Poornima Ramanan

Cytomegalovirus Infections in Solid Organ Transplantation: A Review

Cytomegalovirus (CMV) continues to have a tremendous impact in solid organ transplantation despite remarkable advances in its diagnosis, prevention and treatment. It can affect allograft function and increase patient morbidity and mortality through a number of direct and indirect effects. Patients may develop asymptomatic viremia, CMV syndrome or tissue-invasive disease. Late-onset CMV disease continues to be a major problem in high-risk patients after completion of antiviral prophylaxis. Emerging data suggests that immunologic monitoring may be useful in predicting the risk of late onset CMV disease. There is now increasing interest in the development of an effective vaccine for prevention. Novel antiviral drugs with unique mechanisms of action and lesser toxicity are being developed. Viral load quantification is now undergoing standardization, and this will permit the generation of clinically relevant viral thresholds for the management of patients. This article provides a brief overview of the contemporary epidemiology, clinical presentation, diagnosis, prevention and treatment of CMV infection in solid organ transplant recipients.

Rothia Bacteremia: a 10-Year Experience at Mayo Clinic, Rochester, Minnesota

ABSTRACT Rothia spp. are Gram-positive cocco-bacilli that cause a wide range of serious infections, especially in immunocompromised hosts. Risk factors for Rothia mucilaginosa (previously known as Stomatococcus mucilaginosus) bacteremia include prolonged and profound neutropenia, malignancy, and an indwelling vascular foreign body. Here, we describe 67 adults at the Mayo Clinic in Rochester, MN, from 2002 to 2012 with blood cultures positive for Rothia. Twenty-five of these patients had multiple positive blood cultures, indicating true clinical infection. Among these, 88% (22/25) were neutropenic, and 76% (19/25) had leukemia. Common sources of bacteremia were presumed gut translocation, mucositis, and catheter-related infection. One patient died with Rothia infection. Neutropenic patients were less likely to have a single positive blood culture than were nonneutropenic patients. Antimicrobial susceptibility testing was performed on 21% of the isolates. All of the tested isolates were susceptible to vancomycin and most beta-lactams; however, four of six tested isolates were resistant to oxacillin. There was no difference between the neutropenic and nonneutropenic patients in need of intensive care unit care, mortality, or attributable mortality.

Parametrial Anisakidosis: A case report and review of literature

ABSTRACT Anisakidosis is a parasitic infection caused by anisakid nematodes in the genera Anisakis and Pseudoterranova. Infection is not uncommon in the United States due to increased raw seafood consumption. We report the first known case of parametrial anisakidosis in a 42-year-old woman and review existing literature.

Gordonia Bacteremia: A Case Series and Review of the Literature

ABSTRACT Gordonia species are ubiquitous aerobic actinomycetes that rarely cause infection in humans. We report the second known case of Gordonia otitidis catheter-related bacteremia in an immunocompromised patient and review four additional cases of Gordonia bacteremia seen at our institution over the past 14 years. In addition, the existing literature on Gordonia infections is reviewed.

Clinical Significance of Low-Positive Histoplasma Urine Antigen Results

ABSTRACT Histoplasma urine antigen (UAg) detection is an important biomarker for histoplasmosis. The clinical significance of low-positive (<0.6 ng/ml) UAg results was evaluated in 25 patients without evidence of prior Histoplasma infection. UAg results from 12/25 (48%) patients were considered falsely positive, suggesting that low-positive UAg values should be interpreted cautiously.

Syndromic Panel-Based Testing in Clinical Microbiology

SUMMARY The recent development of commercial panel-based molecular diagnostics for the rapid detection of pathogens in positive blood culture bottles, respiratory specimens, stool, and cerebrospinal fluid has resulted in a paradigm shift in clinical microbiology and clinical practice. This review focuses on U.S. Food and Drug Administration (FDA)-approved/cleared multiplex molecular panels with more than five targets designed to assist in the diagnosis of bloodstream, respiratory tract, gastrointestinal, or central nervous system infections. While these panel-based assays have the clear advantages of a rapid turnaround time and the detection of a large number of microorganisms and promise to improve health care, they present certain challenges, including cost and the definition of ideal test utilization strategies (i.e., optimal ordering) and test interpretation.

