Responding to Communicable Disease Outbreaks: The Importance of Surveillance

Responding to Communicable Disease Outbreaks: The Importance of Surveillance

Assignment C: Case

Introduction

An effective surveillance system identifies where disease is occurring, who is being affected and provides direction on the prioritization of resources for control efforts. Early Warning Systems (EWS) have become an integral part of efficient disease surveillance system (ewrs.ecdc.europa.eu).

The Centers for Disease Control and Prevention define surveillance to be the ongoing, systematic collection, analysis, interpretation, and dissemination of data about a health-related event for use in public health action to reduce morbidity and mortality and to improve health. In particular surveillance is focused on the reporting of disease and the analysis of excess in the number of cases (www.who.int). Furthermore one can recognize the importance of not only how many but where do cases arise, as the use of spatial data can substantially enhance the information given by simple count data. Indeed the location of a health event can be related to its occurrence, and one will want to assess whether this association exists in particular data sets.

In public health surveillance, inference questions are usually framed to determine whether this spatial distribution is unusual or not. Statistical spatial methods for these data can be developed to answer the questions in (1): at a given time point, is the spatial distribution of cases as expected? If not, are there specific areas in the region with an excess or lack of cases?

The answers to these questions will better inform a public health office when deciding whether and where any action should be taken. Alternatively to clustering or cluster detection approaches, disease mapping methods provide an estimation inferential approach to answering these questions. Specifically they focus on estimating a change in the spatial distribution of cases from a reference population across a fixed study region. The variable estimated is a measure of disease occurrence, for example some form of risk (incidence, prevalence), or a comparative risk (rate difference, rate ratio, odds ratio) depending on the context. Consequently we can frame disease mapping methods as a comparison of two components across a study region. Depending on the resolution of the spatial information, the data available can either consist of a random measurement of the number of cases at several fixed locations or areas in the study region, or the data can be given as random locations of cases in the study region (www.influenzacentre.org).

This paper highlights the importance of disease surveillance system. This paper also presents a discussion on the effectiveness of HealthMap, an interactive project and website that is in extensive use of health professionals, working in public and private health institutions. This paper has two sections. The first section describes a case assignment on HealthMap. The second section presents an SLP assignment that highlights effectiveness of surveillance strategies and their impact on public health domain.

Discussion

This section provides information about the functional operations and implementation of HealthMap, a global website that caters to the needs of users around the ...