Surveillance system integration: reporting the results of a global multicountry survey.

OBJECTIVES: Currently, there is no comprehensive picture of the global surveillance landscape. This survey examines the current state of surveillance systems, levels of integration, barriers and opportunities for the integration of surveillance systems at the country level, and the role of national public health institutes (NPHIs). STUDY DESIGN: This was a cross-sectional survey of NPHIs. METHODS: A web-based survey questionnaire was disseminated to 110 NPHIs in 95 countries between July and August 2022. Data were descriptively analysed, stratified by World Health Organization region, World Bank Income Group, and self-reported Integrated Disease Surveillance (IDS) maturity status. RESULTS: Sixty-five NPHIs responded. Systems exist to monitor notifiable diseases and vaccination coverage, but less so for private, pharmaceutical, and food safety sectors. While Ministries of Health usually lead surveillance, in many countries, NPHIs are also involved. Most countries report having partially developed IDS. Surveillance data are frequently inaccessible to the lead public health agency and seldomly integrated into a national public health surveillance system. Common challenges to establishing IDS include information technology system issues, financial constraints, data sharing and ownership limitations, workforce capacity gaps, and data availability. CONCLUSIONS: Public health surveillance systems across the globe, although built on similar principles, are at different levels of maturity but face similar developmental challenges. Leadership, ownership and governance, supporting legal mandates and regulations, as well as adherence to mandates, and enforcement of regulations are critical components of effective surveillance. In many countries, NPHIs play a significant role in integrated disease surveillance.

[Evaluation of various public health infectious diseases surveillance systems based on a generic protocol]. / Évaluation de différents systèmes de surveillance (en maladies infectieuses) à partir d'un protocole générique.

BACKGROUND: InVS, the French Institute of Public Health, coordinates and conducts several public health surveillance systems. In 2009, an evaluation protocol aiming at evaluating different surveillance systems was developed according to the international recommendations. METHODS: Between 2009 and 2013, four evaluations in the field of infectious diseases were performed by panels of independent public health experts using a generic protocol. RESULTS-CONCLUSION: This article presents the protocol, the mains results of each of the four evaluations and their impact on the Institute's surveillance strategy. It also addresses the strengths and the limitations of this standardized approach.

Factors associated with hospital mortality in community-acquired legionellosis in France.

The aims of this study were to describe the clinical, biological and radiological features of community-acquired (CA) Legionnaires' disease (LD) and identify the predictors of mortality in hospitalised patients. Demographic data, risk factors, clinical and biological features, medical management, complications, and outcome from 540 hospitalised patients with confirmed CA LD were prospectively recorded. 8.1% of patients (44 out of 540) died. The predictors of survival after Kaplan-Meier analysis were male sex (p = 0.01), age <60 yrs (p = 0.02), general symptoms (p = 0.006), intensive care unit (ICU) stay (p<0.001), and class II-III Pneumonia Severity Index score (p = 0.004). Six predictors of death were identified by multivariate analysis: age (per 10-yr increment) (relative hazard (RH) 1.50, 95% CI 1.21-1.87), female sex (RH 2.00, 95% CI 1.08-3.69), ICU admission (RH 3.31, 95% CI 1.67-6.56), renal failure (RH 2.73, 95% CI 1.42-5.27), corticosteroid therapy (RH 2.54, 95% CI 1.04-6.20) and C-reactive protein (CRP) >500 mg · L(-1) (RH 2.14, 95% CI 1.02-4.48). Appropriate antibiotic therapy was prescribed for 70.8% (292 out of 412) of patients after admission and for 99.8% (537 out of 538) of patients after diagnosis confirmation. In conclusion, female sex, age, ICU stay, renal failure, corticosteroid treatment and increased level of CRP are significant risk factors for mortality in CA LD.

Deferral from donating blood of men who have sex with men: impact on the risk of HIV transmission by transfusion in France.

BACKGROUND: In France, men who have sex with men (MSM) are permanently excluded from blood donation. This policy is felt to be discriminatory by MSM activists. Furthermore, the policy is not fully respected because some MSM do not report their sexual behaviour before donating. METHODS: We estimated the fraction of the current risk of HIV attributed to MSM. We then constructed a model based on data obtained from behavioural and epidemiological surveys to assess the impact of a new strategy in which MSM would only be deferred if they report more than one sexual partner in the last 12 months. RESULTS: Thirty-one HIV seroconversions occurred among repeat donors between 2006 and 2008, giving a risk of one in 2 440 000 donations. Fifteen of these seroconversions (48%) were MSM. If all MSM had abstained from donating blood, the risk would have been 1 in 4 700 000 donations, half the current risk. The new strategy would result in an overall HIV risk of between 1 in 3 000 000 (close to the current risk) to 1 in 650 000 donations (3·7 times higher than the current risk). CONCLUSIONS: Changing the current MSM deferral policy may increase the risk of transfusion-transmission of HIV. However, this does not take into account a possible better compliance with MSM with a less stringent policy that would be perceived as more equitable. Conversely, relaxing the policy could encourage some MSM to seek an HIV test in blood centres. Thus, further qualitative study is needed to assess possible changes in compliance linked to a new policy.

