Individual and contextual risk factors for chikungunya virus infection: the SEROCHIK cross-sectional population-based study.

The purpose of the study was to weigh the community burden of chikungunya determinants on Reunion island. Risk factors were investigated within a subset of 2101 adult persons from a population-based cross-sectional serosurvey, using Poisson regression models for dichotomous outcomes. Design-based risk ratios and population attributable fractions (PAF) were generated distinguishing individual and contextual (i.e. that affect individuals collectively) determinants. The disease burden attributable to contextual determinants was twice that of individual determinants (overall PAF value 89.5% vs. 44.1%). In a model regrouping both categories of determinants, the independent risk factors were by decreasing PAF values: an interaction term between the reporting of a chikungunya history in the neighbourhood and individual house (PAF 45.9%), a maximal temperature of the month preceding the infection higher than 28.5 °C (PAF 25.7%), a socio-economically disadvantaged neighbourhood (PAF 19.0%), altitude of dwelling (PAF 13.1%), cumulated rainfalls of the month preceding the infection higher than 65 mm (PAF 12.6%), occupational inactivity (PAF 11.6%), poor knowledge on chikungunya transmission (PAF 7.3%) and obesity/overweight (PAF 5.2%). Taken together, these covariates and their underlying causative factors uncovered 80.8% of chikungunya at population level. Our findings lend support to a major role of contextual risk factors in chikungunya virus outbreaks.

Rheumatism and chronic fatigue, the two facets of post-chikungunya disease: the TELECHIK cohort study on Reunion island.

Prolonged fatigue is increasingly reported among chikungunya virus (CHIKV)-infected populations. We investigated the relationships between CHIKV exposure, long-lasting rheumatic musculoskeletal pain (LRMSP) and chronic fatigue. 1094 participants (512 CHIKV seropositive and 582 seronegative) of the TELECHIK population-based cohort were analysed considering the duration of the manifestations throughout an average 2-year follow-up. Weighted prevalence rates and prevalence ratios for LRMSP, idiopathic chronic fatigue (ICF), and chronic fatigue syndrome (CFS)-like illness, both latter syndromes adapted from Centers for Disease Control (CDC)-1994/Fukuda criteria, were compared. Population attributable fractions (PAF) were estimated to assess the contribution of CHIKV infection to each of the three phenotypes. Among 362 adult subjects who had reported either rheumatic pain or fatigue at the onset of the infection, weighted prevalence rates of LRMSP, ICF and CFS-like illness were respectively of 32.9%, 38.7% and 23.9%, and of 8.7%, 8.5% and 7.4% among initially asymptomatic peers (P < 0.01, respectively). Each of the three outcomes was highly attributable to chikungunya (PAF of 43.2%, 36.2% and 41.0%, respectively). In the sub-cohort of CHIKV-infected subjects, LRMSP, ICF and CFS-like illness, which overlapped in 70%, accounted for 53% of the chronic manifestations. In addition to rheumatic disease, chronic fatigue could be considered in caring for patients with chronic chikungunya disease.

Helicobacter pylori resistance to clarithromycin in Reunion Island.

OBJECTIVE: The increasing resistance of Helicobacter pylori to clarithromycin led to developing new eradication treatment regimens. The objective of our observational study was to determine the proportion of H. pylori strains resistant to clarithromycin in infected patients in Reunion Island and to suggest a first-line treatment in agreement with the local ecology. PATIENTS AND METHODS: We included 200 patients who underwent esophagogastroduodenoscopy at the University Hospital of Saint-Pierre from February to July 2014. H. pylori was isolated from 73 patients. RESULTS: A wild-type susceptibility profile to clarithromycin was observed in 64 isolates (87.7%) and nine isolates (12.3%) had a resistant mutation profile. CONCLUSION: With a proportion of resistant strains below the critical threshold of 15%, physicians in Reunion Island may continue to prescribe the usual treatment regimen as a first-line option (clarithromycin, amoxicillin, and proton pump inhibitor for 14 days).

