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PubMed1993

Acetic acid visualization of the cervix to detect cervical dysplasia.

OBJECTIVE: To determine whether acetic acid visualization of the cervix can identify cervical dysplasia and improve detection of lesions missed by Papanicolaou test screening. METHODS: During a 2-year period, patients attending family planning clinics for regular gynecologic examinations had acetic acid applied to the cervix, followed by gross visualization without magnification. Patients with suspicious acetowhite lesions and normal Papanicolaou tests were referred for colposcopic evaluation. Findings from these examinations and corresponding biopsy results were analyzed retrospectively. RESULTS: Eighty-five women were referred for colposcopy because of abnormal acetowhite areas on the cervix. Thirteen patients (15%) had cervical intraepithelial neoplasia (CIN) (nine CIN I, four CIN II), 22 (26%) had koilocytosis, and 16 (19%) had benign histologic findings. In total, 51 patients had suspicious lesions at colposcopy for which biopsies were performed, and 34 (40%) had normal colposcopic examinations. CONCLUSIONS: Acetic acid visualization of the cervix can detect dysplasia otherwise missed by Papanicolaou test screening. However, further refinements in technique are required to decrease false-positive findings and unnecessary referrals for colposcopy.

Acetates↗
PubMed1996

Body mass and breast cancer. Relationship between method of detection and stage of disease.

BACKGROUND: Obesity is associated with advanced stage breast cancer at diagnosis and a poorer prognosis. Stage of breast cancer at diagnosis is also strongly influenced by the method of cancer detection. The objective of this study was to determine the relationship between body mass index (BMI) and breast cancer disease stage, taking into account the method of cancer detection (i.e., self-detection, screening mammography, and clinical breast examination [CBE]). METHODS: From 1988 to 1990, 2863 patients with invasive breast cancer were identified through a statewide, population-based, cancer reporting system and were interviewed as part of a larger study of breast cancer etiology. Stage of disease was classified as either localized or nonlocalized (regional and distant disease combined). The relation between BMI and disease stage was examined by using multiple logistic regression adjusting for age, education, race, year of diagnosis, and prior mammography use. RESULTS: Thirty-eight percent (1092 of 2863) of the women had nonlocalized breast cancer. A strong dose-response relationship was observed between increased BMI and the likelihood of nonlocalized disease (P < 0.001). However, this association was present only among the 55% of women (1585 of 2863) who self-detected their tumors. The odds ratios for nonlocalized cancer increased from 1.0 for the lowest quintile of BMI to 1.3, 1.6, 1.7, and 1.8 for the second through fifth quintiles, respectively, for this group. CONCLUSIONS: Greater body mass was associated with nonlocalized breast cancer; however, this association was restricted to women who detected their own cancer. No association was found between BMI and stage of disease among cases detected by either mammography or CBE.

Adult↗
PubMedDate not supplied

Herpes simplex virus detection in oral mucosa lesions in patients undergoing oncologic therapy.

UNLABELLED: The presence of Herpes Simplex Virus (HSV) has been a frequent detection in gingivitis and ulcerations of oral mucosa in patients undergoing oncologic therapy. In these patients, lesions tend to show atypical clinical patterns, leading to misdiagnosis. OBJECTIVES: To detect HSV, using an ELISA test, in oral lesions of patients under oncologic therapy, to determine localization of these lesions in the oral cavity, to relate their presence with the general diagnosis of the patient and to compare the test results with the previous clinical diagnosis of the lesions. STUDY DESIGN: Thirty lesions where examined in nineteen pediatric patients under oncologic therapy. Direct samples of all lesions were taken and an ELISA test for HSV type I and II was applied to them. General diagnosis of the patients was consigned, as well as localization of the lesions in the oral cavity and clinical diagnosis of them. A database was elaborated with all the information. RESULTS: 33% of lesions were positive to the test, most of them in patients with acute myeloid leukemia. Localization of lesions was not restricted to areas of mucosa attached to periosteum, but also in areas like the dorsum of the tongue. Positive predictivity of clinical diagnosis was 56,25% and negative predictive index was 92,86%. Sensitivity of the test was 90% and specificity was 65%. CONCLUSIONS: It is very important to corroborate clinical diagnosis of gingivitis and ulcerative lesions of the oral cavity of patients under oncologic therapy with laboratory tests, because of the atypical clinical presentation that can lead to misdiagnosis.

Child↗
PubMed1988

A new perimetric color vision analyzer.

