Although persistence of B. melitensis
in wild ruminants has not been
reported, and these animals are considered
an epidemiologic dead-end
reservoir (3), the unexpected prevalence
observed (≈50%) suggests that
Alpine ibex could be the source of
bovine brucellosis reemergence in the
study area in France. Strict surveillance
policies have prevented infection
of domestic livestock with B. melitensis
in the study area since 1999.
However, cohabitation of domestic
and wild ruminants on pastures during
the summer is rare but possible.
Clinical signs and lesions observed
in chamois and Alpine ibex are consistent
with those reported for chamois
and Alpine ibex with brucellosis
(4,5). However, positive cultures were
obtained from conventional target organs
(knee, testes, and lymph nodes)
but also from urogenital fluids, which
indicates the potential for excretion of
the organism.
The fact that births occur during
periods and in places where female
Alpine ibex are not in close contact
with other wild/domestic species
(because of higher altitude or rocky
peaks) could explain the low transmission
rate of B. melitensis to these animals.
It also suggests that the venereal
route might contribute to transmission
within Alpine ibex during the mating
season in winter. This report demonstrates
the need for maintaining an active/
reactive surveillance system for
livestock and wildlife in brucellosisfree
regions.