Protect yourself from sandfly bites | Daily News

Protect yourself from sandfly bites

Leishmaniasis is a worldwide vector borne zoonotic disease caused by several heteroxenous intracellular parasitic organisms of genus Leishmania. The disease has several different forms including three main forms, namely, visceral leishmaniasis (VL), cutaneous leishmaniasis (CL), and mucocutaneous leishmaniasis (MCL), where VL is considered to be the most virulent form of the disease. Although several case reports provide evidences for sexual or vertical transmission, the main method of transmission of this disease is through the bite of the female sand flies of subfamily Phlebotominae. The sand fly bite is believed to occur from dawn to dusk. But the Sri Lankan experience shows otherwise and indicates that people are bitten by this disease carrying insect even during day times. The life cycle of the Leishmania parasite has a biological phase within the body of the sand fly and that has to be completed for the disease to be transmitted to a human. The Sinhala name for the sand fly is either velimessa or hohaputuwa. Leishmaniasis has been listed as one of the eight major neglected tropical parasitic diseases with prevalence in more than 90 countries where 88 of them are endemic to the disease.

Senior Registrar in Community Medicine and Head of the Health Care Quality Unit, Department of Health, Southern Province, Dr. Amila Chandrasiri MBBS (Colombo), MSc, MD (Community Medicine), Diploma in International Relations) talks about Leishmaniasis.

Q - What is Leishmaniasis?

A- Leishmaniasis is a parasitic disease caused by the parasite Leishmania donovani. It is seen in tropical countries. Recently it emerged in Sri Lanka as well especially in the Southern province. So we need to pay attention and be aware of this disease.

It appears in several forms. The most common forms are skin or cutaneous Leishmaniasis, which causes skin sores, and internal or Visceral Leishmaniasis, which affects several internal organs (usually spleen, liver, and bone marrow). It can cause ulcers in nose, mouth, or throat (which is known as Mucosal Leishmaniasis).

Q - Is it a deadly disease?

A- Yes. But skin form is usually not fatal. But if left untreated severe (advanced) cases of Visceral Leishmaniasis can bring death.

Q - How is Leshmaniasis transmitted?

A- It is spread by the bite of sand fly (phlebotomine). These insects are so tiny and can move very fast. People usually are bitten when they work outside.

Q - What are the symptoms of Leishmaniasis?

A- Some have asymptomatic infections. Commonest presenting complain is a non healing ulcer - The ulcer may start out as a little bump and may end up as ulcers (like a volcano, with a raised edge and central crater); skin ulcers may be covered by scab or crust. The sores usually are painless but can be painful. Some people have swollen glands near the sores (for example, under the arm, if the sores are on the arm or hand).

In internal type fever, weight loss, enlargement (swelling) of the spleen and liver can be seen.

Q - What are the investigations done for Leishmaniasis?

A- For definitive diagnosis, tissue samples from skin sores (for cutaneous leishmaniasis) or from bone marrow (for visceral leishmaniasis) can be examined for the parasite under a microscope. In addition to that antibody tests can also be done. Full Blood Count also shows certain changes like low red blood cell count (anemia), a low white blood cell count, and a low platelet count.

Q - How do you treat Leishmaniasis patients?

A- There are few treatment methods depending on type of Leishmaniasis. For skin type, a special therapy call cryotherapy is being done. In addition to that injecting drugs around the ulcer is also done. Oral drugs are given. For visceral type, IV drugs (as injections) are also given.

Q - How can we prevent Laishmaniasis?

A- It is difficult to control vector. Best way is avoiding bites. Avoid outdoor activities, especially from dusk to dawn (evening, night till next morning), when sand flies generally are the most active. Apply insect repellent to exposed skin and wear long-sleeved shirts, long pants, and socks.


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