The Simian Flu, like standard plague types, starts off with six symptom trees. However, the most notable of these six trees is the Neuro-enhancement 1 tree, which is separate from its peers, and does not connect with the web. What is surprising about these symptoms is that they greatly increase human intelligence and help man, unlike any symptoms before them. However, at Neuro-enhancement 3, very small numbers of casualties start appearing, and, at Total Brain Death, it kills in large numbers.
It also has symptoms that were previously only in the Smallpox, Swine Flu, and Nipah Virus scenarios: Headache, Subconjunctival Bleed, Pharyngitis, Meningitis, and Haemoptysis. It also introduces the symptoms Joint Pain, Epistaxis, Gastric Ulceration, Hydrocephalus, Hypocoagulability, and Subconjunctival Haemorrhage.
- Photophobia - Sensitivity and pain when eyes exposed to sunlight. Slows future research speed but slightly reduces infection rates
- Subconjunctival Bleed - Bleeding underneath the conjunctiva turns the eyes red
- Subconjunctival Haemorrhage - Blood vessels between conjunctiva and sclera burst, causing severe red eyes with occasional external bleeding. Decreases future research speed.
- Blindness - Primary visual cortex disconnected causing blindness. Significantly reduced awareness and causes fatal accidents
- Rash - The skin becomes blistered and painful, slightly increasing infectivity
- Joint Pain - Inflammation in the joints causes pain when moving. Decreases chance of infection due to reduced movement.
- Hydrocephalus - Cerebrospinal fluid accumulates in cavities in the brain, increasing intracranial pressure. Highly lethal without treatment
- Hypocoagulability - Significantly reduced blood clotting ability results in heavy external bleeding. Often fatal due to exsanguination
- Internal Haemorrhaging - Flesh eating pathogens breaks down arterial membranes causing rapid internal bleeding and death
- Headache - Disturbance of the pain-sensitive structures around the brain. Reduces concentration.
- Fever - Increase in temperature, contagiousness and severe dehydration, which can be fatal
- Coma - Neuropathic effects in the brain stem cause loss of consciousness and sometimes death. Significantly harder to cure
- Meningitis - Acute inflammation of the protective membranes covering of the brain and spinal cord. Highly fatal
- Neuro-enhancement 1 - Virus able to enter brain cells and modify DNA, improving existing neural pathways. Increases human intelligence.
- Neuro-enhancement 2 - Virus able to further modify brain cell DNA, triggering development of new neural pathways. Increases human intelligence.
- Neuro-enhancement 3 - Virus aggressively manipulates brain cell DNA, accelerating neural growth. Increases intelligence but with chance of immune response
- Total Brain Death - Comprehensive replacement of brain cell DNA triggers massive immune response, leading to complete and irreversible loss of brain function.
- Pharyngitis - Sore throat causes discomfort and increases likelihood that coughing will spread disease
- Coughing - Chance of infection by spreading pathogen into surroundings. especially in high density, urban areas
- Sneezing - Fluid discharge through sneezing greatly increases infection rates.
- Epistaxis - Haemorrhage of the nasal mucous membranes cause severe nosebleeds, increasing likelihood of infection
- Haemoptysis - Coughing up blood from inflamed bronchi increases infectivity and is fatal in extreme cases.
- Hemorrhagic Shock - Failure of the heart to pump effectively causes oxygen depravation, loss of consciousness and death
- Pneumonia - Serious fluid build and discharge from the lungs. People in cold climates especially vulnerable
- Pulmonary Hemorrhage - Severe bleeding in the upper respiratory tract and the trachea. Increasing infectivity and often fatal.
- Nausea - Irritated stomach lining leads to discomfort. Slight chance of infection when kissing.
- Vomiting - The expulsion of infected material through projectile vomiting increases the risk of infection.
- Diarrhoea - Pathogen active in digestive tract, causing infection through feces and potentially lethal dehydration. Poor countries especially vulnerable.
- Dysentery - A complete breakdown in the digestive tract causes infected sewage, dehydration, starvation and death
- Gastric Ulceration - Multiple sores develop in the lining of the stomach, causing severe pain in the abdominal region. Can be lethal