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

In other words, by being familiar with the disease, you can, at the very least, round up the usual suspects.. Klee AL, Maldin B, Edwin B, IPoshni I, Mostashari F, Fine A, et al. Once control and prevention measures have been implemented, they must continue to be monitored. The team members must be selected before departure and know their expected roles and responsibilities in the field. 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. 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. For example, acquired immunodeficiency syndrome (AIDS) and severe acute respiratory syndrome (SARS) both began with relatively specific case definitions. The answer is public health surveillance. (46,47) Thus, the investigations resulted not only in the development of appropriate control and prevention strategies, but also in increased knowledge about a health problem not previously seen or studied in the Western hemisphere. Objectives 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. In a case-control study, the investigator asks both case-patients and a comparison group of persons without disease (controls) about their exposures. 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. This aggregation of cases seems to be unusual, but frequently the public (and sometimes the health agency) does not know the denominator. A dentists mask and gloves are intended to protect the dentist from a patients blood, secretions, and droplets, as well to protect the patient from the dentist. 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. The hypotheses should be testable, since evaluating hypotheses is the next step in the investigation. Odds ratios. 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. Lesson 5 Public Health Surveillance Public health surveillance is the mechanism that public health agencies use to monitor the health of their communities. These incubation periods can be compared with a list of incubation periods of known diseases to narrow the possibilities. N Engl J Med 1987;316:9938. Here are five key steps to conducting a proper workplace investigation. Good preparation in both categories is needed to facilitate a smooth field experience. 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. For example, in the investigation of Legionnaires disease (Table 6.11), what about Grocery Store A linked it to disease? While epidemiology can implicate vehicles and guide appropriate public health action, laboratory evidence can confirm the findings. Public health workers must therefore look for additional cases to determine the true geographic extent of the problem and the populations affected by it. 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. In response, health departments have made great strides in attempting to keep the public informed. Torok TJ, Tauxe RV, Wise RP, Livengood JR, Sokolow R, Mauvais S, et al. Most, perhaps all, used cell phones. The characterization often provides clues about etiology, source, and modes of transmission that can be turned into testable hypotheses (see Step 7). 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 following 10 suggestions will help you conduct a more cost-effective and successful surveillance. Return to text. Later on, when hypotheses have come into sharper focus, the investigator may tighten the case definition by dropping the possible and sometimes the probable category. The reasons for conducting active surveillance at this time are twofold. Whether an apparent problem should be investigated further is not strictly tied to verifying the existence of an epidemic (more cases than expected). In addition, no illness was reported among students who did not go on the field trip, and no cases of E. coli O157 were reported in the community that week. Surveillance remains fundamental to understanding the evolution of the virus, the risk factors for severe disease and the impact of vaccination and public health and social measures. A 95% confidence interval, the interval used most commonly by epidemiologists, corresponds to a p=0.05 cut-off. Washington, DC: American Public Health Association, 2004. If you do not have the clinical background to verify the diagnosis, bring a qualified clinician with you. Adapted from: Lukacs SL, Hsu V, Harper S, Handzel T, Hayslett J, Khabbaz R,,et al. For example, the diagnosis in one neighborhood of four adults with cancer may be disturbing to residents but may well be within the expected level of cancer occurrence, depending on the size of the population, the types of cancer, and the prevalence of risk factors among the residents. Active surveillance requires substantially more time and resources and is therefore less commonly used in emergencies. Why do the people living in one particular area have the highest attack rate? Like its precursor of telephone wiretapping, it must be subjected to meaningful judicial process before it is authorized. 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. 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. (35) Specifically, the epidemic curve indicated that the outbreak was basically over, because no new case had been reported in the previous two weeks. If surveillance has not been ongoing, now is the time to initiate active surveillance. If you are traveling to another country, you will need a passport and often a visa. Return to text. 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. MMWR 2003;52:5657. In practice, choosing who the most appropriate control group is may be quite difficult. In some investigations, investigators develop a data collection form tailored to the specific details of that outbreak. Source: Treadwell TA, Koo D, Kuker K, Khan AS. Which item shows the highest attack rate? 