A new apparatus was developed for mapping the extrafoveal color vision, the perimetric color vision analyzer. A yellow test object with varying degrees of saturation is presented on a cathode ray tube color display in a random sequence at one of 10 points around the fixation spot. The background is a mosaic pattern consisting of gray spots of the same size and shape as the test object, with various luminances. Background patterns with or without a test object are presented alternately. The subject is instructed to press a key when he detects a yellow object in the background pattern. The luminance of the test object is in the same range as the background gray spots. Since the luminance of background spots is changed synchronously at random when the test object appears, the subject can detect the test object only by the difference in color saturation. The results show the color contrast sensitivity at every designated point in the central visual field. The clinical application of the perimetric color vision analyzer revealed extrafoveal color defects which could not be evaluated with conventional color vision tests. It also showed that in some chorioretinal and optic nerve disorders the topographic pattern of color contrast sensitivity disagrees with that of luminance contrast sensitivity measured with automated static perimetry.

Adult↗
PubMed2006

Early detection and treatment of schizophrenia: how early?

OBJECTIVE: Whereas early detection and therapy of schizophrenic psychoses until some time ago concentrated on frank schizophrenia, during the last years some centres have also started to treat patients even before a clear diagnosis could be established. This paper attempts to discuss if and when this is justified in the light of recent research. METHOD: Mini review of literature. RESULTS: The rationale for early detection and treatment of schizophrenia is based on several observations: diagnosis and treatment of schizophrenia are often seriously delayed. Consequences of the disease are severe already in the early undiagnosed phase of the disorder and early treatment seems to improve the course of the disease. It can therefore be stated quite safely that patients should be treated as early as possible. However, the question of how early has not been sufficiently answered up to now. CONCLUSION: We are at the moment in an ethical dilemma between either diagnosing and treating this disorder too late or too early. The only way and prerequisite for solving this dilemma is a more reliable identification of individuals at risk and the beginning disease process.

Diagnosis, Differential↗
PubMedDate not supplied

A phase II study of cis-diamminedichloroplatinum and 5-fluorouracil in advanced upper aerodigestive neoplasms.

Thirty patients with advanced head and neck cancer of diverse histologies received the combination of cis-diamminedichloroplatinum (CDDP) (100 mg/m2) and 5-fluorouracil (5-FU) (1,000 mg/m2/24 hours X 4 days) at 3-4 week intervals. Among all study participants, the median time to progression was 3.9 months and the median survival was 7.2 months. Among 20 patients with squamous cell carcinoma, we observed five objective regressions (25%). None of the responders had prior chemotherapy; four had extensive prior radiation therapy. Among 10 patients with non-squamous cell carcinoma neoplasms, we detected three objective responses (30%). Histopathology of the responding patients included poorly differentiated sarcoma, anaplastic carcinoma, and malignant mixed parotid tumor. Significant gastrointestinal toxicities included moderate-to-severe nausea (60%), vomiting (43%), and stomatitis (57%). Leukopenia (less than 4,000 cells/mm3) and thrombocytopenia (less than 130,000 cells/mm3) affected 78% and 41% of patients, respectively, without sepsis or hemorrhage.

Adenocarcinoma↗
PubMed1995

Quantitative analysis of computed tomography scans of the lungs for the diagnosis of pulmonary emphysema. A validation study of a semiautomated contour detection technique.

RATIONALE AND OBJECTIVES: To develop an analytic software package based on automated contour detection for the objective and reproducible assessment of emphysema from computed tomography (CT) scans. METHODS: A semiautomated technique was developed for the definition of lung contours in CT cross-sections followed by the assessment of pulmonary CT parameters describing the disease state. For 78 images, the semiautomated contour detection was performed and compared with contours drawn by an experienced radiologist by calculating the systematic area difference (bias) and differences in pulmonary CT parameters such as the mean lung density (MLD). In addition, intraobserver and interobserver variabilities were determined in a subset of 15 images. RESULTS: The areas enclosed by the semiautomatically detected contours were slightly larger than the manual ones (bias < 2.1%). The biases in the observer studies were smaller in the semiautomated versus the manual case (0.3% vs. 1.3%). The standard deviation of the MLD differences with a manual analysis was larger by a factor of five than in the semiautomated case. On average, manual analysis required 2 minutes, 18 seconds per lung; this time was reduced to 11.5 to 29 seconds with the semiautomated approach, depending on the respiration state. CONCLUSIONS: The semiautomated approach is preferred over the manual approach because of its higher consistency and its shorter analysis time.

