| Abstract: |
Background: Communicable disease outbreaks remain a significant public health concern in hilly regions such as Himachal Pradesh, where environmental and seasonal factors influence transmission. This study aimed to analyse outbreak patterns over a five-year period (2021–2025) to understand their temporal, spatial and disease-specific distribution. Methods: A retrospective descriptive study was conducted using secondary data from the Integrated Disease Surveillance Programme (IDSP) for January 2021 to December 2025. Data on district, disease/illness, number of cases, deaths and time of occurrence were analysed. Descriptive epidemiological methods were applied to assess distribution by time, place and disease. Seasonal trends were evaluated by grouping months into four categories. Frequencies, proportions and percentage contributions were calculated. Results: A total of 34 outbreaks were reported, comprising 3,937 cases and 2 deaths. The highest number of outbreaks occurred in 2024 (17, 50.0%), accounting for the majority of cases (2,964) and all deaths. Acute diarrheal disease was the most common outbreak (18 outbreaks; 2,796 cases, 71.0%), followed by Hepatitis A (8 outbreaks; 702 cases, 17.8%). Dengue contributed 9.6% of cases, while HFMD and jaundice were minimal. Hamirpur (22.0%), Solan (20.6%) and Mandi (20.4%) together contributed over 60% of total cases. Most outbreaks occurred during monsoon (15 outbreaks; 1,478 cases) and post-monsoon periods (6 outbreaks; 1,208 cases), with peaks in November, October and June. Conclusion: Outbreaks were predominantly waterborne with clear seasonal clustering and geographic variation. Strengthening surveillance and targeted preventive measures are essential to reduce outbreak burden. [ABSTRACT FROM AUTHOR] |