United States
 Environmental Protection
                   Office of Science and Technology
                   Office Of Water
                   Washington DC, 20460
March 2002

    Mycobacteria belong to the
        Order Actinomycetales,
       Family Mycobacteriaceae, and
       Genus Mycobacterium.

    There are approximately 90 recognized
     species of Mycobacteria, over 20 of
     which are known to cause disease in

    Non-tuberculosis mycobacteria (NTM)
     have been identified in numerous
     environmental sources, including water.

    There has been recent interest  in the
     NTM species, due to their ability to
     cause disease in humans and animals
     after environmental exposures.

  Characteristics and Classification:
    Mycobacteria are rod-shaped bacteria
     which require oxygen for growth.  Each
     species has  an acid-fast staining
     property during some stage of its
     growth cycle.

    Mycobacterium have been referred to
     as the 'ducks of the microbial world'
     due to their thick, waxy, outer coating
     which enables them to thrive in  aquatic

    The various  species of Mycobacteria
     are classified based on their growth
                             rates in culture into the following three
                             categories: slow growers, rapid growers
                             and those not yet cultivated.

                          ENVIRONMENTAL OCCURRENCE

                           NTM have been found to be ubiquitous
                             in the environment.

                           NTM species have been isolated from
                             numerous water sources, including
                             waste water, surface water,
                             recreational water, ground water and
                             tap water.

                           Piped water supplies are readily
                             colonized by mycobacteria.  Biofilms
                             may serve as a reservoir for these
                             opportunistic pathogens.

                           Few studies are available which
                             quantify the concentrations of NTM in
                             water. Some reports indicate that NTM
                             have been recovered in 11 % to 38% of
                             raw water samples at concentrations of
                             <0.1 to 48 organisms per milliliter of

                          HEALTH EFFECTS IN HUMANS

                          Transmission to Humans:
                           NTM are  not thought to be transmitted
                             by the human to human route, but are
                             instead thought to be transmitted from
                             environmental sources.

  Exposure pathways of potential
   concern include ingestion, inhalation
   and entry of organisms  through
   abraded skin.

  The clinical symptoms seen following
   infection with NTM depend greatly on
   the mycobacterial species.

  Common clinical syndromes include:
    Pulmonary infection
     Infection of the lymph nodes
     Ear infection
     Skin & soft tissue infection
     Catheter-associated infection
    Whole Body (e.g., blood) ifection

  In general, symptoms seen in children
   are similar to those reported in adults.
   Pulmonary disease is relatively rare in
   children.  The most common form of
   clinically significant NTM infection in
   children is infection of the lymph nodes
   in the neck.

  Treatment of NTM infection depends  on
   the location and extent of disease
   involvement, status of the host's
   immune system, and the mycobacterial
     Treatment of pulmonary and whole
      body infections most often requires
      a multidrug regimen.
     Treatment for cutaneous lesions
      may include surgical removal or
      drug therapy. Often, cutaneous
      lesions will disappear without
      requiring treatment.

Disease Occurrence and Outbreaks:
  NTM diseases are not reportable,
   therefore, information regarding the
   occurrence of disease outbreaks is
likely to be underestimated.  However,
human infections due to NTM appear to
be increasing at a significant rate
across the United States.

CDC estimates that NTM diseases
(non-AIDS related) occur in 1.8 out of
100,000 individuals per year in the
U.S., of which approximately 72% are
attributable to M. avium complex

It has been estimated that in the U.S.,
25% to 50%  of individuals with AIDS
will develop NTM diseases, primarily
attributable to MAC.  The recent use of
highly active anti-retro viral therapy
(HAART) in AIDS patients suggests a
decrease in the risk and rate of NTM
infections in these individuals.

Waterborne NTM  have been
associated with hospital (nosocomial)
outbreaks worldwide. These disease
outbreaks usually involve sternal
wound infections,  plastic surgery
wound infections or postinjection
abscesses. Mycobacterial infections in
patients undergoing dialysis treatment
have also been reported.

