Current Opinion in Infectious Diseases最新文献

Purpose of review: Diarrhea is one of the main reasons for morbidity and mortality in patients with HIV, especially in low and middle-income countries. We review updates on approach, diagnosis and management of diarrhea in patients with HIV.

Recent findings: Duration of symptoms, characteristics of the diarrhea as small-bowel or large-bowel type, presence of constitutional symptoms and current CD4 + cell count are the most important parameters to be noted in the history, and give important clues to diagnosis. Multiple pathogens can co-exist in severely immune compromised patients. Stool microscopy with modified AFB and trichrome stains, though standard, have been largely replaced by multiplex PCR, except in resource limited settings. Computerized tomography scans are helpful when there are constitutional symptoms; and endoscopic biopsy remains the gold standard when noninvasive tests are nondiagnostic. Diagnostic workup can be negative in a subset of the HIV population, which could be due to antiretroviral agents or HIV per se. Treatment involves replacement of fluids & electrolytes and etiology-appropriate antimicrobials. ART should be optimized in all patients, and itself often results in clinical improvement.

Summary: Managing chronic diarrhea in HIV positive patients requires a multimodal approach, but is usually successful even in resource-limited settings provided access to ART is available.

Purpose of review: Several gastrointestinal diseases have emerged in the recent decade, representing significant public health problems in the tropics. We aim to review advances in the epidemiology, diagnosis, and treatment of cholera, typhoid fever, and parasitic diseases.

Recent findings: Cholera cases are increasing each year, yet few vaccines are available to prevent it. Simplifying single-dose regimens of oral vaccines is promising. Typhoid fever incidence and mortality rates are decreasing, but antibiotic resistance is rising. Typhoid conjugate vaccines are the most efficacious, but several issues remain unsolved regarding their implementation.

Summary: Despite better epidemiological tools, diagnostic methods, and therapeutic alternatives, the diarrheal diseases reviewed remain a significant public health problem in the tropics. If a reduction in their burden is aimed at the short- term, investment in water access, sanitation, hygiene, and better vaccines is needed.

Purpose of review: Neurological manifestations of dengue (NeuroDengue) are uncommon but can often mimic those of other tropical infections. This review aims to present new insights on dengue encephalitis, emphasizing pathogenesis, clinical features, and diagnostic challenges. We highlight unique neuroimaging patterns, observed through MRI, which may aid in diagnosing NeuroDengue. The aim is to significantly enhance early recognition and management of this underreported but severe complication of dengue, providing valuable insights for healthcare professionals.

Recent findings: Recent research has improved our understanding of dengue encephalitis and the neurotropism of the dengue virus in regions such as the thalamus, basal ganglia, and cortex. Notable MRI findings include the 'double doughnut' sign and microhaemorrhages, although these findings are nonspecific and may also appear in other flavivirus encephalitides. A definitive diagnosis requires a positive cerebrospinal fluid (CSF) PCR for the dengue virus, often combined with antibody testing in both CSF and serum. Additionally, elevated levels of IL-6 and TNF-α in CSF indicate enhanced inflammatory responses, which strengthens the early identification of dengue encephalitis and informs potential management strategies.

Summary: Evidence affirms the neurotropic nature of dengue, confirmed by positive CSF PCR results. MRI typically reveals T2 hyperintensities in specific brain areas, along with the presence of micro-haemorrhages, and the 'double doughnut' sign. Recent advancements in diagnostics include analysing CSF dengue antibody indices and neuroinflammatory markers. Dengue serotypes 2 and 3 exhibit heightened neurovirulence, with seizures occurring in 30-40% of cases. While supportive management with fluids is crucial, a subset of patients may benefit from intravenous, immunoglobulin (IVIG) and steroids. Early identification of dengue encephalitis could significantly improve patient outcomes.

Purpose of review: Human toxoplasmosis remains a significant, yet often underrecognized, global health concern. This review highlights emerging advances in prevention and management, offering timely updates for clinicians and researchers.