Adult↗
PubMed2006

Does the 'inverse screening law' apply to oral cancer screening and regular dental check-ups?

OBJECTIVE: Early detection through regular screening is a measure used in certain cancer prevention strategies. This approach has been advocated for the prevention of oral cancers in the UK. The objective of this study was to assess whether people at higher risk of oral cancer in the UK visit dentists on a regular basis, and thereby afford opportunities for oral cancer screening. METHODS: Data from two large national surveys were used. Firstly, data from the Health Survey for England, 2001, were used to assess the relationship between dental attendance (the outcome measure) and recognized oral cancer risk factors; there were 13,784 participants with complete data. We used known risk factors for oral cancer (age >40 years, male sex, alcohol intake >28 units per week, cigarettes >20 per day, and fruit and vegetables <5 times a day) to generate a risk score for oral cancer. Logistic regression was used to compute the odds ratios for regular dental attendance according to risk score. All analyses used education and social class as covariates. We also used data from the British Household Panel Survey to assess whether dental attendance behaviour is sustained over a set period of time (5,547 participants with complete data). RESULTS: In persons in the higher risk category (as defined above) of the five risk factors, age, sex, alcohol, smoking, and fruit/vegetables, 68%, 56%, 52%, 43% and 60%, respectively reported regular dental check-ups. In persons with 0, 1, 2, 3, 4 and 5 of these risk factors, the odds ratio for regular dental check-ups was 1.00, 0.93, 0.81, 0.64, 0.50 and 0.28, respectively. The probability of regular dental attendance was low in all groups with a higher risk of oral cancer. In the longitudinal sample, the low probability of visiting a dentist regularly was stable over time. CONCLUSION: Opportunistic screening for oral cancer in general dental practice in the UK is unlikely to be an effective preventive strategy.

Adult↗
PubMed1998

Exercise tolerance in asymptomatic elderly men with fluoroscopically detected coronary artery calcification.

STUDY OBJECTIVE: The value of detecting coronary artery calcification (CAC), by cardiac imaging, for the diagnosis of coronary artery disease (CAD) in asymptomatic middle-aged men has been demonstrated. However, the incidence of CAC increases with age. The functional significance of CAC remains unknown in asymptomatic elderly men. The purpose of this study is to explore whether CAC in asymptomatic aging men signifies the presence of cardiovascular dysfunction during exercise. DESIGN: This study was designed to address whether elderly asymptomatic men, selected because they have CAC, have reduced exercise tolerance due to functionally significant CAD. PARTICIPANTS AND SETTING: Thirty-eight asymptomatic male volunteers (ages 50 to 75 years, mean [+/-SD] 64+/-7 years) with a normal resting ECG and at least one coronary risk factor, in a population study. Nineteen subjects had CAC detected by digital subtraction fluoroscopy in at least two major coronary arteries, and 19 subjects had no identifiable CAC. METHODS AND RESULTS: Each subject underwent a symptom-limited incremental exercise test with 12-lead ECG monitoring and respiratory gas analysis. Four indexes of exercise oxygen transport were evaluated: peak oxygen uptake (VO2), lactic acidosis threshold, peak VO2/heart rate ratio, and VO2 relative to a work rate increase. Eleven of 38 subjects (28%) were found to have reduced oxygen transport, which was defined as an abnormal reduction in more than two of the above four indexes of oxygen transport. Five of the 11 subjects with reduced oxygen transport had CAC, and 6 subjects did not (not significant). Only one subject with CAC had exercise ST depression. CONCLUSION: Significant CAC in asymptomatic men over age 50 does not signify exercise limitation due to CAD.

Aged↗
PubMed2001

[Changes of NK cell's activity and T lymphocyte subpopulation in peripheral blood of patients with laryngocarcinoma].

OBJECTIVE: By detecting the changes of NK cell's activity and T lymphocyte subpopulation in the peripheral blood of the patients with laryngocarcinoma, the immune function level of the patients could be judged and the prognosis of the patients could be predicted. METHOD: The NK cell's activity in 47 patients with laryngocarcinoma was tested, and T lymphocyte subpopulation in 35 patients were detected with flow cytometer, and compared with the normal control group of 45 volunteers and the group of 15 patients with polyp of vocal cord. RESULT: The NK cell's activity in the patients with laryngocarcinoma was lower than both of the normal control group and the polyp of vocal cord patients group, and the more severe was the degree of disease, the lower of the NK cell's activity was. The NK cell's activity in the pharyngocacinoma patients group in the 3-6 days after operation was lower than that in preoperation significantly; in the same time when the NK cell's activity was droping, CD3 and the ratio of CD4/CD8 became lower. CONCLUSION: By detecting the changes of both NK cell's activity and the T lymphocyte subpopulation in patients with laryngocarcinoma, the immune function level of the patients can be judged objectively, which is of the important clinic significance.