Investigation of a leptospirosis outbreak in triathlon participants, Réunion Island, 2013.

We report herein the investigation of a leptospirosis outbreak occurring in triathlon competitors on Réunion Island, Indian Ocean. All participants were contacted by phone or email and answered a questionnaire. Detection and molecular characterization of pathogenic Leptospira was conducted in inpatients and in rodents trapped at the vicinity of the event. Of the 160 athletes competing, 101 (63·1%) agreed to participate in the study. Leptospirosis was biologically confirmed for 9/10 suspected cases either by real-time PCR or serological tests (MAT or ELISA). The total attack rate, children's attack rate, swimmers' attack rate, and the attack rate in adult swimmers were respectively estimated at 8·1% [95% confidence interval (CI) 4·3-14·7], 0%, 12·7% (95% CI 6·8-22·4) and 23·1% (95% CI 12·6-33·8). Leptospirosis cases reported significantly more wounds [risk ratio (RR) 4·5, 95% CI 1·6-13], wore complete neoprene suits less often (RR 4·3, 95% CI 1·3-14·5) and were most frequently unlicensed (RR 6·6, 95% CI 2·9-14·8). The epidemiological investigation supported that some measures such as the use of neoprene suits proved efficient in protecting swimmers against infection. PCR detection in rats revealed high Leptospira infection rates. Partial sequencing of the 16S gene and serology on both human and animal samples strongly suggests that rats were the main contaminators and were likely at the origin of the infection in humans.

Taenia solium porcine cysticercosis in Madagascar: Comparison of immuno-diagnostic techniques and estimation of the prevalence in pork carcasses traded in Antananarivo city.

Taenia solium cysticercosis was reported in official veterinary and medical statistics to be highly prevalent in pigs and humans in Madagascar, but few estimates are available for pigs. This study aimed to estimate the seroprevalence of porcine cysticercosis among pigs slaughtered in Antananarivo abattoirs. Firstly, the diagnostic performance of two antigen-ELISA techniques (B158B60 Ag-ELISA and HP10 Ag-ELISA) and an immunoblotting method were compared with meat inspection procedures on a sample of pigs suspected to be infected with (group 1; n=250) or free of (group 2; n=250) T. solium based on direct veterinary inspection in Madagascar. Sensitivity and specificity of the antigen ELISAs were then estimated using a Bayesian approach for detection of porcine cysticercosis in the absence of a gold standard. Then, a third set of pig sera (group 3, n=250) was randomly collected in Antananarivo slaughterhouses and tested to estimate the overall prevalence of T. solium contamination in pork meat traded in Antananarivo. The antigen ELISAs showed a high sensitivity (>84%), but the B158B60 Ag-ELISA appeared to be more specific than the HP10 Ag-ELISA (model 1: 95% vs 74%; model 2: 87% vs 71%). The overall prevalence of porcine cysticercosis in Antananarivo slaughterhouses was estimated at 2.3% (95% credibility interval [95%CrI]: 0.09-9.1%) to 2.6% (95%CrI: 0.1-10.3%) depending on the model and priors used. Since the sample used in this study is not representative of the national pig population, village-based surveys and longitudinal monitoring at slaughter are needed to better estimate the overall prevalence, geographical patterns and main risk factors for T. solium contamination, in order to improve control policies.

Influenza season in Réunion dominated by influenza B virus circulation associated with numerous cases of severe disease, France, 2014.

The 2014 seasonal influenza in Réunion, a French overseas territory in the southern hemisphere, was dominated by influenza B. Resulting morbidity impacted public health. Relative to the total number of all-cause consultations over the whole season, the rate of acute respiratory infection (ARI) consultations was 6.5%. Severe disease occurred in 32 laboratory-confirmed influenza cases (31.7 per 100,000 ARI consultations), 16 with influenza B. The observed disease dynamics could present a potential scenario for the next European influenza season.

Endemicity of leptospirosis in domestic and wild animal species from Reunion Island (Indian Ocean).

