what are the 5 steps of surveillance?

The final task is to summarize the investigation, its findings, and its outcome in a report, and to communicate this report in an effective manner. A questionnaire could be distributed to determine the true occurrence of clinical symptoms, or laboratory specimens could be collected to determine the number of asymptomatic cases. Based on these data and knowledge of the incubation period of hepatitis A, the period of exposure was probably in early to mid-October. After a hypothesis that might explain an outbreak has been developed, the next step is to evaluate the plausibility of that hypothesis. (42) At which meal do you think the critical exposure occurred? A spot map may even plot sites of recreational or other outdoor exposures. When you roll out the solution, request feedback on the success of the change made. The circumstances may allow you to learn more about the disease, its modes of transmission, the characteristics of the agent, host factors, and the like. 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. Efforts to prevent fecal-oral transmission often focus on rearranging the environment to reduce the risk of contamination in the future and on changing behaviors, such as promoting hand washing. If the tests confirm that all of those case-patients were infected with the same organism, for example norovirus, the other persons with compatible clinical illness are all presumed to be part of the same outbreak and to be infected with the same organism. Using the epidemiologic data, the investigators were able to implicate the ultrasonic mist machine that sprayed the fruits and vegetables. Public health officials initially used the following case definition:(25), Eosinophil count 2,000 cells/mm3 in the absence of any other known cause of eosinophilia (in particular, parasitic or fungal infection, end-stage renal disease, leukemia, allergic disorder, or drug reaction). 1. Staff from different agencies have different perspectives, approaches, and priorities that must be reconciled. If you need to go back and make any changes, you can always do so by going to our Privacy Policy page. In a community outbreak, a random sample of the healthy population may, in theory, be the best control group. J Epidemiol Comm Health 1989;43:3114. The need for communicating with the public health and clinical community has long been acknowledged, but the need for communicating quickly and effectively with elected officials and the public became obvious during the epidemics of West Nile Virus encephalitis, SARS, and anthrax. Jernigan DB, Raghunathan PL, Bell BP, Brechner R, Bresnitz EA, Butler JC, et al. It is not intended to be an online course. Some investigators use a more quantitative approach and calculate a population attributable risk percent for each food. By dividing the number of cases by the size of the population, county-specific rates of ehrlichiosis can be calculated (Figure 6.9). Communitywide outbreak of Legionnaires disease associated with a grocery store mist machine. Return to text. For the month of August, 12 new cases of tuberculosis and 12 new cases of West Nile virus infection were reported to a county health department. Table 6.9 shows the standard notation for a two-by-two table. Step 1. In a similar fashion, if the time of exposure and the times of onset of illness are known but the cause has not yet been identified, the incubation period can be estimated from the epidemic curve. 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. Similarly, late cases may represent unrelated cases, cases with long incubation periods, secondary cases, or persons exposed later than most others (for example, someone eating leftovers). For airborne diseases, strategies may be directed at modifying ventilation or air pressure, and filtering or treating the air. N Engl J Med 1977;297:118997. Jani AA, Barrett E, Murphy J, Norton D, Novak C, Painter J, Toney D. A steamship full of trouble: an outbreak of Salmonella Typhimurium DT 104 gastroenteritis at a holiday banquet Virginia, 2003. They also enrolled two controls per case, a total of 54 controls. (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. Define your research question. The curve shows where you are in the course of the epidemic still on the upswing, on the down slope, or after the epidemic has ended. Surveillance is the monitoring of behavior, many activities, or information for the purpose of information gathering, influencing, managing or directing. 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). Traditionally, the information described above is collected on a standard case report form, questionnaire, or data abstraction form. Centers for Disease Control and Prevention. N Engl J Med 2001;344:180714. Salmonellosis associated with marijuana: a multistate outbreak traced by plasmid fingerprinting. If you need specialized laboratory work such as confirmation in a reference laboratory, DNA or other chemical or biological fingerprinting, or polymerase chain reaction, you must secure a sufficient number of appropriate specimens, isolates, and other laboratory material as soon as possible. 