Adult↗
PubMed2005

What is the minimum duration of head-up tilt necessary to detect orthostatic hypotension?

OBJECTIVE: There is uncertainty as to the minimum duration of head-up tilt (HUT) needed to detect orthostatic hypotension (OH). The orthostatic duration has variably been recommended to be 1, 2, 3, and 5 minutes. The purpose of the current study was 1) to determine the minimum duration of HUT necessary to detect OH and 2) to identify different patterns of orthostatic blood pressure (BP) response in patients with OH. DESIGN/METHODS: We evaluated the medical records of 66 consecutive patients (mean age 70.0+/-10.1 years; 64% male) seen at Mayo Clinic-Rochester from 2000-2001 who fulfilled the criteria for OH (systolic blood pressure [SBP] reduction > or = 20 mmHg within 3 minutes of HUT) during routine clinical autonomic studies. All patients completed an autonomic reflex screen with continuous monitoring of heart rate and BP during supine rest and 5 minutes of 70 degree HUT. Severity of autonomic deficits was quantified with the Composite Autonomic Severity Score (CASS). RESULTS: Overall, BP was the lowest at 1 minute with gradual and partial recovery over the following 4 minutes. Eighty-eight percent of patients (N=58) developed OH by 1 minute of HUT, with an additional 11% (N=7) developing OH by 2 minutes and the remaining 1% (N=1) developing OH by 3 minutes. We identified two broad patterns of SBP response to HUT. Forty-eight percent (N=32) of patients demonstrated an initial drop in SBP (> or = 20 mm Hg),which remained stable until tilt-back. Thirty-six percent (N=24) demonstrated an initial drop (> or = 20 mmHg) followed by a progressive decline in SBP until tilt-back. Repeated measures analysis of variance confirmed that the SBP change in response to HUT differed significantly among patients with a stable vs. progressive pattern [F(3,32)=25.1, p<0.001). Patients with the progressive pattern also had more severe adrenergic impairment on the CASS (p=0.03) and were more likely to have their tilt test terminated early (prior to 5 minutes) due to presyncope (p<0.0001) than patients with the stable pattern. CONCLUSIONS: One minute of HUT will detect OH in the great majority (88%) of patients and three minutes will detect the balance. Orthostatic stress beyond 2 minutes is necessary to detect the pattern of progressive OH. Since this group has more severe adrenergic deficits than the group with stable OH, we suggest that the progressive pattern is due to greater impairment of compensatory reflexes. Recognition of the group with progressive fall in BP is important since this group may be at greater risk of orthostatic syncope.

Aged↗
PubMed2004

DD3PCA3 RNA analysis in urine--a new perspective for detecting prostate cancer.

OBJECTIVES: Serum tPSA lacks specificity. The DD3(PCA3) gene is highly specific for prostate cancer and is detectable in prostate cancer cells shed into urine after rectal palpation. A newly developed nucleic acid sequence based amplification assay (uPM3) for detecting DD3(PCA3) RNA in urine samples was evaluated prospectively in patients referred for prostate cancer detection. METHODS: The uPM3 assay simultaneously detects the relative expression of DD3(PCA3) RNA and PSAmRNA as a marker for prostate cells in urine. Urine samples were collected after attentive digital rectal palpation prior to transrectal guided prostate biopsy. Samples were provided as a single void specimen (20-30 ml), stabilized in phosphate buffer and centrifuged. Lysis was performed on cell pellets DD3(PCA3) RNA and PSAmRNA were extracted and amplification was performed using isothermic nucleic acid based amplification (NASBA). The two targets were detected in real-time using specific beacons as probes in a thermostated spectrofluorimeter. Parameters of the amplification curve were defined after a logistic curve fitting routine and a classification tree model was constructed to predict the outcome of patients (i.e. cancer and non-cancer). RESULTS: 201 patients were included in this prospective study. 158/201 analyzed urine samples contained enough prostate cells sufficient for DD3(PCA3) analysis (79% adequacy rate). Prostate cancer was found in 62 (39%) of the evaluable patients. Overall sensitivity, specificity, positive predictive value and negative predictive value for the uPM3 assay at a cut-off 0.5 probability were 82%, 76%, 67% and 87% respectively as compared to 98%, 5%, 40% and 83% respectively for tPSA (at a cutoff of 2.5 ng/ml). In the tPSA categories <4, 4-10 and >10 ng/ml sensitivity was 73%, 84% and 84% and specificity was 61%, 80% and 70%, respectively. The AUC (area under the curve) was 0.87 (CI 0.81-0.92). CONCLUSION: The uPM3 assay showed excellent clinical performances and a specificity far superior to tPSA.

