The United States Centers for Disease Control reports an on-going outbreak
of Salmonella Heidelberg infections in people who have been in contact with calves.
What makes this worrisome is that these bacteria are resistant to
most antibiotics.
Since the last update on August 2, eight more
people have been reported ill from six states.
That brings the total to 54 people in 15
states.
Seventeen (35 per cent) of them have been
hospitalized. None have died.
Illnesses started on dates ranging from
January 27, 2015 to October 15, 2017.
Eighteen (33 per cent) of the sick people are
children under the age of five.
Epidemiologic and laboratory investigations
linked ill people in this outbreak to contact with calves, including dairy
calves.
Some of the ill people interviewed reported
that they became sick after their dairy calves became sick or died.
Eighty-three per cent of the sick people were in contact with calves.
Ongoing surveillance in veterinary diagnostic
laboratories showed that calves in several states continue to get sick with the
outbreak strains of multidrug resistant Salmonella
Information collected earlier in the outbreak
indicated that most of the calves came from Wisconsin.
Whole genome sequencing has identified
multiple antimicrobial resistance genes in outbreak-associated isolates from 43
ill people, 87 isolates from cattle, and 11 isolates from animal environments.
Isolates from eight ill people were resistant
to amoxicillin-clavulanic acid, ampicillin, cefoxitin, ceftriaxone,
streptomycin, sulfisoxazole, and tetracycline, and had reduced susceptibility
to ciprofloxacin. Seven isolates were also resistant to
trimethoprim-sulfamethoxazole.
Five were also resistant to nalidixic acid.
Three were also resistant to chloramphenicol.
All eight isolates tested were susceptible to
azithromycin and meropenem.
