中国疾病预防控制中心周报最新文献

What is already known about this topic?: Persistent infection with high-risk human papillomavirus (hrHPV) is recognized as the primary cause of cervical cancer and its precancerous lesions. However, most HPV infections are transient and naturally clear. Currently effective triage tools for distinguishing between transient HPV infections and clinically relevant hrHPV-induced diseases are lacking, leading to excessive referrals and overtreatment.

What is added by this report?: This is the first large-scale, prospective, multicenter study to evaluate the triage performance of host DNA six-methylation marker assay (ASTN1, DLX1, ITGA4, RXFP3, SOX17, and ZNF671) in women who are hrHPV-positive in China. Compared with HPV genotyping and cytology [≥ atypical squamous cells of undetermined significance (ASCUS)] screening, the six-methylation marker assay demonstrated superior triage performance, with sensitivities of 82.2% and 90.3% and specificities of 92.4% and 84.1% for cervical intraepithelial grade II/III and worse (CIN2+ and CIN3+), respectively. Further subgroup analysis of women <30 years of age revealed its efficacy. The methylation positivity rate increased with the severity of cervical lesions, and the most significant marker was ZNF671. Moreover, the six-methylation marker assay required the fewest colposcopy referrals, with only 1.32 and 2.39 per CIN2+ and CIN3+ cases, respectively, highlighting its strong health and economic advantages.

What are the implications for public health practice?: The large number of women with HPV infections in China each year has led to excessive cytological screenings and colposcopy referrals. A feasible triage tool for women who are hrHPV-positive significantly reduces unnecessary medical resource utilization and offers substantial health and economic benefits.

Introduction: Recent sentinel surveillance has revealed a rising prevalence of human adenovirus type 21 (HAdV-21) among HAdV infections in China. This study aimed to elucidate the molecular features of currently circulating HAdV-21 strains in China.

Methods: Whole-genome sequencing (WGS) was performed on 23 HAdV-21 strains isolated from acute respiratory infection cases, 56.5% involving lower respiratory tract infections, across 7 Chinese sentinel surveillance provincial-level administrative divisions (PLADs) (2023-2024). These sequences, along with 50 previously reported HAdV-21 genomes from 6 countries (1956-2019), were integrated into a WGS dataset for comprehensive phylogenetic, genetic variation, and recombination analyses.

Results: WGS categorized the HAdV-21 strains into 3 subtypes: HAdV-21a, HAdV-21b, and historical HAdV-21p (isolated in the 1950s). HAdV-21a (1956-2024, involving 5 of the 6 countries) and HAdV-21b (2005-2024, involving 3 of the 6 countries) exhibited extensive spatiotemporal distributions. Recent Chinese strains (2023-2024) belonged to HAdV-21a and HAdV-21b (HAdV-21a/b), showing extremely high genetic homology with Chinese 2019 strains (genetic distance: 0.00007) and global strains (distance: <0.00040). Phylogenetic analysis confirmed that HAdV-21a/b shared a common ancestor and maintained a highly conserved genome despite decades of circulation. Sequence variation analysis identified shared and subtype-specific mutations in these two subtypes. Recombination pattern analysis further revealed that HAdV-21a/b acquired an HAdV-3-derived fragment in the E4 region (breakpoint: nt32,843).

Conclusions: Recombinant HAdV-21a/b subtypes have co-circulated in China in recent years with remarkable genetic conservation. Enhanced surveillance is essential to quantify associated disease burden and guide targeted prevention and control strategies.

What is already known about this topic?: The Measles-Mumps-Rubella (MMR) vaccine plays a crucial role in preventing mumps. Before the implementation of the two-dose MMR vaccine policy, baseline data on mumps virus antibody seroprevalence and geometric mean concentrations (GMCs) among children and adolescents in Fujian Province were available.

What is added by this report?: This report provides a post-policy evaluation following the introduction of Fujian's two-dose MMR policy in June 2020. The 2023 survey shows an overall seroprevalence of 79.53% and a GMC of 265.61 U/mL. Compared with 2018, significant improvements were observed in children under 2 years; however, a concerning decline was noted among adolescents aged 15-17 years. Antibody levels peaked shortly after vaccination, and two doses were found to confer significantly higher immunity than one dose within a 270-day period.

What are the implications for public health practices?: The two-dose MMR policy has been effective in improving early childhood immunity. However, the observed waning immunity in adolescents underscores the urgent need for ongoing serological surveillance, particularly in individuals aged 6-19 years, to inform potential recommendations for booster vaccinations.

What is already known about this topic?: At present, relatively few theoretical studies exist on the immunization strategies of tuberculosis vaccines, especially regarding the types of subunit protein vaccines suitable for combined application with Bacillus Calmette-Guérin (BCG).

What is added by this report?: The study demonstrated that EPCP009, a novel subunit vaccine candidate, maintains BCG colonization in murine spleens while enhancing protection. Notably, a single dose of EPCP009 combined with BCG was superior to multiple doses in terms of both short-term (6-week) and long-term (12-week) protection.

What are the implications for public health practice?: These studies provide a theoretical basis for enhancing the immune strategy of tuberculosis vaccines and contribute to the development of combined BCG and subunit protein vaccines.

Introduction: This study aimed to establish a robust method for monitoring measles vaccine-induced immunity and assessing population-level serostatus.

