Bloodstream infection caused by Yersinia enterocolitica in a host with ankylosing spondylitis: a case report and literature review.

The extraintestinal infections caused by Yersinia enterocolitica are very rare, especially in the form of spontaneous bloodstream infection at people without history of blood transfusion. Their clinical symptoms and treatments are still not very clear for now. Here, we report a case of spontaneous bloodstream infection caused by Y. enterocolitica in a 56-year-old Chinese male. The patient presented to outpatient with fever for 1 week, he was diagnosed ankylosing spondylitis for 10 years, and suffered from the pain in his neck, lumbosacral region and limbs constantly. After 4 days of outpatient treatment, there was no sign of improvement so he admitted to inpatient department. Ceftriaxone and metronidazole were initiated in the previous 3 days, the temperature did not drop (highest temperature is 38.3 ℃) and the limb joint pain was aggravated. On day 4, antibiotic therapy was changed to moxifloxacin as the growth of Y. enterocolitica showed in blood culture, then changed to amikacin and piperacillin/tazobactam according to culture susceptibility. The patient received a total of 24 days antibacterial treatment before discharge, his body temperature returned to normal, but he remains continuous pain in lumbosacral region and limbs after negative blood culture, which was considered to be caused by AS. Gastrointestinal symptoms such as vomiting, diarrhea and abdominal pain were not reported during the hospitalization, which usually appears in patients with Yersinia enterocolitica infection. We reviewed 12 septicemia cases without the history of blood transfusion from the literature. Not all hosts were under a low immunity or have a clear history of exposure. Clinical symptoms and antibiotic agents were also different from case to case. Physicians should consider the rare diagnosis of Y. enterocolitica infection in patients without clear history of exposure and typical symptoms. And distinguish between pain caused by AS and aseptic arthritis caused by Y. enterocolitica.