Early Warning and Response System (EWARS) for chikungunya, zika and dengue outbreaks: The innovated WHO-TDR tool.

Abstract Background. In the Americas, endemic cities for Aedes-borne diseases such as chikungunya, Zika and dengue face great challenges particularly since the recent outbreaks of CHIKV and ZIKV, all transmitted by the same insect vector Aedes aegypti and albopictus. Areas, such as Colombia and Mexico with the highest incidence and most frequent outbreaks of the three diseases are located in tropical environments due to their favorable eco-epidemiological conditions for vector breeding. In Colombia, the city of Cúcuta on the border with Venezuela is one of such highly endemic areas. Likewise, in Mexico a number of municipalities has very similar environmental conditions. This is why these urban areas provide the opportunity to test the Early Warning and Response System (EWARS), developed originally for dengue outbreaks, also for the other two diseases (Chikungunya and Zika). Methodology. Through the retrospective analysis of epidemiological, climate and entomological data produced by the national surveillance systems in Colombia and Mexico, we intended to predict outbreaks with a high sensitivity and positive predictive value (PPV) through alarm signals by using the EWARS tool. The registered outbreaks of DENV 2012-2016, CHIKV 2014-2016 and ZIKV 2015-2016 were analyzed for 2 years retrospectively (“run in period”) and one year of analysis (“evaluation period”). Outbreak prediction for dengue and Zika was for both countries but for Chikungunya in Colombia only due to the availability of surveillance data. Results. In Mexico, the sensitivity of different alarm signals for correctly predicting an outbreak ranged between 74-92% for dengue, 77–93% for chikungunya and 78-97% for Zika. Their Positive Predictive Values ranged between 51-68% for dengue, 48-92% for chikungunya and 11-100% for Zika. The lag time between predictions and start of the outbreak (i.e. the time available for early response activities) was for dengue 3-5 weeks, for chikungunya 10-13 weeks and for Zika 3-5 weeks. Conclusion. The implementation of an early warning and response system (EWARS) could substantially reduce the magnitude and occurrence of outbreaks and the elevated social and economic toll.

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The Early Warning And Response System (EWARS-TDR) For Dengue Outbreaks: Can It Also Be Applied To Chikungunya And Zika Outbreak Warning?

10.21203/rs.3.rs-498936/v1 ◽

2021 ◽

Author(s):

Rocio Cardenas ◽

Laith Hussain-Alkhateeb ◽

David Benitez-Valladares ◽

Gustavo Sanchez-Tejeda ◽

Axel Kroeger

Keyword(s):

Positive Predictive Value ◽

Early Warning ◽

Predictive Value ◽

Large City ◽

High Sensitivity ◽

Surveillance Systems ◽

Insect Vector ◽

Alarm Signals ◽

Response System ◽

Dengue Outbreaks

Abstract Background. In the Americas, endemic countries for Aedes-borne diseases such as dengue, chikungunya, and Zika face great challenges particularly since the recent outbreaks of CHIKV and ZIKV, all transmitted by the same insect vector Aedes aegypti and Ae. albopictus. The Special Program for Research and Training in Tropical Diseases (TDR- WHO) has developed together with partners an early warning and Response System (EWARS) for dengue outbreaks based on a variety of alarm signals with a high sensitivity and positive predictive value (PPV). The question is if this tool can also be used for the prediction of Zika and chikungunya outbreaks.Methodology. We conducted in nine districts of Mexico and one large city in Colombia a retrospective analysis of epidemiological data (for the outbreak definition) and of climate and entomological data (as potential alarm indicators) produced by the national surveillance systems for dengue, chikungunya and Zika outbreak prediction covering the following outbreak years: for dengue 2012-2016, for Zika 2015-2017, for chikungunya 2014-2016. This period was divided into a “run in period” (to establish the “historical” pattern of the disease) and an “analysis period” (to identify sensitivity and PPV of outbreak prediction). Results. In Mexico, the sensitivity of alarm signals for correctly predicting an outbreak was 92% for dengue, and 97% for Zika (chikungunya data could not be obtained in Mexico); the PPV was 68% for dengue and 100% for Zika. The time period between alarm and start of the outbreak (i.e. the time available for early response activities) was for dengue 6-8 weeks and for Zika 3-5 weeks. In Colombia the sensitivity of the outbreak prediction was 92% for dengue, 93% for chikungunya and 100% for Zika; the PPV was 68% for dengue, 92% for chikungunya and 54% for Zika; the prediction distance was for dengue 3-5 weeks, for chikungunya 10-13 weeks and for Zika 6-10 weeks. Conclusion. The implementation of an early warning and response system (EWARS) could predict outbreaks of three Aedes borne diseases with a high sensitivity and positive predictive value and with a lag time long enough for preparing an adequate outbreak response in order to reduce the magnitude or avert the occurrence of outbreaks with their elevated social and economic tolls.

