Laboratory-Guided Detection of Disease Outbreaks: Three Generations of Surveillance Systems by ProQuest


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									       Laboratory-Guided Detection of Disease Outbreaks
                                  Three Generations of Surveillance Systems
                                            Vitali Sintchenko, MD, PhD; Blanca Gallego, PhD

● Context.—Traditional biothreat surveillance systems are                Three approaches to infectious disease surveillance that in-
vulnerable to incomplete and delayed reporting of public                 volve clinical laboratories are contrasted: (1) laboratory-
health threats.                                                          initiated infectious disease notifications, (2) syndromic sur-
   Objective.—To review current and emerging approaches                  veillance based on health indicators, and (3) genotyping
to detection and monitoring of biothreats enabled by lab-                based surveillance of biothreats. Advances in molecular di-
oratory methods of diagnosis and to identify trends in the               agnostics enable rapid genotyping of biothreats and inves-
biosurveillance research.                                                tigations of genes that were not previously identifiable by
   Data Sources.—PubMed (1995 to December 2007) was                      traditional methods. There is a need for coordination be-
searched with the combined search terms ‘‘surveillance’’                 tween syndromic and laboratory-based surveillance. Insuf-
and ‘‘infectious diseases.’’ Additional articles were identi-            ficient and delayed decision support and inadequate inte-
fied by hand searching the bibliographies of selected                     gration of surveillance signals into action plans remain the
papers. Additional search terms were ‘‘public health,’’ ‘‘dis-           2 main barriers to efficient public health monitoring and
ease monitoring,’’ ‘‘cluster,’’ ‘‘outbreak,’’ ‘‘laboratory no-           response. Decision support for public health users of bio-
tification,’’ ‘‘molecular,’’ ‘‘detection,’’ ‘‘evaluation,’’ ‘‘gen-        surveillance alerts is often lacking.
omics,’’ ‘‘communicable diseases,’’ ‘‘geographic informa-                   Conclusions.—The merger of the 3 scientific fields of
tion systems,’’ ‘‘bioterrorism,’’ ‘‘genotyping,’’ and ‘‘infor-           surveillance, genomics, and informatics offers an oppor-
matics.’’ Publication language was restricted to English.                tunity for the development of effective and rapid biosur-
The bibliographies of key references were later hand                     veillance methods and tools.
searched to identify articles missing in the database search.               (Arch Pathol Lab Med. 2009;133:916–925)

B   iosurveillance has been made a health care priority be-
      cause of rising concerns over emerging infectious dis-
eases and possible bioterrorism.1,2 The number of micro-
                                                                         demiology presents new challenges to countries, both in
                                                                         terms of the understanding and monitoring of determi-
                                                                         nants of infections and in terms of service provision and
bial threats—in the form of newly identified pathogens,                   the implementation of appropriate prevention measures.
infections crossing the species barrier to people, diseases                 Traditional biothreat surveillance systems are vulnera-
and vectors adapting to new environments, and microbial                  ble to the incomplete and delayed reporting of public
agents appearing in more virulent forms—has multiplied                   health threats.4 Recent outbreaks of reemerging and new
to an unprecedented degree.2,3 New and newly recognized                  communicable diseases have highlighted inefficiencies in
infectious diseases are now being reported at the rate of                public health monitoring and control systems. Specifically,
about 1 per year. At least 33 completely new pathogens,                  many outbreaks have been characterized by delayed rec-
including HIV and severe acute respiratory syndrome, have                ognition and/or public health response.5,6 For example,
emerged during the past 3 decades.3 In addition, the ep-                 analysis of 51 outbreaks reported in the United States be-
idemiology of well-known infectious diseases has been                    tween 1999 and 2000 demonstrated that only 42% were
changing because of the globalization of trade and in re-                detected within 1 week of the first case, and 29% were
sponse to immunization campaigns. This changing epi-                     identified after a month or more.7 Such delays diminish
                                                                         the window of opportunity to mount effective response
                                                                         measures and are likely to be costly to society.8 It was
  Accepted for publication January 6, 2009.
                                                                         estimated that in Canada, a 1-week delay in the imple-
  From the Centre for Infectious Diseases and Microbiology, Western      mentation of control measures for severe acute respiratory
Clinical School, The University of Sydney, Westmead Hospital (Dr         syndrome resulted in a 2.6-fold increase in the mean ep-
Sintchenko), and the Centre for Health Informatics, University of New    idemic size and a 4-week extension of the mean epidemic
South Wales (Drs Sintchenko and Gallego), Sydney, Australia.             duration.9 Deaths from anthrax would be expected to dou-
  Based on a presentation delivered at the First World Congress On  
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