Sandfly Bites and Cutaneous Leishmaniasis

The information here should be relevant for sandfly bites anywhere in the world, but it is based on my experiences with sandfly bites in the Philippines. In the US, sandflies are often called noseeums or no-see-ums. In the Philippines, sandflies are only known by the name nicnics or nic nics.

Many of the beaches of the Philippines, especially in Palawan, have sandflies. I have been bitten on the Palawan beaches of Port Barton (San Vicente), El Nido and the west coast of Puerto Princesa including Sabang. They mostly bite around sunrise and sunset you won’t see them because they are so small – hence the other name no-see-ums. The next day the bites will become extremely itchy. If you are bitten, serious lesions can develop in only a few days. The affliction that I have experienced numerous times is called Cutaneous Leishmaniasis. These are the skin sores resulting from a tropical infection by parasitic protozoa of the genus Leishmania, which are spread by the (female) sand fly. The sores are sometimes mistakenly called tropical ulcers, but any bite can develop into that in the tropics.

You will know you have Cutaneous Leishmaniasis developing if all normal treatment fails and the wounds become progressively bigger and finally become painful. Infection dwells underneath the scabs, and in my case, it was much more serious than it looked. The parasite destroys the skin cells, leaving a huge cavern underneath the scab. These wounds are not to be left for a better time to treat -they can leave permanent scars.

Prevention

The most effective preventative is to apply insect repellant with a high concentration of DEET. In Palawan, "OFF!" is widely sold and has the recommended high concentration of DEET. You can also mix the repellant with sun tan lotion, coconut oil or any other oil. Filipino locals use mostly coconut oil, although eucalyptus oil is preferred by those who can afford it. Sun tan lotion works just as well. I once took off my T-shirt for about 15 minutes so as to get a bit of sun on my skin. On this occasion I was only bitten where the T-shirt had covered my torso - there were no bites on the areas where I had applied sun-tan lotion.

Treatment

If treated early enough, the bites should not develop beyond being just itchy insect bites.

Sandfly bites may develop into Cutaneous Leishmaniasis. If this happens, there are two topical antibacterial medications that may be used to treat it. Mupirocin Bactroban is the local brand for a 2% antibacterial ointment, and it is widely available in the Philippines. The antibiotic Amoxicillin is my preferred treatment. This oral Amoxicillin is available in capsules and tablets, but it is best to get the capsules. It isreadily available throughout the Philippines at about P7 per capsule The amoxicillin powder in the capsule is sprinkled onto the bite (not swallowed!). The tablet can also be used but needs to be ground up first. All of the Filipinos who I have spoken to only use Amoxicillin to treat sandfly bites. The advantage of amoxicillin powder is that it dries up the sore and becomes part of the scab – this is a real advantage in the tropics where the humidity is very high. Bactroban is a cream and therefore does not dry up the bite.

If no scab has formed yet, clean the area with alcohol or a betadine solution and apply some Amoxicillin powder or antibacterial ointment. Keep this up for a few days. I always cover the bite with an adhesive bandage and some gauze so that I don’t scratch the itch in my sleep.

If a scab has already formed, do the following. Mix hydrogen peroxide with betadine 50/50 - using a ball of cotton wool, dab the wound with this mix. It will dissolve the scabs and reveal what's underneath. Once the wound is open and clean, apply Amoxicillin powder or antibacterial ointment. Cover with a patch of open weave gauze and tape into place. Repeat this process twice a day or more until the wounds are no longer infected and starting to heal. Repeat treatment immediately after your shower. This can take one week to 10 days +, depending on severity. If the bites are seriously infected, you may need to take a full course of oral antibiotics – see a doctor about this.

Pictures of My Sandfly Bites

If you want to see what my sandfly bites looked like, then click below. Warning - the pictures are a little horrible.

Pictures of My Sandfly Bites

For more information about Leishmaniasis

The Tropical Disease Research (TDR) centre (supported by WHO, UNICEF and others) has good information about this disease. Click on their "animated life-cycle of Leishmaniasis" and see how the parasite multiplies and destroys the body cells.

http://www.who.int/tdrold/diseases/leish/lifecycle.htm (needs Flash player)

Please note that I am not a medical professional. The information and treatment is based on what I have learnt from my many experiences of sand fly bites, plus what I have garnered from people who live in sandfly infected areas in the Philippines.