Symptom Combos

Symptom Combos are special combinations of Symptoms (and in some cases Transmission traits) that can affect plague stats, as well as trigger special events which can slow or speedup Cure progression, or draw attention to the disease. All combos have an achievement associated with them.

Note that it seems to take a while for symptom combos to appear and take effect. Also note that the list may not be complete.

Combos

To achieve a combo, one must evolve two or more different symptoms. They range from two tier 1 symptoms to eight symptoms and two infections, so using them is a viable strategy for new players and advanced players alike.

Standard

Name	Effects	Symptoms
Projectile Vomiting	Increases Infectivity	Vomiting Coughing
Walking Dead	Decreases Cure research rate	Insomnia Anaemia
Profuse Bleeding	Slightly increases lethality, greatly increases infectivity	Haemophilia Skin Lesions
Oops	Lowers productivity but draws attention to the plague.	Diarrhoea Sneezing
Public Defecation	Increases infectivity and draws attention to disease	Insanity Diarrhoea
Swine Flu	Slight increase in work needed for a Cure	Coughing Diarrhoea Insomnia Nausea Pneumonia Vomiting Livestock I Livestock II

Necroa Virus

Name	Effects	Symptoms
Vampire Bat	Increases Severity, Infectivity, and Lethality.	Vampiric Hunger Bat 1 Bat 2
Blood in the Air	Increases Severity	Cathemeral Shift Delirium Hyperosmia
Tank	Slight Severity boost	Anabolic Boost Bone Dysplasia
Spitter	Slight Severity boost	Naja Mortis Enhanced Sensory Integration
Boomer	Slight Severity boost	Autothysis Liquefactive Necrosis
Cranial Dispersion	Severity Boost	Cranial Elephantitis Air 3
Walking Contradiction	Slight Severity decline	Photophobia, Cathemeral Shift
Runner	Slight Severity boost	Enhanced Motor Control Engorged Quadriceps
Bath Time	Infectivity Boost	Autophagia Cannibalism Polyphagia

Simian Flu

Name	Effects	Symptoms
Assassin	Increases Ape combat abilities	Ape Rampage Primal Awareness
Blind Genius	Increases Cure Production	Blindness Neuro-enhancement 3
Discovery Channel	Increases Ape to Ape transmission	Primal Hunt Social Cohesion
Fly Magnet	Increases cross-species transmission	Hominidae Bridge Diarrhoea
Red Ape Redemption	Increases Ape combat abilities	Horseback Riding Weapon Creation
Rude Awakening	Increases Ape to Ape transmission	Scouts Excrement
Zombie Panic	Slows Research Speed	Subconjunctival Haemorrhage Total Brain Death Bat 2 Blood 2

Neurax Worm (Santa's Little Helper)

Name	Effects	Symptoms
On The Naughty List	Decreases happiness	Gluttony Intoxication Sloth
Ultimate Christmas	Increases happiness and infectivity	Digital Elf Red-Nosed Guide Red-Suited Pilot

Trivia

The Boomer, Tank, Runner and Spitter combos are references to zombies from Valve's Left 4 Dead franchise.|}|}