Current Infectious Disease Reports最新文献

Purpose of review

Small intestinal bacterial overgrowth (SIBO) is a chronic gastrointestinal disorder wherein excessive and abnormal growth of bacteria in the small bowel generally causes abdominal pain, bloating, and change in bowel habits. Our understanding of the underlying pathology and microbiome changes in SIBO has advanced greatly in the last 20 years in parallel with advances in treatment methods and diagnostics. Here, we review many of the latest findings that describe the pathophysiology of SIBO as well as its risk factors, clinical behavior, diagnosis, and management.

Recent findings

Studies have begun to employ advanced molecular assays to sequence the small bowel microbiome to reveal the changes evident in SIBO. An increase in the abundance of members of the Enterobacteriaceae is the main alteration to the gut microbiome that correlates with SIBO diagnosis and symptom severity, and enhancement of specific gas-producing pathways has been demonstrated in SIBO. Diagnostic methods continue to evolve with novel methods of small bowel aspiration and changes to interpretation of hydrogen breath tests. Elemental diets are the newest treatment modality that offer an exciting alternative to antibiotic therapy.

Summary

The study of SIBO provides valuable insights into the small bowel microbiome, particularly using molecular testing. Exciting changes to our understanding and treatment of SIBO are already in progress. Future work will be able to better elucidate not only the altered microbiology, but also its gold standard of diagnosis, treatment modalities, and secondary prevention.

Purpose of Review

As children and adolescents with cystic fibrosis (CF) have lived longer, they have become more susceptible to pulmonary infection with nontuberculous mycobacteria (NTM). Most NTM infections are caused by the Mycobacterium avium complex (MAC) or Mycobacterium abscessus. We review what is currently known and recommended for treatment of these infections.

Recent Findings

Treatment of MAC infection is standardized and evidence-based, involving a combination of three oral drugs for 12 months. Treatment of M. abscessus infections is more difficult and not standardized owing to the: lack of bactericidal drugs; variability of drug susceptibilities; inability of in vitro antibiotic susceptibility testing to predict clinical success; lack of randomized trial data to guide therapy; need for initial parenteral therapy; higher rate of adverse reactions to the necessary medications; and high cost and limited availability of some of the drugs. Treatment involves an initial several month period including one or more parenteral antibiotics followed by a prolonged continuation phase using several of the best available oral antibiotics. Dual beta-lactam antibiotic and phage therapies offer some hope for improved outcomes in refractory cases.

Summary

The goals for therapy of M. abscessus infections should be considered prior to the onset of treatment, and often are aimed toward improvement in symptoms and quality of life rather that eradication of the organism.

Purpose of Review

Mpox, formerly known as monkeypox, is a zoonotic illness caused by a virus that is part of the Orthopoxvirus family. Originally identified in humans in the Democratic Republic of Congo in 1970, the disease has been endemic in central African nations. In 2022, an outbreak of Monkeypox warranted a declaration by the World Health Organization (WHO) that the virus was a Public Health Emergency of International Concern. Prior literature documented the dermatological manifestations of the disease, but fewer papers have described and navigated the complexities of mpox gastrointestinal manifestations. We aim to update the current literature on the gastrointestinal (GI) manifestations of mpox, through a review of the literature via PubMed search for English language papers reporting GI manifestations of the virus.

Recent Findings

Individual reports of symptomatic manifestations of mpox have been reported. Upper and lower GI symptoms have been described and, in multiple cases, required multidisciplinary team care to successfully treat the patients.

Summary

GI manifestations of mpox disease are reported in a variety of severities and, in some instances, may require multidisciplinary management.

Purpose of Review

Climate change has significantly impacted the ecological interactions between pathogens, vectors and human populations. Regional variations in temperature and precipitation patterns have shifted the geographic spread and seasonality of infectious diseases. Cases of meningoencephalitis, in particular those caused by vector-borne infections, are likewise expected to display changes in seasonality and geographic distribution. We review the current evidence on the impact of climate change on the epidemiology of vector-borne meningoencephalitis in the Americas.

Recent Findings

Epidemiologic data and climate models have shown a northward expansion of Lyme disease, West Nile virus, La Crosse virus and Eastern Equine virus infections. Similar geographic shifts are expected to occur with St Louis virus, Everglades virus and Powassan virus infections. These increased incidence is deemed to be the result of warmer winters and heavier precipitation seasons.

Summary

Climate change has led to epidemiologic changes of vector-borne meningoencephalitis in the Americas, and further changes are expected to occur. The impact of climate change on the incidence, seasonality and geographic distribution of vectors and pathogens should be monitored closely.

Purpose of Review

Norovirus is a leading cause of diarrhea in transplant recipients. Norovirus can cause a severe acute syndrome in this patient population. Transplant recipients can also develop a chronic diarrheal syndrome with associated frailty, prolonged viral shedding, hospitalizations, and rejection, with associated mortality. Despite the significant burden of disease and improved diagnostics, there are no specific treatments to target norovirus. We aim to review the virology, epidemiology, diagnosis, clinical presentation, management, and prevention of norovirus.

