Abstract Background The aim of our retrospective study was to evaluate the earliest COVID19-related signal to anticipate requirements of intensive care unit (ICU) beds. Although the number of ICU beds is crucial during the COVID-19 epidemic, there is no recognized early indicator to anticipate it. Methods In the Ile-de-France region, from February 20 to May 5, 2020, emergency medical service (EMS) calls and the response provided (ambulances) together the percentage of positive reverse transcriptase polymerase chain reaction (RT-PCR) tests, general practitioner (GP) and emergency department (ED) visits, and hospital admissions of COVID-19 patients were recorded daily and compared to the number of ICU patients. Correlation curve analysis was performed to determine the best correlation coefficient, depending on the number of days the indicator has been shifted. Primary endpoint was the number of ICU patients. Results EMS calls, percentage of positive RT-PCR tests, ambulances used, ED and GP visits of COVID-19 patients were strongly associated with COVID-19 ICU patients with an anticipation delay of 23, 15, 14, 13, and 12 days respectively. Hospitalization did not anticipate ICU bed requirement. Conclusion The daily number of COVID19-related telephone calls received by the EMS and corresponding dispatch ambulances, and the proportion of positive RT-PCR tests were the earliest indicators of the number of COVID19 patients requiring ICU care during the epidemic crisis, rapidly followed by ED and GP visits. This information may help health authorities to anticipate a future epidemic, including a second wave of COVID19 or decide additional social measures.

In September 2014, the SOS Médecins network has detected an increase in the number of cases of gastroenteritis as vomiting than other monitoring networks (specific or nonspecific) could not identify. The complementarity of the source to this monitoring has enabled to show the added value it could have particularly in terms of geographical coverage and completeness of coding.

