What is a sand fly the diseases it causes and how to treat it

Despite its small size, the sandfly is one of the most dangerous disease-carrying insects, primarily transmitting leishmaniasis. This disease causes painful skin ulcers and, in some cases, can spread to internal organs, becoming life-threatening. Many people don't initially notice its bite, but if left untreated, it can lead to serious health complications. In this Dalili Medical article, we’ll discuss in detail the symptoms of a sandfly bite, how to distinguish it from other insect bites, and the best treatment and prevention methods.

When Does the Sandfly Appear?
The sandfly transmits the Leishmania parasite through its bite and is most active from dusk until dawn—during the evening, twilight, and night. It is more common in rural areas, especially in places with high humidity or animal gatherings.

What Does a Sandfly Bite Look Like?
A sandfly bite appears as dark spots or skin lesions that develop in stages, starting as red bumps (erythematous papules), then progressing into plaques and scars. This can occur months or even years after visceral leishmaniasis infection. In some cases, ulcers may spread to multiple areas and persist for years or even decades if left untreated.

Does the Sandfly Fly Long Distances?
No, sandflies do not travel far. They usually move only about 100 meters from their breeding sites. This makes their spread easy, especially if their breeding areas are close to humans, increasing the risk of infection. Sandflies typically bite exposed areas of the body, such as the face, hands, and legs.

☠️ How to Kill a Sandfly?

Lifespan
A sandfly lives for about 2 to 6 weeks and dies naturally after that.

Heat & Climate Changes
Extreme heat or cold affects them, causing them to die faster if the weather is unsuitable.

Insecticides
Powerful insecticides like pyrethroids can quickly kill them if sprayed in their habitats.

Natural Remedies
Certain essential oils, such as tea tree, peppermint, and lavender, help repel sandflies and reduce their presence.

Manual Killing
If you spot one, you can kill it manually or use sticky insect traps.

Predators
Spiders, ants, dragonflies, and some birds prey on sandflies, helping to control their population.

Diseases Transmitted by Sandflies

Sandflies are not just annoying insects—they are dangerous vectors for parasitic diseases, the most serious being leishmaniasis, but they can also carry lesser-known diseases.

1. Leishmaniasis – The Deadliest Disease They Transmit

Cause: Leishmania parasites.

How Does It Spread?
A sandfly bites an infected animal, such as dogs or rodents, and then transmits the parasite to humans through its bite.

Types of Leishmaniasis:

Cutaneous leishmaniasis → Causes skin ulcers that may leave permanent scars.
Visceral leishmaniasis (Kala-azar) → Affects the liver and spleen and is extremely dangerous.
Mucocutaneous leishmaniasis → Attacks the nose, mouth, and throat tissues, leading to severe disfigurement.

Symptoms:

Slow-healing skin ulcers
High fever and fatigue (especially in visceral leishmaniasis)
Weight loss & organ enlargement (liver and spleen swelling)

Treatment:

Anti-parasitic medications like Glucantime or Amphotericin B.

2. Phlebotomus Fever – Also Known as Sandfly Fever

Cause: A virus from the Bunyaviridae family.

How Does It Spread?
The sandfly bites a human and transmits the virus, though it is less dangerous than leishmaniasis.

Symptoms:

Sudden high fever
Severe headache & extreme fatigue
Muscle and joint pain
In rare cases, it may lead to meningitis.

Treatment:
There is no direct cure, but symptoms improve over time with pain relievers and fever reducers.

3. Other Bacterial & Parasitic Infections

In some cases, sandflies may transmit bacteria or other parasites, leading to skin infections or digestive issues. However, these are much rarer than leishmaniasis.

Does a Sandfly Bite Hurt?

No, the bite is not painful at first because the sandfly is very small, and its proboscis is thin. This means a person may not feel the bite at the time. However, after a while, the bite area starts to itch intensely and swell, caused by the saliva injected by the sandfly while feeding on blood.

Symptoms of a Sandfly Bite

The symptoms vary depending on the type of parasite transmitted by the sandfly, but in general, it can cause:

1. Localized Symptoms (at the bite site)

Redness and swelling of the skin.
Severe itching that can last for several days.
Pain or a burning sensation at the bite site.
Ulcer formation in case of Leishmania infection.

2. Symptoms of Cutaneous Leishmaniasis (if the sandfly transmits the Leishmania* parasite)*

An open ulcer develops at the bite site within weeks.
The edges of the ulcer become raised and hardened, with a fluid-filled center.
Multiple ulcers may appear, especially if the affected area is scratched.
Swelling of nearby lymph nodes may occur.