Recent findings: Recent venison-associated outbreaks in the United States have emphasized the risk of ocular toxoplasmosis and severe disease in immune competent individuals and the need for heightened clinical suspicion. Updated guidelines for hematopoietic stem cell transplant (HSCT) recipients now recommend systematic screening, qPCR monitoring, and prophylaxis to reduce mortality from Toxoplasma gondii reactivation. Emerging evidence suggests that chronic T. gondii infection may contribute to adverse pregnancy outcomes, challenging the long-held assumption that chronic infection is protective against these complications. Although the potential association between chronic T. gondii infection and neuropsychiatric disorders remains debated, its public health relevance warrants further investigation.

Summary: Improved clinical awareness, applied preventive strategies, and expanded research are essential to mitigate the broader health impact of chronic T. gondii infection. Future well designed studies and rigorous analyses are critical to defining maternal-fetal risks and potential neuropsychiatric effects, providing the evidence needed to update clinical guidelines and inform public health policies.

Purpose of review: Diarrhea is a common complaint in solid organ transplant recipients. We review both infectious and noninfectious causes of diarrhea and their management.

Recent findings: Diagnostics for diarrhea have now commonly incorporated multiplex gastrointestinal panels that provide rapid testing and identification of pathogens. The rate of Clostridium difficile in the transplant population has increased and fidaxomicin is now recommended as the therapy of choice for first episode and recurrences where available. Oral vancomycin remains an alternative. Norovirus is important to rule out in cases of chronic diarrhea. Nitazoxanide has shown mixed results when used as norovirus therapy. SARS-CoV-2, despite being a respiratory virus, can infect gut epithelium and present with diarrhea. Noninfectious causes especially mycophenolate-related as well as inflammatory bowel disease should be in the differential especially when no infectious cause has been identified.

Summary: A detailed history, diagnostics including molecular testing and endoscopy, and targeted therapies for infectious causes are the mainstay for management of diarrhea in the transplant recipient.

Purpose of review: Schistosomiasis affects over 250 million individuals worldwide and has been associated with infertility, which can harm the mental, physical, and social well being of individuals. This review aims to summarize the multiple ways in which schistosome infection can affect fertility in females and males, through functional, hormonal, and systemic processes.

Recent findings: Schistosome infection causes functional genital tract damage through granuloma formation and fibrosis, which can lead to organ damage and obstruction in the male and female genital tracts. Hormone imbalances caused by the release of estrogen-like metabolites by schistosome worms can dysregulate the hypothalamic-pituitary-gonadal axis and disturb the menstrual cycle, ovulation, and male reproductive function. Systemic and local tissue immunologic changes in response to schistosomes may lower sperm and semen quality, hinder implantation in the uterus, or contribute to early spontaneous abortions.

Summary: Via an array of mechanisms, schistosome infections can impair both female and male fertility. Studies in this neglected area are limited, and further investigation into disease processes and potential therapies for both females and males are greatly needed.

Purpose of review: Cerebral malaria (CM) in children has high mortality and leads to substantial long-term cognitive impairment. We review recent advances in defining the pathogenesis of brain injury in pediatric cerebral malaria.

Recent findings: The cascade of events leading to brain injury in pediatric CM includes blood-brain barrier (BBB) impairment due to local hypoxemia, ischemia, and endothelial activation after sequestration of infected erythrocytes; and oxidative stress after release of free heme. Tumor necrosis factor alpha (TNF-α), reactive oxygen species, CD8+ T cells and parasite toxins can then cross the impaired BBB and through activation of central nervous system immune responses and direct cytotoxicity lead to neuronal injury. Acute kidney injury and hyperuricemia may worsen BBB impairment and cerebral edema. Cytotoxic or vasogenic edema, abnormal blood flow states, and increased microvascular hemoglobin are present in pediatric CM, but their relationship to brain injury is not yet fully defined.