Leptospirosis is the major infectious disease on Reunion Island but little is known about the animal reservoir. We conducted a wide-ranging survey that included samples from 574 animals belonging to 12 species. The seroprevalence and prevalence of renal carriage varied greatly depending on the species, with the highest seroprevalence (79·5%) found in Norway rats, and the lowest (13·2%) in tenrecs. The renal carriage rate ranged from 84·6% in mice to 0% in tenrecs. Our results suggest that rodents are the most important reservoirs of leptospirosis on Reunion Island. The epidemiological role that animals play in human infection is discussed. For the first time, we quantified the renal concentration of leptospires in ten naturally infected mammals. The history of Reunion Island colonization probably explains why the circulating Leptospira serogroups were similar to those found in Europe. Our study provides evidence that will help implement preventive measures against this zoonosis.

Influence of risk factors on renal leptospiral load in naturally infected wild black rats.

In 2009, a survey was conducted in Reunion Island to determine the renal leptospiral load in black rats trapped in the field. The concentration of leptospires in kidney tissue was calculated using qPCR. Our results showed high inter-individual variations of renal bacterial load in naturally infected black rats (mean=8.27 ± 4.72 log-genome copies per mg kidney tissue). The objective of this study was to model the renal leptospiral load in 50 naturally infected black rats as a function of sex, age, and weight. Statistical analysis by sex showed that, in naturally infected males, the renal leptospiral load was correlated with weight (p-value=0.032). Moreover, our model showed that weight and sex were significant explanatory variables for the renal leptospiral load in naturally infected young black rats (R(2)=0.953). Laboratory experimentation could not replicate naturally acquired infection, but field studies also present many limitations. Our study is the first attempt to explain individual variations in the renal leptospiral load in naturally infected reservoir animals but further research is needed.

Reunion, a sentinel territory for influenza surveillance in Europe.

In Réunion, a French overseas territory located in the southern hemisphere, increase in influenza activity is generally observed several months earlier than in Europe. Influenza activity is monitored in Réunion through a multi-source surveillance system including sentinel practitioners network, hospital emergency department, laboratory and mortality. Since 2009, three successive influenza epidemics occurred on the island. The largest was observed in 2009 while epidemics in 2010 and 2011 were much weaker. In terms of circulating strains, B viruses were predominant at the beginning of the 2009 epidemic but they were completely evicted once A(H1N1)pdm09 circulation started. In 2010, A(H1N1)pdm09 virus was predominant again, but a constant co-circulation of B viruses was observed. In 2011, A(H3N2) virus circulated. The same viruses were identified a few months later in mainland France in the respective seasons. Since 2009, virus circulation, epidemiological trends and health impact of influenza have been similar to those observed in Europe. Influenza surveillance in Réunion may therefore give reliable early information which should be considered apart from the surveillance in mainland France. Then, it might be even a more suitable predictor for Europe than other temperate southern hemisphere countries.

[Perceived morbidity and community burden of chikungunya in La Reunion]. / Morbidité perçue et impact communautaire du chikungunya a l'île de La Réunion: enquête de cohorte en population TELECHIK.

BACKGROUND: Persistence of clinical manifestations, especially polyarthralgia and fatigue, is a characteristic feature of chikungunya virus (CHIK-v) infection. The purpose of this study was to measure the impact of prolonged or late-onset manifestations of CHIK-v infection on the self-perceived health of people on Reunion Island. METHODS: This retrospective cohort survey, dubbed TELECHIK survey, was conducted eighteen months after the end of the chikungunya outbreak on a representative random sample from the SEROCHIK population-based survey conducted on Reunion Island. A total of 1094 subjects whose CHIK-v specific IgG antibody status had been documented were interviewed about current symptoms. RESULTS: Analysis of data showed 45% of CHIK+ vs 14% of CHIK- subjects reporting musculoskeletal pain (P < 0.001), 56% vs. 44% reporting fatigue (P = 0.003), 77% vs. 53% reporting cerebral manifestations (P < 0.001), 51% vs. 34% reporting sensorineural impairments (P < 0.001), 18% vs. 13% reporting digestive complaints (P = 0.06), and 38% vs. 32% reporting skin involvement (P = 0.13). The mean delay between infection and interview was two years (range, 15-34 months). Analysis of data after correction for age, gender, body mass index and comorbidity indicated that rheumatic pain, fatigue, cerebral manifestations and sensorineural impairments were more likely in CHIK+ than CHIK- subjects but the likelihood of digestive and skin manifestations was the same. CONCLUSION: With a mean delay of two years after infection, 45% to 77% of CHIK+ subjects reported prolonged or late-onset symptoms attributable to CHIK-v. These results indicate that persistent manifestations of chikungunya infection have a heavy impact on rheumatologic, neurological and sensorineural health.