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. Development. Figure 6.7 Desk Locations of Persons with Nasal Swabs Positive for Bacillus anthracis, Hart Building Washington, DC, 2001. Saving Lives, Protecting People, Principles of Epidemiology in Public Health Practice, Third Edition, Find cases systematically and record information, As necessary, reconsider, refine, and re-evaluate hypotheses, Compare and reconcile with laboratory and/or environmental studies, Implement control and prevention measures, /nchstp/tb/pubs/ssmodules/module7/ss7background.htm, Deputy Director for Public Health Science and Surveillance, Center for Surveillance, Epidemiology, and Laboratory Services, Division of Scientific Education and Professional Development, U.S. Department of Health & Human Services, A peripheral eosinophil count of 1,000 cells/mm. Aha! 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. CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website. They are often helpful in explaining why an outbreak occurred. This approach ensures that the investigation proceeds without missing important steps along the way. Table 6.3 Line Listing of 7 Persons with Suspected Eosinophilia-myalgia, * Severe enough to affect the patients ability to pursue usual daily activities, Eventually, public health officials agreed on the following revised case definition:(26). 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. Although this confidence interval is quite wide and includes a wide range of values compatible with the data in the study, it does not include the null hypothesis value of 1.0. Source Ramsey AH, Belongia EA, Gale CM, Davis JP. For example, during an investigation of an outbreak of Legionnaires disease in Louisiana, members of the investigative team discussed what they knew based on the descriptive epidemiology. This information forms the basis for predicting whether more or fewer cases will occur in the near future. Therefore, the epidemic curve can be used to identify the likely period of exposure. If you are arriving from outside the area, you should arrange in advance when and where you are to meet with local officials and contacts when you arrive in the field. It permits the investigator to distinguish epidemic from endemic disease. The investigators thus began to consider vehicles of transmission to which young adults were commonly exposed. The preparations can be grouped into two broad categories: (a) scientific and investigative issues, and (b) management and operational issues. Most countries use Demographic and Health Survey (DHS) data for health programs and . N Engl J Med 2001;344:180714. Baseline surveillance data is a useful resource for making this decision. The expected number is usually the number from the previous few weeks or months, or from a comparable period during the previous few years. The controls must not have the disease being studied, but should represent the population in which the cases occurred. 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. For a notifiable disease, the expected number is based on health department surveillance records. The investigators asked case-patients and controls how much time they spent in the store and where they went in the store. 5S is a methodology for creating an organized and productive workspace by sorting, straightening, shining, standardizing, and sustaining. Spot maps are useful for demonstrating cases within a geographic area, but they do not take the size of the underlying population into account. Considering the third criterion listed earlier, notice that almost all (53 out of 57) of the cases could be accounted for by the beef. (36) A year later, a member of a local cult admitted that the cult had intentionally contaminated the salads bars with Salmonellaorganisms. 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. The first step in an investigation is to determine whether the reported number of cases is unusual. Public health dispatch: outbreak of listeriosis northeastern United States, 2002. A Detailed Intake Sheet Start by gathering as much information as you can from the client up front. ], Table 6.4 Line Listing of 26 Persons with Symptoms School District A, December 2003. 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. They may be able to answer some critical questions: What were their exposures before becoming ill? Method for calculating population attributable risk percent: ARP = Attack rate (risk) in total population, ARU = Attack rate (risk) in unexposed group. Gov. The "contents" of a communication consists of any information . 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. Transporting stool samples for analysis 3. 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. A dictionary of epidemiology, 4th ed. data dissemination Confidentiality is an important issue in implementing control measures. Discovery and. In other words, epidemiologists cannot afford to conduct an investigation that is quick and dirty. They must conduct investigations that are quick and clean.(22) Under such circumstances, epidemiologists find it useful to have a systematic approach to follow, such as the sequence listed in Table 6.2. Presented at 51st Annual Epidemic Intelligence Service Conference, April 2226, 2004, Atlanta. 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. The earliest case occurred during the week of October 28. Identify, define, and measure the health problem of interest, (Science Olympiad, Disease Detectives, Division C, 2021), Collect and compile data about the problem (and if possible, factors that influence it), Provide these data and their interpretation to those responsible for controlling the health problem, Monitor and periodically evaluate the usefulness and quality of surveillance to improve it for future use. For example, contaminated foods should be discarded, and surgical equipment is routinely sterilized to prevent transmission. An investigation of an outbreak of SalmonellaMuenchen in Ohio illustrates how a reexamination of hypotheses can be productive. Using 5S as a foundation, advanced processes and tools to implement lean production can be developed. Table 6.9 Standard Notation of a Two-By-Two Table. Long-term prognosis for clinical West Nile Virus infection. We should carefully scrutinize any surveillance that threatens our intellectual privacy. If the epidemic curve points to a narrow period of exposure, what events occurred around that