American bat lyssavirus infection

Bat lyssavirus infection is a rare but serious illness that affects the central nervous system. It is closely related to the rabies virus and other lyssaviruses, and the infection it causes is almost always fatal.

Bat lyssavirus is carried by some bats and is found in certain regions. Human infection is extremely rare, with only a handful of cases ever recorded.

Symptoms#

Symptoms can appear within days, or sometimes not for months or even years after exposure. Early symptoms are flu-like and can include fever, headache and fatigue.

The illness then progresses quickly to:

• muscle weakness
• changes in sensation
• confusion
• convulsions
• loss of consciousness

Once symptoms begin, the infection is almost always fatal, with death usually occurring within one to two weeks.

How it spreads#

The virus can pass to people from infected bats through bites or scratches, or when bat saliva makes contact with broken skin, the eyes, nose or mouth. It has been found in fruit bats, flying foxes and insect-eating microbats.

It is safest to assume that any bat could potentially carry and spread the virus.

Who is at risk#

People who come into close contact with bats through their work, volunteering or recreation are at increased risk. This can include:

• bat handlers and carers
• veterinarians and associated workers
• wildlife officers
• researchers
• cave explorers
• other workers such as power-line workers

Members of the public should never attempt to handle bats. Only people who are appropriately trained and vaccinated should handle wildlife.

Preventing infection#

Vaccination is recommended for people with an increased risk of bat exposure. As part of preventive (pre-exposure) vaccination, three vaccine doses are given over about one month.

For people with ongoing bat exposure, periodic blood testing every three years is recommended to check whether a booster dose is needed.

What to do if you are exposed#

If you are bitten or scratched by a bat, or its saliva contacts your broken skin, eyes, nose or mouth, act quickly even if you have been vaccinated before:

• Wash the wound thoroughly with soap and water immediately, for at least 15 minutes.
• After washing, apply an antiseptic with anti-viral action, such as an iodine preparation (for example povidone-iodine, iodine tincture or aqueous iodine solution) or alcohol (ethanol), to all wounds.
• Seek medical care as soon as possible.

A doctor may recommend treatment to reduce the risk of infection. This can involve a combination of several vaccine doses given over about a month together with an injection of immunoglobulin.

If you find a bat that may be sick or injured, do not handle it. Contact a local wildlife service so that trained handlers can manage the animal.

Diagnosis and treatment#

Diagnosis is made through laboratory testing of blood, spinal fluid, skin and nervous tissue. However, it can be difficult to confirm and may only be possible after death.

There is no effective cure for bat lyssavirus infection. Once a person becomes ill, treatment is supportive only. This is why prevention and prompt post-exposure treatment are so important.

Key points#

• Symptoms of bat lyssavirus infection can occur within days or up to several years after exposure.
• Symptoms quickly progress to muscle weakness, sensory changes, confusion, convulsions and loss of consciousness.
• People at high risk of bat exposure are recommended to be vaccinated.
• Preventive vaccination involves three vaccine doses given over about one month.
• Members of the public should never handle bats; only trained, vaccinated people should handle wildlife.

Where to get help#