# Rabies Presentation
## Title
RABIES
Lynn Hoang · Bryce Lawson · Olivia Popescu
A Zoonotic Viral Disease
Microbiology Presentation
## Definition
01 — Definition
What is Rabies?
~100%
Fatal once symptoms appear
One of the deadliest diseases known to medicine
Lyssavirus · Rhabdoviridae · Zoonosis
| Number | Fact |
| --- | --- |
| 01 | Zoonotic viral disease — attacks the Central Nervous System |
| 02 | Family Rhabdoviridae · Genus Lyssavirus |
| 03 | Present on every continent except Antarctica |
| 04 | From Latin rabere — "to rage" |
## Morphology & Genetics
02 — Pathogen
Morphology & Genetic Makeup
Morphology
| Point |
| --- |
| Distinctive **bullet-shaped** virion |
| Enveloped in a lipoprotein membrane studded with **glycoprotein spikes** used for host attachment |
Genetic Makeup
| Point |
| --- |
| A **non-segmented −ssRNA** virus |
| Encodes **5 essential proteins** (N, P, G, M, L) for replication |
RHABDOVIRUS STRUCTURE
## Metabolism & Growth
03 — Biology
Metabolism & Growth
Zero
Independent metabolism
Entirely host-reliant — a molecular parasite
How It Hijacks
| Step | Point |
| --- | --- |
| 01 | Binds ACh receptors on neuron surface via glycoprotein spikes |
| 02 | Commandeers host **ribosomes & ATP** to build viral proteins |
| 03 | Replicates genome entirely within the **cytoplasm** |
Survival Limits
Obligate Intracellular · Lyssavirus
Outside a living host, the virus is fragile — sunlight, desiccation, and detergents destroy it rapidly.
| Label | Value | Note |
| --- | --- | --- |
| Optimal Temp | 37°C | Core body temperature |
| Killed by | Heat & Low pH | Rapidly inactivated outside host |
| Environment | Obligate Intracellular | Cannot replicate outside a living cell |
## History & Lab Safety
04 — Background
History & Lab Safety
History
| Point |
| --- |
| One of the **oldest recorded diseases** — documented in Mesopotamian laws |
| Historically called **"hydrophobia"** due to the characteristic fear of water in the "furious" stage |
Lab Safety
| Level | Description |
| --- | --- |
| BSL-2 | Required for routine clinical diagnostic work (testing samples) |
| BSL-3 | Required for research involving live, high-titer virus or large-scale production |
## Transmission
05 — Spread
Transmission
Methods of Infection
| Icon | Title | Description |
| --- | --- | --- |
| :icon-syringe: | Bites | Most common route of transmission |
| :icon-eye: | Mucous Membranes | Via scratches or saliva contact with eyes, nose, or mouth |
Global Vectors
| Animal | Stat | Description |
| --- | --- | --- |
| Dogs | 99% | Responsible for 99% of human rabies cases globally |
| Bats | NA | Primary source of human rabies in North America |
| Wild Carnivores | Reservoir | Raccoons, skunks, foxes — key reservoir species |
## Pathogenesis
06 — Pathogenesis
The Journey
| Step | Description |
| --- | --- |
| Bite | Virus replicates locally in **muscle cells** at the wound site |
| Entry | Enters the **Peripheral Nervous System** via neuromuscular junction |
| Travel | Moves via **retrograde axonal transport** up the nerve |
| Evasion | Stays **hidden inside nerves** — invisible to the immune system |
| CNS | Reaches the **Central Nervous System** — causes rapid encephalitis |
## Reproduction & Immune Evasion
07 — Replication & Defense
Reproduction
| Step | Name | Description |
| --- | --- | --- |
| 1 | Absorption | G-protein spikes bind to host receptors |
| 2 | Penetration | Virus enters via endocytosis |
| 3 | Synthesis | L-protein creates mRNA; host ribosome translates 5 viral proteins |
| 4 | Assembly | New virions assemble in cytoplasm, forming **Negri bodies** |
| 5 | Budding | New viruses push through host membrane to infect next cell |
Immune Evasion
| Point |
| --- |
| Phosphoprotein **blocks STAT 1 & 2 signaling**, weakening Interferon (IFN) response |
| **Minimizes apoptosis** to avoid early immune detection |
| Maintains **Blood-Brain Barrier integrity** to keep antibodies out |
| Limits Glycoprotein expression, **blocking Dendritic cell & T-cell activation** |
## Diagnosis
08 — Diagnosis
Diagnosis
| Test Name | Abbreviation | Description |
| --- | --- | --- |
| Reverse Transcriptase Polymerase Chain Reaction | RT-PCR (LN 34) | Detects rabies genetic material via antemortem skin biopsy from the nape of the neck and saliva. Fluorescent probe detects viral genetic material in a single-tube reaction. |
| Immunohistochemistry | IHC | Detects the virus in formalin-fixed tissues embedded in paraffin. Rabies antigen is identified by red stains using the streptavidin-biotin complex method. |
| Fluorescent Antibody Test | FAT | Detects rabies-neutralizing antibodies in CSF or serum of an unvaccinated person — a positive signal indicates rabies infection. |
## Treatment
09 — Treatment
Treatment
Once symptoms appear, there is **no effective treatment**.
| Icon | Title | Description |
| --- | --- | --- |
| :icon-phone: | Seek Help Immediately | Contact a healthcare provider as soon as possible after potential exposure |
| :icon-droplets: | Clean the Wound | Gently and thoroughly clean the wound site immediately |
| :icon-shield-check: | Post-Exposure Vaccination | Doctor will provide vaccination — can be administered even before symptoms if not previously vaccinated |
| :icon-activity: | HRIG Shots | Human Rabies Immune Globulin (HRIG) — injected around the wound if not vaccinated before exposure |
## Conclusion
09 — Summary
Conclusion
| Point |
| --- |
| Rabies is caused by a **−ssRNA lyssavirus** with a characteristic bullet-shaped morphology |
| It travels via **retrograde axonal transport**, evading immune detection until it reaches the brain |
| Once clinical symptoms appear, survival is **near impossible** — making prevention critical |
| PEP (Post-Exposure Prophylaxis) remains the **only effective intervention** after exposure |
| Despite being entirely preventable, rabies still kills an estimated **59,000 people** per year globally |
Awareness, vaccination, and prompt treatment save lives.
## Test Questions
10 — Review
Test Questions
Click any question to highlight it
| Number | Question |
| --- | --- |
| 1 | What family and genus does the rabies virus belong to? |
| 2 | Describe the morphology of the rabies virion. What are the 5 proteins it encodes? |
| 3 | How does the rabies virus evade the host immune system during its journey to the CNS? |
| 4 | What is the primary global vector for human rabies transmission, and what percentage of cases does it cause? |
| 5 | Why is rabies considered nearly 100% fatal once clinical symptoms appear, and what is the window for effective treatment? |
## Works Cited
10 — References
Works Cited
Add your full citations below. See the linked document for the full reference list.
https://docs.google.com/document/d/1LRwTXimLi1nfntIO1phCj5glUf-efwep-O_Oqh6l_Pw/edit?usp=sharing
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