Assessing the utility of public health surveillance using specificity, sensitivity, and lives saved

In modern surveillance of public health, data may be reported in a timely fashion and include spatial data on cases in addition to the time of their occurrence. This has lead to many recent developments in statistical methods to detect events of public health importance. However, there has been relatively little work about how to compare such methods. One powerful rationale for performing surveillance is earlier detection of events of public health significance; previous evaluation tools have focused on metrics that include the timeliness of detection in addition to sensitivity and specificity. However, such metrics have not accounted for the number of persons affected by the events. We re-examine the rationale for this surveillance and conclude that earlier detection is preferred because it can prevent additional morbidity and mortality. On the basis this observation, we propose evaluating the number of cases prevented by each detection method, and include this information in assessing the value of different detection methods. Using this approach incorporates more information about the events and the detection and provides a sound basis for making decisions about which detection methods to employ.

Integrating research, surveillance, and practice in environmental public health tracking

The Centers for Disease Control and Prevention in the U.S. Department of Health and Human Services is working with selected state and local health departments, academic centers, and others to develop an environmental public health tracking initiative to improve geographic and temporal surveillance of environmental hazards, exposures, and related health outcomes. The objective is to support policy strategies and interventions for disease prevention by communities and environmental health agencies at the federal, state, and local levels. The first 3 years of the initiative focused on supporting states and cities in developing capacity, information technology infrastructure, and pilot projects to demonstrate electronic linkage of environmental hazard or exposure data and disease data. The next phase requires implementation across states. This transition could provide opportunities to further integrate research, surveillance, and practice through attention to four areas. The first is to develop a shared and transparent knowledge base that draws on environmental health research and substantiates decisions about what to track and the interpretation of results. The second is to identify and address information needs of policy and stakeholder audiences in environmental health. The third is to adopt mechanisms for coordination, decision making, and governance that can incorporate and support the major entities involved. The fourth is to promote disease prevention by systematically identifying and addressing population-level environmental determinants of health and disease.

A century of census tracts: health & the body politic (1906-2006)

In 2006, the U.S. celebrates the 100th birthday of the census tract. These geographic units, born out of concerns for urban well-being, were first proposed in 1906 to provide a "convenient and scientific city map system" for the City of New York. They were employed for the first time in the U.S. census in 1910 in eight cities, via a joint effort involving the U.S. Census Bureau and state and local health departments. Initially termed "sanitary areas" because of their relevance to planning for public health and health services, census tracts are now widely used by all sectors of government and by myriad disciplines in the health, social, and geographic sciences for research as well as policy development, implementation, and evaluation. In this article, I describe the census tract's underappreciated origins, give examples of its current use in analyzing and addressing social disparities in health and health care, and discuss its continued significance and implications for population health and the public data required for informed democratic governance.

Statutory basis for public health reporting beyond specific diseases

Statutory authority for public health surveillance is necessarily broad as previously uncharacterized diseases are regularly discovered. This article provides specific information about general disease reporting provisions in each state. The intent of these reporting laws and the Health Insurance Portability and Accountability Act Privacy Rule is to support this critical disease surveillance function for the benefit of the entire population.

Dead bird clusters as an early warning system for West Nile virus activity

An early warning system for West Nile virus (WNV) outbreaks could provide a basis for targeted public education and surveillance activities as well as more timely larval and adult mosquito control. We adapted the spatial scan statistic for prospective detection of infectious disease outbreaks, applied the results to data on dead birds reported from New York City in 2000, and reviewed its utility in providing an early warning of WNV activity in 2001. Prospective geographic cluster analysis of dead bird reports may provide early warning of increasing viral activity in birds and mosquitoes, allowing jurisdictions to triage limited mosquito-collection and laboratory resources and more effectively prevent human disease caused by the virus. This adaptation of the scan statistic could also be useful in other infectious disease surveillance systems, including those for bioterrorism.

Public health surveillance for Australian bat lyssavirus in Queensland, Australia, 2000-2001

From February 1, 2000, to December 4, 2001, a total of 119 bats (85 Megachiroptera and 34 Microchiroptera) were tested for Australian bat lyssavirus (ABLV) infection. Eight Megachiroptera were positive by immunofluorescence assay that used cross-reactive ntibodies to rabies nucleocapsid protein. A case study of cross-species transmission of ABLV supports the conclusion that a bat reservoir exists for ABLV in which the virus circulates across Megachiroptera species within mixed communities.

Polio eradication initiative in Africa: influence on other infectious disease surveillance development

BACKGROUND

The World Health Organization (WHO) and partners are collaborating to eradicate poliomyelitis. To monitor progress, countries perform surveillance for acute flaccid paralysis (AFP). The WHO African Regional Office (WHO-AFRO) and the U.S Centers for Disease Control and Prevention are also involved in strengthening infectious disease surveillance and response in Africa. We assessed whether polio-eradication initiative resources are used in the surveillance for and response to other infectious diseases in Africa.

METHODS

During October 1999-March 2000, we developed and administered a survey questionnaire to at least one key informant from the 38 countries that regularly report on polio activities to WHO. The key informants included WHO-AFRO staff assigned to the countries and Ministry of Health personnel.

RESULTS

We obtained responses from 32 (84%) of the 38 countries. Thirty-one (97%) of the 32 countries had designated surveillance officers for AFP surveillance, and 25 (78%) used the AFP resources for the surveillance and response to other infectious diseases. In 28 (87%) countries, AFP program staff combined detection for AFP and other infectious diseases. Fourteen countries (44%) had used the AFP laboratory specimen transportation system to transport specimens to confirm other infectious disease outbreaks. The majority of the countries that performed AFP surveillance adequately (i.e., non polio AFP rate = 1/100,000 children aged <15 years) in 1999 had added 1-5 diseases to their AFP surveillance program.

CONCLUSIONS

Despite concerns regarding the targeted nature of AFP surveillance, it is partially integrated into existing surveillance and response systems in multiple African countries. Resources provided for polio eradication should be used to improve surveillance for and response to other priority infectious diseases in Africa.