Rabies is a viral disease that affects the central nervous system and is almost always fatal once symptoms appear. Rabies is spread through the bite or scratch of an infected animal, most commonly dogs. Rabies causes inflammation of the brain and spinal cord and is fatal if left untreated. So is it too late if you have rabies? Here is a closer look at rabies and what to do if exposed.
How is rabies transmitted?
Rabies is transmitted through the saliva of infected animals. The rabies virus is spread through bites, scratches, or even just contact with saliva from an infected animal. In the United States, wild animals like raccoons, skunks, bats, and foxes are the most common sources of rabies. However, in other parts of the world, stray dogs are the main vector.
The rabies virus travels through nerves up to the brain once introduced by a bite or scratch. The incubation period (time between exposure and onset of symptoms) is quite variable but can range from 2 weeks to several months. The average incubation period is 1-3 months. During the incubation period, there are no signs or symptoms.
What are the symptoms of rabies?
The initial symptoms of rabies are similar to the flu including:
- Fever
- Headache
- Nausea
- Vomiting
- Fatigue
As the disease progresses and the virus spreads to the brain, more specific symptoms develop:
- Insomnia
- Anxiety
- Confusion
- Agitation
- Hallucinations
- Excessive salivation
- Difficulty swallowing
- Fear of water (hydrophobia)
- Paralysis
Once clinical signs appear, rabies is virtually 100% fatal. Patients often die within a week or two of symptom onset.
Is it too late if you have symptoms of rabies?
Unfortunately, once someone has developed symptoms of rabies, it is almost always too late for treatment. There are only a handful of documented cases of rabies survivors once symptoms appeared. This is because by the time symptoms start, the virus has already spread to the brain and spinal cord. At this point, treatment is very challenging.
There are some experimental treatments like the Milwaukee Protocol that have helped a small number of patients recover. This approach involves inducing a medical coma and antiviral medications. However, it has very low success rates and may cause severe side effects.
In general, once symptoms start, rabies is essentially 100% fatal. However, receiving fast treatment after exposure but before symptoms can still prevent the disease.
What to do if you may have been exposed to rabies
If you are bitten, scratched, or exposed to the saliva of a potentially rabid animal, you should seek medical care as soon as possible. Time is of the essence if exposed to rabies:
- Immediately wash any bite wounds or scratches thoroughly with soap and water.
- Contact your doctor or go to an emergency room.
- Report the incident to animal control to identify the animal involved.
- Get the rabies post-exposure prophylaxis (PEP) as soon as possible.
Rabies PEP consists of:
- Cleaning and flushing the wound.
- A fast-acting rabies vaccine given in 4 doses over 14 days.
- Rabies immune globulin injected near the wound.
As long as PEP is administered before symptoms start, it is nearly 100% effective in preventing rabies. However, the shorter the time between exposure and starting PEP, the better. PEP should ideally begin within 24 hours but certainly within 72 hours.
Rabies Vaccination for Prevention
Vaccinating pets, livestock, and wild animal populations is key for rabies prevention. Many parts of the world have implemented mandatory pet vaccination policies leading to reduced human rabies deaths. Pre-exposure rabies vaccination is also recommended for certain high-risk groups like:
- Veterinarians
- Animal handlers
- Laboratory workers
- Travelers going to areas with endemic rabies
The pre-exposure vaccine simplifies treatment after exposures and is given as 3 injected doses over 21-28 days.
Rabies Vaccine Schedule
| Dose | Timing |
|---|---|
| First Dose | Day 0 |
| Second Dose | Day 7 |
| Third Dose | Day 21-28 |
Booster doses of the vaccine are recommended every 2 years for people at ongoing risk.
Global Impact of Rabies
While rabies deaths are rare in the US, it remains a serious problem globally. The World Health Organization (WHO) estimates rabies causes around 59,000 human deaths worldwide each year. Over 95% of cases occur in Africa and Asia where canine rabies is endemic.
India has the highest rate of human rabies deaths, accounting for about 36% of global rabies deaths. Approximately 20,000 die every year in India due to rabies.
Children are especially vulnerable, representing about 40% of those killed by rabies worldwide. This is due to children being more likely to encounter stray dogs and may not report minor bites or scratches.
Countries with Highest Rabies Deaths
| Country | Deaths per year |
|---|---|
| India | 20,000 |
| China | 7,000 |
| Indonesia | 4,500 |
| Pakistan | 3,500 |
| Nigeria | 2,500 |
| Philippines | 2,000 |
| Bangladesh | 1,500 |
In the US, human rabies cases have declined to around 1-3 each year thanks to animal control and vaccination programs. However, the estimated public health costs for rabies prevention still exceeds $300 million per year.
Preventing Rabies in Dogs
Vaccinating dogs is a key strategy for controlling rabies spread and preventing human infections. Most rabies-related human deaths are caused by dog bites. The World Health Organization (WHO) has set a goal to eliminate human deaths from dog-transmitted rabies by 2030.
Mass vaccination campaigns of dog populations have led to a reduction in canine rabies cases in many countries. However, in parts of Africa and Asia, large populations of unvaccinated stray dogs help fuel rabies transmission.
In addition to vaccination, proper animal control, public education, and post-exposure prophylaxis are also critical parts of rabies prevention in endemic areas.
New Rabies Treatment Approaches
While PEP remains the gold standard after exposures, researchers are working on better rabies treatments including:
- New monoclonal antibodies: Lab-engineered antibodies that neutralize the rabies virus and may prevent it from reaching the brain.
- Antiviral therapy: Drugs like favipiravir, ribavirin, and ketamine that may inhibit viral replication.
- RNA interference: Using small RNA molecules to interfere with viral replication.
These new approaches could potentially be used alongside PEP to improve outcomes. However, more research is still needed.
Conclusion
Rabies is almost always fatal once the symptoms start, making it vital to seek fast medical attention if potentially exposed. While rabies is rare in the US and other developed countries, it remains a serious public health threat in parts of Africa and Asia. Widespread pet vaccination campaigns and public education are critical to eliminating human rabies deaths globally. Ongoing research also offers hope for improved prevention and treatment approaches in the future.