Diagnosis: Rabies Encephalitis
This patient has rabies encephalitis, and the 6-day survival after symptom onset represents an unusually prolonged clinical course for this uniformly fatal disease.
Clinical Diagnosis
The combination of hydrophobia (fear of water) and aerophobia (fear of air) following a stray dog bite 6 months prior is pathognomonic for rabies 1, 2. These classic neurological signs, along with the patient's attempt to sip water through cotton (indicating severe pharyngeal spasm triggered by attempts to drink), confirm the diagnosis 2.
- Hydrophobia and aerophobia are highly specific for rabies - these symptoms were significantly associated with antemortem diagnosis in U.S. cases (odds ratio 11.0) 2
- The 6-month incubation period falls within the documented range for rabies, which averages 1-3 months but can occur days to years after exposure 1
- The stray dog bite represents the highest-risk exposure, as rabid dogs pose the greatest hazard worldwide and are responsible for most human rabies deaths 1, 3
Why the Patient Survived 6 Days
The 6-day survival after symptom onset is longer than typical but not unprecedented for rabies encephalitis. Several factors explain this prolonged clinical course:
Typical Disease Progression
- Most rabies patients die within 3-7 days after clinical onset when receiving only supportive care 1
- The median time from symptom onset to antemortem diagnosis in confirmed U.S. cases was 7 days (range 3-17 days) 2
- This patient's 6-day survival falls within the expected range for untreated or palliatively treated rabies
Factors Influencing Survival Duration
Viral load and site of inoculation:
- The incubation period and clinical course may be influenced by the bite site, virus dose, and viral strain 3
- Facial bites (not specified in this case) can lead to faster progression, while peripheral limb bites may result in slower disease evolution 1
Clinical form of rabies:
- There are encephalitic (furious) and paralytic (dumb) forms of rabies with different clinical courses 4, 3
- The presence of hydrophobia and aerophobia suggests the encephalitic form, which typically progresses more rapidly than the paralytic form 4
Individual host factors:
- The patient's immune response, as evidenced by the 6-month incubation period, suggests some degree of initial viral containment 1
- However, once clinical symptoms appear, rabies is virtually always fatal regardless of the clinical course duration 4
Critical Missed Opportunity
This death was entirely preventable. The patient should have received postexposure prophylaxis immediately after the stray dog bite 5, 1.
- Stray or unwanted dogs that bite should be euthanized immediately and tested for rabies, with the patient beginning prophylaxis pending results 5
- Prophylaxis includes thorough wound cleansing, rabies vaccine, and rabies immunoglobulin, which is nearly 100% effective when administered before symptom onset 1, 4
- None of the 32 confirmed U.S. rabies deaths from 1980-1996 received postexposure prophylaxis before clinical disease onset 2
Why Rabies is Uniformly Fatal
Once clinical symptoms develop, rabies is incurable with current medical interventions 1, 4:
- The Milwaukee protocol (therapeutic coma) has been shown to be ineffective and should no longer be used 4
- Rare survival cases (fewer than 15 documented worldwide) typically involve severe neurological sequelae 6
- Current care entails palliative measures only once symptoms appear 1
The key message: Rabies prevention through immediate postexposure prophylaxis after any stray dog bite is the only effective intervention, as the disease is virtually 100% fatal after symptom onset 1, 4.