Mannose-binding lectin-associated serine protease 2(MASP-2) is a member of serine protease family and plays a crucial role in activating the complement lectin pathway. When mannose residues on the surface of a pathogen are recognized by mannose-binding lectins (MBL) or fibrinogen collagen (FCN), MASP-2 is activated. This activation then triggers the cleavage of C4 and C2 to form C3 convertase, thereby initiating the lectin pathway of the complement system. Numerous studies have demonstrated that MASP-2 gene polymorphisms and serum levels are closely related with various diseases, including tumors, infectious diseases, autoimmune diseases and so on. In this review, we summarize the relationships between MASP-2 and tumors, infectious diseases, autoimmune diseases. We aim to provide a theoretical basis for the early diagnosis, prognosis evaluation and clinical treatment of various diseases.
Humans ; Mannose-Binding Protein-Associated Serine Proteases/metabolism* ; Neoplasms/metabolism* ; Autoimmune Diseases/genetics* ; Animals ; Polymorphism, Genetic ; Communicable Diseases/genetics*

OBJECTIVES: To investigate the epidemiological characteristics and changing trends of communicable diseases among children and adolescents in China from 1990 to 2021. METHODS: Based on the Global Burden of Disease Database, epidemiological indicators for communicable diseases among the population aged under 20 years in China from 1990 to 2021 were selected to analyze the burden of communicable diseases in this population, and a comparative analysis was performed with global data as well as data from Western Europe and North America. RESULTS: In 1990-2021, the overall burden of communicable diseases tended to decrease among children and adolescents in China. In 2021, the prevalence rate of communicable diseases in China was lower than the global prevalence rate and was higher than that in Western Europe and North America. There was a significant reduction in the mortality rate of communicable diseases, and the gap with Western Europe and North America gradually narrowed year by year. The overall incidence rate, mortality rate, and disability-adjusted life year rate of communicable diseases in males were higher than those in females, and respiratory infections and intestinal infections were more common in children aged <5 years, while the incidence rate of sexually transmitted diseases was higher in adolescents. CONCLUSIONS From 1990 to 2021, the disease burden of communicable diseases among the population under 20 years old in China has significantly decreased. However, there is still a certain gap compared to developed regions. Strengthening the prevention and control of diseases such as respiratory infections and acquired immunodeficiency syndrome, as well as enhancing health interventions for children under 5 years old, will help improve the overall health level of children and adolescents in China.
Humans ; Adolescent ; Communicable Diseases/mortality* ; Child ; China/epidemiology* ; Male ; Female ; Child, Preschool ; Infant ; Young Adult ; Cost of Illness ; Infant, Newborn

Climate and weather significantly influence the duration, timing, and intensity of disease outbreaks, reshaping the global landscape of infectious diseases. Rising temperatures and shifts in precipitation patterns driven by climate change can directly impact the survival and reproduction of pathogens and vector organisms. Moreover, climate change is expected to exacerbate extreme weather events, including floods and droughts, which can disrupt infrastructure and increase the risk of water- and foodborne diseases. There are potential shifts in the temporal and spatial patterns of infectious disease transmission owing to climate change. Furthermore, climate change may alter the epidemiology of vaccine-preventable diseases. These climatic variations not only affect the ecological characteristics of pathogens and vectors but also indirectly influence human behaviors and socioeconomic conditions, further amplifying disease transmission risks. Addressing this challenge requires an interdisciplinary collaboration and comprehensive public health strategies. This review aims to synthesize the current evidence on the impact of climate change on climate-sensitive infectious diseases and elucidate the underlying mechanisms and transmission pathways. Additionally, we explored adaptive policy strategies to mitigate the public health burden of infectious diseases in the context of climate change, offering insights for global health governance and disease control efforts.
Climate Change ; Communicable Diseases/transmission* ; Humans ; Animals ; Global Health

