Infectious disease surveillance serves three critical goals for managing public health threats like dengue, a disease listed as nationally notifiable in the United States. The surveillance system aims to describe the current burden and epidemiology (including seasonality and age distribution) to justify interventions, monitor disease trends (including the impact of control measures), and identify outbreaks and new pathogens. For an outbreak-prone disease like dengue, ongoing surveillance facilitates the early detection of an outbreak, enabling a rapid public health response. While passive surveillance, where medical professionals report cases, is commonly implemented because it requires fewer resources, it is prone to missing cases. Therefore, for a complete and responsive system, passive surveillance should be complemented by active surveillance during an outbreak, where public health staff actively engage in searching the community to find symptomatic patients and conduct contact tracing.
To achieve comprehensive case identification, various methods must be employed. Identifying cases in medical facilities captures severe cases requiring hospital treatment; however, community-based surveillance is essential to capture the full burden of disease, including milder cases or those who do not seek health care. Furthermore, population-based surveillance is preferred over sentinel surveillance if the goal is to produce generalizable rates of disease (incidence and mortality rates) across a defined geographic area. To ensure detailed information for investigation and targeted control efforts, case-based surveillance, which collects individual-level data on person, place, and time, is recommended over aggregated surveillance, although systems may temporarily transition to aggregated data if the case volume becomes overwhelming. Finally, an effective case definition strategy should use syndromic surveillance (monitoring clinical symptoms without laboratory confirmation) as a sensitive alert system for suspect cases, followed by laboratory-confirmed surveillance to provide the necessary specificity and definitive identification of the etiologic agent.
For diseases requiring rapid response, such as monkeypox (Mpox), surveillance information must be disseminated quickly as surveillance is an action-oriented public health tool. I would choose real-time and online tools to facilitate rapid intervention. The Health Alert Network (HAN) is vital for quickly disseminating confirmed disease reports and information (including required actions) to medical and public health professionals at a national level. Similarly, the Program for Monitoring Emerging Diseases (ProMED) acts as an important early warning of outbreaks by consolidating and verifying reports from media and observers, disseminating this free information rapidly via email and the Internet. These rapid tools are complemented by periodic dissemination tools (such as surveillance bulletins or the MMWR/ WER), which provide formal, regular summaries of disease trends and case counts to stakeholders. Additionally, online platforms like HealthMap provide an innovative way to display collected data geographically on an interactive interface, enhancing real-time situational awareness.