["Veille sanitaire": tools, functions, process of healthcare monitoring in France]. / Veille sanitaire : outils, fonctions, processus.

In France, the term "veille sanitaire" is widely used to designate healthcare monitoring. It contains, however, a set of concepts that are not shared equally by the entire scientific community. The same is true for activities that are part of it, even if some (surveillance for example) are already well defined. Concepts such as "observation", "vigilance", "alert" for example are not always clear. Furthermore, the use of these words in everyday language maintains this ambiguity. Thus, it seemed necessary to recall these definitions as already used in the literature or legislation texts and to make alternative suggestions. This formalization cannot be carried out without thinking about the structure of "veille sanitaire" and its components. Proposals are provided bringing out concepts of formated "veille" (monitoring) and non-formatted "veille" (monitoring). Definitions, functions, (methods and tools, processes) of these two components are outlined here as well as the cooperative relationship they sustain. The authors have attempted to provide the scientific community with a reference framework useful for exchanging information to promote research and methodological development dedicated to this public health application of epidemiology.

The impact of the prevention programme of hepatitis C over more than a decade: the French experience.

To assess the impact of the French national hepatitis C prevention programme initiated in 1999, we analysed trends in hepatitis C virus (HCV) prevalence, testing and characteristics of HCV-infected patient at first referral from 1994 to 2006. We used four data sources: Two national population-based sero-prevalence surveys carried out in 1994 and 2004; two surveillance networks, one based on public and private laboratories throughout France and the other on hepatology reference centres, which aim to monitor, respectively, trends of anti-HCV screening and of epidemiological-clinical characteristics of HCV patients at first referral. Between 1994 and 2004, the anti-HCV prevalence for adults aged 20-59 years decreased from 1.05 (95% confidence interval 0.75-1.34) to 0.71 (0.52-0.97). During the same period, those anti-HCV positive with detectable HCV RNA decreased from 81 to 57%, whereas, the proportion of anti-HCV positive persons aware of their status evolved from 24 to 56%. Anti-HCV screening activity increased by 45% from 2000 to 2005, but decreased in 2006 (-10%), while HCV positivity among those tested decreased from 4.3 to 2.9%. The proportion of cirrhosis at first referral remains around 10% between 2001 and 2006, with many patients with excessive alcohol consumption (34.7% among males) or viral co-infections (HIV seropositivity for 5.2% patients). Our analysis indicates that the national programme had a positive impact at the population level through improved prevention, screening and management. There is still a need to identify timely those at risk for earlier interventions, to assess co-morbidities better and for a multidisciplinary approach to HCV management.

International travels and fever screening during epidemics: a literature review on the effectiveness and potential use of non-contact infrared thermometers.

Several countries plan to introduce non-contact infrared thermometers (NCIT) at international airports in order to detect febrile passengers, thus to delay the introduction of a novel influenza strain. We reviewed the existing studies on fever screening by NCIT to estimate their efficacy under the hypothesis of pandemic influenza. Three Severe Acute Respiratory Syndrome (SARS) or dengue fever interventions in airports were excluded because of insufficient information. Six fever screening studies in other gathering areas, mainly hospitals, were included (N= 176 to 72,327 persons; fever prevalence= 1.2% to 16.9%). Sensitivity varied from 4.0% to 89.6%, specificity from 75.4% to 99.6%, positive predictive value (PPV) from 0.9% to 76.0% and negative predictive value (NPV) from 86.1% to 99.7%. When we fixed fever prevalence at 1% in all studies to allow comparisons, the derived PPV varied from 3.5% to 65.4% and NPV was >or=99%. The low PPV suggests limited efficacy of NCIT to detect symptomatic passengers at the early stages of a pandemic influenza, when fever prevalence among passengers would be =or<1%. External factors can also impair the screening strategy: passengers can hide their symptoms or cross borders before symptoms occur. These limits should be considered when setting up border control measures to delay the pandemic progression.

