In January 2005, a train derailment on the premises of a textile mill in South Carolina released 42 to 60 tons of chlorine gas in the middle of a small town. Medical records and autopsy reports were reviewed to describe the clinical presentation, hospital course, and pathology observed in persons hospitalized or deceased as a result of chlorine gas exposure. Eight persons died before reaching medical care; of the 71 persons hospitalized for acute health effects as a result of chlorine exposure, 1 died in the hospital. The mean age of the hospitalized persons was 40 years (range, 4 months-76 years); 87% were male. The median duration of hospitalization was 4 days (range, 1-29 days). Twenty-five (35%) persons were admitted to the intensive care unit; the median length of stay was 3 days. Many surviving victims developed significant pulmonary signs and severe airway inflammation; 41 (58%) hospitalized persons met Po2/Fio2 criteria for acute respiratory distress syndrome or acute lung injury. During their hospitalization, 40 (57%) developed abnormal x-ray findings, 74% of those within the first day. Hypoxia on room air and Po2/Fio2 ratio predicted severity of outcome as assessed by the duration of hospitalization and the need for intensive care support. This community release of chlorine gas caused widespread exposure and resulted in significant acute health effects and substantial health care requirements. Pulse oximetry and arterial blood gas analysis provided early indications of outcome severity.

Acute health effects after exposure to chlorine gas released after a train derailment.

Objective: To evaluate the performance of a rapid HIV antibody test used with whole blood and oral fluid in settings where the test is likely to be used. Design: In four separate studies, we compared the accuracy of the rapid test performed on whole blood and oral fluid specimens with the results of conventional HIV tests. Methods: Oral fluid and whole blood from persons of unknown HIV status recruited from clinics, labor and delivery units, and outreach venues were tested with the OraQuick Advance rapid HIV-1/2 antibody test. Sensitivity and specificity were compared with results of the enzyme immunoassay (EIA) and Western blot algorithm used by the study sites. Results: OraQuick sensitivity was 99.7% with whole blood and 99.1 % with oral fluid from 327 persons who were HIV antibody positive by the conventional algorithm. OraQuick specificity was 99.9% with whole blood and 99.6% with oral fluid from 12 010 HIV-negative persons; EIA specificity was 99.7%. A cluster of 16 false-positive oral fluid tests occurred in one study, in which specificity was lower (99.0%) than in the other three studies (99.6-99.8%). Conclusions: In diverse settings in four studies, the OraQuick test showed high sensitivity and specificity for HIV antibody in whole blood and oral fluid specimens. Slightly more false-positive and false-negative results occurred with oral fluid than with whole blood, but performance with both specimen types was similar to, or better than, that of conventional ElAs.

Performance of an oral fluid rapid HIV-1/2 test : experience from four CDC studies. Commentary

Objective To evaluate the performance of a rapid HIV antibody test used with whole blood and oral fluid in settings where the test is likely to be used. Design In four separate studies, we compared the accuracy of the rapid test performed on whole blood and oral fluid specimens with the results of conventional HIV tests. Methods Oral fluid and whole blood from persons of unknown HIV status recruited from clinics, labor and delivery units, and outreach venues were tested with the OraQuick Advance rapid HIV-1/2 antibody test. Sensitivity and specificity were compared with results of the enzyme immunoassay (EIA) and Western blot algorithm used by the study sites. Results OraQuick sensitivity was 99.7% with whole blood and 99.1% with oral fluid from 327 persons who were HIV antibody positive by the conventional algorithm. OraQuick specificity was 99.9% with whole blood and 99.6% with oral fluid from 12 010 HIV-negative persons; EIA specificity was 99.7%. A cluster of 16 false-positive oral fluid tests occurred in one study, in which specificity was lower (99.0%) than in the other three studies (99.6-99.8%). Conclusions In diverse settings in four studies, the OraQuick test showed high sensitivity and specificity for HIV antibody in whole blood and oral fluid specimens. Slightly more false-positive and false-negative results occurred with oral fluid than with whole blood, but performance with both specimen types was similar to, or better than, that of conventional EIAs.