time? But it is often more complete than passive surveillance. Type A botulism from sauteed onions. Emerg Infect Dis 2002;8:398-401. Interpreting an epidemic curve. What does she do when she goes to Luverne? Your literature review should be guided by a central research question. Palmer SR. They help us to know which pages are the most and least popular and see how visitors move around the site. Oftentimes, the media is unaware an outbreak investigation is going on until this stage. Typically, hypotheses in a field investigation are evaluated using a combination of environmental evidence, laboratory science, and epidemiology. A detailed description of statistical testing is beyond the scope of this lesson, but the following text presents some key features and formulas. If you only had data through Week 35, that is, through point A, you might conclude that the outbreak is still on the upswing, with more cases to come. Person characteristics that are usually described include both host characteristics (age, race, sex, and medical status) and possible exposures (occupation, leisure activities, and use of medications, tobacco, and drugs). Emerg Infect Dis 2002;8:101928. Investigation of bioterrorism-related anthrax, United States, 2001: epidemiologic findings. Was she a friend or acquaintance of any of the Luverne cases? Are intervention measures working? . Disease surveillance involves a constellation of information systems that identify and record health related outcomes. Review the six case report forms in Figure 6.1. If the map shows a cluster or other pattern (such as cases along a road), the investigator must consider possible explanations perhaps water supplies, wind currents, or proximity to a restaurant or grocery. In a natural disaster (hurricane or flood), the Federal Emergency Management Agency (FEMA) may be the lead. The descriptive epidemiology may provide useful clues that can be turned into hypotheses. This often occurs when a study has relatively few people. For other diseases and conditions, the expected number may be based on locally available data such as hospital discharge records, mortality statistics, or cancer or birth defect registries. An outbreak may provide an experiment of nature that would be unethical to set up deliberately but from which the scientific community can learn when it does happen to occur. 28 Feb 2023 16:47:07 An example of the line listing from the 2001 anthrax investigation is shown in Table 6.5. 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. When designing a case-control study, you must consider a variety of other issues about controls, including how many to use. You also need to know what supplies or equipment to bring to protect yourself. If criminal or bioterrorist intent is suspected, law enforcement agencies and the Federal Bureau of Investigation (FBI) may be in charge, or at least involved. Using the epidemiologic data, the investigators were able to implicate the ultrasonic mist machine that sprayed the fruits and vegetables. When is the likely dates of exposure, based on the minimum incubation period before the first case? And also, relevant authorities can monitor road conditions with the live surveillance cameras. To be classified as confirmed, a case usually must have laboratory verification. Consider the gastroenteritis and beef consumption data presented in Table 6.8. Emerg Infect Dis 2004;10:140511. 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. Did this person ever go to Luverne? In most outbreak investigations, the primary goal is control of the outbreak and prevention of additional cases. Lukacs SL, Hsu V, Harper S, Handzel T, Hayslett J, Khabbaz R, et al. Secondly, it helps the audit body confirm the scope of activity and plan the Stage 2 audit. Learn about the Anniversary. When they visited the dairy, they quickly recognized that the dairy was inadvertently adding far more than the recommended dose of vitamin D to the milk. When designing a case-control study, one of the most important decisions is deciding who the controls should be. What is the peak of the outbreak or the median date of onset? Confirmed: A suspected or probable case with laboratory confirmation. Government surveillance of the Internet is a power with the potential for massive abuse. The strategy of being more inclusive early on is especially useful in investigations that require travel to different hospitals, homes, or other sites to gather information, because collecting extra data while you are there is more efficient than having to return a second time. 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. It may be repeated several times during the course of an investigation as additional cases are identified or as new information becomes available. This confidence interval indicates that the study is consistent with risk ratios for the beef/gastroenteritis association in that range. 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. Description: Map showing the counties of Wisconsin. Adapted from: Tan C. A preventable outbreak of pneumococcal pneumonia among unvaccinated nursing home residents in New Jersey during 2001. Emerg Infect Dis 2004;10:63742. 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. 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. Research for a new drug begins in the laboratory. Since this technique is not precise, widen the probable period of exposure by, say, 20% to 50% on either side of these dates, and then ask about exposures during this widened period in an attempt to identify the source. As an example, consider again the outbreak of Legionnaires disease that occurred in Louisiana described at the end of Step 6. To draw an epidemic curve, you first must know the time of onset of illness for each case. An employer is bound by principles of procedural fairness in imposing discipline, and this generally entails an obligation on the employer to investigate the circumstances before disciplining an employee. Step 5. In a second study they compared restaurant exposures of case-patients and healthy restaurant patrons to identify a specific menu item, a meat and cheese sandwich. What vehicles are commonly implicated? : 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. The global goals to end the COVID-19 emergency are to reduce SARS-CoV-2 transmission and the impact of COVID-19 disease. For other diseases, particularly those with a relatively short incubation period, hour of onset may be more suitable (see Lesson 6). The average incubation period for coccidioidomycosis is 12 days, with a minimum incubation period of 7 days. While Jackson (n=11) and Rusk (n=9) Counties had fewer cases than Chippewa, their populations are much smaller, and they turned out to have higher rates of disease. 