Rabies: Symptoms, Types, Causes and Treatment

Rabies remains one of the world’s most feared infectious diseases, often shrouded in myth and misunderstanding. Yet, the reality is even more sobering: once clinical symptoms develop, rabies is almost always fatal. However, rabies is also entirely preventable with timely intervention. In this article, we’ll explore the symptoms, types, causes, and treatments for rabies—arming you with crucial knowledge about this ancient zoonotic disease that still affects tens of thousands each year.

Symptoms of Rabies

Rabies is infamous for its severe and dramatic symptoms, but its early signs can be subtle and nonspecific. Understanding the progression of rabies symptoms can help in early recognition and timely intervention, which is critical for survival.

Stage	Key Features	Onset	Source
Prodromal	Pain/itching at bite, fever, fatigue, anxiety	2-10 days	3 4
Neurological (Furious)	Hydrophobia, agitation, hallucinations, hypersalivation	2-7 days after prodrome	1 2 3 4
Neurological (Paralytic)	Muscle weakness, flaccid paralysis	Variable	2 4
Late/Terminal	Seizures, coma, death	Rapid progression	3 4 5

Table 1: Key Symptoms of Rabies

The Progression of Rabies Symptoms

Rabies develops through a series of stages, each with its distinctive clinical features. Recognizing these can be lifesaving, especially in endemic regions.

Prodromal Phase

The initial phase, lasting 2–10 days, is often overlooked because its symptoms resemble those of common viral illnesses. Patients may experience:

• Fever, headache, and malaise
• Pain, numbness, or itching at the site of the bite or scratch (in up to 80% of cases)
• Fatigue and sometimes anxiety or depression

These vague symptoms make early diagnosis challenging, especially without a known animal bite history 3 4.

Neurological Phase

Rabies then progresses to its classic neurological manifestations, appearing as one of two main types: furious (encephalitic) or paralytic (dumb).

• Furious Rabies (80% of cases):

  • Hydrophobia (fear of water and difficulty swallowing due to pharyngeal spasms)
  • Aerophobia (fear of drafts or air)
  • Agitation, confusion, hallucinations
  • Hypersalivation (“foaming at the mouth”)
  • Restlessness and hyperactivity

  Notably, the hallmark symptom—hydrophobia—appears in almost all classic cases 1 2 3 4.

• Paralytic Rabies (20% of cases):

  • Progressive muscle weakness, starting at the site of the bite
  • Flaccid paralysis resembling Guillain-Barre syndrome
  • Absence of hydrophobia and agitation

  This form is often misdiagnosed due to its subtle presentation 2 4.

Late/Terminal Phase

If untreated, rabies rapidly advances to:

• Convulsions and seizures
• Coma
• Death, usually within days to a week after symptom onset

Even with intensive care, the outcome is almost always fatal once symptoms have appeared 3 4 5.

Types of Rabies

Rabies presents in more than one clinical form, and recognizing these distinctions is important for diagnosis and understanding the disease’s progression. Each type impacts the nervous system differently.

Type	Key Features	Prevalence	Source
Encephalitic (Furious)	Agitation, hydrophobia, hyperactivity	~80%	2 3 4
Paralytic (Dumb)	Muscle weakness, ascending paralysis	~20%	2 4
Atypical	Unusual or mixed features, rare	Rare	2

Table 2: Main Types of Rabies

Understanding the Clinical Types of Rabies

Encephalitic (Furious) Rabies

This is the “classic” form most often depicted in media. Encephalitic rabies is characterized by:

• Extreme agitation and aggression
• Hydrophobia and aerophobia due to painful pharyngeal spasms
• Periods of hyperactivity alternating with lucidity
• Mental status changes, but the mind often remains clear until very late

This form is most common and typically leads to death within a week of neurological symptom onset 2 3 4.

Paralytic (Dumb) Rabies

Paralytic rabies accounts for about 20% of cases and can be mistaken for other neurological diseases:

• Weakness begins at the bite site and spreads
• Flaccid paralysis, often ascending
• Minimal agitation or hydrophobia
• Mimics conditions like Guillain-Barre syndrome

This form progresses more slowly but is just as lethal 2 4.

Atypical Rabies

Rarely, rabies may present with mixed or unusual neurological features, which complicates diagnosis. These atypical forms are very uncommon and generally lack the dramatic symptoms of the other two types 2.

Causes of Rabies

Rabies is a zoonotic disease, meaning it spreads from animals to humans. Its transmission, reservoirs, and pathogenesis have been well studied, but misconceptions persist.

