The yeast Starmerella bacillaris (synonym Candida zemplinina) shows high genetic diversity in winemaking environments.

The yeast Candida zemplinina (Starmerella bacillaris) is frequently isolated from grape and wine environments. Its enological use in mixed fermentation with Saccharomyces cerevisiae has been extensively investigated these last few years, and several interesting features including low ethanol production, fructophily, glycerol and other metabolites production, have been described. In addition, molecular tools allowing the characterization of yeast populations have been developed, both at the inter- and intraspecific levels. However, most of these fingerprinting methods are not compatible with population genetics or ecological studies. In this work, we developed 10 microsatellite markers for the C. zemplinina species that were used for the genotyping of 163 strains from nature or various enological regions (28 vineyards/wineries from seven countries). We show that the genetic diversity of C. zemplinina is shaped by geographical localization. Populations isolated from winemaking environments are quite diverse at the genetic level: neither clonal-like behaviour nor specific genetic signature were associated with the different vineyards/wineries. Altogether, these results suggest that C. zemplinina is not under selective pressure in winemaking environments.

Field evaluation of clinical features during chikungunya outbreak in Mayotte, 2005-2006.

BACKGROUND: To record and assess the clinical features of chikungunya fever (CHIKF), with a view to enable diagnosis based on clinical criteria rather than costly laboratory procedures in field conditions. METHODS: As part of a cross-sectional serologic survey conducted in Mayotte after a massive chikungunya outbreak in 2006, we collected data on clinical features of chikungunya infection and assessed the performance and accuracy of clinical case definition criteria combining different symptoms. RESULTS: Of 1154 participants included, 440 (38.1%) had chikungunya-specific IgM or IgG antibodies by enzyme-linked immunosorbent assay (ELISA). Of symptomatic participants, 318 (72.3%) had confirmed chikungunya, the dominant symptoms reported were incapacitating polyarthralgia (98.7%), myalgia (93.1%), backache (86%), fever of abrupt onset (85%) and headache (81.4%). There was a strong linear association between symptomatic infection and age (chi(2) for trend = 9.85, P < 0.001). Only 52% of persons with presumptive chikungunya sought medical advice, principally at public primary health care facilities. The association of fever and polyarthralgia had a sensitivity of 84% (95% CI: 79-87) and a specificity of 89% (95% CI: 86-91). This association allowed to classify correctly 87% (95% CI: 85-89) of individuals with serologically confirmed chikungunya. CONCLUSIONS: Our results suggest that the pair fever and incapacitating polyarthralgia is an accurate and reliable tool for identifying presumptive CHIKF cases in the field. These criteria provide a useful evidence base to support operational syndromic surveillance in laboratory-confirmed chikungunya epidemic settings.

Rift Valley fever, Mayotte, 2007-2008.

After the 2006-2007 epidemic wave of Rift Valley fever (RVF) in East Africa and its circulation in the Comoros, laboratory case-finding of RVF was conducted in Mayotte from September 2007 through May 2008. Ten recent human RVF cases were detected, which confirms the indigenous transmission of RFV virus in Mayotte.

A major epidemic of chikungunya virus infection on Reunion Island, France, 2005-2006.

In January 2005, an epidemic of chikungunya fever broke out in the Comoro Islands and lasted until May 2005. In April, cases were also reported in Mayotte and Mauritius. On Réunion Island, the first cases were reported at the end of April. Surveillance of this epidemic required an adaptive system, which at first was based on active and retrospective case detection around the cases reported, then relied on a sentinel network when the incidence increased. Emerging and severe forms of infection were investigated. Death certificates were monitored. By April 2006, the surveillance estimate was 244,000 cases of chikungunya virus infection, including 123 severe cases and 41 of maternoneonatal transmission, with an overall attack rate of 35%. Chikungunya infection was mentioned on 203 death certificates and significant mortality was observed. This epidemic highlighted the need for a mutual strategy of providing information on arboviral diseases and their prevention and control between countries in the southwestern Indian Ocean.

Enhanced 3-Sulfanylhexan-1-ol Production in Sequential Mixed Fermentation with Torulaspora delbrueckii/Saccharomyces cerevisiae Reveals a Situation of Synergistic Interaction between Two Industrial Strains.

