Epidemiological Insights into Foodborne Pathogens Through qPCR Exploration of Prevalence — Beijing Municipality, China, January 2022–April 2023
A comprehensive study conducted in Beijing on the prevalence of foodborne pathogens reports a high incidence of infections, particularly from Clostridium perfringens, Salmonella enterica, enterotoxigenic Escherichia coli (ETEC), and adenovirus, in 1,011 stool samples collected from patients with symptoms of foodborne illness. Utilizing quantitative polymerase chain reaction (qPCR), researchers found that a striking 71.22% of patients were affected by multiple concurrent infections. These findings clearly articulate the challenges faced by densely populated urban environments in managing food safety and underscore the importance of utilizing advanced, culture-independent diagnostic tests (CIDTs) to enhance disease monitoring and public health responses. The data indicate that foodborne pathogens are not only common but vary seasonally and demographically, suggesting that foodborne illness risks may depend on one's age and the time of the year. This research sets a precedent for further assessments of foodborne disease prevalence using advanced molecular diagnostic tools and could lead to improved interventions to strengthen food safety.
For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.075

Trends and Age-Period-Cohort Effect on Incidence of Varicella Under Age 35 — China, 2005–2021
A comprehensive study spanning 2005–2021 has revealed significant trends in varicella (chickenpox) incidence in China, highlighting gender and age-specific patterns. Utilizing data from the Chinese infectious diseases reporting system, which covers 31 provincial-level administrative divisions (PLADs), researchers analyzed 4,108,983 male and 3,295,186 female varicella cases. The study employed age-period-cohort models to investigate the influences of age, time period, and birth cohort on the disease's incidence. A notable rise in varicella cases was observed in the 15–19 and 10–14 age groups, with the highest incidence among males aged 15–19 and in both genders in the 25–29 age group. The risk was greater in males below 20 years but lower between 20 and 35 years compared to females. Younger cohorts under 20 also showed increased risk. The study’s findings underscore the necessity of targeted varicella prevention, especially considering gender differences and the high risk in younger cohorts. The increase in varicella cases is partly attributed to improved disease diagnosis and reporting, as well as potential environmental factors like climate change. The study also highlights the impact of social changes, like the introduction of the two-child policy in China and the current vaccination strategies, on the disease’s prevalence. These insights are crucial for shaping effective varicella vaccination and prevention strategies, particularly for high-risk groups and in light of the observed gender and age disparities.
For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.076

Salmonella Grumpensis Causing Diarrhea in Children — Shanghai Municipality, China, 2023
A study conducted by the Shanghai CDC reports the rare occurrence of Salmonella enterica serotype Grumpensis (S. Grumpensis) identified in two pediatric patients with severe diarrhea. This serotype was previously unrecorded in China’s local Salmonella genome database. Through whole genome sequencing (WGS) and antimicrobial susceptibility testing (AST), it was discovered that both isolates belonged to sequence type (ST) 2060, sharing a high degree of genetic similarity indicative of a common source or transmission chain. Despite no further cases or identifiable sources of infection, the temporal proximity and genetic match of isolates raise concerns of a potential outbreak. The study also revealed the global presence of S. Grumpensis across 11 countries, emphasizing the need for enhanced surveillance and international genomic data sharing. The AST findings show complete susceptibility to a range of antibiotics, contrasting with the observed treatment response in one of the patients, suggesting the need for careful follow-up testing. This incident underscores the importance of public health laboratories in early detection of infectious disease outbreaks, encouraging a coordinated approach to public health that prioritizes genomic surveillance and cross-sectoral communication.
For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.077

Trends in Fruit and Vegetable Intake Among the Labor Force Population — China, 2010–2018
A substantial assessment of Chinese labor force dietary habits, spanning from 2010–2018, reveals a decrease in low fruit and vegetable consumption, yet with minimal change in vegetable intake. This analysis, involving 337,179 participants across four national surveys, identified a significant rise in daily fruit intake from 86.5g to 120.5g and vegetable intake from 332.1g to 371.3g. Despite these increases, in 2018, 77.1% had inadequate fruit intake, and 38.4% fell short in vegetables, with significant disparities across socioeconomic and geographic segments. Interestingly, adults with low socioeconomic status (SES), especially in rural areas, maintained consistent, less diverse diets over time. The study suggests that while China's overall consumption of fruits and vegetables remains high, targeted interventions should focus on lower SES populations to reduce health inequities. As the trend is upward, continuous policy-driven strategies to improve access and affordability of these key food groups are imperative to meet the Healthy China Action Plan (2019–2030) goals. Limitations of the study include potential recall bias due to self-reported data and a focus on consumption trends rather than their relation to chronic diseases.
For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.078

Construction of Prediction Model of Foodborne Disease Outbreaks and Its Trend Prediction — Guizhou Province, China, 2023–2025
A recent study leveraged the “Guizhou Foodborne Disease Outbreak Surveillance System” database to forecast trends in foodborne disease outbreaks in Guizhou Province, China against meteorological data from 2012 to 2022. Utilizing a combination of seasonal autoregressive integrated moving average (SARIMA) and the autoregressive integrated moving average with exogenous regressors (ARIMAX) models, the study anticipated a stable trend in foodborne illnesses in the province, with one to two potential peak periods annually. The data revealed a significant correlation between outbreak rates and climatic variables such as rainfall, temperature, and humidity. The ARIMAX model, which considers multiple related input sequences, outperformed individual SARIMA and Prophet models, however, the combined SARIMA-ARIMAX model achieved the highest predictive accuracy. These findings are crucial for public health planning, allowing for targeted preventive measures during periods of elevated risk. The study underscores the importance of accurate reporting and the consideration of various impacts—ranging from climate to cultural—on foodborne disease incidences for improving prediction models.
For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.079