Summary about Disease
Leishmaniasis is a parasitic disease caused by infection with Leishmania parasites, which are transmitted through the bite of infected female phlebotomine sandflies. The disease exists in several forms, the most common being cutaneous leishmaniasis (skin sores) and visceral leishmaniasis (affects internal organs). Leishmaniasis is endemic in parts of the tropics, subtropics, and southern Europe.
Symptoms
Cutaneous Leishmaniasis: Characterized by skin sores or ulcers, which can start as papules or nodules and develop into open sores. These sores can be painless or painful and may heal on their own, though they can leave scars.
Visceral Leishmaniasis: Affects internal organs like the spleen, liver, and bone marrow. Symptoms include fever, weight loss, fatigue, enlargement of the spleen and liver (hepatosplenomegaly), and anemia.
Mucocutaneous Leishmaniasis: Affects the mucous membranes of the nose, mouth, and throat. Symptoms include nasal congestion, nosebleeds, and ulcers in the mouth or nose. This form often develops after cutaneous leishmaniasis and can cause severe disfigurement.
Causes
Leishmaniasis is caused by protozoan parasites of the genus Leishmania. These parasites are transmitted to humans through the bite of infected female phlebotomine sandflies. Sandflies become infected when they bite animals (such as rodents, dogs, and other mammals) that have Leishmania. Different species of *Leishmania* cause different forms of the disease.
Medicine Used
Medications used to treat leishmaniasis vary depending on the type of leishmaniasis, the geographic location, and the patient's overall health. Common medications include:
Liposomal amphotericin B: Often the first-line treatment for visceral leishmaniasis.
Miltefosine: An oral medication used for both visceral and cutaneous leishmaniasis.
Sodium stibogluconate: An older medication, still used in some regions, primarily for cutaneous leishmaniasis.
Pentamidine: An alternative treatment for visceral leishmaniasis.
Paromomycin: Sometimes used in combination with other medications.
Is Communicable
Leishmaniasis is not directly communicable from person to person through casual contact. It is transmitted through the bite of an infected sandfly. However, transmission can occur via blood transfusion, shared needles, or congenitally (from mother to child).
Precautions
Avoid sandfly bites: Use insect repellent containing DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone. Wear long sleeves and pants, especially during dawn and dusk when sandflies are most active.
Use bed nets: Sleep under insecticide-treated bed nets.
Control sandfly breeding: Reduce standing water around your home, as sandflies breed in moist environments.
Control reservoir hosts: In some areas, controlling rodent or dog populations can help reduce the spread of leishmaniasis.
Screen blood donors: In endemic areas, screening blood donors for Leishmania can help prevent transmission through blood transfusions.
How long does an outbreak last?
Outbreaks of leishmaniasis can vary in duration depending on factors such as the Leishmania species involved, the vector sandfly's life cycle and population dynamics, environmental conditions, and the effectiveness of public health interventions. Localized outbreaks in specific regions can last for months or even years if control measures are not implemented effectively. Larger epidemics affecting multiple regions can persist for extended periods, especially in areas with ongoing transmission and limited resources for disease control.
How is it diagnosed?
Microscopy: Examining samples (skin scraping, tissue biopsy, bone marrow aspirate) under a microscope to identify Leishmania parasites.
Culture: Growing Leishmania parasites from samples in a laboratory.
Polymerase Chain Reaction (PCR): Detecting Leishmania DNA in samples. This is a highly sensitive and specific test.
Serology: Detecting antibodies against Leishmania parasites in blood samples. This is useful for visceral leishmaniasis but may be less reliable for cutaneous leishmaniasis.
Skin test (Montenegro skin test): Useful in some regions to detect past exposure to Leishmania.
Timeline of Symptoms
Cutaneous Leishmaniasis: The incubation period (time between sandfly bite and symptom onset) can range from a few weeks to several months. The first sign is often a small papule or nodule at the bite site, which gradually enlarges and may ulcerate.
Visceral Leishmaniasis: The incubation period is typically 2 to 6 months, but can range from 10 days to over a year. Initial symptoms may include fever, fatigue, and weight loss. As the disease progresses, enlargement of the spleen and liver (hepatosplenomegaly) and anemia become more prominent.
Mucocutaneous Leishmaniasis: This form usually develops months or years after the initial cutaneous infection.
Important Considerations
Leishmaniasis can be a serious and potentially fatal disease, especially visceral leishmaniasis.
Early diagnosis and treatment are essential to prevent complications.
The choice of treatment depends on the type of leishmaniasis, the severity of the infection, and the patient's overall health.
People traveling to or living in endemic areas should take precautions to avoid sandfly bites.
Some medications used to treat leishmaniasis can have significant side effects, so careful monitoring is necessary.
Co-infection with HIV can make leishmaniasis more severe and difficult to treat.
Drug resistance is a growing concern in some regions.