The COVID-19 pandemic highlighted critical gaps in the Philippine health laboratory system, including limited testing capacities, insufficient trained personnel, and inadequate resource distribution. To address these issues, the Philippine government established the Office for Health Laboratories (OHL) and sought technical assistance from the Japan International Cooperation Agency (JICA) through the Project for Strengthening the Philippine National Health Laboratory Network for Infectious Diseases (PHeLNIDs). This project aims to enhance the National Health Laboratory Network's (NHLN) capacity for infectious disease surveillance and response. Phase 1 of the PHeLNIDs project included focus group discussions (FGDs) conducted across 17 regions to assess challenges and develop recommendations for a tier-based laboratory network. Key findings revealed logistical, workforce, transportation, and data management challenges that hinder the effectiveness of specimen referral workflows. Recommendations emphasized decentralizing diagnostic capabilities through subnational reference laboratories, strengthening logistics, and implementing an Integrated Laboratory Information Management System (ILIMS). This article underscores the importance of laboratory decentralization, capacity building, and improved resource management to enhance laboratory-based surveillance and response to emerging infectious diseases. The proposed interventions aim to bolster the Philippine laboratory network, reduce turnaround times, and improve public health outcomes.

Hansen’s disease remains a critical health issue in tropical countries like the Philippines. Delayed diagnosis, especially in the context of indiscriminate corticosteroid use, can lead to severe complications. This case highlights the importance of proper referral, ruling out infections, and cautious steroid use.

A 29-year-old Filipino male presented with a 4-year history of erythematous, scaly plaques on his face and scalp, for which he had not sought treatment. One year later, the plaques spread to his trunk, accompanied by arthralgia. Misdiagnosed with psoriasis, he self-medicated with clobetasol and dexamethasone for three years. Over time, he developed signs of Cushing syndrome. Two months before consultation, after a fall, he experienced lower extremity weakness, hypoesthetic plaques on his legs, and blurred vision, but continued using steroids. Upon admission, he was diagnosed with iatrogenic Cushing syndrome. Steroid tapering reduced generalized edema, revealing nodules on his ears and extremities. Slit-skin smear and histopathology confirmed Hansen’s disease. Unfortunately, he succumbed to septic shock before completing treatment.

Misdiagnosis and prolonged steroid use pose risks by masking infections like leprosy. In regions where infectious diseases are prevalent, clinicians should exercise caution before prescribing steroids, as overuse can lead to “therapeutic incognito,” complicating diagnosis. Early referral to dermatologists for undiagnosed or refractory skin lesions is critical in preventing complications. This case emphasizes the importance of educating healthcare providers on judicious steroid use and ruling out infections. Delayed diagnosis of leprosy, as demonstrated here, can lead to severe outcomes, reinforcing the need for timely intervention and thorough patient evaluation.

The rise in global life expectancy has led to an increase in the older population, presenting significant challenges in managing infectious diseases. Aging affects the innate and adaptive immune systems, resulting in chronic low-grade inflammation (inflammaging) and immune function decline (immunosenescence). These changes would impair defense mechanisms, increase susceptibility to infections and reduce vaccine efficacy in older adults. Cellular senescence exacerbates these issues by releasing pro-inflammatory factors, further perpetuating chronic inflammation. Moreover, comorbidities, such as cardiovascular disease and diabetes, which are common in older adults, amplify immune dysfunction, while immunosuppressive medications further complicate responses to infections. This review explores the molecular and cellular mechanisms driving inflammaging and immunosenescence, focusing on genomic instability, telomere attrition, and mitochondrial dysfunction. Additionally, we discussed how aging-associated immune alterations influence responses to bacterial, viral, and parasitic infections and evaluated emerging antiaging strategies, aimed at mitigating these effects to improve health outcomes in the aging population.
Humans ; Aging/physiology* ; Communicable Diseases/immunology* ; Immunosenescence/physiology* ; Inflammation/immunology* ; Genomic Instability

The Qa-1 in mice is homologous to human leukocyte antigen E(HLA-E), and both of them belong to the non-classical major histocompatibility complex I b(MHC-I b) molecules. Qa-1 is capable of presenting self or exogenous antigen peptides to interact with two distinct receptors, namely T cell receptor (TCR) and natural killer cell group 2 member A (or C) (NKG2A/C), thus playing an important role in immune response and regulation. Qa-1-restricted regulatory CD8⁺ T cell (CD8⁺ Treg) is one of the most studied CD8⁺ Treg subgroups, which can maintain immune homeostasis and autoimmune tolerance by exerting immunosuppressive effects. Consequently, Qa-1-restricted CD8⁺Treg cells are closely associated with the occurrence and development of various clinical diseases, such as tumors, infections, autoimmune diseases, and transplant rejections. This paper provides a comprehensive review of the phenotypic characteristics, functional effects, regulatory mechanisms of Qa-1-restricted CD8⁺ Treg cells, as well as the latest research progresses of Qa-1-restricted CD8⁺ Treg cells involved in the pathogenesis of infectious diseases.
Humans ; Animals ; T-Lymphocytes, Regulatory/immunology* ; Histocompatibility Antigens Class I/immunology* ; CD8-Positive T-Lymphocytes/immunology* ; Communicable Diseases/immunology*

