Bird mite infestation

What is a bird mite?

Bird mites are minute (< 1 mm long), oval-shaped arachnids with eight legs. There are several species of bird mite. The most common species that affect humans in Australia are the domestic starling mite, Ornithonyssus bursa, from the family Macronyssidae, and the red poultry mite Dermanyssus gallinae, from the family Dermanyssidae.

Poultry-mite infestation

Bites 

Dermanyssus gallinae 

Where does one find bird mites?

Bird mites are naturally found where birds, such as poultry, sparrows, starlings, or pigeons, and their nests are located. Bird mites prefer warm and humid living conditions and are most active during the spring and early summer.

What is bird-mite infestation?

Bird mites normally feed on the blood of birds. After young birds leave their nests, the mites may encounter humans while searching for a new bird host. Bird mites can bite anywhere on the human body but are more often experienced on exposed skin.

Although they may feed on human blood, bird mites are not able to complete their life cycle on humans and they do not burrow beneath the skin.

Who gets bird-mite infestation?

People who are at high risk of bird-mite infestations include poultry farmers; people living in close proximity to bird nests; people who rear birds as a hobby (eg, pigeon racers, breeders, pet keepers, etc); vets, and zoo workers. Exposure to bird mites can also occur when using second-hand furniture, or when working/living in buildings that­ have been infested by bird mites.

What are the clinical features of bird-mite infestation?

A bird-mite infestation presents as itchy bites.

• The bitten areas are intensely itchy, especially at night or in the early morning.
• Symptoms are sometimes described as including a ‘crawling’ sensation that is caused by the mites injecting saliva when feeding.
• There may be numerous small red papules and vesicles (the bite reactions).

What are the complications of bird mite infestation?

Complications of bird mite infestation may include:

• Secondary bacterial infection due to scratching
• Sleep disturbance due to intense itchiness
• Depression or anxiety.

How is bird-mite infestation diagnosed?

The suspicion of bird-mite infestation should be raised when the patient presents with the symptoms and clinical features of scabies but is not responding to the apparently appropriate treatment. A detailed history should be taken, including considering the season and the time of day when symptoms occur, the patient’s occupation, hobbies, and living conditions.

Bird mites are too small to be seen without magnification. They can be collected with transparent adhesive tape and examined with a microscope. The identification of the species might require consultation with a specialist entomologist (a scientist who studies insects and arachnids).

What is the differential diagnosis for bird-mite infestation?

Bird-mite infestation can be clinically difficult to distinguish from other mite and insect infestations, such as scabies, fleas, body lice, mosquitoes, sandflies, horse flies, spiders, centipedes, bed bugs, ticks, midges, and harvest mites. Unlike scabies mites, bird mites do not result in burrows in the skin.

What is the treatment for bird-mite infestation?

Treatment involves identifying and eradicating the mites. The skin should be cleansed to remove any mites.

• A loofah pad may be used to scrub the skin in the shower.
• Emollients can be added to the bath or shower to reduce itching.
• Coal tar products can be used as a shampoo and body wash once or twice daily.
• Diluted bleach solution can be used in the shower or bath to reduce infection (bleach is also used to clean the bathroom).

Prescribed treatments

• Topical steroids are applied to the bites to decrease inflammation.
• Oral antihistamines can reduce inflammation and itch.
• Antibiotics are indicated if there is a secondary bacterial infection.

How can you prevent bird-mite infestation?

Bird-mite infestation can be prevented by removing bird nests located near living and working areas.

• Wear fully protective clothing during the process to prevent the transfer of bird mites to humans.
• If there is an infestation of bird mites in a building, it may be necessary to consult with a qualified pest-control operator.
• To eradicate bird mites, treat the area with an approved insecticide surface spray or insecticide powder.
• Heavily infested furniture might need to be destroyed and replaced.
• Carpets require daily vacuuming or, in case of heavy infestation, will possibly require replacement.
• Bed linen or clothing should be changed and washed in hot water frequently.

What is the outcome for bird-mite infestation?

The bites should clear up after the bird mites are successfully eradicated.