Rabies is a deadly viral disease that is transmitted through the bite or scratch of an infected animal. Once symptoms of rabies appear, the disease is nearly always fatal. However, with proper treatment soon after exposure, rabies can be prevented. So how long can you expect to live for if you do contract rabies? Here is a quick overview of rabies and life expectancy.
Quick Answer: Without treatment, most people who develop rabies symptoms will die within 2-10 days. With aggressive treatment, some people have survived for weeks, but rabies is almost always fatal once symptoms begin.
What is Rabies?
Rabies is caused by the rabies virus. It infects the central nervous system and causes inflammation of the brain and spinal cord. The rabies virus is spread through the saliva or brain/nervous system tissue of an infected animal, usually through a bite or scratch.
In up to 99% of cases, rabies is transmitted through the bite of an infected animal such as a dog, bat, or raccoon. Less than 1% of cases occur from scratches or open wounds that come in contact with saliva or brain tissue from an infected animal.
Once a person is exposed to the rabies virus, it can take 2-8 weeks for symptoms to appear as the virus spreads through the nerves to the brain. This time period is called the incubation period.
Signs and Symptoms
The initial symptoms of rabies often feel like the flu including:
- Fever
- Headache
- Nausea
- Vomiting
- General weakness or discomfort
As the disease progresses and the virus spreads to the brain, more specific symptoms appear including:
- Insomnia
- Confusion
- Agitation
- Hallucinations
- Partial paralysis
- Increased saliva production
- Difficulty swallowing
Later stages of the disease lead to symptoms like:
- Fear of water (hydrophobia)
- Inability to move parts of the body
- Erratic behavior
- Violent muscle spasms
Ultimately, rabies causes paralysis, coma, and death generally within 2-10 days once these symptoms are observed.
Life Expectancy Without Treatment
If rabies is left untreated and the symptoms progress to the later stages, almost all cases are fatal.
According to the CDC, the survival rate is essentially 0% in humans once rabies symptoms begin, even with intensive care treatment in a hospital. Less than 15 known cases of human rabies survivors have ever been documented globally, making it one of the most deadly infectious diseases.
Most rabies deaths occur within 2-10 days of the initial symptoms. Once symptoms reach the advanced stage involving difficulty swallowing, fear of water, and paralysis, death usually occurs within a couple days. The paralysis and coma associated with end-stage rabies ultimately leads to respiratory failure and cardiac arrest.
Factors Affecting Life Expectancy
Some factors influence how quickly rabies progresses and can slightly affect life expectancy once symptoms start.
- Site of the bite/exposure: Bites on highly innervated parts of the body like the face or hands progress faster than bites on less innervated areas like the legs or trunk.
- Severity of exposure: More severe bites that involve deeper wounds or introduction of more virus may progress faster.
- Age: Rabies progresses faster in younger patients, especially under 16 years old.
- Health: Those with weaker immune systems may succumb to rabies more quickly.
However, while these factors can influence how fast someone may die from rabies, they rarely change the overall life expectancy by more than a day or two once symptoms are present. Almost all untreated rabies cases are fatal within 10 days at most.
Life Expectancy with Treatment
While rabies remains almost universally fatal once symptoms start, getting preventative treatment soon after exposure and before symptoms can greatly increase life expectancy.
The Milwaukee Protocol is an experimental treatment approach intended to inhibit the virus and its lethal effects. It involves placing the patient into a medically-induced coma and administering a cocktail of antiviral drugs and other therapies.
This technique has been tried in over 35 human cases of rabies worldwide. Unfortunately, it has only resulted in about 8% of patients surviving. Of the 6 known survivors:
- Survival ranged from 37 days to 8 years after treatment
- All survivors had major neurological impairment and disabilities after recovery
- Only one patient survived without intensive rehabilitation and permanent brain damage
So while it has shown a very low rate of success, aggressive treatment like the Milwaukee Protocol has enabled a small number of patients to live weeks to years longer compared to the typical 2-10 days survival. However, even with this approach, rabies remains largely fatal once symptomatic.
Preventative Vaccination
The key to improving life expectancy with rabies is preventative vaccination started as soon as possible after a potential rabies exposure, before any symptoms develop.