5 BIOSURVEILLANCE SYSTEMS The definitions of biosurveillance, disease surveillance, and public health surveillance all include the word systematic. Consider, for example, the outbreak of hepatitis A illustrated by the epidemic curve in Figure 6.5. Part 5: STEPS Instrument. In other situations, the media may have already spread the word. We had two specialists from Africa. Next, compute a measure of association, such as a risk ratio or odds ratio. Confidence intervals. Some people have changed their behaviors in response to surveillance. Moreover, the healthcare worker may lose the trust of the patient, which can affect adherence to TB treatment. After the cause was known and diagnostic tests were developed, investigators could use the laboratory test to learn about the true spectrum of illness, and could broaden the case definition to include those with early infection or mild symptoms. The health department is responsible for protecting the publics health, but how does it learn about cases of communicable diseases from which the public might need protection? In an outbreak context, hypotheses are generated in a variety of ways. In response, health departments have made great strides in attempting to keep the public informed. These cookies may also be used for advertising purposes by these third parties. The date of onset of the first case was during the week of October 28. Half of the students traveled from December 2 to December 7 (Tour A); the other half traveled from December 3 to December 8 (Tour B). However, in the outbreak setting, the difference may be irrelevant. Frequently, one person with an illness knows or hears of others with the same illness. 1. Return to text. Centers for Disease Control and Prevention. 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. In many other investigations, however, the circumstances are not as straightforward, and information from the series of cases is not sufficiently compelling or convincing. (32), Figure 6.6 Cases of Pneumonia by Room, Nursing Home A New Jersey, 2001. SEER is supported by the Surveillance Research Program (SRP) in NCI's Division of Cancer Control and Population Sciences (DCCPS). Alternatively, they may conduct active surveillance by telephoning or visiting the facilities to collect information on any additional cases. Emerg Infect Dis 2002;8:398-401. Table 6.7 includes data from an investigation of an outbreak of Salmonella Typhimurium gastroenteritis following a companys holiday banquet in December 2003. To test the statistical significance of this finding, a chi-square test can be computed using the formula shown earlier. More commonly, officials discover an increase in the number of cases of a particular disease and then decide that a field investigation is warranted. Epidemic curves are a basic investigative tool because they are so informative (see Lesson 6). First, review the clinical findings and laboratory results. 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. (That is, do all of the cases occur with one incubation period?). Snow; Phone: 555-1200; Date of Report: 11/24/06. Presented at the 53rd Annual Epidemic Intelligence Service Conference; 2004 Apr 1923; Atlanta. J Infect Dis 1992;165: 7369. 1. However, case-patients were far more likely to shop at a particular grocery store, as shown in the following two-by-two table.35, Table 6.11 Exposure to Grocery Store A Among Cases and Controls, Legionellosis Outbreak Louisiana, 1990. Using analytic epidemiology, the investigators determined quantitatively that case-patients and controls were about equally exposed to cooling towers. Baseline surveillance data is a useful resource for making this decision. As a result, investigators could accurately characterize the typical clinical features of the illness, risk factors for illness, and cause of the illness. Vaccinations promote development of specific antibodies that protect against infection. Yes. 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. Table 6.5 Line Listing of Demographic, Clinical, and Exposure Characteristics of 22 Cases of Bioterrorism-Related AnthraxUnited States, 2001. Fraser DW, Tsai TF, Orenstein W, Parkin WE, Beecham HJ, Sharrar RG, et al. Single case of disease caused by an uncommon agent (e.g., glanders, smallpox, viral hemorrhagic fever, inhalational or cutaneous anthrax) without adequate epidemiologic explanation, Unusual, atypical, genetically engineered, or antiquated strain of an agent (or antibiotic-resistance pattern), Higher morbidity and mortality in association with a common disease or syndrome or failure of such patients to respond to usual therapy, Unusual disease presentation (e.g., inhalational anthrax or pneumonic plague), Disease with an unusual geographic or seasonal distribution (e.g., tularemia in a non-endemic area, influenza in the summer), Stable endemic disease with an unexplained increase in incidence (e.g., tularemia, plague), Atypical disease transmission through aerosols, food, or water, in a mode suggesting deliberate sabotage (i.e., no other physical explanation), No illness in persons who are not exposed to common ventilation systems (have separate closed ventilation systems) when illness is seen in persons in close proximity who have a common ventilation system, Several unusual or unexplained diseases coexisting in the same patient without any other explanation, Unusual illness that affects a large, disparate population (e.g., respiratory disease in a large population may suggest exposure to an inhalational pathogen or chemical agent), Illness that is unusual (or atypical) for a given population or age group (e.g., outbreak of measles-like rash in adults), Unusual pattern of death or illness among animals (which may be unexplained or attributed to an agent of bioterrorism) that precedes or accompanies illness or death in