Mycobacterium Avium Complex Infections: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Mycobacterium Avium Complex Infections?
An infectious disease specialist usually treats MAC infections. Lung specialists called pulmonologists may also be involved, especially when the lungs are damaged or the diagnosis is unclear. A primary care doctor often makes the first referral. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Mycobacterium avium complex, often called MAC, is a group of germs found in soil, water, and dust. These germs can cause lung infections in some people. The infection is not usually passed from person to person, and most people breathe in the germs without ever getting sick.
Symptoms
MAC lung infections often start slowly, with symptoms lasting weeks or months. Common signs include a lingering cough, fatigue, fever, night sweats, and unexplained weight loss. Because these symptoms overlap with many other conditions, doctors often need tests to find the cause.
Causes and who gets it
People get MAC infections by breathing in the germs or, less often, by swallowing them. The germs live in tap water, hot tubs, soil, and plumbing. The infection is more common in women over age 50, people with lung diseases such as bronchiectasis or COPD, and people with weakened immune systems.
How doctors diagnose it
Diagnosis usually starts with a chest X-ray or CT scan. Doctors also test sputum, the mucus from the lungs, to see if MAC germs are growing in it. Because MAC germs can be present without causing disease, doctors look at test results together with symptoms before deciding on treatment.
Treatment
Not every person with MAC germs in their lungs needs treatment. When treatment is needed, doctors usually prescribe a combination of antibiotics taken for a year or more. These medicines are strong, so doctors watch patients closely for side effects, and follow-up tests show whether treatment is working.
When to see a doctor
Talk to a doctor if you have a cough lasting more than a few weeks, unexplained weight loss, fevers, or night sweats. These symptoms have many possible causes, and most are not MAC. Anyone with a lung condition or weakened immune system should mention that during the visit.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance for visits, while a concierge doctor usually charges more and often works alongside insurance. Both offer longer appointments, which makes it easier to discuss symptoms that have lasted for months. They can order imaging and lab tests, manage other health problems, and refer patients to a specialist when MAC is confirmed or suspected. After the specialist sets a treatment plan, the primary care doctor can often handle follow-up visits and watch for side effects.
Common questions
Is MAC infection contagious?
No, MAC infection does not spread from person to person. People pick up the germs from the environment, such as water and soil.
Why does treatment take so long?
MAC germs grow slowly and have a protective outer wall, so antibiotics need many months to work. Stopping too early raises the chance the infection comes back.
Can I prevent a MAC infection?
There is no sure way to prevent it, but people prone to these infections are sometimes advised to avoid hot tubs and reduce swallowing water from household plumbing. Ask a doctor which steps make sense for you.
Sources
- Centers for Disease Control and Prevention - About Nontuberculous Mycobacteria (NTM) Infections | NTM
- MedlinePlus - HIV and Infections
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
