China Analyzes 14 Key Infectious Diseases

Focus Shifts to Intestinal, Respiratory, and Sexually Transmitted Infections

A comprehensive study has delved into the data of notifiable infectious diseases (NIDs) in China, zeroing in on specific categories that impact public health. The analysis aimed to understand the burden of these diseases across the nation.

Data Classification and Selection

The research categorized 41 NIDs into five transmission groups, as defined by the Chinese Center for Disease Control and Prevention. This study, however, concentrated on three main areas: intestinal, respiratory, and sexually transmitted/blood-borne infections. Diseases with insufficient or missing data in the Global Burden of Disease (GBD) 2021 database, such as poliomyelitis and scarlet fever, were excluded.

Notable exclusions also included cholera due to its extremely low incidence and Severe Acute Respiratory Syndrome (SARS) due to a lack of recent reported cases. This refined approach led to the inclusion of 14 specific NIDs monitored between 2010 and 2020 across 31 provincial-level administrative divisions, excluding Taiwan, Hong Kong, and Macau.

Detailed Disease Scope

The selected diseases comprise four intestinal infections: hepatitis A, hepatitis E, paratyphoid fever, and typhoid fever. Within the respiratory category, the study included diphtheria, measles, meningitis, pertussis, and tuberculosis (TB).

The sexually transmitted and blood-borne infection group features five diseases: gonorrhea, hepatitis B, hepatitis C, human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), and syphilis. This focused selection ensures a robust analysis of these significant public health threats.

Methodology and Data Sources

The study adhered to the established standards of the International Classification of Diseases (ICD) for data classification. It cross-referenced coding systems used by the China CDC with the WHO’s ICD-10 standard to ensure data comparability and consistency.

Incident cases and death data for the 14 NIDs from 2010 to 2020 were sourced from the Data-center of China Public Health Science. Life expectancy figures were obtained from the China Statistical Yearbook. Disease durations were determined through expert consultation and existing literature. Disability weights (DWs), crucial for calculating the disease burden, were derived from the Global Health Data Exchange (GHDx) and further refined based on symptom prevalence in China.

Calculating Disease Burden (DALYs)

The research employed a simplified Disability-Adjusted Life Year (DALY) formula, consistent with WHO methodologies, to quantify the disease burden. DALYs are calculated by summing Years of Life Lost (YLLs) and Years Lived with Disability (YLDs).

The core formulas used are:

YLL = N × L

YLD = I × d × DW

DALY = YLL + YLD

Here, N represents the number of deaths, L is the standard life expectancy at the age of death, I is the number of incident cases, d is the average duration of the disease, and DW is the disability weight.

For HIV/AIDS and syphilis, DALYs were calculated for each disease stage and then aggregated. The disability weights for most diseases were sourced from GBD 2021, with pertussis using GBD 2019 data. The study also calculated 95% uncertainty intervals for DALYs using 10,000 Monte Carlo simulations to account for data variability.

Visualizing and Ranking Disease Trends

The calculated DALYs for the 14 NIDs were visualized using various graphical methods. Line charts depicted temporal disease burden changes, while bubble charts illustrated the relative contribution of each disease within its category. Pie charts showed the proportional burden across disease categories, and heatmaps provided an annual trend overview.

A key aspect of the analysis involved ranking the 14 NIDs based on their 11-year average DALYs from national surveillance data. These rankings were then compared with estimates from the GBD 2021 to identify any disparities in disease prioritization between the two data sources.

Comparing Data Sources

Discrepancies between national surveillance data and GBD 2021 estimates were quantified by calculating the ratios of the 11-year average DALYs from both sources. This comparative analysis helps to understand potential differences in data collection and modeling methodologies.

Infectious Disease Control Policies in China

The study also reviewed China’s prevention and control policies for NIDs. This involved searching official websites of government departments like the China CDC and the National Health Commission using keywords related to disease control and surveillance. The information gathered was used to construct a historical timeline of key policies, guidelines, and disease elimination milestones.

Data extraction and integration were managed using Microsoft Excel 2021, with all subsequent analyses and visualizations performed using R version 4.4.0. This rigorous approach ensures the reliability and clarity of the findings.