Adult↗
PubMed1998

Why do anatomic backgrounds reduce lesion detectability?

RATIONALE AND OBJECTIVES: Developing metrics of medical image quality requires an understanding of how anatomic backgrounds reduce human visual detection performance. Visual psychophysics has shown that there are two distinct ways in which a complex background can degrade performance: (1) the presence of a deterministic high-contrast background, (2) variability in the background from location to location. The authors investigated how these two sources of performance degradation reduce human visual performance locating a lesion in anatomic backgrounds. METHODS: Human performance localizing a disk-shaped lesion in one of four locations (four alternative forced choice) was measured for three background conditions. In the first condition the background was a uniform gray. In the second condition (the repeated background condition) an anatomic background was sampled on each trial and used as a background for the four possible lesion locations. In the third condition (the different background condition) four different anatomic backgrounds were sampled on each trial and used for the four possible lesion locations. Test images consisted of computer simulated lesions mathematically projected on digital x-ray coronary angiograms. RESULTS: For five levels of lesion contrast, visual detection performance for two observers decreased significantly from the uniform background condition to the repeated background condition, and decreased even further for the different background condition. CONCLUSIONS: Study results show that both the presence of a deterministic high-contrast background and the background variations contribute to performance degradation of human visual detection of signals in anatomic backgrounds.

Diagnostic Imaging↗
PubMed1990

Clarifying confusion: the confusion assessment method. A new method for detection of delirium.

OBJECTIVE: To develop and validate a new standardized confusion assessment method (CAM) that enables nonpsychiatric clinicians to detect delirium quickly in high-risk settings. DESIGN: Prospective validation study. SETTING: Conducted in general medicine wards and in an outpatient geriatric assessment center at Yale University (site 1) and in general medicine wards at the University of Chicago (site 2). PATIENTS: The study included 56 subjects, ranging in age from 65 to 98 years. At site 1, 10 patients with and 20 without delirium participated; at site 2, 16 patients with and 10 without delirium participated. MEASUREMENTS AND MAIN RESULTS: An expert panel developed the CAM through a consensus building process. The CAM instrument, which can be completed in less than 5 minutes, consists of nine operationalized criteria from the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R). An a priori hypothesis was established for the diagnostic value of four criteria: acute onset and fluctuating course, inattention, disorganized thinking, and altered level of consciousness. The CAM algorithm for diagnosis of delirium required the presence of both the first and the second criteria and of either the third or the fourth criterion. At both sites, the diagnoses made by the CAM were concurrently validated against the diagnoses made by psychiatrists. At sites 1 and 2 values for sensitivity were 100% and 94%, respectively; values for specificity were 95% and 90%; values for positive predictive accuracy were 91% and 94%; and values for negative predictive accuracy were 100% and 90%. The CAM algorithm had the highest predictive accuracy for all possible combinations of the nine features of delirium. The CAM was shown to have convergent agreement with four other mental status tests, including the Mini-Mental State Examination. The interobserver reliability of the CAM was high (kappa = 0.81 - 1.0). CONCLUSIONS: The CAM is sensitive, specific, reliable, and easy to use for identification of delirium.

Aged↗
PubMed1999

A systematic review of vision screening tests for the detection of amblyopia.