The rabies vaccine series involves receiving 4-5 vaccine shots usually over a 2-4 week period. Vaccination should start within 24 hours after exposure for the best chance of success. This protocol can prevent the rabies virus from spreading in the body and essentially provides lifelong protection from developing rabies.
If given promptly after exposure, the rabies vaccine is nearly 100% effective in preventing the fatal disease. It allows for essentially normal life expectancy rather than the 2-10 day range if treatment is delayed until after symptoms arise.
Typical Disease Progression and Life Expectancy
To summarize the typical rabies disease course and life expectancy:
| Phase | Timing | Life Expectancy |
|---|---|---|
| Exposure to rabies virus through bite/scratch | Day 0 | Years if treated immediately with vaccine |
| Incubation period: No symptoms present | 2-8 weeks after exposure | Years if treated immediately with vaccine |
| Early flu-like symptoms develop | 2-10 weeks after exposure | 2-10 days once symptoms start |
| Central nervous system dysfunction and paralysis | 1-2 weeks after initial symptoms | 2-4 days once these symptoms appear |
| Respiratory failure and death | 1-3 days after paralysis | 1-2 days once this stage reaches |
As highlighted in this progression, life expectancy shifts dramatically once rabies symptoms appear. At this point, survival is often measured in days rather than weeks or years.
Immediate vaccination provides the only means of restoring normal life expectancy by preventing symptoms and fatality.
Can Rabies Be Cured?
Unfortunately, there is no effective cure for rabies once symptoms develop. No medical therapies have been discovered that can clear the rabies virus from the body and brain. Intensive supportive treatment like the Milwaukee Protocol temporarily prolongs life in a few cases. But most patients still succumb within days or weeks at most.
Preventative vaccination remains the only reliable medical defense against rabies. If given before symptoms arise, the rabies vaccine triggers an immune response that provides long-term protection against the virus and preserves normal life expectancy.
Treatment Once Symptomatic
The Milwaukee Protocol and other intensive care measures have prolonged life for days to weeks in some rabies cases. But they have not enabled true recovery once neurological symptoms are present. Supportive treatments for symptomatic rabies include:
- Medically-induced coma – slows the virus and nervous system dysfunction
- Antiviral drugs -may inhibit the virus but cannot cure at this stage
- IV fluids and nutrition – provide basic support
- Respiratory assistance – manages impaired breathing
- Medications to reduce brain swelling
However, while these interventions can temporarily stall the rapid progression of rabies, patients almost invariably die even with aggressive hospital care once symptoms develop.
Preventative Vaccination
In contrast to the poor outcomes once symptomatic, getting vaccinated promptly after exposure to rabies virtually guarantees survival and preserves normal life expectancy.
When administered within 24 hours, the rabies vaccine is 100% effective at preventing the disease. It triggers antibody production that neutralizes rabies virus particles before they can infect cells and spread in the body.
Getting vaccinated even days after exposure is still highly effective at preventing rabies. The vaccine can stop the infection as long as symptoms are not yet present.
Therefore, rapid preventative vaccination is the key to maintaining a normal life span following potential rabies contact.
Key Points
To summarize the prognosis and life expectancy for rabies:
- Without treatment, less than 1% of rabies cases survive and life expectancy is 2-10 days once symptoms start.
- Prolonged life support like the Milwaukee Protocol has extended life for days to weeks in less than 15 cases worldwide.
- Preventative vaccination within 24 hours of exposure is nearly 100% effective and allows for decades of normal life expectancy.
- Once rabies symptoms emerge, no treatments have been proven capable of curing the disease.
- Immediate vaccination after contact with an infected animal is critical for maintaining life expectancy and preventing this almost universally fatal disease.
The Bottom Line
Rabies remains one of the most deadly infectious diseases nearly 100 years after the first rabies vaccine was developed. The key to combating its high fatality rate lies in prompt preventative vaccination after potential rabies exposure rather than relying on unproven treatments once symptoms develop.
If you suspect you may have been exposed to rabies, seek immediate medical attention for assessment of your risk and potential administration of the rabies vaccine series. With timely prophylactic immunization, even severe rabies exposures can often be overcome and result in completely normal life expectancy. However, delaying treatment until after the onset of symptoms will sadly almost assure an early death in all cases of this formidable disease.