humans, Unusual pattern of death or illness among humans (which may be unexplained or attributed to an agent of bioterrorism) that precedes or accompanies illness or death in animals, Ill persons who seek treatment at about the same time (point source with compressed epidemic curve), Similar genetic type among agents isolated from temporally or spatially distinct sources, Simultaneous clusters of similar illness in noncontiguous areas, domestic or foreign, Large number of cases of unexplained diseases or deaths. Food-specific attack rates for those who did and did not eat each of 9 items served only at this banquet are presented. The risk ratio is calculated as the ratio of the attack rates or risks, i.e., 65.4% divided by 11.4%, which equals 5.7. As you design your fitness program, keep these points in mind: Consider your fitness goals. Finding and reporting children with AFP 2. For example, in the investigation of the outbreak of E. coli O157:H7 among visitors to a county fair, the epidemiologists were able to identify one very strong risk factor consumption of beverages with ice purchased from a vendor in zone 6. Odds ratios. Typically, the Stage 1 ISO 9001 audit is a desktop . So they can make real-time traffic reports, helping . For example, in an outbreak of hypervitaminosis D that occurred in Massachusetts in 1991, investigators found that all of the case-patients drank milk delivered to their homes by a local dairy. Vehicle borne transmission may be interrupted by elimination or decontamination of the vehicle. This risk ratio indicates that persons who ate the beef were 5.7 times more likely to become ill than those who did not eat the beef. If this happens, the epide-miologist will be hot on its tracks, ready to catch the disease in the Feedback on . If you are traveling to another country, you will need a passport and often a visa. Discuss the situation with someone knowledgeable about the disease and about field investigations, and review the applicable literature. Only occasionally do public health officials decide to conduct a field investigation before confirming an increase in cases and verifying the diagnosis. : no; Lab Comments: arthritis, arthralgias, fatigue; Physician Reporting: Dr. Steere; Phone: 555-1234; Date of Report: 11/24/06. Given recent concerns about bioterrorism, investigators should consider intentional dissemination of an infectious or chemical agent when trying to determine the cause of an outbreak. The 95% confidence interval ranged from 2.3 to 78.7. Anthrax outbreak averted: public health response to a contaminated envelope on Capital HillWashington, DC, 2001. The goal is to identify potential vulnerabilities and address them to prevent sensitive information from being lost, stolen, or compromised. In practice, however, persons in a random sample may be difficult to contact and enroll. The annual spending is so vastabout $230 billion on pharmaceuticals and $122 billion on devicesthat even minor efficiency gains could free up billions of dollars for investments elsewhere. Since both the peak and the median of the outbreak occurred during the week of November 4, the most likely period of exposure was a month earlier, in early October. For example, while investigating an outbreak of diarrhea on a cruise ship, investigators usually try to identify the causative organism from stool samples from a few afflicted persons. : Yes; Hospital Alerted: Yes; Lab Results: WB IgM+, WB IgG+; Comments: Erythema migrans; Physician Reporting: Dr. Howard; Phone: 555-1950; Date of Report: 11/24/06. AFP-SURVEILLANCE Nationwide AFP (acute flaccid paralysis) surveillance is the gold standard for detecting cases of poliomyelitis. Talking directly with some patients gives you a better understanding of the clinical features, and helps you to develop a mental image of the disease and the patients affected by it. In other words, they should be similar to the cases except that they dont have the disease. 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. Disease surveillance involves a constellation of information systems that identify and record health related outcomes. Adapted from: European Programme for Intervention Epidemiology Training [Internet]. Scan the column of attack rates among those who ate the specified items and consider the three criteria listed on the previous page. A large community outbreak of salmonellosis caused by intentional contamination of restaurant salad bars. Type A Clostridium botulinum was then identified from a pan of leftover sauted onions used to make only that particular sandwich.(44). In an outbreak of 50 or more cases, one control per case will usually suffice. The investigators asked case-patients and controls how much time they spent in the store and where they went in the store. It permits the investigator to distinguish epidemic from endemic disease. Other investigations, particularly those of a newly recognized disease or syndrome, begin with a relatively specific or narrow case definition. In 1989, a worldwide epidemic of a previously unrecognized syndrome occurred. The affected population had a greater proportion of persons who were black, female, young, and less likely to smoke than persons in a typical Legionnaires outbreak. Verifying the diagnosis is important: (a) to ensure that the disease has been properly identified, since control measures are often disease-specific; and (b) to rule out laboratory error as the basis for the increase in reported cases. What are the