A preliminary estimation of the reproduction ratio for new influenza A(H1N1) from the outbreak in Mexico, March-April 2009.

As of 12 May 2009, 5,251 cases of the new influenza A(H1N1) have been officially reported to the World Health Organization (WHO) from 30 countries, with most of the identified cases exported from Mexico where a local epidemic has been going on for the last two months. Sustained human-to-human transmission is necessary to trigger influenza pandemic and estimating the reproduction ratio (average number of secondary cases per primary case) is necessary for forecasting the spread of infection. We use two methods to estimate the reproduction ratio from the epidemic curve in Mexico using three plausible generation intervals (the time between primary and secondary case infection). As expected, the reproduction ratio estimates were highly sensitive to assumptions regarding the generation interval, which remains to be estimated for the current epidemic. Here, we suggest that the reproduction ratio was less than 2.2 - 3.1 in Mexico, depending on the generation interval. Monitoring and updating the reproduction ratio estimate as the epidemic spreads outside Mexico into different settings should remain a priority for assessing the situation and helping to plan public health interventions.

Toxoplasmosis among pregnant women in France: risk factors and change of prevalence between 1995 and 2003.

BACKGROUND: Congenital toxoplasmosis may affect any organ, produce severe complications such as hydrocephalus and lead to ocular lesions which can appear late after birth. Fetal outcome can be fatal. During pregnancy, the mother can become infected, particularly by eating undercooked meat or poorly washed raw fruits and vegetables. In France, prevention of congenital toxoplasmosis is based on serial serology tests, performed repeatedly until delivery for pregnant women who remain negative then at the first prenatal visit. METHODS: We used toxoplasmosis serology data collected during national perinatal surveys conducted in 1995 and 2003 to estimate toxoplasmosis prevalence, assess risk factors and ascertain time trends in prevalence. In each survey, socioeconomic variables as well as the serological status for toxoplasmosis were collected for all pregnant women who had terminated a pregnancy during a given week period. RESULTS: In 2003, 15,108 pregnant women were included; the prevalence of Toxoplasma infection was 43.8% (95% CI: 43.0-44.6). Prevalence increased with age and was greater for those who lived in the Southwest of France, the greater Paris area and in overseas districts. In 2003, as in 1995, prevalence increased with education level, occupational status of the household and number of pregnancies. Prevalence decreased 19% between 1995 and 2003. The decrease was significantly greater for pregnant women aged less than 30 years than for those aged more or equal to 30 years. CONCLUSION: Although it decreased over time, toxoplasmosis prevalence remained higher in France than in other European countries. With more than one out of two women in France susceptible of having Toxoplasma infection, it is important to promote preventive measures to avoid infection during pregnancy.

Reported cases of congenital syphilis in the French national hospital database.

In France, the resurgence of syphilis infection since the beginning of the 2000s, with cases reported among women of reproductive age is a reason for concern considering the possible occurrence of congenital syphilis (CS). Using the French national private and public hospital database, we investigated the number of children with a diagnosis of CS born in France in 2004. Six cases less than one year old were identified as probable CS in the database. Two of these cases were adopted children from outside Europe, whereas the other four were born in France. The mothers of these last four infants tested positive for syphilis during the third trimester of pregnancy, two of them during premature delivery. Three of the four mothers were born abroad. Specific socio-cultural conditions may have been responsible for a lack of antenatal care responsible for the disease. Since CS is a preventable disease and the treatment of syphilis infection is cost-effective, we conclude that surveillance of CS cases and assessment of syphilis screening practises during pregnancy should be performed to prevent the occurrence of CS cases in France.

Principles and uses of HIV incidence estimation from recent infection testing--a review.

Since the 1990s, the development of laboratory-based methods has allowed to estimate incidence of human immunodeficiency virus (HIV) infections on single samples. The tests aim to differentiate recent from established HIV infection. Incidence estimates are obtained by using the relationship between prevalence, incidence and duration of recent infection. We describe the principle of the methods and typical uses of these tests to characterise recent infection and derive incidence. We discuss the challenges in interpreting estimates and we consider the implications for surveillance systems. Overall, these methods can add remarkable value to surveillance systems based on prevalence surveys as well as HIV case reporting.The assumptions that must be fulfilled to correctly interpret the estimates are mostly similar to those required in prevalence measurement. However, further research on the specific aspect of window period estimation is needed in order to generalise these methods in various population settings.

[Airborne transmission of infectious agents]. / La transmission aérienne des agents infectieux.

