M. avium, M. intracellulare, and M. chimaera are each saprotrophic organisms present in soil and water; entry into hosts is usually via the gastrointestinal tract, but also can be via the lungs.
Pulmonary involvement symptoms are similar to tuberculosis (TB), and include fever, fatigue, weight loss, and coughing up blood.
[citation needed] MAC causes disseminated disease in up to 40% of people with HIV in the United States, producing fever, sweats, weight loss, and anemia.
[11][12][13] Disseminated MAC (DMAC) characteristically affects people with advanced HIV disease and peripheral CD4 cell counts less than 50 cells/uL.
Effective prevention and therapy of MAC has the potential to contribute substantially to improved quality of life and duration of survival for HIV-infected persons.
However, Jerome Reich and Richard Johnson describe a series of six patients with MAC infection of the right middle lobe or lingula who did not have any predisposing lung disorders.
Disseminated disease was previously the common presentation prior to the advent of highly active antiretroviral therapy (HAART).
[14] Before prophylaxis is administered, patients should be assessed to ensure that they do not have the active disease due to MAC, M. tuberculosis, or any other mycobacterial species.
[14] Rifabutin, by mouth daily, is recommended for the people's lifetime unless disseminated MAC develops, which would then require multiple drug therapy.
Although other drugs, such as azithromycin and clarithromycin, have laboratory and clinical activity against MAC, none has been shown in a prospective, controlled trial to be effective and safe for prophylaxis.
[14] Postinfection treatment involves a combination of antituberculosis antibiotics, including rifampicin, rifabutin, ciprofloxacin, amikacin, ethambutol, streptomycin, clarithromycin or azithromycin.
The Public Health Service, therefore, recommends that regimens be based on the following principles:[14] Clinical manifestations of disseminated MAC—such as fever, weight loss, and night sweats—should be monitored several times during the initial weeks of therapy.
The microbiologic response, as assessed by blood culture every 4 weeks during initial therapy, can also be helpful in interpreting the efficacy of a therapeutic regimen.
There is no evidence that a person's reluctance to spit has any causal role in NTM infection, the chief reason for the term having been applied to older women presenting with the condition.
The article states:[citation needed] Victorian women presumably believed "ladies don't spit," and consequently might have been predisposed to develop lung infection.
While her avoidance of shaking hands might be interpreted as "fastidiousness", two alternative explanations may be just as probable: The scholars highlight the literary malapropism,[29] but some in the medical community have adopted the term regardless, and peer-reviewed medical journals still sometimes mention the Lady Windermere syndrome, although it is increasingly viewed as a outdated and sexist term for a serious bacterial infection.