A 22-month-old boy was admitted to our hospital with one-day history fever and mid diarrhea. At admission, his armpit temperature was 39.7℃, respire was 30 times pear minute, pulse rate was 130 beats pear minute. Then, he took general laboratory tests, and blood culture was collected immediately. The test results showed as follow: white blood cell (hereafter referred to as WBC): 11.5*109 /L (reference range [hereafter referred to as RR]: 8.0–10.0*109 /L), neutrophils: 8.1*109 /L (RR: 3.0–8.0*109 /L), C-Reaction-Protein (hereafter referred to as CRP):104.23 mg/L (RR: < 8.00 mg/L), procalcitionin (hereafter referred to as PCT): 1.77 ng/mL(RR: <0.50 ng/mL), mycoplasma pneumoniae antibody (MP-IgM): negative, rotavirus antibody : negative, the remaining biochemical tests were basically normal. The child was initially diagnosed as an upper respiratory infection and treated with cefathiamidine and rehydration for empirical treatment.
After three days treatment, the child’s condition improved and his body temperature returned to normal (36°C), a complete blood count and (CRP) test did again, and the result was follows: WBC: 7.4*109/L, neutrophils: 2.8*109 /L, CRP: 23.18 mg/L.
The blood culture indicate positive after 11.6 hours of incubation in BD 9120 ( Becton–Dickinson, New Jersey, United States ) automated blood culture system, the positive bottle was transferred to blood agar plate and Macconkey agar plate for separation and culture, subsequently, identification and drug susceptibility tests were carried out for the isolated bacteria (VITEK 2 COMPACT). The culture results showed Aeromonas salmonicida subsp. Salmonicida growth, and the drug susceptibility test results were presented in table. 1.
Day 4, the treatment medication was adjusted from cefathiamidine to ceftriaxone according to the results of drug sensitivity. Day 6, the child had no more fever and his general condition was good. Here was the last laboratory tests result: WBC: 7.8*109/L; neutrophils: 2.3*109 /L; CRP: 9.33 mg/L; PCT: 0.410 ng/mL. Then the child was discharged from hospital at the request of his parents and did not back to hospital for any physical discomfort after that. We called for a follow-up visit three days later, and his condition was very good.