Airborne transmission is one of the different ways infectious diseases spread. Airborne transmission often has an environmental source, as for legionellosis. It can also have an infectious human source. For a given infectious agent, the mode of transmission can be multiple. This is the case for influenza that can be spread by airborne transmission but also directly through respiratory secretion and indirectly through the contaminated environment. If airborne transmission may occur from person to person, it is most often a transmission from or through the environment.

[Principles of an outbreak investigation in public health practice]. / Les principes de l'investigation d'une épidémie dans une finalité de santé publique.

An outbreak (or epidemic) is a higher number of cases of a given disease in a given population and time interval. A timely investigation has for aim to identify the source and vehicle of the outbreak and provides unique opportunities to better understand its occurrence and the role of contributing risk factors to implement the most appropriate measures to control it and prevent further recurrences. The investigation of an outbreak is based on a multidisciplinary approach (clinical, epidemiological, environmental, and microbiological) with a descriptive and analytical (hypothesis testing) phase. In this article, we describe the methodological approach of a field outbreak investigation illustrated by examples taken from our experience. The investigation includes the following steps: establishing the existence of the outbreak; defining the disease; finding cases; describing cases by time, place, and person characteristics; establishing a hypothesis related to the mode of occurrence; testing the hypotheses; conducting an environmental investigation; conducting a microbiological investigation; controlling the outbreak, preventing further occurrences, and writing an investigation report to share experience with the public health and scientific community. The investigation of an outbreak is an evolving process: information gathered or conclusions made at a given stage must be fully used for following steps. The social, institutional, and political background associated with outbreaks usually makes their investigation complex and should be taken into account. The earlier the outbreak is detected and investigated in close relation with public health authorities, the greater will be the potential preventive impact of control measures.

A large multi-pathogen waterborne community outbreak linked to faecal contamination of a groundwater system, France, 2000.

A large waterborne outbreak of infection that occurred during August 2000 in a local community in France was investigated initially via a rapid survey of visits to local physicians. A retrospective cohort study was then conducted on a random cluster sample of residents. Of 709 residents interviewed, 202 (28.5%) were definite cases (at least three liquid stools/day or vomiting) and 62 (8.7%) were probable cases (less than three liquid stools/day or abdominal pain). Those who had drunk tap water had a three-fold increased risk for illness (95% CI 2.4-4.0). The risk increased with the amount of water consumed (chi-square trend: p < 0.0001). Bacteriological analyses of stools were performed for 35 patients and virological analyses for 24 patients. Campylobacter coli, group A rotavirus and norovirus were detected in 31.5%, 71.0% and 21% of samples, respectively. An extensive environmental investigation concluded that a groundwater source to this community had probably been contaminated by agricultural run-off, and a failure in the chlorination system was identified. This is the first documented waterborne outbreak of infection involving human C. coli infections. A better understanding of the factors influencing campylobacter transmission between hosts is required.

Absence of infection in asymptomatic contacts of index SARS case in France.

The first case of severe acute respiratory syndrome (SARS) in France was diagnosed in March 2003. We conducted a serological survey to assess whether or not asymptomatic persons who had been in contact with this patient during his infectious stage had been infected. They were interviewed and asked to provide a blood sample for SARS coronavirus immunoglobulin G antibody testing. Despite the likely high infectivity of the SARS patient, no asymptomatic SARS infection was found in any of the 37 contacts included. These findings support a SARS case definition that is essentially based on clinical and epidemiological assessment, should SARS re-emerge.

Absence of infection in asymptomatic contacts of index SARS case in France.

The first case of severe acute respiratory syndrome (SARS) in France was diagnosed in March 2003. We conducted a serological survey to assess whether or not asymptomatic persons who had been in contact with this patient during his infectious stage had been infected. They were interviewed and asked to provide a blood sample for SARS coronavirus immunoglobulin G antibody testing. Despite the likely high infectivity of the SARS patient, no asymptomatic SARS infection was found in any of the 37 contacts included. These findings support a SARS case definition that is essentially based on clinical and epidemiological assessment, should SARS re-emerge.

Rectal lymphogranuloma venereum surveillance in France 2004-2005.