Cause	Description	Example Reservoirs	Source
Animal Bite	Virus-laden saliva enters via bite/scratch	Dogs, bats, raccoons	3 4 5 6 8
Saliva Contact	Saliva contacts mucous membrane/open wound	Rare, but possible	3 5 6
Organ Transplant	Infected tissue transplanted	Very rare (human cases)	12
Animal Reservoirs	Species maintaining virus in nature	Dogs, bats, foxes, skunks	6 8

Table 3: Main Causes and Modes of Rabies Transmission

How Rabies Spreads

Animal Bites: The Primary Route

• Over 99% of human rabies cases are caused by bites from infected dogs, especially in Asia and Africa 3 6 8.
• Wildlife such as bats, raccoons, foxes, and skunks are important reservoirs in the Americas and Europe 6 8.
• The virus is present in the saliva of infected animals and is introduced into the body via bites or deep scratches.

Less Common Transmission Modes

• Contact of infected saliva with mucous membranes or open wounds can, very rarely, transmit rabies 3 5 6.
• Organ transplantation from an infected donor has caused a handful of human rabies cases 12.

The Virus and Its Pathogenesis

• Rabies virus is a neurotropic RNA virus in the Lyssavirus genus, family Rhabdoviridae 3 4 5.
• After entering the body, the virus travels via peripheral nerves to the spinal cord and brain, eventually replicating in the central nervous system and spreading to other tissues, including the salivary glands 3 5 6 8.

Incubation Period

• Incubation varies widely, from as short as five days to several years; typically 1–3 months 3 4 5 6.
• Bites to the head, face, or neck have shorter incubation periods due to proximity to the brain 1.

Treatment of Rabies

While rabies is nearly always fatal once symptoms appear, it is 100% preventable with appropriate and timely intervention. Understanding current and future treatment strategies is key to reducing mortality.

Approach	Description	Effectiveness	Source
Post-exposure Prophylaxis (PEP)	Wound cleaning, vaccine, immunoglobulin	Nearly 100% if early	4 5 8 12 14
Supportive Care	ICU monitoring, sedation, symptom control	Palliative, not curative	4 10 12
Experimental Therapies	Antivirals, immunomodulators, therapeutic coma	Experimental, inconsistent	10 11 12 13 14
Pre-exposure Prophylaxis	Vaccination for high-risk groups	Preventive	12 14

Table 4: Approaches to Rabies Treatment and Prevention

Rabies Prevention and Treatment: What Works

Post-Exposure Prophylaxis (PEP): The Gold Standard

PEP is the cornerstone of rabies prevention and is nearly 100% effective if started before symptoms develop:

• Immediate wound cleaning with soap and water
• Rabies vaccination (series of injections)
• Rabies immunoglobulin (RIG) for severe or high-risk exposures (e.g., deep or multiple wounds, bites to the face/head)
• Newer options include monoclonal antibodies (RMAb) as potential alternatives to RIG 4 12 14

PEP is highly effective but must be administered promptly; once symptoms appear, it is too late 4 5 8 12 14.

Supportive and Palliative Care

Once clinical rabies develops, treatment focuses on comfort and supportive care:

• Sedation and pain management
• Mechanical ventilation if needed
• Intensive monitoring and nursing care

Unfortunately, these measures do not alter the fatal course of the disease 4 10 12.

Experimental and Future Therapies

Attempts to treat symptomatic rabies have included:

• Various antivirals (e.g., ribavirin, favipiravir, interferon-alpha), but results are disappointing in humans 10 11 12 13
• Induced (therapeutic) coma (“Milwaukee Protocol”)—initially promising but later shown largely ineffective and now discouraged 11 12
• New research into live-attenuated vaccines, monoclonal antibodies, nucleic acid-based vaccines, and RNA interference offers hope for future curative strategies, but these remain experimental 14

Pre-Exposure Prophylaxis

People at high risk—such as veterinarians, laboratory workers, and travelers to endemic areas—should receive pre-exposure rabies vaccination. This simplifies and enhances PEP if exposure occurs 12 14.

Conclusion

Rabies is a devastating but entirely preventable disease. Its grim reputation as a “death sentence” remains true for those who develop symptoms, but modern science offers powerful tools for prevention and, potentially, future cure. Here’s what we’ve covered:

• Symptoms: Rabies progresses from subtle early symptoms to dramatic neurological deterioration, ending almost invariably in death if untreated 1 2 3 4 5.
• Types: There are two main clinical types—encephalitic (furious) and paralytic (dumb)—each with distinctive features 2 3 4.
• Causes: Rabies is transmitted primarily by bites from infected animals, with dogs responsible for most human cases worldwide 3 4 5 6 8.
• Treatment: Post-exposure prophylaxis is nearly 100% effective if given promptly; once symptoms develop, treatment is mainly supportive, with research ongoing into more effective therapies 4 5 8 10 11 12 13 14.

Key Takeaways:

• Rabies is 100% preventable with timely intervention.
• Early recognition and immediate action after exposure are essential.
• Once symptoms appear, rabies is almost always fatal, highlighting the need for public awareness and access to vaccines.
• Continued research holds promise for future curative treatments.

Empowering communities with knowledge and access to rabies prevention can save countless lives—a goal within our reach, if we act together.