340
W. B . SCHAEFER
seems to be relatively more prevalent in free-living birds, such as ducks
(Schaefer et al., 1973b). M. avium 3 appeared to have been limited to
European countries until recently, when a strain of this type was isolated
in the U.S.A. from a tree duck by Thoen (unpublished data, verified by
Schaefer). The bacteriological and epidemiological features of Danish M .
avium infections in animals and in man were described by Engbaek et al.
(1968), and enzootics of avian tuberculosis in pigs by Kleeberg and Nel
(1969), and J~rgensen et al. (1972).
Infections with M. intracellulare, M . scrofulaceum, and other atypical
mycobacteria are nearly always sporadic and caused in man as well as in
animals predominantly by the serotypes represented in the typing procedure
(Schaefer, 1968; Schaefer et al., 1969). Epidemics have been encountered
only in circumstances where the bacteria could multiply freely in a closed
reservoir such as a swimming pool or water storage tanks. Four such
occurrence have been observed: (1) Swimming pool infections by Mycobacterium marinum. They occurred in Sweden (Line11 and Norden, 1954),
England (Morgan and Blowers, 1964), and the U.S.A. I n the latter instance, it was at a very old, poorly built outdoor swimming pool receiving
its water from natural hot springs and from a river. The water was not
chlorinated and contained 1000 bacteria ( M . marinum)/ml. Some 300 cases
of skin infection by this organism were found. Most of the lesions were on
the elbows because these were injured when holding on to a rope at the
edge of the pool. These injuries evidently served as the bacterial port of
entry (Schaefer and Davis, 1961). (2) An outbreak of tuberculin reactivity
among chickens was observed on three neighbouring farms in Czechoslovakia and a mycobacterium called M. brunense (Kazda, 196713) later
identified as M . intracellulare serotype 8, was the causative agent (Kubin
et al., 1969). The infection was traced to open tanks from which the chickens
received their drinking water. T h e tanks were heavily contaminated by the
mycobacteria. Elimination of the source of infection terminated the tuberculin sensitivity within a few months (Kazda, 1967a). (3) An outbreak of
lymphadenitis affecting 67% of the pigs of a deep litter piggery in S.E.
Queensland was due to M. intracellulare serotype 6. The source of infection
was the deep litter which was never changed and the water from a trough
in the deep litter pen (Tammenagi and Simmons, 1968; Reznikov, 1970).
(4) Finally, contamination of numerous specimens of sputa by M . intracellulare serotype 8 has been observed in a hospital and traced to the
presence of the bacteria in the water storage tank (Schaefer, unpublished
observations).
ACKNOWLEDGEMENTS
Our thanks are due to Dr Mayer B. Goren for writing the section on the chemistry
of the type-specific antigens and to Mr Ned Eig for revising the manuscript.
W. B . SCHAEFER
seems to be relatively more prevalent in free-living birds, such as ducks
(Schaefer et al., 1973b). M. avium 3 appeared to have been limited to
European countries until recently, when a strain of this type was isolated
in the U.S.A. from a tree duck by Thoen (unpublished data, verified by
Schaefer). The bacteriological and epidemiological features of Danish M .
avium infections in animals and in man were described by Engbaek et al.
(1968), and enzootics of avian tuberculosis in pigs by Kleeberg and Nel
(1969), and J~rgensen et al. (1972).
Infections with M. intracellulare, M . scrofulaceum, and other atypical
mycobacteria are nearly always sporadic and caused in man as well as in
animals predominantly by the serotypes represented in the typing procedure
(Schaefer, 1968; Schaefer et al., 1969). Epidemics have been encountered
only in circumstances where the bacteria could multiply freely in a closed
reservoir such as a swimming pool or water storage tanks. Four such
occurrence have been observed: (1) Swimming pool infections by Mycobacterium marinum. They occurred in Sweden (Line11 and Norden, 1954),
England (Morgan and Blowers, 1964), and the U.S.A. I n the latter instance, it was at a very old, poorly built outdoor swimming pool receiving
its water from natural hot springs and from a river. The water was not
chlorinated and contained 1000 bacteria ( M . marinum)/ml. Some 300 cases
of skin infection by this organism were found. Most of the lesions were on
the elbows because these were injured when holding on to a rope at the
edge of the pool. These injuries evidently served as the bacterial port of
entry (Schaefer and Davis, 1961). (2) An outbreak of tuberculin reactivity
among chickens was observed on three neighbouring farms in Czechoslovakia and a mycobacterium called M. brunense (Kazda, 196713) later
identified as M . intracellulare serotype 8, was the causative agent (Kubin
et al., 1969). The infection was traced to open tanks from which the chickens
received their drinking water. T h e tanks were heavily contaminated by the
mycobacteria. Elimination of the source of infection terminated the tuberculin sensitivity within a few months (Kazda, 1967a). (3) An outbreak of
lymphadenitis affecting 67% of the pigs of a deep litter piggery in S.E.
Queensland was due to M. intracellulare serotype 6. The source of infection
was the deep litter which was never changed and the water from a trough
in the deep litter pen (Tammenagi and Simmons, 1968; Reznikov, 1970).
(4) Finally, contamination of numerous specimens of sputa by M . intracellulare serotype 8 has been observed in a hospital and traced to the
presence of the bacteria in the water storage tank (Schaefer, unpublished
observations).
ACKNOWLEDGEMENTS
Our thanks are due to Dr Mayer B. Goren for writing the section on the chemistry
of the type-specific antigens and to Mr Ned Eig for revising the manuscript.