Sandflies & Civil War

The Syrian civil war has set the stage for the reemergence of a rare infectious disease. Transmitted through the bite of the sandfly, Leishmaniasis is a parasite that can affect many different parts of the body. The most prevalent form in the Middle East is called Cutaneous Leishmaniasis, which causes disfiguring welts and scarring of the skin. A more lethal variant known as Visceral Leishmaniasis can also damage the spleen and liver.

Since the Syrian conflict began in 2011, the number of Leishmaniasis cases has skyrocketed from 3,000 to over 100,000. Water shortages and poor sanitation have combined to create conditions ripe for the transmission of the disease. To make matters worse, the pentavalent antimonial drugs used to treat Leishmaniasis are becoming increasingly scarce.  In times of conflict, Public Health tools such as surveillance, multi-sector response, and international collaboration rapidly diminish states Dr. Peter Hotez, Dean of the National School of Tropical Medicine at Baylor College of Medicine and President of the Sabin Vaccine Institute.

Lifecycle: Sandfly & Human Stages

 

Signs & Symptoms

Cutaneous Leishmaniasis:

• Skin sores usually occur within a few weeks or months of a sand fly bite
• Lesions may vary in size and appearance over time
• Sores may begin as papules (bumps) or nodules (lumps) and then form into ulcers (raised edge and central crater) that may be covered by scab or crust.
• Skin lesions are usually painless but can be painful.
• Some individuals may have swollen lymph nodes near the sores

Visceral Leishmaniasis:

• Affects several internal organs (spleen, liver, and bone marrow) and may be life threatening
• Usually develops within months (sometimes as long as years) of the sand fly bite
• Patients usually have fever, weight loss, enlargement of the spleen and liver
• Infected individuals will also have low blood counts: a low red blood cell count (anemia), a low white blood cell count (leukopenia), and a low platelet count (thrombocytopenia)

Treatment: Moving from Injectable to Oral Medications

The majority of cutaneous Leishmaniasis cases occur in Afghanistan, Algeria, Brazil, Colombia, the Islamic Republic of Iran, Pakistan, Peru, Saudi Arabia and the Syrian Arab Republic. According to the CDC recommendations for Health Professionals:

Therapy of cutaneous leishmaniasis may be indicated to:

• decrease the risk for mucosal dissemination/disease
• accelerate healing of the skin lesions
• decrease the risk for relapse (clinical reactivation) of the skin lesions
• decrease the local morbidity caused by large or persistent skin lesions, particularly those on the face or ears or near joints
• decrease the reservoir of infection in geographic areas where infected persons (vs. non-human animals) serve as reservoir hosts (such as in Kabul, Afghanistan, and other Leishmania tropica-endemic areas, where transmission is anthroponotic)

In general, the first sign of a therapeutic response to adequate treatment is decreasing induration (lesion flattening). The healing process for large, ulcerative lesions often continues after the end of therapy. Relapse (clinical reactivation) typically is noticed first at the margin of the lesion.

Treatment usually consists of intravenous or intra-muscular medications for approximately 3-4 weeks, and many are generic options with internationally-mediated price controls. However, Miltefosine is currently the only oral medication to treat cutaneous and visceral forms.

Novel and low-cost therapies are on the horizon, such as thermotherapy.

 

Prevention: Cover up and Apply Insect Repellant

Preventive medicine could be the key to controlling the current epidemic. Bed nets and insecticides have been shown to control sand fly populations, while drug administration can help limit transmission between individuals. However, these measures will be difficult to enact until the conflict is over and the sandfly is much smaller than the mosquito and more difficult to use nets as a barrier. In the meantime, researchers in the US are working to develop a vaccine.

 

Looking for more information? Learn about Global Leishmaniasis from the WHO.

Report written by Paul Hausknecht