known risk factors? CDC twenty four seven. The global goals to end the COVID-19 emergency are to reduce SARS-CoV-2 transmission and the impact of COVID-19 disease. The next step, verifying the diagnosis, is closely linked to verifying the existence of an outbreak. These cookies perform functions like remembering presentation options or choices and, in some cases, delivery of web content that based on self-identified area of interests. This condition was characterized by severe myalgias (muscle pains) and an elevated number of a particular type of white blood cell called an eosinophil. Response is the how organizations respond to whatever challenges disasters bring such as supply chain . Presented at 53rd Annual Epidemic Intelligence Service Conference, April 1923, 2004, Atlanta. The first step in interpreting an epidemic curve is to consider its overall shape. Epidemiology in search of infectious diseases: methods in outbreak investigation. The local staff know the people in the community and their practices, and often have hypotheses based on their knowledge. However, in many outbreak settings, the population is not well defined and speed of investigation is important. Description: Map showing the counties of Wisconsin. What vehicles are commonly implicated? As noted earlier, many outbreaks are brought to the attention of health authorities by concerned healthcare providers or citizens. If an outbreak affects a restricted population such as persons on a cruise ship, in a school, or at a work site, and if many cases are mild or asymptomatic and therefore undetected, a survey of the entire population is sometimes conducted to determine the extent of infection. The population attributable risk percent describes the proportion of illness in the entire study population that could be attributable to a given exposure, assuming that those who became ill in the unexposed group and a similar proportion in the exposed group must be attributable to something else. Some clusters turn out to be true outbreaks with a common cause, some are sporadic and unrelated cases of the same disease, and others are unrelated cases of similar but unrelated diseases. 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. Finally, before departing, you should have a plan of action. Note that while this approach is typical in the United States, some countries prefer to acquire laboratory samples from every affected person, and only those with a positive laboratory test are counted as true cases. What additional information might be helpful in making this determination? Hypervitaminosis D associated with drinking milk. 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. The opposite can also occur a p-value less than 0.05 can actually be a chance finding rather than the true explanation of the outbreak. But it is often more complete than passive surveillance. It is often used if an outbreak has begun or is suspected to keep close track of the number of cases. Indeed, the Dictionary of Epidemiology defines outbreak as an epidemic limited to localized increase in the incidence of disease, e.g., village, town, or closed institution.(23). Several counties are shaded to indicate the number of cases in that location. A Detailed Intake Sheet Start by gathering as much information as you can from the client up front. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance. Visit my father and buy the locally produced ground beef that he sells in his store. Surveillance systems capture information to understand disease trends in the general population. An outbreak of an acute respiratory disease, coccidioidomycosis, occurred among volunteers, group leaders, and archaeologists who began working at a Native American archaeological site in Utah on June 18.(30). Consider the following data from an outbreak of gastroenteritis among college football players. The investigation of an outbreak from an animal source may include state and federal departments of agriculture and/or the Food and Drug Administration (FDA). In addition, investigators must consider logistical issues, such as how to contact potential controls, gain their cooperation, ensure that they are free of disease, and obtain appropriate exposure data from them. Since a two-by-two table has 1 degree of freedom, a chi-square larger than 3.84 corresponds to a p-value smaller than 0.05. Public health dispatch: outbreak of listeriosis northeastern United States, 2002. Source Ramsey AH, Belongia EA, Gale CM, Davis JP. You could calculate a p-value that is not less than 0.05 and consequently fail to reject the null hypothesis, which may turn out to be true. Centers for Disease Control and Prevention. Suspected: A case that meets the clinical case definition. The plan should include how often and when to have conference calls with involved agencies, who will be the designated spokesperson, who will prepare health alerts and press releases, and the like. If surveillance has not been ongoing, now is the time to initiate active surveillance. The cases that stand apart may be just as informative as the overall pattern. 