Over one month our team (one of 14 in the division) saw 3 cases of Group B Streptococcus (GBS) bacteremia with musculoskeletal (MSK) complications. The first patient was a 65-year-old male admitted with 2 days of fever and right wrist tenosynovitis and shoulder pain. He had raised white cell count (WCC) of 15.16 x 109/L, C-reactive protein (CRP) 269mg/L and procalcitonin 18.8mcg/L. Blood culture isolated GBS and following 4 weeks of antibiotics, fever and MSK symptoms resolved. The second patient was a 65-year-old male with kidney disease, hospitalized with 5 days of fever, myalgia, neck pain and painful swollen right middle finger. WCC was 18.11 x 109/L, CRP was 186 mg/L and blood culture grew GBS. He received 6 weeks of antibiotics with full recovery. Patient 3 was a 61-year-old female who presented with 4 days of fever, right hip pain and left hand erythema. She had leukocytosis WCC 18.59 x 109/L and elevated CRP 332mg/L and procalcitonin 2.9mcg/L. Again blood culture grew GBS and she received 4 weeks of antibiotics as per right hip and hand septic arthritis. Although no patient underwent arthrocentesis to confirm MSK infections, their clinical response to antibiotics supported this diagnosis. All 3 patients did not have gastrointestinal (GI), genitourinary (GU) or soft tissue infections preceding GBS bacteremia; and none had risk factors for GBS. However all had consumed a raw fish dish between 4 to 14 days prior to onset of symptoms. Molecular typing confirmed they were afflicted with the same Serotype III ST283 strain of GBS, which was subsequently reported to be responsible for a country-wide outbreak of GBS infections, a few which were lethal; associated with 2 species of freshwater fish: Song and Toman fish; eaten raw.
Group B Streptococcus, also known as Streptococcus agalactiae, colonises the human GI and GU tract, but can cause severe disease in neonates, pregnant women and other adults. Especially at risk are patients with diabetes, liver disease and cancer. GBS can cause bacteremia, pneumonia, endocarditis and MSK infections but the exact source is unknown. Breaches in the GI or GU mucosal may be implicated. GBS is also known to cause infections in cultured fish such as Nile Tilapia and Gulf Killifish but human GBS infection from eating fish was not previously described. Our patients were part of an outbreak of 238 people infected with GBS in the first half of 2015. The historical infection rate was 150 cases/year. Raw Song and Toman fish had long been enjoyed by the local populace; it was unclear why the outbreak occurred now. Following public education and advisory against consumption of raw fish, GBS infection rates had declined.
Foodborne infection is a major public health concern. Although GBS was not known to be transmitted through food, this outbreak indicated a link between raw fish consumption and infection.
To cite this abstract:Garuna Murthee K, Kang ML. A Spate of Bacteremia with Bone and Joint Infections: Something Is Fishy!. Abstract published at Hospital Medicine 2016, March 6-9, San Diego, Calif. Abstract 515. Journal of Hospital Medicine. 2016; 11 (suppl 1). https://www.shmabstracts.com/abstract/a-spate-of-bacteremia-with-bone-and-joint-infections-something-is-fishy/. Accessed May 21, 2019.