Reducing Exposure to NTM

It should be stressed that there have been no formal studies of any intervention to reduce
NTM exposure to demonstrate that it will reduce the chance of reinfection with NTM after
successful treatment. However, these studies are difficult to conduct, and common sense
should prevail. Any intervention that is simple, cost effective and easy to implement that
has some evidence base in theory should be considered.
Tap water
Flushing of taps:
The impact of stagnation of water in pipes leading to taps that are infrequently used has
been shown to increase NTM in ‘first catch’ samples. This can simply be overnight
stagnation. For taps used infrequently, a 5-minute flush is recommended before use of the
water from that tap. For taps used on a daily basis, a shorter flush on first use for the day is
recommended (e.g. 200ml) (1)*
Removal of mesh aerators: Mycobacteria attach to the large surface area provided by the
mesh, form biofilm and then proliferate. As such, numbers of mycobacteria coming through
taps with them attached are greater than taps without. Their removal may help to reduce
exposure to NTM from tap water. (2) *

Underbench/ pre-tap water filtration: These devices are often cartridge based systems
installed under kitchen benches or anywhere after the main supply of water enters the
premises. Examples include Microfiltered water dispensers (MWDs) with composite filters,
and Reverse-osmosis water dispensers (ROWDs). Adequate and continuous maintenance of
these devices is crucial. Whilst they may filter other bacteria, chemicals and sediment, they
have been shown to increase the numbers of mycobacteria in tap water (3). When
implemented in an aged care facility they were associated with widespread bacterial
contamination, and for ROWDs worsening of nutritional quality of the drinking water and
are generally not recommended for patients susceptible to NTM.

Point of use filtration: Numerous types of devices that treat the water at the point of use
(POU devices) are commercially available, making use of different refinement treatments.
Such devices are marketed as being able to eliminate unpleasant odors and tastes and to
remove any undesirable substances from the tap water. They often include systems for the
addition of CO2 and for the cooling of the water. Many of them make claims to remove
bacteria, but testing has not included NTM.
Some have been shown to remove mycobacteria from tap water.(3-5) However, this effect
is limited to 1-3 weeks depending on the device, after which mycobacteria have started to
grow within the filtration device and numbers will increase significantly in the water passing
through. If POU devices are used they need to be changed every fortnight.
Temperature control: Hot water storage units should be set at a minimum of 60C (many
can heat water to 75-80C). A tempering device or thermostatic mixing valve can be
installed at the tap to ensure the maximum temperature of water delivered from the tap is
50 C to reduce scalding risk (45C recommended for children and the elderly).

Shower heads: Replace plastic showerheads with metal ones (less likely to harbour biofilm
where NTM grow). Soaking shower heads in vinegar for 60 minutes has been recommended
as a means of cleaning. * However the process needs to be repeated at least every 6
months (A plastic bag containing the vinegar can be attached by a rubber band to the
shower head if it can’t be removed easily for soaking). Household bleach has been
recommended as an alternative. This does reduce bacteria, however they do grow back and
in one study, this led to growth of NTM with increased resistance to chlorine.(6)
Ventilation: ensure adequate bathroom ventilation to clear contaminated shower aerosols
and steam. The use of exhaust fans, and leaving windows open will help alleviate steam
build up. Replace/clean filters on exhaust fans as per manufacturers instructions (usually
every 6mths) *

Measures to reduce reflux and nocturnal micro aspiration: Reflux of stomach contents into
the oesophagus, particularly at night when lying flat, can result in spillage of contaminated
food or water into the lungs.(7) *

  •  Maintain a healthy weight and avoid tight-fitting clothing (both lead to increased
    pressure on the stomach)
  • Avoid foods and drinks that trigger heartburn. Everyone has specific triggers.
    Common triggers such as fatty or fried foods, tomato sauce, alcohol, chocolate, mint,
    garlic, onion, and caffeine may make heartburn worse. Avoid foods you know will
    trigger your heartburn.
  • Eat smaller meals. Avoid overeating by eating smaller meals.
  • Don’t lie down after a meal. Wait at least three hours after eating before lying down
    or going to bed.
  • Elevate the head of your bed.  Place wood or cement blocks under the feet of your
    bed so that the head end is raised by 10-15cm. If it's not possible to elevate your
    bed, you can insert a foam wedge at 30 between your mattress and bottom sheet
    to elevate your body from the waist up. Raising your head with additional pillows is
    not effective.
  • Don’t smoke. Smoking decreases the lower esophageal sphincter’s ability to function

Cleaning of Nebulisers and airway clearance devices:

  •   Nebulisers should be cleaned after each use.
  • The use of unit dose vials for medication is recommended (rather than a larger
    volume that is repeatedly accessed, when contamination can occur).

The use of steam sterilisation is recommended using a table top steam sterilizer marketed
for baby bottles. (8)
Alternatives recommended by the Cystic Fibrosis Foundation include (2003 CF IP&C
guideline, Category II)
Heat methods:
Place in boiling water and boil for 5 minutes
Place in a microwave-safe receptacle
submerged in water and microwave for 5 minutes. Use a dishwasher if the water is more
than or equal to 70C or 158F for 30 minutes
Use an electric steam sterilizer.
Cold methods:
            a. Soak in 70% isopropyl alcohol for 5 minutes b. Soak in 3% hydrogen peroxide for 30
             i. Rinse off the cold-method disinfectant using sterile water, not tap water; the final rinse
                must be with sterile water
            ii. Air dry the nebulizer parts before storage
                These alternatives may be effective for most cystic fibrosis related pathogens, but not
                necessarily eradicate NTM from nebulisers.

Other water related exposures: Indoor pools, hot tubs, steam saunas, hydrotherapy pools
and other leisure activities that involved aerosolisation of water should be avoided.
CPAP humidifiers, neti pots/nasal rinse devices and other devices that require water for
humidification/aerosolisation, should be used with sterile/boiled water only.

Soil and dust exposure: NTM have been grown from soil and aerosols generated when
gardening. Whilst there are no studies examining the effectiveness of masks it would be
reasonable for high risk patients to use personal-protection whilst engaging in these
activites. Moistening soil/potting mix prior to use may also reduce the aerosolisation and
subsequent inhalation of contaminated soil particles.

Vacuum cleaner dust has been shown to harbour NTM.(9) When vacuum cleaners are used
a fine particulate exhaust is generated that may be a risk for inhalation of NTM. Whilst there
have been no rigorous studies, it would be reasonable to avoid the exhaust of vacuum
cleaners and to wear a mask when emptying or changing bags/cartridges.
Construction sites: avoid exposure to construction and renovation activities that generate
dust to decrease exposure to potential pathogens