Re-emergence of dengue in Reunion, France, January to April 2012.

Since January 2012, 20 autochthonous cases of dengue virus (DENV) infection have been identified in Réunion. The first cases were detected on the western coast, but the two co-circulating viruses (DENV-1 and DENV-3) seemed to have spread later to different cities of the island. There is a non-negligible risk of increase in viral transmission over the following weeks, so health professionals and public health authorities in Réunion are preparing to face a potential epidemic.

Patients' impatience is an independent determinant of poor diabetes control.

AIMS: Some individuals have a preference for the present rather than for the future. We investigated the impact of this impatient relationship to temporality on adherence to medication and HbA(1c) level in type 2 diabetic patients. METHODS: An observational, cross-sectional monocenter study in 90 patients consulting for a health check-up at a Center for Preventive Medicine. We used questionnaires assessing adherence to medication, impatience in a fictive monetary choice (preferring a smaller amount now to a higher amount later) and in daily life situations, foresight, locus of control, and social deprivation. RESULTS: Impatience in the monetary choice was associated with non-adherence to medication (P=0.005). In a multivariate logistic regression model, the risk of observing HbA(1c)≥7% was associated with a long duration of diabetes (OR 5.2, CI 1.7-15.7, P=0.003), monetary impatience (OR=5.1, CI 1.7-15.4, P=0.004), a high "chance and other people" score of the locus of control (OR=5.1, CI 1.7-15.7, P=0.004), a suboptimal foresight (OR 3.9, CI 1.2-12.0, P=0.02). A decision-tree analysis (CHAID algorithm) showed that in this cohort of 90 patients, the 11 people who were adherent to medication, patient in the monetary scenario, had optimal foresight, and gave importance neither to chance nor to other people, had all HbA(1c) below 7%. CONCLUSION: An impatient relationship to temporality was found associated with non-adherence to medication and uncontrolled HbA(1c) in type 2 diabetic patients. Treatment strategies for chronic diseases should be tailored according to this novel dimension of psychology.

[Outbreak of influenza pandemic virus A(H1N1) 2009 infections in the Emergency Department, Saint-Pierre, Réunion Island, July-September 2009]. / Caractéristiques des syndromes grippaux pris en charge aux urgences du centre hospitalier régional de Saint-Pierre, île de la Réunion, au cours de l'épidémie à virus pandémique A(H1N1) 2009 (juillet-septembre 2009).

A new H1N1 virus originating from swine recently emerged as the first influenza pandemic of the 21st century. On July 3, 2009, this new influenza A(H1N1) virus (S-OIV) of swine origins was identified in Réunion Island, a French overseas department located in the southern hemisphere. The present study describes the characteristics of the epidemic from July 3 to September 30, 2009. Among the 479 patients included in our study (236 males, 37.3 ± 19.0 years), 255 (53.2%) were reported to have comorbidities or risk factors (RF) for complications. Complications occurred in 160 patients (33.4%). The most common complications were bronchial hyperreactivity (52.7%), pneumonia (32.1%), and decompensation caused by comorbidity (17.9%). 111 patients (23.2%) required hospitalization. Patients aged 65 and over, accounted for 11.9% of all patients, 32.4% of hospitalized patients and 22.5% of complicated S-OIV infections. Regardless of age, comorbidity and/or RF were reported in 80.0% of complicated S-OIV infections and 91.0% of hospitalized patients. Recommendations for surveillance, prevention and policy for persons with RF, particularly respiratory disease, are justified. However, the absence of risk factors did not prevent the occurrence of complications, present in 14.3% of the cases.