OBJECTIVE: To review the test characteristics and the quality of evidence regarding available screening tests for the detection of amblyopia in preschool-aged children to help primary care practitioners select a screening strategy. DESIGN: Systematic review of published studies. DATA SOURCES: The MEDLINE database was searched from 1966 through January 1999 using a broad and inclusive strategy. A total of 9551 citations were identified. STUDY SELECTION: All studies that compared the results of commercially available screening tests in preschool-aged children to ophthalmologic examination. DATA EXTRACTION: The setting of the study, the age of the population, the type of screening test, criteria for a positive screen, criteria for the ophthalmologic examination, test characteristics, and measures of reliability were abstracted by 2 reviewers for each selected study. DATA SYNTHESIS: Four eligible articles were identified that studied the test characteristics of 3 screening tests. None of these studies were performed in a primary care setting. Each study used different criteria for failure of the ophthalmologic examination. None of the studies measured observer or test reliability. CONCLUSIONS: Few high-quality data exist regarding the performance of preschool vision screening. Important future work should include the development of a consensus gold standard ophthalmologic examination and evaluation of screening tests in the primary care setting.

Amblyopia↗
PubMed2000

99mTc-MIBI and 99mTc-MDP scintimammography for detecting breast carcinoma.

OBJECTIVE: To assess the value of scintimammography with both 99mTc-MIBI and 99mTc-MDP in detecting breast cancer. METHODS: A total of 35 women with clinical findings of suspicious breast lesions were studied with both 99mTc-MIBI and 99mTc-MDP scintimammography. All patients underwent surgery within one week and the final diagnostic results (histopathological) were obtained. RESULTS: Eighteen of 35 abnormalities of breast were pathologically confirmed as breast cancer and 17 as benigN lesions. In this group of patients studied, the sensitivity, specificity and accuracy of 99mTc-MIBI scintimammography were 77.8%, 88.2% and 82.9%, respectively and those of 99mTc-MDP scintimammography were 72.2%, 88.2% and 80.0%, respectively. There was no significant difference between 99mTc-MIBI and 99mTc-MDP scintimammography. CONCLUSION: This study showed the high diagnostic accuracy of both 99mTc-MIBI and 99mTc-MDP scintimammography in detecting breast cancer. Both can be used as non-invasively assess breast cancer invasiveness before surgery.

Adult↗
PubMed2004

[Application of fluorescent real-time reverse transcriptase-polymerase chain reaction in detecting influenza viruses].

OBJECTIVE: To apply fluorescent real-time reverse transcriptase-polymerase chain reaction (RT-PCR) in detecting influenza viruses. METHODS: A total of 207 oral swab samples were obtained in 16 collections from SARS patients and suspected influenza outbreak cases. They were subjected to influenza virus detection by fluorescent real-time RT-PCR, MDCK cell culture, and hemagglutinin inhibition assay. RESULTS: Out of 207 samples, 79 (38.16%) were positive for influenza viruses when tested by fluorescent real-time PCR, and 62 (29.95%) positive when tested by MDCK cell culture. There was a statistically significant difference between them (chi square=8.64, P less than 0.005). From 104 cases in 9 collections dual serum samples were obtainable. When tested with hemagglutinin inhibition assay, 64 cases (61.54%) showed a 4-fold increase against H3N2 antigen. CONCLUSION: This study showed that fluorescent real-time PCR is a reliable, sensitive, and fast method for detecting influenza viruses.

Cell Culture Techniques↗
PubMed2005

An evaluation model for syndromic surveillance: assessing the performance of a temporal algorithm.

INTRODUCTION: Syndromic surveillance offers the potential to rapidly detect outbreaks resulting from terrorism. Despite considerable experience with implementing syndromic surveillance, limited evidence exists to describe the performance of syndromic surveillance systems in detecting outbreaks. OBJECTIVES: To describe a model for simulating cases that might result from exposure to inhalational anthrax and then use the model to evaluate the ability of syndromic surveillance to detect an outbreak of inhalational anthrax after an aerosol release. METHODS: Disease progression and health-care use were simulated for persons infected with anthrax. Simulated cases were then superimposed on authentic surveillance data to create test data sets. A temporal outbreak detection algorithm was applied to each test data set, and sensitivity and timeliness of outbreak detection were calculated by using syndromic surveillance. RESULTS: The earliest detection using a temporal algorithm was 2 days after a release. Earlier detection tended to occur when more persons were infected, and performance worsened as the proportion of persons seeking care in the prodromal disease state declined. A shorter median incubation state led to earlier detection, as soon as 1 day after release when the incubation state was < or =5 days. CONCLUSION: Syndromic surveillance of a respiratory syndrome using a temporal detection algorithm tended to detect an anthrax attack within 3-4 days after exposure if >10,000 persons were infected. The performance of surveillance (i.e., timeliness and sensitivity) worsened as the number of persons infected decreased.

Algorithms↗