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Validation of the Early Warning and Response System (EWARS) for dengue outbreaks: Evidence from the national vector control program in Mexico

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009261 ◽

2021 ◽

Vol 15 (12) ◽

pp. e0009261

Author(s):

David Benitez-Valladares ◽

Axel Kroeger ◽

Gustavo Sánchez Tejeda ◽

Laith Hussain-Alkhateeb

Keyword(s):

Vector Control ◽

Early Warning ◽

Disease Transmission ◽

Indoor Residual Spraying ◽

Alarm Signals ◽

Dengue Outbreak ◽

Response System ◽

Adequate Response ◽

Dengue Outbreaks ◽

The Impact

Background During 2017, twenty health districts (locations) implemented a dengue outbreak Early Warning and Response System (EWARS) in Mexico, which processes epidemiological, meteorological and entomological alarm indicators to predict dengue outbreaks and triggers early response activities. Out of the 20 priority districts where more than one fifth of all national disease transmission in Mexico occur, eleven districts were purposely selected and analyzed. Nine districts presented outbreak alarms by EWARS but without subsequent outbreaks (“non-outbreak districts”) and two presented alarms with subsequent dengue outbreaks (“outbreak districts”). This evaluation study assesses and compares the impact of alarm-informed response activities and the consequences of failing a timely and adequate response across the outbreak groups. Methods Five indicators of dengue outbreak response (larval control, entomological studies with water container interventions, focal spraying and indoor residual spraying) were quantitatively analyzed across two groups (”outbreak districts” and “non-outbreak districts”). However, for quality control purposes, only qualitative concluding remarks were derived from the fifth response indicator (fogging). Results The average coverage of vector control responses was significantly higher in non-outbreak districts and across all four indicators. In the “outbreak districts” the response activities started late and were of much lower intensity compared to “non-outbreak districts”. Vector control teams at districts-level demonstrated diverse levels of compliance with local guidelines for ‘initial’, ‘early’ and ‘late’ responses to outbreak alarms, which could potentially explain the different outcomes observed following the outbreak alarms. Conclusion Failing timely and adequate response of alarm signals generated by EWARS showed to negatively impact the disease outbreak control process. On the other hand, districts with adequate and timely response guided by alarm signals demonstrated successful records of outbreak prevention. This study presents important operational scenarios when failing or successding EWARS but warrants investigating the effectiveness and cost-effectiveness of EWARS using a more robust designs.

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Validation of the Early Warning and Response System (EWARS) for dengue outbreaks: Evidence from the national vector control program in Mexico

10.1101/2021.02.23.432448 ◽

2021 ◽

Author(s):

David Benitez-Valladares ◽

Axel Kroeger ◽

Gustavo Sánchez Tejeda ◽

Laith Hussain-Alkhateeb

Keyword(s):

Vector Control ◽

Early Warning ◽

National Level ◽

Indoor Residual Spraying ◽

False Alarms ◽

Outbreak Response ◽

Effective Response ◽

Dengue Outbreak ◽

Response System ◽

Dengue Outbreaks

AbstractBackgroundDuring 2017, twenty health districts (locations) in Mexico implemented a dengue outbreak early warning and response system (EWARS) that uses epidemiological, meteorological and entomological variables (alarm indicators) to predict dengue outbreaks and triggers early response activities.Eleven of these districts were analyzed as they presented reliable information. Nine districts presented outbreak alarms but without subsequent outbreaks (“non-outbreak districts”) and two presented after the alarms dengue outbreaks (“outbreak districts”). This study is concerned with i) if the alarms without outbreaks were false alarms or if the control services had established effective response activities averting an outbreak and ii) if vector control activities can mitigate or even avert dengue outbreaks.MethodsFive components of dengue outbreak response (larval control, entomological studies with water container interventions, focal spraying, indoor residual spraying, space spraying) were quantitatively analyzed across two groups (”outbreak districts” and “non-outbreak districts”).ResultsThe average coverage of vector control and responses were higher in non-outbreak districts and across all five components. In the “outbreak districts” the response activities started late and were of much lower intensity compared to “non-outbreak districts”. District vector control teams demonstrated diverse compliance with local guidlines for ‘initial’, ‘early’ and ‘late’ responses to outbreak alarms which could explain the different outcomes observed following the outbreak alarms.Conclusionfindings from this study plausibly demonstrates important operational scenarios when succeeding or failing alarms signals generated by EWARS at national level. This study presents evidence warranting for further investigation into the effectiveness and cost-effectiveness of EWARS using gold-standard designs.