Lymphogranuloma venereum (LGV) is a sexually transmitted infection (STI) caused by Chlamydia trachomatis strains belonging to the L1, L2 or L3 genotype. An alert about an outbreak of LGV among MSM in the Netherlands was published in January 2004. The first cases of rectal LGV in France were retrospectively diagnosed in March 2004 and sentinel surveillance for LGV was implemented in April 2004. Most of the participating centres were located in the cities of Paris and Bordeaux. Only confirmed rectal LGV cases were included in the surveillance. Rectal specimens from men that were found to be positive for C trachomatis by PCR were sent to the National Reference Centre for Chlamydia infection for genotyping. Simple epidemiological data provided by clinicians and genotyping results were sent to the Institut de Veille Sanitaire (InVS) where data were anonymously recorded. A total of 328 C. trachomatis rectal strains isolated in men were genotyped by the end of December 2005. Of these, 244 (74%) were LGV strains belonging to the L2 genotype. No L1 or L3 C. trachomatis genotype was found. Diagnosis was made retrospectively for 46 cases. The median age of patients with LGV was 39 years. HIV status was known for 96 patients: 82/96 (85%) were HIV-infected. Most LGV cases were diagnosed in the Paris area (92%). Among the remaining 26% C. trachomatis strains, genotypes Da and G were the most frequent. As with syphilis in recent years, the emergence of LGV in Europe is mainly affecting HIV-infected MSM. The screening and treatment of STIs should be included in the clinical follow-up of all HIV-infected MSM.

Rectal lymphogranuloma venereum surveillance in France 2004-2005.

Lymphogranuloma venereum (LGV) is a sexually transmitted infection (STI) caused by Chlamydia trachomatis strains belonging to the L1, L2 or L3 genotype. An alert about an outbreak of LGV among MSM in the Netherlands was published in January 2004. The first cases of rectal LGV in France were retrospectively diagnosed in March 2004 and sentinel surveillance for LGV was implemented in April 2004. Most of the participating centres were located in the cities of Paris and Bordeaux. Only confirmed rectal LGV cases were included in the surveillance. Rectal specimens from men that were found to be positive for C trachomatis by PCR were sent to the National Reference Centre for Chlamydia infection for genotyping. Simple epidemiological data provided by clinicians and genotyping results were sent to the Institut de Veille Sanitaire (InVS) where data were anonymously recorded. A total of 328 C. trachomatis rectal strains isolated in men were genotyped by the end of December 2005. Of these, 244 (74%) were LGV strains belonging to the L2 genotype. No L1 or L3 C. trachomatis genotype was found. Diagnosis was made retrospectively for 46 cases. The median age of patients with LGV was 39 years. HIV status was known for 96 patients: 82/96 (85%) were HIV-infected. Most LGV cases were diagnosed in the Paris area (92%). Among the remaining 26% C. trachomatis strains, genotypes Da and G were the most frequent. As with syphilis in recent years, the emergence of LGV in Europe is mainly affecting HIV-infected MSM. The screening and treatment of STIs should be included in the clinical follow-up of all HIV-infected MSM.

[Limited impact of the harm-reduction policy on HCV among drug-users. The ANRS-Coquelicot survey example]. / L'impact limité de la réduction des risques sur la transmission du VHC chez les usagers de drogues. L'exemple de l'étude ANRS-Coquelicot.

BACKGROUND: In France, a harm-reduction policy was implemented in the late 1980s with the aim of reducing the prevalence of HIV and hepatitis C virus infection among drug users. The ANRS-Coquelicot survey was designed to measure the prevalence of HIV and HCV infection among drug users, and to examine determinants of at-risk behaviors. METHODS: In 2002, information was collected from 166 drug users recruited in all types of services specializing in drug use and harm reduction in Marseille, France. Self-reported HIV and HCV serostatus was compared with the results of serological tests done on capillary blood collected on filter paper. RESULTS: The self-reported and biologically documented prevalence rates of HIV infection were identical (22 %). In contrast, the self-reported prevalence of HCV infection was 52 %, while the biologically documented prevalence was 73 %. Overall, 30 % of HCV-infected drug users were unaware of their status. Forty-four per cent of drug users under 30 years of age were HCV-seropositive, suggesting that they had been infected early during drug use. CONCLUSION: The harm-reduction policy seems to have had a marked impact on HIV transmission among drug users, but a much more limited impact on HCV transmission.

[Modes of hepatitis C virus transmission: methodological approaches]. / Les modes de transmission du virus de l'hépatite C : approches méthodologiques.

Since the mid-1990s, hepatitis C virus (HCV) transmission through blood transfusion has become very rare in western countries. Better understanding of the current modes of transmission is needed. However, risk factors have been mainly estimated on prevalent HCV infections. In this paper we describe the methods of the main case-control studies and their contribution to the knowledge on modes of HCV transmission. We also report the results of a case-control study of incident HCV infections recently carried out in France which confirms the continuing major role of IV drug use and suggests that transmission related to invasive care remained a potential source of new HCV infection between 1995 and 2001.