3. Symptoms of Visceral Leishmaniasis (Kala-azar) (if the parasite spreads to the bloodstream and internal organs—this is the most dangerous type)

High fever.
Rapid weight loss & loss of appetite.
Swelling of the liver and spleen (causing abdominal bloating).
Anemia, extreme fatigue, and dizziness.
Darkening of the skin (hence the name “Black Fever”).

4. General Symptoms That May Occur

Persistent headache.
Muscle and joint pain.
Nausea or vomiting (in some cases).

When Should You See a Doctor?

If the ulcer does not heal within 3 weeks or starts to grow.
If you develop severe fatigue, fever, or unexplained weight loss.
If you are in an area known for Leishmania outbreaks, such as rural and desert regions.

Where Do Sandflies Live?

Sandflies prefer hot and humid areas, such as villages, deserts, and agricultural lands. They hide in cracks, caves, under rocks, and among plant debris. Their activity increases at night, especially in summer, and they prefer dark, humid places away from wind.

Why Are Sandflies Dangerous?

Sandflies are not just ordinary insects—they transmit Leishmaniasis, a skin disease that can cause ulcers and permanent scars if left untreated. They feed on human and animal blood, and because their proboscis is very thin, their bite often goes unnoticed at first. However, it later causes severe itching and inflammation.

Characteristics of the Sandfly

1. Size & Appearance

Very small, about 2-3 mm in size.
Light yellow or brown in color, covered in fine hairs, giving them a dusty look.
Transparent wings, which are relatively large and remain spread out rather than folded like regular flies.
Long, thin legs that help them move easily.

2. Flying & Movement

Their flight is irregular, more like jumping than flying.
Slower than mosquitoes and usually fly close to the ground.

3. Habitat & Locations

Found in deserts and agricultural areas, where the weather is hot and humid.
Prefer dark, humid places, hiding in cracks, caves, under stones, and among plant debris.
Most active at night, especially in summer.

4. Feeding & Behavior

Male sandflies feed on plant sap, but females need blood to lay eggs.
They bite both humans and animals, and while their bite does not hurt initially, it causes intense itching later.

5. Diseases Transmitted by Sandflies

The most dangerous disease they transmit is Leishmaniasis, which causes skin ulcers and scars.
They can also transmit other parasitic diseases, though Leishmaniasis is the most common.

6. Life Cycle

Sandflies go through four stages: egg → larva → pupa → adult fly.
They require humidity and warmth to reproduce, and their eggs are laid in dark, moist places, such as damp soil or under rocks.

How to Prevent Sandfly Bites?

Use insecticides and mosquito nets at night.
Wear long clothing in areas where sandflies are common.
Seal cracks and openings in walls to prevent them from hiding.
Dispose of organic waste and eliminate breeding grounds.

Life Cycle of the Sandfly

The sandfly goes through four stages in its life cycle and requires specific conditions such as temperature, humidity, and a food source to complete its development.

1. Egg Stage

After the female feeds on blood, she lays her eggs in moist, shaded areas, such as wall cracks, under rocks, damp soil, or among plant and animal debris.
The eggs are very small and light-colored, hatching within 6 to 17 days, depending on temperature and humidity.

2. Larva Stage

Once the egg hatches, a tiny, legless white larva emerges, which later darkens to a grayish color.
The larva feeds on decaying organic matter, such as plant remains or dead insects.
It undergoes four growth stages, shedding its skin each time to grow bigger.
This stage lasts from a few weeks to several months, depending on temperature and humidity.

3. Pupa Stage

When the larva matures, it enters the pupa stage, during which it forms a small cocoon in a safe place like soil or cracks.
During this stage, the sandfly's body transforms into its adult form.
This process takes around 10 days to 3 weeks.

4. Adult Sandfly Stage

After the pupal stage, the adult sandfly emerges, fully developed and ready to fly and reproduce.
Males feed on plant sap, while females require blood meals to lay eggs.
The entire life cycle lasts between 1 to 3 months, depending on environmental conditions.

When Is the Sandfly Dangerous?

Only the female sandfly bites and transmits Leishmaniasis after feeding on the blood of an infected animal or human.
It is active at night and prefers humid, abandoned places.

Difference Between Sandfly and Common Housefly

Although both are types of flies, there are major differences between them in size, appearance, movement, feeding habits, and the diseases they transmit.

