What does "asymptomatic carriage" mean?

Context:

EPIDEMIOLOGY AND RISK FACTORS
Clostridium difficile( C. difficile) is a Gram-positive, spore-forming bacterium usually spread by the fecal-oral route. It is
non-invasive and produces toxins A and B that cause disease,
ranging from asymptomatic carriage, to mild diarrhea, to
colitis, or pseudomembranous colitis. CDI is defined as the
acute onset of diarrhea with documented toxigenic C. difficileor
its toxin and no other documented cause for diarrhea ( 3 ).
Rates of CDI have been increasing since 2000, especially in the
elderly with a recent hospitalization or residing in long-term care
facility (LTCF). Carriage of C. difficileoccurs in 5 – 15 % of healthy
adults, but may be as high as 84.4 % in newborns and healthy infants,
and up to 57 % in residents in LTCF. Transmission in health-care
facilities results mostly from environmental surface contamination
and hand carriage by staffmembers and infected patients.