Infection Risk After Cardiac Surgery and Mycobacteria in Grand Rapids, MI

Mycobacterium chimaera is a type of bacterium known as a non‑tuberculous mycobacterium (NTM). In rare cases, it has been linked to infections in people who have had open-heart (cardiac) surgery.

In Grand Rapids, cardiac surgery is performed at major centers such as Corewell Health (formerly Spectrum Health), Trinity Health Grand Rapids, Metro Health – University of Michigan Health, and other regional hospitals. These hospitals follow strict infection prevention protocols, but it is still important for patients to understand this rare risk and know when to seek medical care.

How Mycobacterium chimaera Is Linked to Cardiac Surgery

During open-heart surgery, a medical device called a heater–cooler unit is often used to regulate a patient’s body temperature. In a small number of cases worldwide, Mycobacterium chimaera has been found in the water tanks of some heater–cooler units.

Although the water in these devices does not come into direct contact with the patient’s blood, the bacteria can, in rare situations, become airborne through the exhaust and potentially reach the surgical field.

  • Fewer than 100 cases have been reported worldwide in people who had heart surgery.
  • Only a very small percentage of patients who undergo cardiac surgery will ever develop any infection from this source.
  • Infections can appear months or even years after surgery, which is why long-term awareness is important.

Grand Rapids hospitals work closely with infection prevention teams and follow guidance from agencies such as the Kent County Health Department and Michigan Department of Health and Human Services to keep this risk extremely low.

What Is Mycobacterium chimaera?

Mycobacterium chimaera is part of a group of bacteria called non‑tuberculous mycobacteria (NTM).

  • NTM are commonly found in the environment, including soil, tap water, and natural water sources such as the Great Lakes and local rivers around Grand Rapids.
  • For most healthy people, these bacteria do not cause illness.
  • In rare situations, especially in people with weakened immune systems or those who have had major surgery with implanted devices, NTM can cause serious infection.

In Michigan’s climate, with humid summers and cold winters, people spend a lot of time indoors, and water systems (including hospital systems) are carefully monitored to reduce any risk of environmental bacteria, including NTM.

Who Is at Higher Risk After Cardiac Surgery?

The risk of Mycobacterium chimaera infection remains very low, but some patients are at higher risk, including those who have had:

  • Open-heart surgery where an artificial (prosthetic) heart valve was inserted
  • Other prosthetic material implanted in the heart or blood vessels (e.g., vascular grafts, patches, prosthetic conduits)

These patients are more likely to have a problem if exposed because bacteria can attach to prosthetic surfaces.

Symptoms to Watch for After Heart Surgery

One challenge with Mycobacterium chimaera infection is that symptoms can be slow to develop and nonspecific. They may begin months or years after surgery.

If you had open-heart surgery in Grand Rapids or elsewhere and you develop any of the following, contact your cardiologist, cardiac surgeon, or primary care provider without delay:

Symptoms Around the Surgical Site

  • Pain, redness, warmth, or swelling near your chest incision
  • Pus or drainage from the wound
  • Wound that is not healing or reopens

General or Systemic Symptoms

  • Prolonged fever or unexplained fever that does not go away
  • Night sweats
  • Unintentional weight loss
  • Marked fatigue or feeling unusually tired
  • Shortness of breath that is new or getting worse
  • Persistent cough or symptoms that may resemble NTM lung disease
  • Joint or muscle pain
  • Nausea, vomiting, or abdominal pain

Because these symptoms can be caused by many different conditions common in West Michigan—such as seasonal viral infections, influenza, or other lung issues related to cold weather—your provider may order specific tests if they know you had prior cardiac surgery.

If you develop concerning symptoms and cannot reach your doctor, you may seek care at:

  • Your hospital’s cardiac surgery clinic
  • A local urgent care or emergency department (e.g., Corewell Health, Trinity Health Grand Rapids, Metro Health)

Be sure to tell them you have had open-heart surgery and when it occurred.

How Are These Infections Treated?

If Mycobacterium chimaera infection is suspected:

  1. Your healthcare team may order:

    • Blood tests
    • Imaging (such as chest X‑ray, CT scan, or echocardiogram)
    • Cultures or biopsies to look for NTM

  2. Confirmed infections are usually treated with:

    • Combination antibiotic therapy over many months
    • In some cases, additional surgery may be needed to remove or replace infected prosthetic material

Treatment is managed by specialists in infectious diseases and cardiac surgery, often working together. Grand Rapids has access to these specialists through major health systems and referral networks in West Michigan.

If You Are Scheduled for Cardiac Surgery in Grand Rapids

Before your surgery, your cardiac team will discuss the overall risks of surgery, including:

  • General infection risk
  • Bleeding, stroke, or other surgical complications
  • Rare risks, such as Mycobacterium chimaera infection from heater–cooler units

Key points for patients in Grand Rapids:

  • The risk of mycobacterial infection from heater–cooler units is extremely low compared to the overall risk of heart surgery and valve infection.
  • The benefits of necessary cardiac surgery—such as improved survival, better heart function, and quality of life—almost always outweigh this very small infection risk.

If you have specific concerns about Mycobacterium chimaera or any infection risk:

  • Discuss them with your cardiac surgeon or cardiologist during your pre‑admission appointments.
  • Ask how your Grand Rapids hospital maintains and monitors its heater–cooler units and infection control practices.

What Grand Rapids Hospitals Are Doing to Protect Patients

Hospitals in Grand Rapids and across Michigan follow strict guidelines to minimize infection risk from heater–cooler units:

  • Regular testing and monitoring of heater–cooler water systems
  • Frequent water changes using appropriate water sources
  • Enhanced disinfection and maintenance protocols
  • Upgrading or replacing older units that may be more prone to contamination
  • Following recommendations from:
    • Kent County Health Department
    • Grand Rapids Public Health
    • Michigan Department of Health and Human Services
    • National and international health agencies

If you have questions about the specific practices at the hospital where you had or will have surgery, you can contact:

  • The cardiac surgery department
  • The hospital’s infection prevention or patient relations team

Infection and Cardiac Surgery: What Grand Rapids Patients Should Remember

  • Infection is a known possible complication of any surgery, including cardiac surgery.
  • Non‑tuberculous mycobacteria (NTM) like Mycobacterium chimaera are common in the environment (soil and water, including in Michigan’s Great Lakes region) but rarely cause disease.
  • The risk of Mycobacterium chimaera infection from heater–cooler units is extremely low.
  • Symptoms can appear long after surgery, so ongoing awareness is important.
  • Early evaluation and treatment improve outcomes if an infection does occur.

When to Seek More Information or Help in Grand Rapids

You should seek medical advice if:

  • You had open-heart surgery (especially with a prosthetic valve or graft) in the past few years, and
  • You develop any persistent or unexplained symptoms such as fever, night sweats, weight loss, or worsening shortness of breath.

Resources for Grand Rapids residents:

  • Your cardiologist or cardiac surgeon at Corewell Health, Trinity Health Grand Rapids, Metro Health, or other local hospitals
  • Your primary care provider
  • Kent County Health Department or Grand Rapids Public Health for general infection and public health information

Staying informed, attending regular follow‑up appointments, and promptly reporting new symptoms are the best ways to protect your health after cardiac surgery in Grand Rapids, Michigan.