Performance of an oral fluid rapid HIV-1/2 test: experience from four CDC studies.

Background. Since 2002, the US Food and Drug Administration has approved 6 rapid human immuno-deﬁciency virus (HIV) tests for use in the United States. To date, there has been no direct comparison of theperformance of all 6 tests.Methods. Persons known to be HIV-infected and persons who sought HIV testing at 2 clinical sites in LosAngeles, California, were recruited for evaluation of 6 rapid HIV tests with whole blood, oral ﬂuid, serum, andplasmaspecimens.Sensitivityandspeciﬁcityoftherapidtestswerecomparedwithvirallysateandimmunoglobulin(Ig) M–sensitive peptide HIV enzyme immunoassays (EIAs).Results. A total of 6282 specimens were tested. Sensitivity was .95% and speciﬁcity was .99% for all rapidtests.ComparedwiththeIgM-sensitiveEIA,rapidtestsgavefalse-negativeresultswithanadditional2–5specimens.All rapid tests had statistically equivalent performance characteristics, based on overlapping conﬁdence intervals forsensitivity and speciﬁcity, compared with either conventional EIA.Conclusions. All 6 rapid tests have high sensitivity and speciﬁcity, compared with that of conventional EIAs. Becauseperformance was similar for all tests and specimen types, other characteristics, such as convenience, time to result,shelflife,andcostwilllikelybedeterminingfactorsforselectionofarapidHIVscreeningtestforaspeciﬁcapplication.In 1998, when the Centers for Disease Control andPrevention (CDC) encouraged the use of rapid humanimmunodeﬁciency virus (HIV) tests to increase the re-ceipt of results among persons tested for HIV [1], onlytheSingleUseDiagnosticSystemforHIV-1(SUDS)wascommercially available in the United States [2]. Since2002, the US Food and Drug Administration (FDA) hasapproved 6 rapid HIV tests [3] that have become in-tegral to initiatives designed to promote more wide-spread HIV testing [4–10].Rapid HIV antibody tests provide results in ,30min [3]. FDA-approved rapid HIV tests (Table 1)employ either immunochromatography (lateralﬂow) or immunoconcentration (ﬂow-through) tech-niques [11] and contain antigens that correspond toenvelope regions of HIV-1 (gp41, gp120, or both).Some tests also have an HIV type 2 (HIV-2) envelope(gp36) antigen. However, recent studies have docu-mented that rapid HIV tests have lower sensitivity,especially during early infection, than that of someconventional assays [12–14]. False-negative test re-sults have also been observed in individuals with ad-vanced disease [15] and in some persons who arereceiving effective antiretroviral therapy (ART) [16,17]. Because test manufacturers do not explicitlyidentify which reference tests were used to calculatesensitivity and speciﬁcity (Table 1), this study wasundertakentocomparecontemporaryrapidHIVtestsand conventional enzyme immunoassays (EIAs) whenperformed on specimens fromthesamepersons.METHODSThe two-phase ﬁeld study was conducted at the Los An-geles Gay and Lesbian Center (LAGLC), an HIV testing