Alternative splicing (AS) is an evolutionarily conserved mechanism that removes introns and ligates exons to generate mature messenger RNAs (mRNAs), extremely improving the richness of transcriptome and proteome. Both mammal hosts and pathogens require AS to maintain their life activities, and inherent physiological heterogeneity between mammals and pathogens makes them adopt different ways to perform AS. Mammals and fungi conduct a two-step transesterification reaction by spliceosomes to splice each individual mRNA (named cis -splicing). Parasites also use spliceosomes to splice, but this splicing can occur among different mRNAs (named trans -splicing). Bacteria and viruses directly hijack the host's splicing machinery to accomplish this process. Infection-related changes are reflected in the spliceosome behaviors and the characteristics of various splicing regulators (abundance, modification, distribution, movement speed, and conformation), which further radiate to alterations in the global splicing profiles. Genes with splicing changes are enriched in immune-, growth-, or metabolism-related pathways, highlighting approaches through which hosts crosstalk with pathogens. Based on these infection-specific regulators or AS events, several targeted agents have been developed to fight against pathogens. Here, we summarized recent findings in the field of infection-related splicing, including splicing mechanisms of pathogens and hosts, splicing regulation and aberrant AS events, as well as emerging targeted drugs. We aimed to systemically decode host-pathogen interactions from a perspective of splicing. We further discussed the current strategies of drug development, detection methods, analysis algorithms, and database construction, facilitating the annotation of infection-related splicing and the integration of AS with disease phenotype.
Animals ; Alternative Splicing/genetics* ; RNA Splicing ; Spliceosomes/metabolism* ; RNA, Messenger/metabolism* ; Communicable Diseases/genetics* ; Mammals/metabolism*

Respiratory infectious diseases (RID) are the major public health problems threatening the people's lives and health.Infection control (IC) is one of the effective tools to contain the occurrence and spread of RID.We collected the articles and data on IC published since January 1,2018 and summarized the achievements,problems,and challenges of IC from administrative control,management control,environment and engineering control,and personal protection in the medical institutions and public places in China.The efforts for IC vary in different regions and medical institutions of different levels.There are still links to be improved for IC from administrative control,management control,environment and engineering control,and personal protection,especially in community-level medical institutions and public areas.It is urgent to strengthen the implementation of IC policies and conduct IC precisely according to local situations.We proposed the following suggestions.First,the existing IC products and tools should be applied to precisely implement the IC measures;second,modern high technology should be employed to develop efficient and convenient IC products and tools;finally,a digital or intelligent IC platform should be built for monitoring infections,so as to contain the occurrence and spread of RID.
Humans ; COVID-19 ; Infection Control ; Communicable Diseases ; China/epidemiology*

Neutrophils play an important role in infectious diseases by clearing pathogens in the early stages of the disease and damaging the surrounding tissues along with the disease progress. Low-density neutrophils (LDNs) are a crucial and distinct subpopulation of neutrophils. They are a mixture of activated and degranulated normal mature neutrophils and a considerable number of immature neutrophils prematurely released from the bone marrow. Additionally, they may be involved in the occurrence and development of diseases through the changes in phagocytosis, the generation of reactive oxygen species (ROS), the enhancement of the ability to produce neutrophils extracellular traps and immunosuppression. We summarizes the role of LDNs in the pathogenesis and their correlation with the severity of infectious diseases such as COVID-19, severe fever with thrombocytopenia syndrome (SFTS), AIDS, and tuberculosis.
Humans ; Neutrophils ; COVID-19/pathology* ; Phagocytosis ; Extracellular Traps ; Communicable Diseases ; Reactive Oxygen Species