Key facts

• Rabies is a serious public health problem in over 150 countries and territories, mainly in Asia and Africa. It is a viral, zoonotic, neglected tropical disease that causes tens of thousands of deaths annually, with 40% being children under 15.
• Dog bites and scratches cause 99% of the human rabies cases, and can be prevented through dog vaccination and bite prevention.
• Once the virus infects the central nervous system and clinical symptoms appear, rabies is fatal in 100% of cases.
• However, rabies deaths are preventable with prompt post exposure prophylaxis (PEP) by stopping the virus from reaching the central nervous system. PEP consists of thorough wound washing, administration of a course of human rabies vaccine and, when indicated, rabies immunoglobulins (RIG). 
• If a person is bitten or scratched by a potentially rabid animal, they should immediately and always seek PEP care.
• WHO and its global partners aim to end human deaths from dog-mediated rabies through a comprehensive One Health approach promoting mass dog vaccination, ensuring access to PEP, health worker training, improved surveillance, and bite prevention through community awareness.

Overview

Dog-mediated rabies

Rabies is a vaccine-preventable, zoonotic, viral disease affecting the central nervous system. In up to 99% of the human rabies cases, dogs are responsible for virus transmission. Children between the age of 5 and 14 years are frequent victims.

Rabies infects mammals, including dogs, cats, livestock and wildlife.

Rabies spreads to people and animals via saliva, usually through bites, scratches, or direct contact with mucosa (e.g. eyes, mouth, or open wounds). Once clinical symptoms appear, rabies is virtually 100% fatal.

The global cost of rabies is estimated to be around US$ 8.6 billion per year including lost lives and livelihoods, medical care and associated costs, as well as uncalculated psychological trauma.

Rabies is present on all continents except Antarctica. Globally there are an estimated 59 000 deaths from rabies annually; however, due to underreporting, documented case numbers often differ from the estimate. 

Rabies, a neglected tropical diseases (NTD), predominantly affecting marginalized populations. Although effective human vaccines and immunoglobulins exist for rabies, these are often inaccessible or unaffordable to those in need.

As of 2018, the average estimated cost of rabies post-exposure prophylaxis (PEP) was US$ 108 (along with travel costs and loss of income), which can be a financial burden on those earning US$ 1–2 per person, daily.

Over 29 million people worldwide receive human rabies vaccine annually.

Rabies from sources other than dogs

In the Americas, where dog-mediated rabies is mostly controlled, hematophagous (blood-feeding) bats are now the primary source of human rabies. Bat-mediated rabies is also an emerging public health threat in Australia and parts of western Europe.

Human deaths following exposure to foxes, raccoons, skunks, and other wild mammals are very rare, and bites from rodents are not known to transmit rabies.

Contraction of rabies through inhalation of virus-containing aerosols, consumption of raw meat or milk of infected animals, or through organ transplantation is extremely rare.

Human-to-human transmission through bites or saliva is theoretically possible but has never been confirmed.

Symptoms

The incubation period for rabies is typically 2–3 months but may vary from one week to one year, depending on factors such as the location of virus entry and the viral load. Initial symptoms of rabies include generic signs like fever, pain and unusual or unexplained tingling, pricking, or burning sensations at the wound site. As the virus moves to the central nervous system, progressive and fatal inflammation of the brain and spinal cord develops. Clinical rabies in people can be managed but very rarely cured, and not without severe neurological deficits.

There are two forms of rabies:

• Furious rabies results in hyperactivity, excitable behaviour, hallucinations, lack of coordination, hydrophobia (fear of water) and aerophobia (fear of drafts or of fresh air). Death occurs after a few days due to cardio-respiratory arrest.
• Paralytic rabies accounts for about 20% of the total number of human cases. This form of rabies runs a less dramatic and usually longer course than the furious form. Muscles gradually become paralysed, starting from the wound site. A coma slowly develops and eventually death occurs. The paralytic form of rabies is often misdiagnosed, contributing to the under-reporting of the disease.

Diagnosis

Currently there are no WHO-approved diagnostic tools for detecting rabies infection before the onset of clinical disease.

Clinical diagnosis of rabies is difficult without a reliable history of contact with a rabid animal or specific symptoms of hydrophobia or aerophobia.

Accurate risk assessment is crucial for deciding on PEP administration.

Once symptoms emerge, and death is inevitable, offering comprehensive and compassionate palliative care is recommended.

Postmortem confirmation of rabies infection is done by various diagnostic techniques that detect whole viruses, viral antigens, or nucleic acids in infected tissues (brain, skin or saliva) (Laboratory techniques in rabies Vol. 1 and Vol. 2).

Where possible, the biting animal should be tested.