Plague Inc. Artificial Organs Scenario: Bacteria Mega-Brutal (3 biohazards) Guide & Walkthrough

The Bacteria plague type is one of the seven available plagues in the Artificial Organs Scenario. Beating the scenario with this plague isn't exactly hard but it requires the timely evolution of specific transmission, abilities, and symptoms. If you'd prefer another plague in order to finish this scenario...

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I've gotta be honest, this plague gave me a hard time. I had to find a good order of evolution to ensure the balance of infectivity and lethality. Combine that with random Genetic Shifts and you got yourself a tough dish to swallow. Genetic shifts are the biggest reason for a fail or success by using my strategy.

In order to get a 3 biohazard score in mega-brutal difficulty, you'll need to infect and kill everyone in the world within 365 days. That being said, you'll need to infect fast and kill soon. Actually you're going to have to start making your bacteria lethal early on, which also means that cure progression starts sooner as well. It isn't going to be that easy though because of the dreaded Genetic Shifts. These random events will give you headaches.

Out of 5 games, I was only able to win 3 of them which makes this strategy a 60% chance to win. Most of my failures were caused by, you guessed it!, Genetic Shifts. Just imagine a symptom costing 27 DNA being sky-rocketed to 47 DNA, that sort of stuff will cause a lot of problems.

Before beginning the strategy, I think it would be best to give you some tips. First, don't worry too much about the cure progression. I've won games even by having a cure completion of 50% and above. Second, Evolve anything you're going to evolve as soon as possible. This counters the possibility of its cost being insanely boosted by Genetic Shifts. Lastly, take note of the pop-ups. These are very important, the first pop-up should appear when we start making the plague lethal and the second shows up immediately after we evolve the Insanity symptoms. One more thing, Devolve any mutated symptom. The bonus DNA you get from those would help speed things up.

Now onto the guide, first the gene setup:

  • ATP Boost
  • Teracyte
  • Sympto-Stasis
  • Genetic Mimic
  • Extremophile
1.) Before selecting a country to start in, evolve the following symptoms:
  • Cysts
  • Hyper-Sensitivity
  • Rash

2.) Start in China then immediately start evolving the next two symptoms as soon as you can:
  • Sweating
  • Skin Lesions

3.) Moving onto transmissions, evolve the following in this order:
  • Water and Air 1
  • Water and Air 2
  • Extreme Bioaerosol

4.) Back to symptoms again, evolve these two:
  • Inflammation
  • Seizures
After you evolve these two, a pop-up should appear saying that Artificial Organs are saving lives. This could appear immediately or after a short while, but it should appear.

5.) Continue by evolving these abilities:
  • Drug Resistance 1 and 2
  • Cold and Heat Resistance 1
  • Cold and Heat Resistance 2
  • Environmental Hardening

6.) Evolve the Insanity symptom. After doing so, a pop-up SHOULD appear saying something like "People rip out artificial organs". If this does not appear, you won't be able to kill fast enough to get a 3 biohazard score because your lethality will be significantly lowered. If you followed the order in which I evolved everything, this pop-up will definitely appear, either immediately or after a short period.

7.) Evolve the finishing symptoms:
  • Necrosis
  • Coma
  • Total Organ Failure
  • Hemorrhagic Shock
  • Internal Hemorrhaging
8.) Now you're just waiting for the end to come. Remaining DNA is best used to evolve Genetic Re-Shuffles or, if you're a sadistic person and want to kill people faster, evolve Systemic Infection. 

That about does it. I hope this guide has helped you attain a 3 biohazard score on the Artificial Organs scenario. Again, my cure progress on all my winning games exceeded 50% but I still got a 3 biohazard score. The main thing you'd want to aim for is finishing within 365 days, the lower the better.

If you've got any questions, tips, or strategies you'd like to share, post them at the comments below and I'll check them out. I'll include the good ones along with this guide. Thanks and Happy Spicy Gaming!


  1. Wendy StoutenburghJuly 13, 2014 at 2:18 AM

    I'm having a really hard time with this one. My best so far was 366 days but the cure was over 50%. I think it doesn't like me.

  2. Following this guide, the virus killed all the hosts before it could infect everyone. I'm going to try again :)

  3. tried this only received 2 biohazard...nonetheless I am happy.

    I played this in normal speed to ensure I don't have overflowed DNA it works thanks!

  4. Weird, I killed everyone in 354 days, with cure at 81% and I only got 2 stars. Is the high cure rate what's killing my score?

  5. I have tried this numerous times... the best I have done is 370 days twice with a cure rate of around 45% need t buy 5 days LOL