what are the 5 steps of surveillance? what are the 5 steps of surveillance?

Public Health Reports 2003; 118:928. Active surveillance requires substantially more time and resources and is therefore less commonly used in emergencies. Manual. Last JM. Alternatively, a case may be permanently classified as probable or possible if the patients physician decided not to order the confirmatory laboratory test because the test is expensive, difficult to obtain, or unnecessary. Define your research question. Figure 6.2c Outbreak of SalmonellaEnteritidis Gastroenteritis Maryland, 2003 (Epidemic Curve by One Day Intervals), Figure 6.2d Outbreak of SalmonellaEnteritidis Gastroenteritis Maryland, 2003 (Epidemic Curve by 6-Hour Intervals). Conceptually, the next step after identifying and gathering basic information on the persons with the disease is to systematically describe some of the key characteristics of those persons. These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. An intentional act, one with either terrorist or criminal intent, should be considered under a variety of circumstances listed in Table 6.6. This confidence interval indicates that the study is consistent with risk ratios for the beef/gastroenteritis association in that range. In response, health departments have made great strides in attempting to keep the public informed. Administration officials say the . In addition, investigators have sometimes found it useful to visit the homes of case-patients and look through their refrigerators and shelves for clues to an apparent foodborne outbreak. Centers for Disease Control and Prevention. Investigators of an outbreak of salmonellosis in The Dalles, Oregon, were stumped when they were able to implicate salad bars in several local restaurants, but could not identify any common ingredients or distribution system. You will be subject to the destination website's privacy policy when you follow the link. Review the six case report forms in Figure 6.1. In December 2003, an outbreak of gastroenteritis occurred among tenth-grade students who had participated in a city-wide field trip. Case definitions: meningococcal disease and viral meningitis. Environmental inspection of the fairgrounds identified lack of chlorination of the well supplying water to that zone. The hypothesis that the locally produced ground beef was the vehicle could easily be tested by asking case-patients and controls (persons without thyrotoxicosis or other thyroid disease) whether they ate ground beef from the same source. Choosing controls. Using analytic epidemiology, the investigators determined quantitatively that case-patients and controls were about equally exposed to cooling towers. As David Kaye and Marietje Schaake smartly suggest, a first step to stem the tide of spyware technology would be for democracies to implement an immediate moratorium on the sale or transfer of private surveillance equipment until accountable rules are drawn up and agreed upon. Steps 1-4, 6 and 7 for gonorrhoea and/or chlamydia (GC/CT) were measured among females aged 16-17 years with a clinic visit at an academic paediatric primary care network in 2019. An intermittent common-source epidemic (in which exposure to the causative agent is sporadic over time) usually produces an irregularly jagged epidemic curve reflecting the intermittence and duration of exposure and the number of persons exposed. Description: The number of exposed cases times the number of unexposed controls divided by the number of exposed controls times the number of unexposed cases. Each of the steps is described below in more detail, based on the assumption that you are the health department staff member scheduled to conduct the next field investigation. Jacobus CH, Holick MF, Shao Q, Chen TC, Holm IA, Kolodny JM, et al. Presented at 53rd Annual Epidemic Intelligence Service Conference, April 1923, 2004, Atlanta. : no; Lab Comments: arthritis, arthralgias, fatigue; Physician Reporting: Dr. Steere; Phone: 555-1234; Date of Report: 11/24/06. The population attributable risk percent may actually be an underestimate in many outbreaks, since it does not take into account such common occurrences as cross-contamination of foods or sampling of a spouses dish. Lesson 5: Public Health Surveillance Section 3: Identifying Health Problems for Surveillance Multiple health problems confront the populations of the world. Coccidioidomycosis among workers at an archaeologic site, northeast Utah. An outbreak of thyrotoxicosis caused by the consumption of bovine thyroid gland in ground beef. But every step you take will make you a little bit safer than average. The greater the difference in attack rates between the exposed and unexposed groups, the larger the relative risk, and the stronger the association between exposure and disease. Long-term prognosis for clinical West Nile Virus infection. Figure 6.7 shows the location of staff in two offices in the U.S. Senates Hart Building who had nasal swabs positive for B. anthracis after an envelope containing anthrax spores was opened in their presence.(33). Public health workers must therefore look for additional cases to determine the true geographic extent of the problem and the populations affected by it. Discovery and Development. Depending on the outbreak, the hypotheses may address the source of the agent, the mode (and vehicle or vector) of transmission, and the exposures that caused the disease. Some epidemiologists apply the term epidemic to situations involving larger numbers of people over a wide geographic area. Positive cerebrospinal fluid (CSF) antigen detection or positive culture. The 95% confidence interval for the risk ratio of 5.7 ranged from 2.2 to 14.6. The preparations can be grouped into two broad categories: (a) scientific and investigative issues, and (b) management and operational issues. The numbering scheme for this step is problematic, because preparing for field work often is not the first step. The key feature of analytic epidemiology is a comparison group. Section 1: Introduction Section 2: Purpose and Characteristics of Public Health Surveillance Section 3: Identifying Health Problems for Surveillance Section 4: Identifying or Collecting Data for Surveillance Section 5: Analyzing and Interpreting Data Section 6: Disseminating Data and Interpretations Section 7: Evaluating and Improving Surveillance Emerg