Methods: This study constructed a vesicular stomatitis virus (VSV)-based pseudotyped virus system expressing envelope proteins from seven major circulating measles genotypes (H1, B3, D4, D8, D9, D11, G3) and the Schwarz vaccine strain (genotype A), thereby enabling a high-throughput neutralization assay for antibody detection.

Results: Vaccination induced a substantial increase in neutralizing antibody geometric mean titers (GMT) post-immunization (4,808 after the first dose; 5,326 after the second dose), with antibody levels remaining elevated in 4-year-old children (GMT: 3,834). Cross-neutralization activity against different genotypes varied by less than 6.4-fold, demonstrating broad protective immunity. However, 12% of adult sera tested were seronegative, revealing the presence of susceptible populations.

Conclusions: This study confirms the robust immunogenicity of the current measles vaccine and establishes a valuable tool for serosurveillance and long-term immunity assessment.

What is already known on this topic?: Pneumococcal conjugate vaccines (PCVs), including the 13-valent PCV (PCV13), effectively reduce the nasopharyngeal carriage of vaccine-type Streptococcus pneumoniae (S. pneumoniae) and prevent invasive pneumococcal disease in children. However, an increasing prevalence of non-vaccine serotypes and serotype replacement has been documented globally, with notable variations in the predominant replacement serotypes across different geographic settings.

What is added by this report?: This study demonstrated that PCV13 vaccination significantly reduced the pharyngeal detection of S. pneumoniae among children with acute respiratory infections, with three to four doses decreasing the detection rate by 30.2%. This reduction encompassed both vaccine and non-vaccine serotypes. Additionally, non-PCV13 serotypes, particularly 10A and 15A/15F, were predominant in positive samples, underscoring the current dominance of non-vaccine serotypes in the study population.

What are the implications for public health practice?: The PCV13 program successfully reduced pneumococcal detection rates, particularly among children who complete the 3-4 dose series. Continued surveillance of circulating S. pneumoniae serotypes is essential to monitor serotype replacement patterns and develop future vaccination strategies.

Artificial intelligence (AI) has broadly reshaped health and medicine, benefiting clinicians, patients, and health systems. However, technical, regulatory, and ethical challenges exist in the application of medical AI, ranging from data scarcity to fairness. We provide our perspective on how to address the major challenges facing widespread clinical adoption from both technical (e.g., building high-quality datasets, using larger and more diverse datasets for training, creating problem formulations that go beyond supervised learning, and combining human skills with AI tools) and ethical (e.g., using highly secure data platforms and strengthening governmental legislation) perspectives.

What is already known about this topic?: Large language models (LLMs) have demonstrated considerable potential in clinical applications. However, their performance in field epidemiology, particularly within Chinese-language contexts, remains largely unexplored.

What is added by this report?: This study evaluates six leading LLMs (ChatGPT-o4-mini-high, ChatGPT-4o, DeepSeek-R1, DeepSeek-V3, Qwen3-235B-A22B, and Qwen2.5-Max) using examination questions from the Zhejiang Field Epidemiology Training Program. For multiple-choice questions, all models except DeepSeek-V3 scored below the 75th percentile of junior field epidemiologists, while for case-based questions, LLMs generally outperformed that percentile. However, LLMs demonstrated significant limitations when addressing questions requiring specialized knowledge. Notably, LLMs may generate inaccurate or fabricated references, presenting substantial risks for inexperienced practitioners.

What are the implications for public health practice?: LLMs demonstrate promising potential for supporting epidemiological investigations. Nevertheless, current LLMs cannot replace human expertise in field epidemiology. Their practical implementation faces considerable challenges, including ensuring output accuracy and reliability. Future efforts should prioritize optimizing performance through verified knowledge databases and establishing robust regulatory frameworks to enhance their effectiveness in public health applications.

What is already known about this topic?: Mpox transmission occurs primarily through close skin-to-skin contact, sexual contact, and exposure to contaminated materials; imported cases can establish local transmission clusters in settings characterized by high international mobility.

What is added by this report?: This report documents the first identified cluster of mpox virus Clade Ib infections in Yiwu, China, an international trade hub. A total of six laboratory-confirmed cases were identified between July 23-August 6, 2025, including one imported source case from Tanzania and five locally linked secondary cases. Among 43 environmental samples, 27 (62.8%) tested positive for MPXV DNA. Ninety close and general contacts were traced and monitored under 21-day health surveillance, with no additional infections detected. We also report a case with oropharyngeal PCR positivity prior to rash onset, suggesting potential pre-symptomatic viral shedding.

What are the implications for public health practice?: Rapid multi-agency collaboration encompassing case identification, isolation protocols, contact tracing, and environmental decontamination proves effective for interrupting transmission in international trade hubs; targeted surveillance and proactive outreach to high-risk social and sexual networks remain essential components of outbreak control.

What is already known about this topic?: As the Chinese population ages, the prevalence of cognitive impairment among older adults continues to increase. Cognitive impairment severely restricts daily activities and creates significant social and economic burdens.

What is added by this report?: Using nationally representative data from the China Survey of Aging and Health (CAHS), this study found that the weighted prevalence of subjective cognitive decline and mild cognitive impairment among individuals aged 65 years and older in China was 38.8% and 28.4% in 2024, respectively, and both showed spatial clustering.

What are the implications for public health practice?: Through the analysis of spatial distribution patterns and identification of high-risk regions of cognitive impairment, this study provides critical information for developing targeted regional prevention and control interventions.