Feature	Sandfly	Common Housefly
Size	Very small (2-3 mm)	Relatively larger (5-8 mm)
Color	Light yellow or dusty brown	Dark gray or black with stripes
Wings	Transparent, large compared to its body, remains open	Transparent, smaller, and folds over its body
Flying Pattern	Irregular, jumps more than flies	Fast and stable flight
Habitat	Moist, dark places (cracks, caves, under rocks)	Open areas, garbage, homes, farms
Feeding	Females suck blood, males feed on plant sap	Feeds on decaying food and waste
Activity	Active at night, especially in summer	Active during the day, at any time
Diseases Transmitted	Leishmaniasis (a serious skin disease)	Typhoid, cholera, dysentery, food poisoning
Prevention	Using mosquito nets, insecticides, wearing long clothes	Proper waste disposal, covering food, spraying insecticides

Conclusion

The sandfly is more dangerous because it transmits Leishmaniasis, which causes severe skin ulcers.
The common housefly is more widespread in homes and spreads digestive diseases.
The sandfly is very small and hard to notice, while the housefly is larger and moves quickly.

Leishmaniasis Disease

Leishmaniasis is a parasitic disease transmitted to humans through the bite of an infected sandfly carrying Leishmania parasites. The disease has different types, with cutaneous leishmaniasis being the most common, causing skin ulcers that can leave permanent scars.

Types of Leishmaniasis

1. Cutaneous Leishmaniasis (Most Common)

✔ Causes skin ulcers that start as a small bump or swelling at the bite site.
✔ The sores may grow over time and leave a permanent scar.
✔ It does not affect internal organs, but it is painful and disfiguring.

2. Visceral Leishmaniasis (Most Dangerous)

✔ Affects internal organs such as the liver, spleen, and bone marrow.
✔ Serious symptoms include:

Persistent fever that does not go away easily.
Rapid weight loss and extreme fatigue.
Enlarged liver and spleen (swollen abdomen).
Anemia and weakened immune system, making the patient vulnerable to other infections.
✔ If not treated quickly, it can be fatal.

3. Mucocutaneous Leishmaniasis (Rare but Severe)

✔ Affects the nose, throat, and mouth.
✔ Causes severe ulcers that destroy mucosal tissues.
✔ Can lead to permanent facial deformities if left untreated.

How Is the Disease Transmitted?

The sandfly bites an infected animal (such as dogs, rodents, or foxes).
The parasite enters the fly’s body and develops inside it.
When the sandfly bites a human, it transmits the parasite, which then spreads in the body.

Symptoms

Cutaneous Leishmaniasis:

✔ Skin bumps or ulcers at the bite site.
✔ May appear as a single lesion or spread over multiple areas.

Visceral Leishmaniasis:

✔ Persistent fever lasting for weeks.
✔ Extreme fatigue and rapid weight loss.
✔ Swollen liver and spleen.
✔ Weak immune system, increasing the risk of other infections.

Mucocutaneous Leishmaniasis:

✔ Nasal congestion or bleeding.
✔ Mouth and throat ulcers, making eating and speaking difficult.

Treatment & Prevention

Treatment:

✔ Anti-parasitic medications such as Glucantime or Amphotericin B (depending on the type of infection).
✔ Some cutaneous cases heal on their own, but treatment is recommended to prevent scarring.
✔ Visceral and mucocutaneous leishmaniasis must be treated quickly because they are life-threatening.

Prevention:

✔ Avoid sandfly bites using mosquito nets and insect repellents.
✔ Wear long clothing in areas where the disease is common.
✔ Control rodents and infected dogs, as they are carriers of the parasite.

Where Are Sandflies Found?

Sandflies prefer hot and humid areas and thrive in specific regions that provide the right environment.

Countries with Sandflies:

Middle East: Egypt, Saudi Arabia, Iraq, Syria, Yemen, Jordan, Palestine, Lebanon.
North Africa: Algeria, Morocco, Tunisia, Libya, Sudan.
South America: Brazil, Bolivia, Peru, Colombia.
South Asia: India, Pakistan, Afghanistan, Iran.
Some European Countries: Turkey, Spain, Italy (in limited areas).

Preferred Habitats:

✔ Rural and desert areas: Sandflies thrive in moist soil, farms, rocks, and animal burrows.
✔ Caves and abandoned places: They prefer dark, quiet locations away from the wind.
✔ Wall cracks and under rocks: They hide in tight spaces during the day and come out at night.
✔ Animal farms: Since dogs, rodents, and livestock can be a food source and disease carriers.

When Are Sandflies Most Active?

✔ Most active in summer and during hot weather.
✔ They are nocturnal, and their bites are more aggressive in warm, humid conditions.
✔ Their population decreases significantly in winter or disappears completely.

How to Avoid Sandfly Bites?