The aim of this work was to study the volatile thiol productions of two industrial strains of Torulaspora delbrueckii and Saccharomyces cerevisiae during alcoholic fermentation (AF) of Sauvignon Blanc must. In order to evaluate the influence of the inoculation procedure, sequential and simultaneous mixed cultures were carried out and compared to pure cultures of T. delbrueckii and S. cerevisiae. The results confirmed the inability of T. delbrueckii to release 4-methyl-4-sulfanylpentan-2-one (4MSP) and its low capacity to produce 3-sulfanylhexyl acetate (3SHA), as already reported in previous studies. A synergistic interaction was observed between the two species, resulting in higher levels of 3SH (3-sulfanylhexan-1-ol) and its acetate when S. cerevisiae was inoculated 24 h after T. delbrueckii, compared to the pure cultures. To elucidate the nature of the interactions between these two species, the yeast population kinetics were examined and monitored, as well as the production of 3SH, its acetate and their related non-odorous precursors: Glut-3SH (glutathionylated conjugate precursor) and Cys-3SH (cysteinylated conjugate precursor). For the first time, it was suggested that, unlike S. cerevisiae, which is able to metabolize the two precursor forms, T. delbrueckii was only able to metabolize the glutathionylated precursor. Consequently, the presence of T. delbrueckii during mixed fermentation led to an increase in Glut-3SH degradation and Cys-3SH production. This overproduction was dependent on the T. delbrueckii biomass. In sequential culture, thus favoring T. delbrueckii development, the higher availability of Cys-3SH throughout AF resulted in more abundant 3SH and 3SHA production by S. cerevisiae.

Increase of fruity aroma during mixed T. delbrueckii/S. cerevisiae wine fermentation is linked to specific esters enhancement.

The aim of this work was to study ester formation and the aromatic impact of Torulaspora delbrueckii when used in association with Saccharomyces cerevisiae during the alcoholic fermentation of must. In order to evaluate the influence of the inoculation procedure, sequential and simultaneous mixed cultures were carried out and compared to pure cultures of T. delbrueckii and S. cerevisiae. Our results showed that mixed inoculations allowed the increase, in comparison to S. cerevisiae pure culture, of some esters specifically produced by T. delbrueckii and significantly correlated to the maximal T. delbrueckii population reached in mixed cultures. Thus, ethyl propanoate, ethyl isobutanoate and ethyl dihydrocinnamate were considered as activity markers of T. delbrueckii. On the other hand, isobutyl acetate and isoamyl acetate concentrations were systematically increased during mixed inoculations although not correlated with the development of either species but were rather due to positive interactions between these species. Favoring T. delbrueckii development when performing sequential inoculation enhanced the concentration of esters linked to T. delbrueckii activity. On the contrary, simultaneous inoculation restricted the growth of T. delbrueckii, limiting the production of its activity markers, but involved a very important production of numerous esters due to more important positive interactions between species. These results suggest that the ester concentrations enhancement via interactions during mixed modalities was due to S. cerevisiae production in response to the presence of T. delbrueckii. Finally, sensory analyses showed that mixed inoculations between T. delbrueckii and S. cerevisiae allowed to enhance the complexity and fruity notes of wine in comparison to S. cerevisiae pure culture. Furthermore, the higher levels of ethyl propanoate, ethyl isobutanoate, ethyl dihydrocinnamate and isobutyl acetate in mixed wines were found responsible for the increase of fruitiness and complexity.

The Chikungunya epidemic on La Réunion Island in 2005-2006: a cost-of-illness study.

BACKGROUND: This study was conducted to assess the impact of chikungunya on health costs during the epidemic that occurred on La Réunion in 2005-2006. METHODOLOGY/PRINCIPAL FINDINGS: From data collected from health agencies, the additional costs incurred by chikungunya in terms of consultations, drug consumption and absence from work were determined by a comparison with the expected costs outside the epidemic period. The cost of hospitalization was estimated from data provided by the national hospitalization database for short-term care by considering all hospital stays in which the ICD-10 code A92.0 appeared. A cost-of-illness study was conducted from the perspective of the third-party payer. Direct medical costs per outpatient and inpatient case were evaluated. The costs were estimated in Euros at 2006 values. Additional reimbursements for consultations with general practitioners and drugs were estimated as € 12.4 million (range: € 7.7 million-€ 17.1 million) and € 5 million (€ 1.9 million-€ 8.1 million), respectively, while the cost of hospitalization for chikungunya was estimated to be € 8.5 million (€ 5.8 million-€ 8.7 million). Productivity costs were estimated as € 17.4 million (€ 6 million-€ 28.9 million). The medical cost of the chikungunya epidemic was estimated as € 43.9 million, 60% due to direct medical costs and 40% to indirect costs (€ 26.5 million and € 17.4 million, respectively). The direct medical cost was assessed as € 90 for each outpatient and € 2,000 for each inpatient. CONCLUSIONS/SIGNIFICANCE: The medical management of chikungunya during the epidemic on La Réunion Island was associated with an important economic burden. The estimated cost of the reported disease can be used to evaluate the cost/efficacy and cost/benefit ratios for prevention and control programmes of emerging arboviruses.

Pandemic influenza 2009 on Réunion Island: A mild wave linked to a low reproduction number.

We studied the epidemic trend following the introduction of the pandemic A(H1N1) 2009 in the subtropical Réunion Island. There, the pandemic wave started from week 30 and lasted until week 38, with an estimated attack rate of 12.85 % for symptomatic infections. The best estimate for the initial reproduction number was Ri = 1.26 [1.08; 1.49]. It results that the herd immunity necessary to stop the epidemic growth is of the same magnitude than the attack rate. Thus, a second wave before the 2010 austral winter seems unlikely, unless a viral mutation.