Animal leptospirosis in small tropical areas.

Leptospirosis is the most widespread zoonosis in the world. Humans become infected through contact with the urine of carrier animals, directly or via contaminated environments. This review reports available data on animal leptospirosis in ten tropical islands: Barbados, Martinique, Guadeloupe, Grenada, Trinidad, New Caledonia, Hawaii, French Polynesia, La Réunion and Mayotte. Leptospirosis is endemic in these insular wild and domestic fauna. Each island presents a specific panel of circulating serovars, closely linked with animal and environmental biodiversity, making it epidemiologically different from the mainland. Rats, mongooses and mice are proven major renal carriers of leptospires in these areas but dogs also constitute a significant potential reservoir. In some islands seroprevalence of leptospirosis in animals evolves with time, inducing changes in the epidemiology of the human disease. Consequently more investigations on animal leptospirosis in these ecosystems and use of molecular tools are essential for prevention and control of the human disease.

[Evolution of resistance to antibiotics from 1997 to 2005 in the Reunion Island]. / Évolution de la résistance aux antibiotiques de 1997 à 2005 à la Réunion.

OBJECTIVE: The groupe hospitalier Sud Reunion (GHSR) is a 1130-bed hospital center, located on the Reunion Island, (Indian Ocean). We studied the profiles of antibiotic resistance in 2005, and compared those with previous data collected in 1997-1998, and with Metropolitan France and European data. MATERIAL AND METHODOLOGY: All bacteriological strains isolated from diagnostic samples in 2005 were analyzed according to CA-SFM recommendations. RESULTS: Since 1997, the rates of resistance to enterobacteria (betalactam, aminoside, quinolone, trimethoprim-sulfamethoxazole), Pseudomonas aeruginosa (ticarcillin, amikacin, ciprofloxacin, fosfomycin), Acinetobacter baumanii (amikacin) has decreased significantly. The rate of methicillin-resistant Staphylococcus aureus (1997: 3.6 %, 2005: 13.4 %) has increased but less than in Metropolitan France. The rate of Streptococcuspneumonia with decreased susceptibility to penicillin has increased (1997: 25.5 %, 2005: 42.9 %), as for Haemophilusinfluenzae which present an important increase of betalactam resistance (1997: 15.5 %, 2005: 37.8 %). CONCLUSION: By comparing our data to 1997 and Metropolitan French data, it seems that the GHSR has managed to protect its hospital-based microbial ecology. However, community germs showed increasing resistance, probably because of an increasing antibiotic pressure, but with resistance rates often inferior to Metropolitan French ones.

Pseudomonas aeruginosa outbreak linked to mineral water bottles in a neonatal intensive care unit: fast typing by use of high-resolution melting analysis of a variable-number tandem-repeat locus.

Pseudomonas aeruginosa is an opportunistic pathogen that causes nosocomial infections in intensive care units. Determining a system of typing that is discriminatory is essential for epidemiological surveillance of P. aeruginosa. We developed a method for the typing of Pseudomonas aeruginosa, namely, multiple-locus variable-number tandem-repeat (VNTR) typing with high-resolution melting analysis (HRMA). The technology was used to genotype a collection of 43 environmental and clinical strains isolated during an outbreak in a neonatal intensive care unit (NICU) that we report. Nineteen strains isolated in other departments or outside the hospital were also tested. The genetic diversity of this collection was determined using VNTR-HRMA, with amplified fragment length polymorphism (AFLP) analysis as a reference. Twenty-five and 28 genotypes were identified, respectively, and both techniques produced congruent data. VNTR-HRMA established clonal relationships between the strains of P. aeruginosa isolated during the outbreak in the NICU and proved, for the first time, the role of mineral water as the inoculum source. VNTR typing with one primer pair in association with HRMA is highly reproducible and discriminative, easily portable among laboratories, fast, and inexpensive, and it demonstrated excellent typeability in this study. VNTR-HRMA represents a promising tool for the molecular surveillance of P. aeruginosa and perhaps for molecular epidemiologic analysis of other hospital infections.

