A 69-year-old man presented on May 1, 2018, to a hospital with fevers and diarrhea. The patient had a complicated history, with cardiovascular problems including an abdominal aortic aneurysm, atrial septal defect status after Amplatzer occluder device placed in 2008, and sick sinus syndrome status post dual-chamber pacemaker placement in 2015.
The patient was diagnosed with primary myelofibrosis with JAK2 mutation in April 2015, treated with lenalidomide and prednisone which were tapered off, and his treatment was switched to ruxolitinib. In November 2016, his disease transformed to secondary acute myelogenous leukemia. He was treated initially with induction chemotherapy with 7 + 3 cytarabine and daunorubicin, and follow-up bone marrow biopsies showed no evidence of leukemia. He was subsequently treated with one course of consolidation chemotherapy with high-dose cytarabine. He ultimately underwent HLA-matched related hematopoietic stem cell transplant from his brother in February 2017. His conditioning regimen was reduced-intensity fludarabine and melphalan. His transplant course was complicated by culture-negative neutropenic fevers and neurotoxicity due to tacrolimus, so he was switched to mycophenolate for graft-versus-host disease (GVHD) prophylaxis. Follow-up bone marrow biopsy showed persistence of fibrosis, but was negative for leukemia, and DNA testing proved that he had over 99% donor DNA in the cell population.
His posttransplant course was complicated by mild GVHD involving the skin and colon diagnosed by sigmoidoscopy. He was treated with high-dose steroids, budesonide, and sirolimus, which were ultimately tapered off by the end of July 2017. However, he developed chronic GVHD involving his mouth in September 2017, which was treated with prednisone, sirolimus, and dexamethasone swish and spit. His prednisone dose was tapered to 30 mg daily by November 2017, and by January 2018, he was only taking prednisone 10 mg daily. By March 2018, it was decreased to 10 mg every other day.
In March 2018, he developed an acute right lower extremity deep vein thrombosis involving his common femoral, profunda, femoral popliteal, posterior tibial, and peroneal veins. He was treated with tissue plasminogen activator, heparin, and thereafter apixaban.
He was admitted in early May 2018 for a week at an outside facility with abdominal pain, diarrhea, and septic shock requiring admission to the intensive care unit, necessitating the use of pressors and stress-dose steroids. He also developed acute renal failure but never required hemodialysis. Both blood and stool cultures were positive for S. enterica serotype Mbandaka. This was believed to be associated with the multistate outbreak of infections linked to cereal. The patient reported that he ate an entire box of cereal within one week prior to becoming ill. Blood culture susceptibilities demonstrated that the organism was susceptible to ampicillin, ceftriaxone, ciprofloxacin, tetracycline, tigecycline, and trimethoprim/sulfamethoxazole.
He was treated with IV ceftriaxone and discharged on amoxicillin/clavulanic acid, completing a total of three weeks of antibiotics. However, about a week after stopping antibiotics, at the end of May 2018, he was readmitted with fevers and diarrhea. Blood cultures were negative, but stool cultures were again positive for S. enterica serotype Mbandaka. He was treated initially with intravenous antibiotics and was discharged on 28 days of trimethoprim/sulfamethoxazole 1 DS tab twice per day. While on antibiotics, his abdominal pain, fevers, and diarrhea resolved.
Approximately seven days after stopping his antibiotics, in early July 2018, he developed a third recurrence of fevers and diarrhea. Blood cultures returned negative, but stool cultures were again positive. He was admitted to the hospital for the third time, treated with intravenous antibiotics for 3 days and discharged home with a second 28-day course of trimethoprim/sulfamethoxazole. Stool studies were also positive for Clostridium difficile, so he received oral vancomycin for treatment. His diarrhea and abdominal pain again resolved. Soon after his discharge, his prednisone dose was decreased to 5 mg every other day, and he was maintained on sirolimus 1 mg daily.
After his third admission, he was evaluated by infectious diseases for his recurrent infections with salmonellosis. A transesophageal echocardiogram was performed, which showed a 0.9-1 centimeter mitral valvular vegetation (Figure 1). This appeared very mobile and was associated with mild eccentric mitral regurgitation. The Amplatz closure device showed no evidence of infection, and his pacemaker leads showed no vegetation.
The patient also had a CT scan of his abdomen which showed a mild increase in the degree of mural thrombus associated with the 2.9 x 2.7 cm calcified abdominal aorta in the lower abdomen, now measuring 10 mm compared to 7 mm on the prior exam from 14 months prior. An indium-111 white blood cell scan was negative.
The patient's antibiotics were converted from oral trimethoprim/sulfamethoxazole to ceftriaxone 2 grams intravenously daily for six weeks. He was maintained on oral vancomycin for his Clostridium difficile infection. Four weeks into intravenous therapy, however, he was rehospitalized again with fevers and diarrhea. Blood and stool cultures were negative, and stool for Clostridium difficile was negative. His fevers and diarrhea ultimately resolved, and he was discharged home.
A follow-up transesophageal echocardiogram prior to discontinuation of intravenous antibiotics showed a smaller linear echodensity, now 0.5 cm, attached to the anterior leaflet of the mitral valve. There continued to be mild mitral regurgitation. Again, both the Amplatz closure device and pacemaker leads showed no vegetation.
Upon completion of six weeks of intravenous antibiotics for endocarditis, the patient restarted trimethoprim/sulfamethoxazole. He was ultimately tapered off oral vancomycin for his infection with Clostridium difficile. Length of therapy for his salmonellosis is to be determined based on follow-up stool testing and immunosuppressive course.