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). How might health officials track behaviors that place citizens at increased risk of heart disease or diabetes? New Engl J Med 1992;326:11737. This is a common mistake. Eosinophilia-myalgia syndrome New Mexico. The case definition may be restricted by time (for example, to persons with onset of illness within the past 2 months), by place (for example, to residents of the nine-county area or to employees of a particular plant) and by person (for example, to persons with no previous history of a positive tuberculin skin test, or to premenopausal women). Transporting stool samples for analysis 3. Step 5. In most outbreak investigations, the primary goal is control of the outbreak and prevention of additional cases. Bopp DJ, Saunders BD, Waring AL, Waring AL, Ackelsberg J, Dumas N, et al. The odds ratio for Grocery Store A is calculated as: An odds ratio of 11 is quite large, indicating that shopping at Grocery Store A was strongly associated with developing legionellosis. They help us to know which pages are the most and least popular and see how visitors move around the site. The conversations about possible exposures should be open-ended and wide-ranging, not necessarily confined to the known sources and vehicles. Return to text. Surveillance in public health is the continuous, watching of the incidence and distribution of health-related events through systematic collection, analysis and interpretation of data needed for the planning, implementation, and evaluation of public health practice. Step 2. Step 3: Work on the plan as a team. Surveillance System of Attacks on Healthcare (SSA) The SSA is a global standardized and systemic approach to collecting data of attacks on health care. ). Return to text. (36) A year later, a member of a local cult admitted that the cult had intentionally contaminated the salads bars with Salmonellaorganisms. 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. This information can be found on disease fact sheets available on the Internet or in the, Identify the peak of the outbreak or the median case and count back on the. Drawing an epidemic curve. What does she do when she goes to Luverne? A retrospective cohort study is the study of choice for an outbreak in a small, well-defined population, such as an outbreak of gastroenteritis among wedding guests for which a complete list of guests is available. In such settings, the case-control study becomes the study design of choice. Blank S, Scanlon KS, Sinks TH, Lett S, Falk H. An outbreak of hypervitaminosis D associated with the overfortication of milk from a home-delivery dairy. The incubation period for hepatitis A ranges from 15 to 50 days (roughly 2 to 7 weeks), with an average incubation period of 2830 days (roughly one month). Regardless of when the decision to conduct a field investigation is made, you should be well prepared before leaving for the field. 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. MMWR 2002;51:9501. 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. This process, in which the outbreak is characterized by time, place, and person, is called descriptive epidemiology. As noted in Step 1, development of a communications plan and communicating with those who need to know during the investigation is critical. Anger. Public health workers must therefore look for additional cases to determine the true geographic extent of the problem and the populations affected by it. Nursing home staff did report that the 2 residents of the south wing who developed pneumonia did spend much of their time in the north wing. An alternative to calculating a p-value is calculating a confidence interval. The main objective of the Surveillance, Monitoring and Reporting unit is to support the collection, analysis, and dissemination of country-level risk factor information to inform and improve public health policy. Lukacs SL, Hsu V, Harper S, Handzel T, Hayslett J, Khabbaz R, et al. For example, the order of the first three listed steps is highly variable a health department often verifies the diagnosis and establishes the existence of an outbreak before deciding that a field investigation is warranted. But you'll need a plan. If the epidemic curve points to a narrow period of exposure, what events occurred around that time? The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website. Both of these influence susceptibility to disease and opportunities for exposure. Centers for Disease Control and Prevention. The following 10 suggestions will help you conduct a more cost-effective and successful surveillance. In most case-control studies, the population is not well defined, and the total number of people exposed (or unexposed) to a suspected vehicle or source is not known. How is it usually transmitted? Many epidemiologists use the terms outbreak and epidemic interchangeably, but the public is more likely to think that epidemic implies a crisis situation. 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 five stages of grief can be summarized as: Denial. Collectively, these systems provide raw data for descriptive epidemiology that is vital for a number of important public health functions, including: Monitoring and reporting on the health status and health related behaviors in . A very small p-value means that the observed association occurs only rarely if the null hypothesis is true. London: Humphrey Milford: Oxford U Press, 1936. Do they have anything in common with others who have the disease? In fact, often these two steps are addressed at the same time. ], Table 6.4 Line Listing of 26 Persons with Symptoms School District A, December 2003. 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. [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). Surveillance identifies new cases and detects importation of wild poliovirus The four steps of surveillance are: 1.