Typhoid fever and paratyphoid fever
Version: November 2025
Introduction
Typhoid fever and paratyphoid fever are bacterial infections caused by Salmonella typhi and Salmonella paratyphi, respectively. They primarily spread through contaminated food and water, often due to poor sanitation and hygiene practices. Common symptoms include prolonged fever, abdominal pain, headache, and lethargy, progressing to severe complications if untreated. These infections are prevalent in developing regions with inadequate sewer systems and limited access to clean water. Vaccines are available for typhoid fever but not for paratyphoid fever. Prevention strategies focus on improving sanitation, promoting handwashing, ensuring safe drinking water, and using appropriate vaccination in high-risk areas.
Highlights
- The incidence of typhoid and paratyphoid fever has shown a significant decline from 2015 to 2025, with the number of cases decreasing from a monthly peak of 1,466 in 2018 to 390 in November 2025.
- The mortality rate remains low, with only sporadic deaths reported across the years. The highest annual death count was in 2020, with three fatalities recorded.
- Generally, the seasonal pattern displays a peak during summer months (July-August), although the magnitude of these peaks has diminished over the years.
- Recent data from 2025 indicates continued low transmission, suggesting effective public health strategies reducing disease burden over the last decade.
Analysis
Cases Analysis
From November 2015 to November 2025, the Chinese mainland saw a fluctuating trend in Typhoid and Paratyphoid cases, alongside minimal mortality. The data shows high case counts starting in late 2015, with peaks during mid-2016, reaching 1344 cases in August. This implies seasonal variation, where warmer months foster increased bacterial growth. Throughout 2017 and 2018, similar patterns emerged, with summer months showing elevated cases, though mortality remained low—with isolated deaths such as in June 2017 where three fatalities were recorded, pointing to sporadic outbreaks or treatment failures.
Starting in 2019, there was a notable decline in cases, particularly accentuated post-2020. Contributing factors may include improved public health measures, better sanitation, or wider vaccine outreach. Despite this overall decrease, seasonal peaks continued, with 2020-2025 summer months witnessing cases stabilizing around 500 to 600. Mortality rates remained consistently low, suggesting effective clinical responses and therapeutic interventions. By 2025, cases reduced to the range of 200 to 400 monthly, showcasing controlled transmission, possibly due to enhanced preventive strategies. The long-term decline in incidence and sustained low mortality rates reflects concerted efforts by health professionals in China to manage and contain these fevers effectively, ensuring reduced burden on the population and healthcare systems.
Deaths Analysis
The analysis of typhoid and paratyphoid fever deaths in the Chinese mainland from November 2015 to November 2025 shows consistently low mortality rates against fluctuating case numbers. Despite sporadic increases in cases, most months report zero fatalities, revealing effective disease management and healthcare interventions. When deaths do occur, they are isolated to a few months each year, indicating sporadic instances rather than outbreaks or sustained increases in disease severity.
Interestingly, fatalities do not necessarily align with peak case months, such as June 2017, where deaths were reported amidst high case numbers, while months like August 2016 reported no deaths despite similar case figures. This suggests successful medical responses and disease management protocols that reduce complications, indicating robustness in healthcare systems and access to treatments and preventive measures like vaccinations and early detection, effectively curtailing mortality.
Overall, the data reflects successful containment strategies in the Chinese mainland, with frequent zero fatality months emphasizing the benefits of public health efforts. The observations suggest that interventions consistently mitigate disease impact on mortality between 2015 and 2025, underscoring the importance of continuous healthcare improvement and public health education to maintain effective disease control and prevention.