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Early warning and response system (EWARS) for dengue outbreaks: Recent advancements towards widespread applications in critical settings

PLoS ONE ◽

10.1371/journal.pone.0196811 ◽

2018 ◽

Vol 13 (5) ◽

pp. e0196811 ◽

Cited By ~ 6

Author(s):

Laith Hussain-Alkhateeb ◽

Axel Kroeger ◽

Piero Olliaro ◽

Joacim Rocklöv ◽

Maquins Odhiambo Sewe ◽

...

Keyword(s):

Early Warning ◽

Response System ◽

Dengue Outbreaks

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D-Dimers, Thrombin Antithrombin III Complexes and Prothrombin Fragments 1 + 2: Diagnostic value in Clinically Suspected Deep Vein Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647449 ◽

1991 ◽

Vol 65 (01) ◽

pp. 028-032 ◽

Cited By ~ 105

Author(s):

B Boneu ◽

G Bes ◽

H Pelzer ◽

P Sié ◽

H Boccalon

Keyword(s):

Deep Vein Thrombosis ◽

Antithrombin Iii ◽

High Sensitivity ◽

Diagnostic Value ◽

Predictive Values ◽

Vein Thrombosis ◽

High Negative Predictive Value ◽

Deep Vein ◽

D Dimer ◽

Mercury Strain Gauge

SummaryThis study was performed to determine the accuracy of D-Dimer fibrin derivatives, thrombin-antithrombin III (TAT) complexes and prothrombin fragments 1 + 2 (F 1 + 2) determinations for the diagnosis of deep vein thrombosis (DVT). One hundred and sixteen consecutive patients referred to the angiology unit of our hospital for a clinically suspected DVT were investigated. They were submitted to mercury strain gauge plethysmography and to ultrasonic duplex scanning examination; in cases of inconclusive results or of proximal DVT (n = 35), an ascending phlebography was performed. After these investigations were completed, the diagnosis of DVT was confirmed in 34 and excluded in 82. One half of the patients were already under anticoagulant therapy at the time of investigation. The 3 biological markers were assayed using commercially available ELISA techniques and the D-Dimer was also assayed with a fast latex method. The normal distribution of these markers was established in 40 healthy blood donors. The most accurate assay for the diagnosis of DVT was the D-Dimer ELISA which had both a high sensitivity (94%) and a high negative predictive value (95%). The D-Dirner latex, TAT complexes and F 1 + 2 were far less sensitive and provided negative predictive values which ranged between 78 and 85%. In spite of positive and significant correlations between the levels of ihe 3 markers, their association did not improve their overall accuracy for detecting D\/L Therefore, with the exception of the D-Dimer ELISA, these markers were of little value for the diagnosis of DVT in this specific population.

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An Urban Air Pollution Early Warning System Based on PM2.5 Prediction Applied in Ploiesti City

Revista de Chimie ◽

10.37358/rc.17.4.5566 ◽

2017 ◽

Vol 68 (4) ◽

pp. 858-863

Author(s):

Mihaela Oprea ◽

Marius Olteanu ◽

Radu Teodor Ianache

Keyword(s):

Air Pollution ◽

Early Warning ◽

Urban Areas ◽

Early Warning System ◽

Urban Air Pollution ◽

Warning System ◽

Air Pollutant ◽

Pollution Level ◽

Urban Air ◽

Prediction Approach

Fine particulate matter with a diameter less than 2.5 �m (i.e. PM2.5) is an air pollutant of special concern for urban areas due to its potential significant negative effects on human health, especially on children and elderly people. In order to reduce these effects, new tools based on PM2.5 monitoring infrastructures tailored to specific urban regions are needed by the local and regional environmental management systems for the provision of an expert support to decision makers in air quality planning for cities and also, to inform in real time the vulnerable population when PM2.5 related air pollution episodes occur. The paper focuses on urban air pollution early warning based on PM2.5 prediction. It describes the methodology used, the prediction approach, and the experimental system developed under the ROKIDAIR project for the analysis of PM2.5 air pollution level, health impact assessment and early warning of sensitive people in the Ploiesti city. The PM2.5 concentration evolution prediction is correlated with PM2.5 air pollution and health effects analysis, and the final result is processed by the ROKIDAIR Early Warning System (EWS) and sent as a message to the affected population via email or SMS. ROKIDAIR EWS is included in the ROKIDAIR decision support system.