Detection and differentiation of norovirus genogroups I and II from clinical stool specimens using real-time PCR

A real-time RT-PCR assay was designed to detect and differentiate norovirus genogroups I (GI) and II (GII), with primers and probes targeting the nonstructural polyprotein gene. Stool samples (n = 100) submitted for routine testing by the BioFire FilmArray® GI panel were also tested by the norovirus GI/GII real-time PCR assays. When compared to the FilmArray GI panel, the norovirus real-time PCR assay demonstrated a sensitivity of 77.5% (62/80) and specificity of 95% (19/20). Specimens yielding discordant results (n = 19) were tested at two outside laboratories for adjudication. Following discordant resolution, the adjusted sensitivity and specificity of the norovirus real-time PCR assays were 96.9% (63/65) and 100% (35/35), respectively. These results suggest that the real-time PCR assays are able to accurately detect and differentiate norovirus GI/GII from clinical stool specimens. Furthermore, our report highlights a potential issue with the specificity of the BioFire FilmArray® norovirus assay, which warrants additional investigation.

Possible Transfusion-Transmitted Babesia divergens–like/MO-1 Infection in an Arkansas Patient

A patient with asplenia and multiple red blood cell transfusions acquired babesiosis infection with Babesia divergens-like/MO-1 organisms and not Babesia microti, the common United States species. He had no known tick exposure. This is believed to be the first transfusion-transmitted case and the fifth documented case of B. divergens-like/MO-1 infection.

Rhodococcus globerulus bacteremia in an allogeneic hematopoietic stem cell transplant recipient: report of the first transplant case and review of the literature

Rhodococcus species are environmental organisms that predominantly cause opportunistic infections in immunocompromised hosts. Rhodococcus equi is the most common species associated with human infections, but there are uncommon but increasing number of cases of infections caused by non‐equi Rhodococcus species. We report a case of Rhodococcus globerulus bacteremia in an allogeneic hematopoietic stem cell transplant recipient, who presented with subacute systemic illness accompanied by severe hepatitis. In the context of this case, we review the literature on Rhodococcus species infections in transplant recipients.

Splenic Rupture as the First Manifestation of Babesia Microti Infection: Report of a Case and Review of Literature

Patient: Female, 79 Final Diagnosis: Splenic rupture due to babesia microti infection Symptoms: Abdominal discomfort • chest pain • fever • tachycardia Medication: — Clinical Procedure: Splenectomy Specialty: Infectious Diseases Objective: Rare disease Background: Babesiosis is an emerging, tick-borne zoonosis caused by intraerythrocytic protozoa of the genus Babesia. Babesia microti is the main pathogen causing human disease and is endemic in the northeastern and upper midwestern parts of the USA. Severity of infection ranges from mild, self-limited, febrile viral-like illness accompanied by nonspecific symptoms to life-threatening infection complicated by severe hemolytic anemia, disseminated intravascular coagulation (DIC), acute respiratory distress syndrome (ARDS), and renal or/and hepatic failure. Splenic rupture (SR) is a very rare but life-threatening complication of severe B. microti infection. Case Report: A 79-year-old female farmer from Wisconsin, USA was admitted during summer with hemorrhagic shock secondary to spontaneous splenic rupture. She was transfused with 3 units of packed red blood cells (PRBC) and underwent emergent splenectomy. Postoperatively, she recovered well and was discharged on postoperative day 4. However, she was re-admitted on postoperative day 10 for febrile hemolytic anemia. Further exposure history was obtained and was significant for multiple tick bites 8 weeks preceding the index hospitalization. She was promptly diagnosed with babesiosis and Lyme disease co-infection. She responded favorably to 10 days of azithromycin and atovaquone and 21 days of oral doxycycline. Conclusions: Despite its rare occurrence, SR due to B. microti infection is a dreaded complication that can rapidly progress to hemorrhagic shock and death. In contrast to other complications of babesiosis, SR is not correlated with parasite burden or immune status of the affected host. Babesiosis should be considered as part of the differential diagnosis in patients from endemic areas presenting with atraumatic splenic rupture.