Recent Findings

A recent retrospective observational study included nine solid organ transplant recipients (5 kidneys, 2 kidney-pancreas, 1 heart, and 1 lung) with chronic norovirus (median duration of diarrhea 12 weeks). Six of these nine patients demonstrated resolution of diarrhea at hospital discharge after oral human immune globulin. A recent phase II randomized controlled trial including solid organ transplant and bone marrow transplant recipients with norovirus compared nitazoxanide with placebo. Nitazoxanide did not demonstrate improved time to resolution of symptoms or duration of viral shedding but may have resulted in transient symptom improvement.

Summary

Norovirus causes significant morbidity and mortality in transplant recipients. Although there are no approved treatment options, there are multiple strategies available, including supportive care, reduction in immunosuppression, intravenous immunoglobulin (IVIG), oral human immune globulin (OHIG), vitamin A, ribavirin, nitazoxanide, and the use of mammalian target of rapamycin (mTOR) inhibitors. Randomized controlled trials are needed to better study these strategies and prevention through the development of a universally available vaccine.

Purpose of Review

Surgical site infections (SSIs) are associated with significant morbidity and mortality. Given the role of endogenous carriage of Staphylococcus aureus, current patient decolonization strategies revolve around the application of topical antiseptic agents prior to and at the time of surgery.

Recent Findings

Intranasal single-application povidone-iodine (PVP-I) on the day of surgery is an emerging, attractive alternative to the established approach of a 5-day course of intranasal mupirocin for preoperative decolonization.

Summary

PVP-I appears more convenient and cost-effective for both patients and healthcare systems, and its role in reducing SSI is under investigation. However, most published literature consists of retrospective, single-center studies primarily done in orthopedic surgical populations. Based on current data, PVP-I appears to be as equally effective in SSI reduction as mupirocin, but larger and better-quality studies are needed to implement a change from currently established preoperative decontamination practices.

Purpose of Review

Surgical site infections are healthcare-associated infections that cause significant morbidity and mortality. Best practices in prevention of these infections are combined in care bundles for consistent implementation.

Recent Findings

Care bundles have been used in nearly all surgical specialties. While the composition and size of bundles vary, the effect of a bundle depends on the number of evidence-based interventions included and the consistency of implementation. Bundles work because of the cooperation and collaboration among members of a team. Bundles for prevention of surgical site infections should address the multiple risk factors for infection before, during, and after the surgery.

Summary

Bundles increase standardization of processes and decrease operative variance that both lead to reductions in surgical site infections.

Abstract

Purpose of Review

Antimicrobial resistance is a growing threat to public health, leading to millions of antibiotic-resistant infections and thousands of deaths annually in the USA. One concerning issue is the rise of extended-spectrum beta-lactamase (ESBL)–producing Enterobacterales. Current treatments often involve intravenous carbapenems, leading to prolonged hospital stays and financial burdens.

Recent Findings

To address this, new oral penem agents, tebipenem and sulopenem, are being investigated. They are administered as prodrugs, enhancing bioavailability before becoming active in the gastrointestinal tract, potentially treating multidrug-resistant infections in outpatient settings. Despite promise in clinical trials, challenges exist, such as tebipenem’s renal excretion, requiring dose adjustments for kidney dysfunction. Additionally, sulopenem failed noninferiority margins in trials, and neither drug has established susceptibility testing standards.

Summary

Tebipenem and sulopenem offer potential oral solutions for antimicrobial resistance, especially in urinary tract infections, but further research is needed for optimal dosing and susceptibility testing.

Purpose of Review

Beta-lactam antibiotics are among the most commonly prescribed drug classes in the hospital setting. The pharmacokinetic/pharmacodynamic index correlated with bactericidal activity of beta-lactam antibiotics is the amount of time drug concentrations exceeds the minimum inhibitory concentration over the course of a dosing interval. Standard dosing is based on preclinical trials conducted in healthy volunteers with considerations for renal function and weight to maintain time over minimum inhibitory concentration for an appropriate percentage of the dosing interval. It is commonly accepted that critically ill patients have altered pharmacokinetics which may impact drug efficacy; however, current dosing strategies do not account for these variances. As such, standard dosing delineated in package inserts may not optimize time over the minimum inhibitory concentration. Therapeutic drug monitoring of beta-lactams has been proposed as a possible method to ensure dose optimization in a state of critical illness. To date, there have been limited clinical studies supporting the routine use of therapeutic drug monitoring of beta-lactams, as well as an uncertainty regarding how the process can be applied in the clinical setting. The purpose of this review is to elucidate the current state of therapeutic drug monitoring of beta-lactams and evaluate clinical outcomes of patients who received therapeutic drug monitoring of beta-lactams compared to the standard of care.

Recent Findings

Recent clinical trials suggest there is little demonstrable benefit in patients’ clinical outcomes when therapeutic drug monitoring of beta-lactams is utilized. A number of studies have been performed with variable trial designs. In these studies, there are different pharmacokinetic/pharmacodynamic targets, pathogens, beta-lactams, and primary outcomes. This makes assessment of therapeutic drug monitoring challenging.

Summary

Therapeutic drug monitoring of beta-lactam antibiotics is limited by lack of compelling clinical evidence demonstrating benefit in patient outcomes. Challenges in clinical trial design make patient selection difficult and may underestimate the impact of therapeutic drug monitoring. Widespread availability of assays with on-site testing and validated monitoring software would allow for use in select patients with unpredictable pharmacokinetics.