Evaluation of the Performance Characteristics of 6 Rapid HIV Antibody Tests

Over half of HIV infections in the United States occur among men who have sex with men (MSM) Awareness of infection is a necessary precursor to antiretroviral treatment and risk reduction among HIV-infected persons We report data on prevalence and awareness of HIV infection among MSM in 2008 and 2011, using data from 20 cities participating in the 2008 and 2011 National HIV Behavioral Surveillance System (NHBS) among MSM Venue-based, time-space sampling was used to recruit men for interview and HIV testing We analyzed data for men who reported ≥ 1 male sex partner in the past 12 months Participants who tested positive were considered to be aware of their infection if they reported a prior positive HIV test We used multivariable analysis to examine differences between results from 2011 vs 2008 HIV prevalence was 19% in 2008 and 18% in 2011 (p = 014) In both years, HIV prevalence was highest among older age groups, blacks, and men with lower education and income In multivariable analysis, HIV prevalence did not change significantly from 2008 to 2011 overall (p = 051) or in any age or racial/ethnic category (p>015 in each category) Among those testing positive, a greater proportion was aware of their infection in 2011 (66%) than in 2008 (56%) (p<0001) In both years, HIV awareness was higher for older age groups, whites, and men with higher education and income In multivariable analysis, HIV awareness increased from 2008 to 2011 overall (p<0001) and for all age and racial/ethnic categories (p<001 in each category) In both years, black MSM had the highest HIV prevalence and the lowest awareness among racial/ethnic groups These findings suggest that HIV-positive MSM are increasingly aware of their infections

http://stacks.cdc.gov/view/cdc/21328/cdc_21328_DS1.pdf

HIV infection and awareness among men who have sex with men-20 cities, United States, 2008 and 2011.

OBJECTIVES: After a train derailment released approximately 60 tons of chlorine from a ruptured tanker car, a multiagency team performed a rapid assessment of the health impact to determine morbidity caused by the chlorine and evaluate the effect of this mass-casualty event on health-care facilities METHODS: A case was defined as death or illness related to chlorine exposure Investigators gathered information on exposure, treatment received, and outcome through patient questionnaires and medical record review An exposure severity rating was assigned to each patient based on description of exposure, distance from derailment, and duration of exposure A case involving death or hospitalization > or = 3 nights was classified as a severe medical outcome Logistic regression was used to examine factors associated with severe medical outcomes RESULTS: Nine people died, 72 were hospitalized in nine hospitals, and 525 were examined as outpatients Fifty-one people (8%) had a severe medical outcome Of 263 emergency department visits within 24 hours of the incident, 146 (56%) were in Augusta, Georgia; at least 95 patients arrived at facilities in privately owned vehicles Patients with moderate-to-extreme exposure were more likely to experience a severe medical outcome (relative risk: 152; 95% confidence interval 48, 478) than those with a lower rating CONCLUSIONS: The rapid investigation revealed significant morbidity and mortality associated with an accidental release of chlorine gas Key findings that should be addressed during facility, community, state, and regional mass-casualty planning include self-transport of symptomatic people for medical care and impact on health-care facilities over a wide geographic area Language: en

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Rapid Assessment of Exposure to Chlorine Released from a Train Derailment and Resulting Health Impact

The development of syndromic surveillance systems to detect potential terrorist-related outbreaks has the potential to be a useful public health surveillance activity However, the perception of how the Health Insurance Portability and Accountability Act of1996 (HIPAA) Privacy Rule applies to the disclosure of certain public health information might affect the ability of state and local health departments to implement syndromic surveillance systems within their jurisdictions To assess this effect, a multiple-question survey asked respondents to share their experiences regarding patient confidentiality and HIPAA Privacy Rule requirements when imple menting syndromic surveillance systems This assessment summarizes the results of a national survey of state terrorism-preparedness coordinators and state epidemiologists and reflects the authors' and others' experiences with implementation

Health information privacy and syndromic surveillance systems.

Introduction
After a train derailment released chlorine gas in Graniteville, South Carolina, in 2005, a multiagency team performed an epidemiologic assessment of chlorine exposure and resulting health effects. Five months later, participants were resurveyed to determine their health status and needs and to assist in planning additional interventions in the community.

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Daniel Drociuk

Papers

Rapid Assessment of Exposure to Chlorine Released from a Train Derailment and Resulting Health Impact

Health information privacy and syndromic surveillance systems.

Follow-up assessment of health consequences after a chlorine release from a train derailment--Graniteville, SC, 2005.

Health Information Privacy and Other Legal Perspectives Concerning Syndromic Surveillance