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. Conclusions Moreover, the healthcare worker may lose the trust of the patient, which can affect adherence to TB treatment. By dividing the number of cases by the size of the population, county-specific rates of ehrlichiosis can be calculated (Figure 6.9). New Engl J Med 1982;306:124953. In other words, they should be similar to the cases except that they dont have the disease. If active surveillance was initiated as part of case finding efforts, it should be continued. Salem, VA; County: Columbia; Sex: Male; Race: black; Disease: Lyme Disease; Date of Onset: 2005; Lab Confirmed? Emerg Infect Dis 2002;8:398-401. In other words, epidemiologists can use analytic epidemiology with its hallmark comparison group to quantify relationships between exposures and disease, and to test hypotheses about causal relationships. Second, many investigators clinicians and non-clinicians find it useful to visit one or more patients with the disease. 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. What are the objectives of this investigation, i.e., what are you trying to accomplish? This is called the risk ratio or the relative risk. All information these cookies collect is aggregated and therefore anonymous. Recognize, however, that the chi-square and similar tests are guides to help you make a decision about a hypothesis. As noted earlier, many outbreaks are brought to the attention of health authorities by concerned healthcare providers or citizens. The chi-square is 9.41, and the 95% confidence interval is 1.625.1. Confidence intervals. Other investigations, particularly those of a newly recognized disease or syndrome, begin with a relatively specific or narrow case definition. What do they think caused their illness? Children under five years age are among the population groups at considerably higher risk of contracting malaria and developing severe disease. Case-patients did, controls did not.(37). 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. The local staff know the people in the community and their practices, and often have hypotheses based on their knowledge. Alternatively, they may conduct active surveillance by telephoning or visiting the facilities to collect information on any additional cases. 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. What are the known risk factors? A communications plan must be established. Customer feedback is one of the best ways to build your restaurant's brand value. 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. Figure 6.3 Typical Epi Curves for Different Types of Spread. London: Humphrey Milford: Oxford U Press, 1936. Adapted from: Acute hemorrhagic conjunctivitis outbreak caused by Coxsackievirus A24Puerto Rico, 2003. In fact, often these two steps are addressed at the same time. Almost half of the world's population was at risk of malaria in 2020. Summary of H.R.1151 - 118th Congress (2023-2024): To hold the People's Republic of China accountable for the violation of United States airspace and sovereignty with its high-altitude surveillance balloon. Presented at 53rd Annual Epidemic Intelligence Service Conference, April 1923, 2004, Atlanta. J Infect Dis 1992;165:7369. Therefore, to test these hypotheses by using analytic epidemiology (see Step 8), specific or tight case definitions are recommended. In smaller outbreaks, you might use two, three, or four controls per case. This phase includes: Evaluation of the company's risks and exposures. Some epidemiologists apply the term epidemic to situations involving larger numbers of people over a wide geographic area. To interrupt vector borne transmission, measures may be directed toward controlling the vector population, such as spraying to reduce the mosquito population that may carry West Nile virus. Making a change shouldn't be a one time action. Eosinophilia-myalgia syndrome New Mexico. Description: Name: Mason, M; Age: 40; Phone: 555-3756; Address: 34 Winifred Ave., Brookville, VA; County: Columbia; Sex: Female; Race: White; Disease: Lyme Disease; Date of Onset: 8/17/2006; Lab Confirmed? As noted earlier, the severity of the illness, the potential for spread, availability of control measures, political considerations, public relations, available resources, and other factors all influence the decision to launch a field investigation. For example, in many hospital outbreaks, investigators use an initial study to narrow their focus. : Yes; Hospital Alerted: Yes; Lab Results: WB IgM+, WB IgG+;Comments: Erythema migrans, arthritis, fatigue, sweats, fever; Physician Reporting: Dr. Farr; Phone: 555-1313; Date of Report: 11/24/06. Fraser DW, Tsai TF, Orenstein W, Parkin WE, Beecham HJ, Sharrar RG, et al. Compared to case-patients who had also eaten the sandwich, controls were more likely to have avoided the onions that came with the sandwich. JAMA 1985;253:12758. This step is critical for several reasons. As a result, investigators often create different categories of a case definition, such as confirmed, probable, and possible or suspect, that allow for uncertainty. Denial. In addition, the p-value is exceedingly small, less than 0.001, and far less than the commonly used cutoff of 0.05. Beef, which had the highest attack rate among those who ate it, the lowest attack rate among those who did not eat it, and could account for almost all (53 of 57) of the cases, was indeed the culprit. 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.