Community-based study to describe the epidemiology of dengue infection in a large cantonment during one transmission season.

Background: Dengue is one of the most important vector-borne disease in India. It has been linked to monsoons when mosquitoes breed profusely in containers. No study exists in Armed Forces wherein a community-based sero-survey has described the epidemiology of dengue. The present study tries to fill this knowledge gap.

Methods: A total of 422 participants were studied for one transmission season of July-December. Blood samples were collected for testing dengue IgG and IgM at the beginning and at end of the study period. The study participants were interviewed at least twice within this period of 6 months to assess clinical condition and follow-up. Point prevalence and incidence were measured. Distribution of presence or absence of symptoms was noted for positive as well as negative cases.

Results: All participants were males. Average age was 31.75 years. Point prevalence at the beginning of transmission season was 11.6% (95% CI: 8.4%-14.6%) and 15.6% (95% CI: 12.1%-19.1%) towards the end. Incidence was found to be 147.4 per 1000 for 6 months. Forty percent of incident cases were asymptomatic.

Conclusion: Healthcare planners and hospital commanders in stations across Armed Forces can use the prevalence and incidence figures obtained in this study as a general guide while planning for prevention and control of dengue. Also, this study points to the fact that dengue transmission in Delhi may have shifted earlier to months of April/May than the conventionally accepted season of July-December.