Although not reported frequently, some
outbreaks of mycobacterial infection
have been reported after exposures in
public swimming areas.

Some false outbreaks have been
reported as a result of contaminated
sampling equipment or water supplies
used for diagnostic procedures.
Therefore, it is important that
precautions be taken when performing
diagnostic tests in order to lessen the
chance of false-positive test results.


  Several of the NTM species are known
   to cause disease in animals. These
   include MAC, M. marinum, M. ulcerans,
   M. paratuberculosis, M. simiae, M.
   fortuitum and M. smegmatis.

  Symptoms seen following infection
   depend on the host organism and the
   species of NTM.

  M. paratuberculosis is the causative
   agent of Johne's disease; a slow,
   progressive infection of the intestine
   which occur mainly in cattle,  sheep and

  M. marinum is an important cause of
   death and economic loss in fish

  M. fortuitum and M. smegmatis are
   known to  produce mastitis in sheep and
   cattle and skin and soft tissue disease
   in domestic house cats.

  Destruction or isolation of infected
   animals is the most common form of
   treatment, however, drug therapy has
   been successful in some cases.


  The general population (healthy
   individuals) is fairly resistant to

  Certain individuals are at increased risk
   for developing NTM associated
   diseases due to the presence of
   predisposing factors, including:
      traumatic breaches of the skin
      pre-existing pulmonary disease or
     lung architectural defects
     generalized congenital and acquired
      immunosuppressive disorders (e.g.,


  The most common method for the
   identification of mycobacterial species
   in water samples is through culture
   isolation. The bacterial culture is
   evaluated for morphology, growth rates
   and other biochemical parameters in
   order to determine the species.

  Several other methods have been
   developed for the detection of
   mycobacteria in samples,  including:
     Polymerase chain reaction (PCR)
     Radiometric methods (BACTEC)
     Nucleic acid probes

  Although promising, these methods
   only provide qualitative information
   regarding the presence of mycobacteria
   in water and do not provide a measure
   of concentration.

  When collecting samples for use in
   culture isolation, a decontamination
   step is necessary to kill the other
   bacteria and fungi present in the water.
   This is because there is a  large
   problem of contamination of samples
   due to the presence of non-
   mycobacterial bacteria which are
   capable of growing at faster rates than
   the species of interest.  Acids, alkalis
   and detergents are often used during
   the decontamination  process since
   mycobacteria are generally more
   resistant to these chemicals than are
   other bacteria.


   In general, two mechanisms can be
   used to eliminate microbes from
   drinking water: removal or disinfection.

   Removal treatments such as filtration,
   sedimentation, coagulation, flocculation
   and adsorption are primarily physical
   operations that remove bacteria from
   the water.

   Disinfection treatment technologies
   may kill bacteria using  chemicals such
   as chlorine, ozone, bromine, iodine or
   hydrogen peroxide which are added to
   the water, or may inactivate microbes
   via UV radiation.

   NTM are relatively resistant to standard
   water disinfection procedures and,
   therefore, can occur in potable water.

   Overall, there is little information
   available regarding the effectiveness of
   various disinfection treatments on
   mycobacterial species  in water.
   However, EPA is actively studying
   methods to reduce the occurrence of
   Mycobacteria in drinking water and will
   update this fact sheet when better
   information becomes available.
   zero organisms (bacteria and viruses),
   including mycobacteria, for drinking
   water.  An MCLG is a non-enforceable
   guideline based solely on an evaluation
   of possible health risks, taking into
   consideration a margin for public


  EPA has established the Safe Drinking
   Water Hotline, a toll-free number for
   further information on drinking water
   quality, treatment technologies, and for
   obtaining Health Advisories or other
   regulatory information.

  Safe Drinking Water Hotline:
   9:00 a.m. - 5:30 p.m. (Eastern Time)
   Monday-Friday (excluding
   holidays).Your state or county health
   officials or experts in your state's
   Department of Environmental
   Protection or Natural Resources may
   also be of assistance.

  EPA has established a Maximum
   Contaminant Level Goal (MCLG) of