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Evaluation of HiCrome KPC Agar for the Screening of Carbapenem-Resistant Enterobacterales Colonization in the ICU Setting of a Tertiary Care Hospital

Journal of Laboratory Physicians ◽

10.1055/s-0041-1732494 ◽

2021 ◽

Author(s):

Ashoka Mahapatra ◽

K Nikitha ◽

Sutapa Rath ◽

Bijayini Behera ◽

Kavita Gupta

Keyword(s):

Tertiary Care ◽

High Sensitivity ◽

Care Hospital ◽

Predictive Values ◽

Klebsiella Pneumoniae Carbapenemase ◽

Carbapenem Resistant ◽

Rectal Swabs ◽

Control And Prevention ◽

Indian Setting ◽

Sensitivity Specificity

Abstract Background Spread of carbapenem-resistant Enterobacterales (CRE) is a significant concern in intensive care unit (ICU) settings. Approaches to routine screening for CRE colonization in all ICU patients vary depending on institutional epidemiology and resources. The present study was aimed to evaluate the performance of HiCrome Klebsiella pneumoniae carbapenemase (KPC) agar for the detection of CRE colonization in ICU settings taking the Centers for Disease Control and Prevention (CDC) recommended method as reference. Methods Two-hundred and eighty rectal swabs (duplicate) from 140 patients were subjected to CRE detection in HiCrome KPC agar and MacConkey agar (CDC criteria). Results Using CDC method, total 41 CRE isolates were recovered comprising of 29 E scherichia coli, 11 Klebsiella, and 1 Enterobacter spp. On the other hand, 49 isolates of CRE recovered from 140 rectal swabs using HiCrome KPC agar, out of which 33 were E. coli, 15 Klebsiella, and 1 Enterobacter sp. Statistical Analysis Sensitivity, specificity, negative, and positive predictive values of CRE screening by HiCrome KPC agar were found to be 100% (91.4–100), 91.9% (84.8–95.8), 83.6% (70.9–91.4), and 100% (95.9–100), respectively, taking the CDC recommended method as reference. Conclusion HiCrome KPC agar has high sensitivity in screening CRE colonization. Further studies are needed to establish its applicability for detecting the predominant circulating carbapenemases in the Indian setting.

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Towards an integrated animal health surveillance system in Tanzania: making better use of existing and potential data sources for early warning surveillance

BMC Veterinary Research ◽

10.1186/s12917-021-02789-x ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Janeth George ◽

Barbara Häsler ◽

Erick Komba ◽

Calvin Sindato ◽

Mark Rweyemamu ◽

...

Keyword(s):

Early Warning ◽

Surveillance System ◽

Animal Health ◽

Health Surveillance ◽

Surveillance Data ◽

Data Sources ◽

Surveillance Systems ◽

Cross Sectional Survey ◽

Traceability System ◽

Spatial Coverage

Abstract Background Effective animal health surveillance systems require reliable, high-quality, and timely data for decision making. In Tanzania, the animal health surveillance system has been relying on a few data sources, which suffer from delays in reporting, underreporting, and high cost of data collection and transmission. The integration of data from multiple sources can enhance early detection and response to animal diseases and facilitate the early control of outbreaks. This study aimed to identify and assess existing and potential data sources for the animal health surveillance system in Tanzania and how they can be better used for early warning surveillance. The study used a mixed-method design to identify and assess data sources. Data were collected through document reviews, internet search, cross-sectional survey, key informant interviews, site visits, and non-participant observation. The assessment was done using pre-defined criteria. Results A total of 13 data sources were identified and assessed. Most surveillance data came from livestock farmers, slaughter facilities, and livestock markets; while animal dip sites were the least used sources. Commercial farms and veterinary shops, electronic surveillance tools like AfyaData and Event Mobile Application (EMA-i) and information systems such as the Tanzania National Livestock Identification and Traceability System (TANLITS) and Agricultural Routine Data System (ARDS) show potential to generate relevant data for the national animal health surveillance system. The common variables found across most sources were: the name of the place (12/13), animal type/species (12/13), syndromes (10/13) and number of affected animals (8/13). The majority of the sources had good surveillance data contents and were accessible with medium to maximum spatial coverage. However, there was significant variation in terms of data frequency, accuracy and cost. There were limited integration and coordination of data flow from the identified sources with minimum to non-existing automated data entry and transmission. Conclusion The study demonstrated how the available data sources have great potential for early warning surveillance in Tanzania. Both existing and potential data sources had complementary strengths and weaknesses; a multi-source surveillance system would be best placed to harness these different strengths.

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