infection.

• Over 2 different species of Leishmania parasites have been identified and studied that include:
  • L. donovani
  • L. infantum
• An uninfected sandfly gets infected by feeding on the blood of infected people or animals (such as dogs, cattle, foxes, or rodents)
• Very rarely, transmission can also take place during the following events:
  • Blood transfusion
  • Sharing of contaminated needles
  • Pregnant women can transmit the parasite to their unborn child
• The transmission risk is high from dawn to dusk when the sandflies are active

What are the Signs and Symptoms of Visceral Leishmaniasis?

Only a small subset of infected individuals develops signs and symptoms of the infection. The signs and symptoms of Visceral Leishmaniasis (that may develop within a few months of infection) include:

• Weight loss that may be significant
• Fever and fatigue
• Enlarged lymph nodes (lymphadenopathy)
• Enlarged spleen and liver (hepatosplenomegaly)
• Low blood cell counts (pancytopenia) that can cause anemia, leukopenia, and thrombocytopenia with accompanying signs and symptoms
• High level of globulin in blood (or hypergammaglobulinemia)
• Skin signs and symptoms may be observed that includes darkening of skin

How is Visceral Leishmaniasis Diagnosed?

A physical examination, assessment of the signs and symptoms, and medical history evaluation of the infected individual may be indicative of Visceral Leishmaniasis. However, the healthcare provider may perform the following tests to definitely diagnose the condition:

• Blood tests to detect antibodies against the parasite
• A tissue sample is obtained from the spleen, liver, or bone marrow and observed under the microscope to detect the parasite
• Bone marrow aspiration
• A biopsy of the enlarged lymph node may also be performed

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Visceral Leishmaniasis?

Visceral Leishmaniasis affects the entire body and can be a fatal condition, if it is left untreated (or inadequately treated). It may lead to complications that include:

• Severe bleeding
• Deadly infections due to immune system damage
• Kidney abnormalities; renal failure is a possibility
• The gastrointestinal tract and lungs can be affected
• Bone marrow involvement may be seen

Post Kala-Azar Dermal Leishmaniasis (PKDL): It is a condition that occurs in 5-60% of the individuals with Visceral Leishmaniasis (also known as Kala-Azar) following treatment. The condition affects the face and other parts of the body. However, some cases are known to resolve automatically without treatment, while others may require additional therapy.

How is Visceral Leishmaniasis Treated?

The treatment for Visceral Leishmaniasis differs from one individual to another. Proper consultation with the infectious disease consultants and public health officers are generally recommended before treatment starts. The treatment measures include:

• Intravenous medication (that may include intramuscular injections)
• Topical ointments, if required
• For fungal (secondary) infections that develop due to Leishmaniasis, antifungal medication are prescribed

The medications administered vary depending upon the type of Leishmania species causing the infection.

How can Visceral Leishmaniasis be Prevented?

Currently, no vaccination has been discovered to prevent Leishmaniasis. Research is being undertaken to develop a vaccine at the earliest. Nevertheless, the following preventive and precautionary measures may be taken to reduce the spread and impact of Visceral Leishmaniasis:

• Avoid exposure to sandfly bites
• Wear protective clothing, such as long sleeves, long pants, and socks, to protect the skin from the insect bites; minimize exposed skin areas
• Use insect repellents containing DEET, permethrin, or deltamethrine; one’s clothing and bed can be suitably sprayed with the repellents
• Prevent entry of sandflies into homes by keeping the windows and doors suitably closed; use finely-meshed bed nets (that are tucked into the mattress) while sleeping
• Sandflies are more active during dusk or at night; knowing their pattern, one can take steps to minimize outdoor activities or take suitable preventive measures against the bites accordingly
• Dogs can be fitted with collars containing insect repellents
• Local strategies (specific to each community or locality) and community development to eliminate Leishmaniasis should be encouraged
• Immediately attend to any condition that results in a weak immune system

What is the Prognosis of Visceral Leishmaniasis? (Outcomes/Resolutions)

• An early diagnosis and treatment of Visceral Leishmaniasis generally results in better prognosis
• A delayed treatment or incomplete treatment may lead to severe complications and recurrence of the infection (after a long duration of time); severe cases can be fatal
• Since Visceral Leishmaniasis generally occurs in individuals with underlying health conditions that affect immunity (such as HIV infection or AIDS), it is often fatal. Death usually results from severe complications of the underlying condition rather than from Visceral Leishmaniasis itself

Additional and Relevant Useful Information for Visceral Leishmaniasis:

Animals, such as dogs, rats, and cattle, can also be infected by Leishmaniasis. According to the World Health Organization, over 70 species of animals act as hosts for the Leishmania organism.