Prevalence, Incidence, Risk Factors, and Awareness Of Dengue Fever Among Patients in Karachi

Abstract

Background: The transmission of dengue fever is drastically increasing and it constitutes a major public health issue in the tropical and sub-tropical regions which includes Pakistan. The largest city of the country, Karachi faces frequent outbreaks of dengue due to rapid urbanization, overcrowding, poor sanitation and favorable climate. In light of several epidemics, however, comprehensive information about prevalence, incidence, associated risk factors and patient awareness is lacking.

Objective: We aimed to determine the prevalence, incidence, environmental and behavioral risk factors, knowledge attitudes and practices of dengue fever patients at a major tertiary care hospital in Karachi.

Methods: A cross sectional study was carried out from August to November 2025 at three largest Government Tertiary-care hospitals in Karachi, Jinnah Postgraduate Medical Centre, Civil Hospital Karachi and Indus Hospital and Health Network. Consecutive non-probability sampling method was used for the recruitment of 1,156 laboratory-confirmed dengue patients aged ≥10 years. Dengue was confirmed by NS1 antigen and IgM/IgG ELISA tests. Details regarding socio-demographic profiles, risk factors and awareness were obtained through pre tested structured questionnaire. Descriptive statistics were done using SPSS version 26.

Results: Among 1,156 patients were included for the study with 58.7% being males and 41.3% females. The most affected age group was 21–30 years (27.0%) followed by that of 10–20 years (21.3%). Among newly detected cases, there was active transmission among 64.2%, and recurrent infections were documented in 35.8%. The main risk factors identified were standing water around houses (70.2%), no satisfactory sanitation (64.5%), absence of mosquito net use (59.6%) and outdoor exposure (54.5%). The maximum cases (40.5%) were seen at the Jinnah Postgraduate Medical Centre.

Conclusion: Dengue fever continues to be a major concern among the patients of Karachi with continued transmission related to environmental factors and insufficient preventive measures. Enhanced surveillance, efficient vector management, better urban environment through sanitation and focus on community based awareness programmes are the need of the hour for mitigation of dengue burden and morbidity.