Epidemiological analysis of infectious disease in border port areas of Heilongjiang Province, 2014-2023.

backgroundHeilongjiang Province shares a 2,981-km border with the Russian Federation and runs the largest land-port network in China. The sheer volume and diversity of cross-border movement at these ports complicates infectious disease surveillance and control. Although some individual ports and pathogens have been examined separately, a province-wide integrated analysis spanning all 18 border port municipalities has been absent. This study aimed to characterise the notifiable-disease burden across those municipalities and to identify the diseases warranting priority attention.

methodsIndividual case records of notifiable infectious diseases reported between 1 January 2014 and 31 December 2023 were retrieved from China's National Infectious Disease Reporting Information Management System. We computed constituent ratios, crude incidence rates, and disease rankings. Joinpoint regression yielded annual percent change (APC) and average annual percent change (AAPC) estimates. Seasonality was characterised by the direct average seasonal index method. Between-group differences were evaluated with χ² or Fisher's exact tests. A two-tailed P < 0.05 was the threshold for statistical significance, and population denominators came from the Heilongjiang Provincial Statistical Yearbook.

resultsOver the decade, 64,865 statutorily notifiable cases (out of 70,244 total reported cases) were recorded, corresponding to a mean annual incidence of 220.30 per 100,000. Respiratory diseases (37.99%) and bloodborne and sexually transmitted diseases (33.68%) jointly accounted for 71.67% of the burden. The five leading diseases were pulmonary tuberculosis (23.56%), hepatitis B (15.81%), influenza (9.85%), syphilis (9.35%), and hand, foot and mouth disease (6.48%). Overall incidence was statistically stable across the period (AAPC 1.85%, 95% CI - 0.18% to 3.93%; P > 0.05), though respiratory diseases trended upward (AAPC 6.61%, P < 0.05) while enteric and zoonotic and vector-borne diseases declined significantly (P < 0.05). Monthly incidence peaked in March (seasonal index 131%) and December (128%). Males outnumbered females (male-to-female ratio 1.51:1; rising to 3.01:1 for zoonotic and vector-borne diseases). The 15-59-year age group contributed 57.54% of cases. Farmers (31.86%), homemakers and the unemployed (23.17%), and students (10.52%) were the principal occupational groups affected. The highest cumulative incidence was observed in Mishan, Suifenhe, Mohe, Muling, and Tongjiang.

conclusionsRespiratory infections should receive heightened prevention efforts in the winter-spring season, whereas bloodborne and sexually transmitted infections call for sustained, risk-focused measures throughout the year. Working-age adults-farmers and homemakers in particular-represent the primary target population. Mishan and Suifenhe warrant reinforced surveillance, and a strengthened China-Russia cross-border joint-prevention mechanism is needed.