Sandflies are very small and hard to see, but they are dangerous because they can transmit leishmaniasis. To protect yourself from their bites, follow these precautions:

Avoid Going Out During Their Active Hours

✔ Sandflies are most active at night, especially at dusk and dawn, so try to avoid open areas during these times.
✔ If you must go out, wear long clothing to cover your skin.

Use Personal Protection

1. Wear the Right Clothes

✔ Wear long-sleeved shirts and pants instead of shorts.
✔ Light-colored clothing is better, as sandflies are attracted to dark colors.
✔ Use socks and closed shoes instead of sandals.

2. Use Insect Repellents

✔ Apply insect repellents containing DEET or Picaridin on exposed skin.
✔ Spray insect repellent on clothes for extra protection.

Secure Your Sleeping Area

1. Protect Your Home & Sleeping Area

✔ Sleep under a mosquito net, especially in areas where sandflies are common.
✔ Install fine mesh screens on windows and doors to keep them out.
✔ Use insecticide sprays in areas where sandflies might hide, such as corners, under furniture, and wall cracks.

Eliminate Their Breeding Sites

Sandflies prefer moist and dark places, so reducing these areas will help keep them away:
✔ Seal cracks and holes in walls and soil.
✔ Clean up organic waste and garbage around the house.
✔ Keep pets away from sleeping areas, as they can attract sandflies.

Stay in Safe Areas

If you live or travel to a region where sandflies are common, take extra precautions:
✔ Stay indoors in closed or air-conditioned places.
✔ Use insecticide-treated bed nets while traveling.
✔ Avoid camping in moist soil, caves, or rocky areas.

What to Do If You Get Bitten?

✔ Wash the bite area immediately with soap and water.
✔ Apply cold compresses to reduce swelling.
✔ Use anti-itch creams like hydrocortisone or antihistamine creams.
✔ If itching is severe, take oral antihistamines (such as Lergic or Zyrtec).
✔ Do not scratch the bite to prevent infection.

Treatment for Sandfly Bites

If you get bitten by a sandfly, you should act quickly to reduce symptoms and prevent complications, especially if the sandfly is carrying Leishmania parasites. Treatment depends on whether it’s a regular bite or a leishmaniasis infection.

Treatment for a Normal Bite (No Infection)

✔ Clean the bite area immediately with soap and antiseptic water.
✔ Apply cold packs or ice wrapped in cloth to reduce swelling.
✔ Use anti-itch creams like hydrocortisone or antihistamine creams.
✔ Take oral antihistamines (such as Lergic or Zyrtec) if the itching is severe.
✔ Avoid scratching the bite to prevent bacterial infections.

If the bite turns into a persistent sore or causes unusual symptoms, see a doctor to check for leishmaniasis infection.

Treatment of Leishmaniasis (If the Bite Becomes an Infection)

If the bite turns into skin ulcers, or you experience fever and persistent swelling, it could be leishmaniasis infection. In this case, treatment should be as follows:

Treatment of Cutaneous Leishmaniasis (Skin Ulcers)

✔ In some cases, the ulcers heal on their own within months, but if they are large or painful, treatment is necessary.
✔ Injection of anti-parasitic medications directly into the ulcers (such as Glucantime or Pentostam).
✔ Cryotherapy (freezing therapy) to destroy the parasites.
✔ If the wound gets infected, topical antibiotics may be required.
✔ If the ulcers leave large scars, cosmetic surgery may be needed.

Treatment of Visceral Leishmaniasis (The Most Dangerous Form)

✔ Immediate hospitalization is required, as this condition can be life-threatening.
✔ Treatment involves strong medications, such as:

Amphotericin B (given intravenously).
Glucantime (the primary treatment).
Miltefosine (an oral anti-parasitic drug).

When to See a Doctor?

You should consult a doctor if:
✔ The bite turns into an ulcer that does not heal or keeps growing.
✔ There is severe swelling or pus at the bite site.
✔ You experience fever, extreme fatigue, or unexplained weight loss.
✔ The bite is located on the face or in sensitive areas like the nose or ear.

Which Doctor Should You Visit?

✔ If the bite causes mild itching and swelling, a pharmacist or dermatologist can recommend anti-itch creams.
✔ If skin ulcers develop, visit a dermatologist or infectious disease specialist for treatment.
✔ If you have symptoms like fever, weight loss, or enlarged liver and spleen, it could be visceral leishmaniasis, and you should see an infectious disease specialist or an internal medicine doctor specializing in tropical diseases.
✔ If the condition worsens or requires hospitalization, the doctor may refer you to a tropical disease specialist or a parasitology expert.