A review of the dynamics and severity of the pandemic A(H1N1) influenza virus on Réunion island, 2009.

On Reunion Island, in response to the threat of emergence of the pandemic influenza A(H1N1)2009 virus, we implemented enhanced influenza surveillance from May 2009 onwards in order to detect the introduction of pandemic H1N1 influenza and to monitor its spread and impact on public health. The first 2009 pandemic influenza A(H1N1) virus was identified in Réunion on July 5, 2009, in a traveller returning from Australia; seasonal influenza B virus activity had already been detected. By the end of July, a sustained community pandemic virus transmission had been established. Pandemic H1N1 influenza activity peaked during week 35 (24-30 August 2009), 4 weeks after the beginning of the epidemic. The epidemic ended on week 38 and had lasted 9 weeks. During these 9 weeks, an estimated 66 915 persons who consulted a physician could have been infected by the influenza A(H1N1)2009 virus, giving a cumulative attack rate for consultants of 8.26%. Taking into account the people who did not consult, the total number of infected persons reached 104 067, giving a cumulative attack rate for symptomatics of 12.85%. The crude fatality rate (CFR) for influenza A(H1N1)2009 and the CFR for acute respiratory infection was 0.7/10 000 cases. Our data show that influenza pandemic did not have a health impact on overall mortality on Réunion Island. These findings demonstrate the value of an integrated epidemiological, virological and hospital surveillance programme to monitor the scope of an epidemic, identify circulating strains and provide some guidance to public health control measures.

Preliminary analysis of the pandemic H1N1 influenza on Reunion Island (Indian Ocean): surveillance trends (July to mid-September 2009).

First infections with the 2009 pandemic H1N1 influenza virus were identified on Reunion Island in July 2009. By the end of July, sustained community transmission of the virus was established. Pandemic H1N1 influenza activity peaked during week 35 (24 to 30 August), five weeks after the beginning of the epidemic and has been declining since week 36. We report preliminary epidemiological characteristics of the pandemic on Reunion Island in 2009 until week 37 ending September 13.

Sporadic cases of chikungunya, Réunion Island, August 2009.

On 28 August 2009, French authorities reported five cases of chikungunya fever on Reunion Island: three confirmed, one probable, and one suspected case under investigation. All three confirmed patients presented with an acute febrile syndrome, arthralgia, myalgia and cutaneaous rash. All live in the same area on the western side of the island.

Simultaneous detection and quantitation of Chikungunya, dengue and West Nile viruses by multiplex RT-PCR assays and dengue virus typing using high resolution melting.

Chikungunya (CHIKV), Dengue (DENV) and West Nile (WNV) viruses are arthropod-borne viruses that are able to emerge or re-emerge in many regions due to climatic changes and increase in travel. Since these viruses produce similar clinical signs it is important for physicians and epidemiologists to differentiate them rapidly. A molecular method was developed for their detection and quantitation in plasma samples and a DENV typing technique were developed. The method consisted in performing two multiplex real-time one-step RT-PCR assays, to detect and quantify the three viruses. Both assays were conducted in a single run, from a single RNA extract containing a unique coextracted and coamplified composite internal control. The quantitation results were close to the best detection thresholds obtained with simplex RT-PCR techniques. The differentiation of DENV types was performed using a High Resolution Melting technique. The assays enable the early diagnosis of the three arboviruses during viremia, including cases of coinfection. The method is rapid, specific and highly sensitive with a potential for clinical diagnosis and epidemiological surveillance. A DENV positive sample can be typed conveniently using the High Resolution Melting technique using the same apparatus.