Infect Dis 2002;8:398-401. : Yes; Hospital Alerted: YesColumbia Medical Ctr; Admission Date: 9/18/2006; Lab Results: WB IgM+, WB IgG-; Comments: Erythema migrans; Physician Reporting: Dr. Fine; Phone: 555-1951; Date of Report: 11/24/06. Certain problems present an immediate threat to health, whereas others are persistent, long-term problems with relatively stable incidence and prevalence among the populations they affect. For some diseases, date of onset is sufficient. (31) For example, clustering of cases in a wing of a nursing home is consistent with either a focal source or person-to-person spread, whereas scattering of cases throughout the facility is more consistent with a widely disseminated vehicle or a source common to the residents that is not associated with room assignment, such as a common dining hall or water supply. Key features of Epi-X include: In recent years, the public has become more aware of and interested in public health. This approach ensures that the investigation proceeds without missing important steps along the way. Using the information about disease and exposure status, the investigator then calculates an odds ratio to quantify the relationship between exposure and disease. Be Open to Feedback. 1. Next, compute a measure of association, such as a risk ratio or odds ratio. We had Thierry Tanoh, the former energy minister of Cte d'Ivoire. Using the epidemiologic data, the investigators were able to implicate the ultrasonic mist machine that sprayed the fruits and vegetables. Use end-to-end encryption. As a field investigator, you must have the appropriate scientific knowledge, supplies, and equipment to carry out the investigation before departing for the field. Source: Jernigan DB, Raghunathan PL, Bell BP, Brechner R, Bresnitz EA, Butler JC, et al. Return to text. Using descriptive epidemiology, the investigators did not see any connection with the towns various cooling towers. The clinical criteria should be based on simple and objective measures such as fever 40C (101F), three or more loose bowel movements per day, or myalgias (muscle pain) severe enough to limit the patients usual activities. The first step in interpreting an epidemic curve is to consider its overall shape. The two most common types of analytic epidemiology studies used in field investigations are retrospective cohort studies and case-control studies, as described in the following sections. In theory, a propagated epidemic one spread from person-to-person with increasing numbers of cases in each generation should have a series of progressively taller peaks one incubation period apart, but in reality few produce this classic pattern. MMWR 2004;53:6324. Unfortunately, analytic studies sometimes are unrevealing. Some spot maps indicate each patients residence. Depending on the type of outbreak, the number of involved agencies may be quite large. Because the Fisher Exact Test is tedious to calculate, let Epi Info or another computer program perform the calculations for you. Several counties are shaded to indicate the number of cases in that location. Procedural Fairness. Thus, a line listing contains key information on every case and can be scanned and updated as necessary. ). Emerg Infect Dis 2002;8:398-401. Although the next conceptual step in an investigation is formulating hypotheses, in reality, investigators usually begin to generate hypotheses at the time of the initial telephone call. The de-voted epidemiologist stays up all night waiting, watching, hoping the dread disease will poke its nose out of its apartment and dart down the street. Return to text. The hypotheses should be testable, since evaluating hypotheses is the next step in the investigation. In contrast to outbreak and epidemic, a cluster is an aggregation of cases in a given area over a particular period without regard to whether the number of cases is more than expected. As an example, consider again the outbreak of Legionnaires disease that occurred in Louisiana described at the end of Step 6. Food-specific attack rates for those who did and did not eat each of 9 items served only at this banquet are presented. Fortunately, for a rare disease such as legionellosis and most other outbreak-associated diseases, the odds ratio from a case-control study approximates the relative risk that would have been found if a cohort study had been feasible. An alternative to calculating a p-value is calculating a confidence interval. To identify the likely period of exposure from an epidemic curve of an apparent point source epidemic: Ideally, the two dates will be similar, and represent the probable period of exposure. Did this person ever go to Luverne? Probable: A suspected case as defined above and turbid CSF (with or without positive Gram stain) or ongoing epidemic and epidemiological link to a confirmed case. [Note that persons infected with E. coli O157 typically experience severe abdominal cramps, bloody diarrhea, and low grade fever after a 1 to 8day incubation period (usually 24 days). New Engl J Med 1982;306:124953. When is the likely dates of exposure, based on the minimum incubation period before the first case? In a case-control study, the investigator asks both case-patients and a comparison group of persons without disease (controls) about their exposures. Once control and prevention measures have been implemented, they must continue to be monitored. Transmission of Norwalk virus during a football game. Create a line listing based on this information. Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. Diagnoses may be uncertain, particularly early in an investigation. Josh Shapiro wants lawmakers to pass a three-year incentive of up to $2,500 a year for newly certified teachers, police officers and nurses in Pennsylvania. The steps listed in Table 6.2 are presented in conceptual order; in practice, however, several steps may be done at the same time, or the circumstances of the outbreak may dictate that a different order be followed. In addition, operational and logistical details are important. We used Youth Risk Behavior Surveillance Survey data to estimate step 1, and electronic health record data for steps 2, 3, 4, 6 and 7. When designing a case-control study, one of the most important decisions is deciding who the controls should be. As a result, investigators could accurately characterize the typical clinical features of the illness, risk factors for illness, and cause of the illness. Confidence intervals. Consider convening a meeting of the case-patients to look for common links or visiting their homes to look at the products on their shelves. And Francois Baird is from South Africa so we had two people from Africa to tell us about how the United States could be doing better. Typically, the Stage 1 ISO 9001 audit is a desktop . Some 31% say they have heard a lot about the government surveillance programs and another 56% say they had heard a little. Finally, a p-value or confidence interval is calculated to assess statistical significance. The STEPS instrument is comprised of three different levels or "steps" of risk factor assessment: Step 1 (questionnaire), Step 2 (physical measures) and Step 3 (biochemical measures). Alternatively, they may conduct active surveillance by telephoning or visiting the facilities to collect information on any additional cases. 5. Before leaving for a field investigation, consult laboratory staff to ensure that you take the proper laboratory material and know the proper collection, storage, and transportation techniques. The relative risk is 5.7, which most epidemiologists would deem a strong association between exposure and disease. Some persons with mild illness may be missed, and some persons with a similar but not identical illness may be included. The shape of the epidemic curve is determined by the epidemic pattern (for example, common source versus propagated), the period of time over which susceptible persons are exposed, and the minimum, average, and maximum incubation periods for the disease. Similarly, to control an outbreak of influenza-like illness in a nursing home, affected residents could be cohorted, that is, put together in a separate area to prevent transmission to others. Preparedness and readiness go hand in hand as organizations and communities prepare for disaster. In some investigations, investigators develop a data collection form tailored to the specific details of that outbreak. When the attack rate for the exposed group is the same as the attack rate for the unexposed group, the relative risk is equal to 1.0, and the exposure is said not to be associated with disease. If the control group is systematically different from the case group in certain ways, a true association between exposure and disease may be missed or a spurious association may be observed between a non-causal exposure and disease. For example, whereas the public health investigation may focus on identifying a pathogen, source, and mode of transmission, a criminal investigation is likely to focus on finding the perpetrator. The earliest case occurred during the week of October 28. In that investigation, a case-control study failed to implicate any plausible food source as a common vehicle. In an outbreak of pneumococcal pneumonia in a nursing home in New Jersey, cases were more common in the north wing than in the south wing (Figure 6.6). (40) The following table shows the number of case-patients and controls who worked in Building X, near a recently excavated site. These procedures should identify what actions a threat should trigger, which people take what steps and who gets notified. In summary, the graph reflects an outbreak (number of cases clearly in excess of usual) beginning during the week of October 28, peaking during the week of November 4, and ending during the week of November 18. Figure 6.9 Rates of Human Granulocytic Ehrlichiosis by County Wisconsin, May 1996December 1998. All information these cookies collect is aggregated and therefore anonymous. Anger. Using the information in the line listing, develop a case definition that you might use for the outbreak investigation. This test indicates the probability of finding an association as strong as or stronger than the one you have observed if the null hypothesis were really true, that is, if in reality the exposure being tested was not related to the disease. Bargaining. Step 10: Maintain Surveillance Some interventions aim to increase a hosts defenses. The classic epidemic curve, such as the one shown in Figure 6.2a from an outbreak of Salmonella enterica serotype Enteritidis, graphs the number of cases by date or time of onset of illness. The two most commonly described host characteristics are age and sex because they are easily collected and because they are often related to exposure and to the risk of disease. One of the first tasks of the field investigator is to verify that a cluster of cases is indeed an outbreak. 5 BIOSURVEILLANCE SYSTEMS The definitions of biosurveillance, disease surveillance, and public health surveillance all include the word systematic. Renault (Claude Rains) to his policemen after Rick Blaine (Humphrey Bogart) had just shot a Nazi officer, Casablanca, 1942. This often occurs when a study has relatively few people. When an outbreak occurs, whether it is routine or unusual, consider what questions remain unanswered about that particular disease and what kind of study you might do in this setting to answer some of those questions. Conclusions To create an effective business continuity plan, a firm should take these five steps: Step 1: Risk Assessment. Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website. (34) The most cases occurred in Washburn (n=21) and Chippewa (n=17) Counties. Stay informed about our latest work in Privacy and Surveillance First name Last name Email ZIP code They can use closed circuit television to. Adapted from: Lukacs SL, Hsu V, Harper S, Handzel T, Hayslett J, Khabbaz R,,et al. Vaccinations promote development of specific antibodies that protect against infection. Using the dates of onset listed below, draw an epidemic curve. Return to text. Early (and continuing) analysis of descriptive data helps you to become familiar with those data, enabling you to identify and correct errors and missing values. Nonetheless, many investigators attempt to enroll such population-based controls through dialing of random telephone numbers in the community or through a household survey. Nash D, Mostashari F, Fine A, Miller J, OLeary D, Murray K, et al. From an epidemiologic point of view, hypotheses are evaluated in one of two ways: either by comparing the hypotheses with the established facts or by using analytic epidemiology to quantify relationships and assess the role of chance.