Post-epidemic Chikungunya disease on Reunion Island: course of rheumatic manifestations and associated factors over a 15-month period.

Although the acute manifestations of Chikungunya virus (CHIKV) illness are well-documented, few data exist about the long-term rheumatic outcomes of CHIKV-infected patients. We undertook between June and September 2006 a retrospective cohort study aimed at assessing the course of late rheumatic manifestations and investigating potential risk factors associated with the persistence of these rheumatic manifestations over 15 months. 147 participants (>16 yrs) with laboratory-confirmed CHIKV disease diagnosed between March 1 and June 30, 2005, were identified through a surveillance database and interviewed by telephone. At the 15-month-period evaluation after diagnosis, 84 of 147 participants (57%) self-reported rheumatic symptoms. Of these 84 patients, 53 (63%) reported permanent trouble while 31 (37%) had recurrent symptoms. Age > or=45 years (OR = 3.9, 95% CI 1.7-9.7), severe initial joint pain (OR = 4.8, 95% CI 1.9-12.1), and presence of underlying osteoarthritis comorbidity (OR = 2.9, 95% CI 1.1-7.4) were predictors of nonrecovery. Our findings suggest that long-term CHIKV rheumatic manifestations seem to be a frequent underlying post-epidemic condition. Three independent risk factors that may aid in early recognition of patients with the highest risk of presenting prolonged CHIKV illness were identified. Such findings may be particularly useful in the development of future prevention and care strategies for this emerging virus infection.

Genetic characterization and phenotypic variability in Torulaspora delbrueckii species: Potential applications in the wine industry.

In this study, several strains of Torulaspora delbrueckii yeast species were evaluated in the laboratory for their enological properties. In a preliminary step, the ability of different molecular methods to discriminate among T.delbrueckii strains was compared. A combination of 7 PCR methods was able to separate 21 strains into 18 groups, while an REA-PFGE method allowed, in one experiment, the separation into 19 groups. The T.delbrueckii strains used presented a wide phenotypic variability in fermentation behaviour, e.g. Lag Phase (LP) duration, T50 parameter (time necessary to ferment half the sugar), and ethanol production. These 3 parameters have to be considered for industrial selection, particularly the LP duration. The majority of T.delbrueckii strains produced 8 to 11% and 7 to 10% ethanol vol. at 17 degrees C and 24 degrees C, respectively, with a maximum ethanol concentration of 12.35 at 17 degrees C and 10.90% vol. at 24 degrees C. The phenotypic variability of this species was also reflected in volatile acidity, glycerol, and aroma production. These experiments confirmed the low volatile acidity and glycerol production of this species and revealed a difference in osmotic stress response, compared to Saccharomyces cerevisiae. T.delbrueckii presented high fermentation purity and produced low levels of undesirable volatile compounds, such as hydrogen sulphide and volatile phenols.

[Electronic transmission of epidemiologic data and monitoring of the chikungunya virus epidemic in Reunion Island, 2006]. / Transmission télématique de données épidémiologiques et surveillance de l'épidémie de chikungunya à la Réunion en 2006.

INTRODUCTION: When the first cases of the 2005-2006 chikungunya epidemic struck Reunion Island, local health authorities set up an island-wide operational epidemiologic surveillance system for these infections. This system relied on vector control teams, which conducted active case-finding around the reported cases, and on a sentinel physician network. In addition, in March 2006, the Sephira and Reunion-Telecom companies, in partnership with the Reunion-Mayotte interregional epidemiology bureau (CIRE), developed an innovative system of epidemiologic monitoring by electronic data transmission. METHODS: This system relied on the participation of volunteer physicians who transmitted epidemiologic data through the data terminals used for the transmission of electronic treatment forms to the health insurance funds. Using the patient's insurance identification card, each physician provided information about consultations related to chikungunya. This information was transmitted, via the Sephira server in France to Reunion-Telecom, which processed, aggregated and transmitted these data weekly to the CIRE. This network was separate from and independent of the sentinel physician network, RESULTS: In all, 44 physicians, accounting for 6% of the general practitioners in Reunion, participated in this system, which went into operation during week 14 of 2006. The data collected allowed an assessment of the trends in the epidemic incidence rate by calculating the percentage of consultations related to chikungunya among all consultations (office visits and house calls). For weeks 14-26 of 2006, when the epidemic transmission had spread across the entire island, the Reunion-Telecom health network data proved to be closely correlated with the results of the sentinel physician network surveillance system used to monitor the epidemic trends (correlation coefficient=0.97). CONCLUSION: The system provided very encouraging results in monitoring disease time trends in a period of massive epidemic. Its simplicity of use and the speed of data transmission are undeniable assets for its future development. Because it offers the possibility of monitoring other diseases with epidemic potential, such as dengue and influenza, it opens new prospects for infectious disease surveillance.