Here is the full list of all 55 Infection Rate achievements.
Receive your first infection.
Kill an enemy with critical strike.
Complete 100 levels on Еasy difficulty.
Complete 100 levels on Normal difficulty.
Complete 100 levels on Hard difficulty.
Complete 100 levels on Insane difficulty.
Kill a special semi-zombie enemy.
Consume Medikit 100 times.
Consume Yellow Syringe 100 times.
Open 100 locked things with weapon or hands.
Make 1000 items.
Use 100 Quest items.
Die 100 times.
Say 100 times "Noob" with chat command.
Kill 100 enemies on Easy difficulty.
Kill 100 enemies on Normal difficulty.
Kill 100 enemies on Hard difficulty.
Kill 100 enemies on Insane difficulty.
Kill 10000 enemies.
Kill 100 enemies with critical strike on Easy difficulty.
Kill 100 enemies with critical strike on Normal difficulty.
Kill 100 enemies with critical strike on Hard difficulty.
Kill 100 enemies with critical strike on Insane difficulty.
Kill 10000 enemies with critical strike.
Unlock every skin and items for Pierre from Extras.
Unlock every skin and items for Dimitri from Extras.
Unlock every skin and items for Samir from Extras.
Unlock every skin and items for Frank from Extras.
Unlock every skin and items for Hiroshi from Extras.
Unlock every skin and items for Stacy from Extras.
Unlock every skin and items for Amanda from Extras.
Unlock every skin and items for Lisa from Extras.
Unlock Insane difficulty from Extras.
Receive 100 times the Vomit effect.
Receive 100 times the Cough effect.
Receive 100 times the Bleeding effect.
Escape 100 times by foot.
Escape 100 times with car.
Escape 100 times with helicopter.
Use Pierre "Kick" skill on 100 enemies.
Use Dimitri "Taunt" skill on 100 enemies.
Make 100 items with Samir "Tool Box".
Kill 100 enemies with Frank Hunting Rifle.
Make 100 items with Hiroshi "Laboratory Bag".
Make 100 items with Stacy "First Aid Case".
Unlock 100 things with Amanda "Breaker" skill.
Make 100 items with Lisa.
Complete The City level on Easy difficulty.
Complete The City level on Normal difficulty.
Complete The City level on Hard difficulty.
Complete The City level on Insane difficulty.
Complete The School level on Easy difficulty.
Complete The School level on Normal difficulty.
Complete The School level on Hard difficulty.
Complete The School level on Insane difficulty.