Summary: New studies of CM in children, including neuroimaging and electrophysiology studies, along with novel in vitro BBB model studies and ongoing experimental CM studies, show promise in improving our understanding of brain injury in CM and identifying interventions to decrease this injury.

Purpose of review: On 11 March 2020, the WHO characterized COVID-19 as a pandemic. A clinical case definition for post-COVID-19 condition in children and adolescents by expert consensus was agreed by the WHO in 2023. It is now 5 years since the WHO declared a pandemic, and this review aims to summarize key advances in our understanding of long COVID over those 5 years.

Recent findings: That symptoms could persist in adults and CYP for months after initial infection was first reported in Autumn 2020. Long COVID in adults is frequently characterized by symptoms of fatigue and breathlessness but brain-fog, joint and muscle pain have been reported much more commonly in adult follow-up than CYP. The most common persisting symptoms experienced by CYP after COVID-19 infection in initial studies, often with less than a year of follow-up, were fatigue, headache, shortness of breath and persisting loss of smell and taste. With longer follow-up, up to 2 years, the commonest symptoms still include not only fatigue, headache and shortness of breath but also sleep difficulties, whereas loss of smell and taste persisted only in a minority. However, many symptoms were almost as common in test-negative controls, raising questions about the causal role of SARS-CoV-2 virus. Predictors of long COVID, as defined, were female sex, history of asthma, allergy problems, learning difficulties at school and family history of ongoing COVID-19 problems.

Summary: The implications of the findings for clinical practice and research are that long COVID is not the same in CYP as adults; both their physical and mental health should be studied; and intervention trials are needed.

Purpose of review: During the COVID-19 pandemic, governments and public health agencies used data science tools and data sources in real time to evaluate pathogen transmissibility, disease burden, healthcare capacity, and evaluate treatment and preventive measures. The purpose of the review is to highlight the application of these data sources and methods during the COVID-19 response.

Recent findings: Advances in the development of common data models enabled multisite data networks to overcome healthcare data fragmentation, enabling national surveillance platforms, and offering unprecedented statistical power to conduct national surveillance and detect emerging clinical entities like MIS-C and long COVID in diverse pediatric populations. These integrated networks were also used in evaluating the effectiveness of vaccines and therapies. New surveillance approaches combining traditional clinical data with novel data sources including wastewater detection, web-based search engines, and mobility patterns yielded comprehensive ensemble approaches that informed public health policy.

Summary: The COVID-19 pandemic highlighted the importance of timely evidence for decision-making during outbreak responses and the benefits of using data science tools to help provide real time, actionable insights, which can help guide our public health response to infectious diseases threats in the future.

Purpose of review: Globally, sequelae of congenital CMV (CCMV) impact an estimated 350 000 children born annually. In this review, we consider new evidence across primary, secondary and tertiary prevention approaches, and remaining evidence gaps.

Recent findings: Education on hygiene precautions can reduce risk of primary CMV acquisition in pregnancy, and may have a role in some settings in reducing CCMV cases resulting from nonprimary infection, but public and health worker knowledge and awareness remains low. Evidence that valaciclovir treatment can reduce CMV vertical transmission has led to renewed interest in antenatal CMV screening in some high-income countries over recent years, although there is a lack of recommendation in most guidelines and significant evidence gaps remain. Newborn CCMV screening has been adopted in some states/provinces in Canada/USA, with first results recently published. Newborn prognostic scoring systems are evolving, with potential for more effective targeting of newborn treatment and tertiary prevention of CCMV disease.

Summary: We make suggestions for clinical practice and research, particularly to address evidence gaps around: safety and effectiveness of antenatal CMV screening and antiviral prophylaxis; findings relating to detection of nonprimary infection in pregnancy; new prognostic neonatal scoring systems; and learning from follow-up of children born into state-wide universal CMV screening programmes.