Two separate terrorist attacks took place in the Paris area in 2015. The first attack began on Jan 7 with a massacre at the satirical magazine Charlie Hebdo and ended 2 days later with two sieges involving major police operations. 17 people were murdered and 20 people were injured. The second attack was a series of coordinated assaults on Nov 13, during which three suicide bombers struck outside a filled stadium and mass shootings took place at cafés, restaurants, and a concert hall. Together, the attackers killed 130 people and injured more than 300 people.1Hirsh M Carli P Nizard R et al.the health professionals of Assistance Publique-Hôpitaux de Paris (APHP)The medical response to multisite terrorist attacks in Paris.Lancet. 2015; 386: 2535-2538Summary Full Text Full Text PDF PubMed Scopus (196) Google ScholarSyndromic surveillance can be used for early detection of abnormal health-related events or to quantify the health effect of major events such as terrorist attacks.2CDCSyndromic surveillance for bioterrorism following the attacks on the World Trade Center—New York City, 2001.MMWR Morb Mortal Wkly Rep. 2002; 51: 13-15PubMed Google Scholar, 3Bravata DM McDonald KM Smith WM et al.Systematic review: surveillance systems for early detection of bioterrorism-related diseases.Ann Intern Med. 2004; 140: 910-922Crossref PubMed Scopus (208) Google Scholar Since 2004, the syndromic surveillance system in France has included individual data collected daily from mortality registry offices (INSEE), hospital emergency departments (OSCOUR network), and emergency doctor house calls (SOS Médecins), all of which are transmitted automatically to the National Institute of Public Health (Saint Maurice, France).4Caserio-Schönemann C Meynard JB Ten years experience of syndromic surveillance for civil and military public health, France, 2004–2014.Euro Surveill. 2015; 20: 35-38Crossref PubMed Scopus (5) Google Scholar During the November attack, hospital physicians and doctors from SOS Médecins were instructed to use a specified code for consultations or disorders they considered related to the event. Implementation of this simple additional procedure made it possible to identify and analyse a potential, specific effect. We have analysed the use of emergency departments after these attacks, with a focus on psychological sequelae and the SOS Médecins labelling procedure.Visits related to stress increased significantly in Parisian emergency departments during both episodes (figure). After Jan 7, 39 visits to emergency departments were related to post-traumatic stress disorder (ICD-10 F43·1) and acute stress reaction (ICD-10 F43·0). Between Nov 14 and Nov 22, stress disorders accounted for 334 visits, most of which took place Nov 14–16. The main diagnoses were mainly acute stress reaction (ICD-10 F43·0) and anxiety disorder (ICD-10 F41·9). Nearly all patients (97%) were aged 15–74 years; 19 people were admitted to hospital. The SOS Médecins labelling procedure identified 93 visits, the number of visits peaked on Nov 16, and anxiety disorder was the most frequent diagnosis.Although the health effect is probably underestimated5Vilain P Pagès F Combes X et al.Health impact assessment of cyclone Bejisa in Reunion Island (France) using syndromic surveillance.Prehosp Disaster Med. 2015; 30: 137-144Crossref PubMed Scopus (11) Google Scholar in both episodes, the events differed clearly in their effect: use of emergency services for stress was much higher in November, 2015, than in any previous month.Our results underline the need to implement a labelling procedure that is both useful and acceptable to doctors fairly rapidly. Syndromic surveillance could be used to measure psychological effects during the week after a terrorist attack, before confirmation of diagnoses, and could be used by health authorities to mobilise a rapid response.We declare no competing interests. We thank Philippe Pirard, Christophe Leroy, Laure Beaujouan, Anne Gallay, Thierry Cardoso, and Jo Ann Cahn. Two separate terrorist attacks took place in the Paris area in 2015. The first attack began on Jan 7 with a massacre at the satirical magazine Charlie Hebdo and ended 2 days later with two sieges involving major police operations. 17 people were murdered and 20 people were injured. The second attack was a series of coordinated assaults on Nov 13, during which three suicide bombers struck outside a filled stadium and mass shootings took place at cafés, restaurants, and a concert hall. Together, the attackers killed 130 people and injured more than 300 people.1Hirsh M Carli P Nizard R et al.the health professionals of Assistance Publique-Hôpitaux de Paris (APHP)The medical response to multisite terrorist attacks in Paris.Lancet. 2015; 386: 2535-2538Summary Full Text Full Text PDF PubMed Scopus (196) Google Scholar Syndromic surveillance can be used for early detection of abnormal health-related events or to quantify the health effect of major events such as terrorist attacks.2CDCSyndromic surveillance for bioterrorism following the attacks on the World Trade Center—New York City, 2001.MMWR Morb Mortal Wkly Rep. 2002; 51: 13-15PubMed Google Scholar, 3Bravata DM McDonald KM Smith WM et al.Systematic review: surveillance systems for early detection of bioterrorism-related diseases.Ann Intern Med. 2004; 140: 910-922Crossref PubMed Scopus (208) Google Scholar Since 2004, the syndromic surveillance system in France has included individual data collected daily from mortality registry offices (INSEE), hospital emergency departments (OSCOUR network), and emergency doctor house calls (SOS Médecins), all of which are transmitted automatically to the National Institute of Public Health (Saint Maurice, France).4Caserio-Schönemann C Meynard JB Ten years experience of syndromic surveillance for civil and military public health, France, 2004–2014.Euro Surveill. 2015; 20: 35-38Crossref PubMed Scopus (5) Google Scholar During the November attack, hospital physicians and doctors from SOS Médecins were instructed to use a specified code for consultations or disorders they considered related to the event. Implementation of this simple additional procedure made it possible to identify and analyse a potential, specific effect. We have analysed the use of emergency departments after these attacks, with a focus on psychological sequelae and the SOS Médecins labelling procedure. Visits related to stress increased significantly in Parisian emergency departments during both episodes (figure). After Jan 7, 39 visits to emergency departments were related to post-traumatic stress disorder (ICD-10 F43·1) and acute stress reaction (ICD-10 F43·0). Between Nov 14 and Nov 22, stress disorders accounted for 334 visits, most of which took place Nov 14–16. The main diagnoses were mainly acute stress reaction (ICD-10 F43·0) and anxiety disorder (ICD-10 F41·9). Nearly all patients (97%) were aged 15–74 years; 19 people were admitted to hospital. The SOS Médecins labelling procedure identified 93 visits, the number of visits peaked on Nov 16, and anxiety disorder was the most frequent diagnosis. Although the health effect is probably underestimated5Vilain P Pagès F Combes X et al.Health impact assessment of cyclone Bejisa in Reunion Island (France) using syndromic surveillance.Prehosp Disaster Med. 2015; 30: 137-144Crossref PubMed Scopus (11) Google Scholar in both episodes, the events differed clearly in their effect: use of emergency services for stress was much higher in November, 2015, than in any previous month. Our results underline the need to implement a labelling procedure that is both useful and acceptable to doctors fairly rapidly. Syndromic surveillance could be used to measure psychological effects during the week after a terrorist attack, before confirmation of diagnoses, and could be used by health authorities to mobilise a rapid response. We declare no competing interests. We thank Philippe Pirard, Christophe Leroy, Laure Beaujouan, Anne Gallay, Thierry Cardoso, and Jo Ann Cahn.

Implementation of a labelling protocol to timely assess the potential health impact of a terrorist attack (occurring in France the 26th of July, 2015) on the population potentially exposed using syndromic surveillance data.

Epidemiological studies are necessary to take public health decisions. Their relevance depends on the quality of data. Doctors in continuous care collect a big amount of data that can be used for epidemiological purpose, but spatial data may be dirty; based on city names, the localization is imprecise, even more if it is misspelled. The only way to identify a city without ambiguity is to use its identifier, which can be retrieved by cleansing geographical textual data. In France, cities are organized in administrative zones called departments and some city names are shared by several cities in several departments. The clear identification of the department and the city name allows to deduce the city unique identifier and to make some spatial analysis such as epidemiological studies. In this paper, we propose a method to cleanse such data, using several steps. After having standardized the text to cleanse, we use the Levenshtein distance to generate a first set of propositions. Finally, the propositions are filtered, by removing the less likely candidates, so that it remains only one, which becomes the chosen city. Tested on a dataset of 9818 entries, we obtained 89.1% of concordance, whereas the standard Levenshtein distance obtained 70.5%. This demonstrates that our method has better results.