Your Diagnosis, Please
A 3-year old boy was referred to the pediatric infectious disease clinic because of persistent fevers for 8 days. He was born at term via spontaneous vaginal delivery. The delivery was complicated by maternal chorioamnionitis and meconium, resulting in a 3-day stay in the neonatal intensive care unit. His past medical history was also notable for a protracted left cervical lymphadenitis at 2.5 years of age. He was treated with 10 days of cephalexin and 3 days of amoxicillin/clavulanate before undergoing incision and drainage, followed by a 10-day course of clindamycin. Tuberculin skin test was negative, and bacterial and acid-fast bacilli cultures did not reveal any pathogens. Clinical resolution required approximately 4–6 weeks.
The patient was up to date on his immunizations. He lived at home with his parents and 2-month-old sister and attended a local daycare. Family history was unremarkable. The family denied animal contact or insect bites. Four days before presentation, the patient had returned from a 14-day trip to Thailand with his family. While in Thailand, he had developed fevers and was treated with a 4-day course of amoxicillin/clavulanate for presumed streptococcal pharyngitis. The following day, he developed nonbloody diarrhea and 2–3 episodes of nonbilious, nonbloody emesis. Upon his return to the United States, he continued to have fevers and a few episodes of watery diarrhea. He was subsequently seen by his pediatrician and was referred to the pediatric infectious disease clinic.
At the clinic, the patient was well appearing. His weight was 15.1 kg (32nd percentile), and height was 102.3 cm (56th percentile). Vital signs revealed a temperature of 37.2°C, heart rate of 123 beats/min, blood pressure of 99/47 mm Hg and respiratory rate of 20 breaths/min. Physical examination was normal. Laboratory studies revealed a white blood count of 10.9 × 103/mm3 with differential of 65% neutrophils, 5% bands, 17% lymphocytes, 4% reactive lymphocytes, 4% monocytes and 4% metamyelocytes; hemoglobin of 9.5 g/dL; hematocrit of 29% and platelet count of 315 × 103/mm3. C-reactive protein was elevated at 13.8 mg/dL (normal <1.0). Monospot test was negative, and Epstein-Barr virus panel revealed past disease. Thick and thin smears for malaria were negative, dengue IgG was positive at 1.72 (<1.64) and IgM was negative. Blood and stool cultures had growth of Gram-negative bacilli, identified as nontyphoidal Salmonella (NTS), Group E serotype Weltevreden, susceptible to ampicillin, ceftriaxone and sulfamethoxazole/trimethoprim. He was admitted to the hospital and was treated with IV ceftriaxone. He defervesced within 48 hours and continued to remain well appearing without hemodynamic instability throughout his admission. Repeat blood cultures after the start of treatment were negative. He received 5 days of IV ceftriaxone and was transitioned to oral sulfamethoxazole/trimethoprim 10 mg/kg/d divided twice a day to complete a 14-day treatment course. After completion of antibiotic therapy, two stool cultures obtained on separate occasions were negative for NTS.
Eight days after completion of antibiotic therapy, fever recurred with a peak temperature of 39.4°C. The patient again presented to the pediatric infectious disease clinic for evaluation. He remained well appearing with normal physical examination. Blood culture again had growth of Gram-negative bacilli, identified as the same pan-susceptible NTS as his previous episode of bacteremia. Given this recurrence, evaluation for a metastatic focus was initiated. Transthoracic echocardiogram, full-body diffusion-weighted magnetic resonance imaging and abdominal ultrasound were all negative. He was treated with IV ceftriaxone for 6 days, and 3 subsequent blood cultures were negative. He was subsequently transitioned to oral high-dose amoxicillin (80 mg/kg/d) every 8 hours for a total duration of 4 weeks.
Further evaluation revealed the patient’s underlying diagnosis.