Emerging Corynebacterium diphtheriae Species Complex Infections, Réunion Island, France, 2015-2020.

Clinical, epidemiologic, and microbiologic analyses revealed emergence of 26 cases of Corynebacterium diphtheriae species complex infections on Réunion Island, France, during 2015-2020. Isolates were genetically diverse, indicating circulation and local transmission of several diphtheria sublineages. Clinicians should remain aware of the risk for diphtheria and improve diagnostic methods and patient management.

Investigation of a vanA linezolid- and vancomycin-resistant Enterococcus faecium outbreak in the Southwest Indian Ocean (Reunion Island).

INTRODUCTION: Dual resistance to linezolid and glycopeptides is a milestone reached by certain extensively drug-resistant (XDR) enterococci. This paper describes the molecular and epidemiological investigations of a linezolid-resistant and vancomycin-resistant Enterococcus faecium (E. faecium) (LVREf) outbreak in the French overseas territory of Reunion Island (Indian Ocean). METHODS: All vancomycin-resistant Enterococcus (VRE) isolates detected on Reunion Island between 2015 and 2019 were included in the study. The VRE isolates were phenotypically characterised and genetically explored by whole-genome sequencing (WGS). RESULTS: Sixteen vancomycin-resistant E. faecium (VREf) isolates were retrieved between 2015 and 2019. Seven isolates obtained in 2019 were involved in the outbreak. These seven LVREf isolates from the 2019 outbreak at the University Hospital of Reunion Island (UHRI) were suspected to be related to a linezolid-susceptible VREf strain imported from India. An epidemiological link was highlighted for six of the seven outbreak cases. All the LVREf outbreak isolates were obtained from rectal swabs (colonisation) and resistant to vancomycin (MIC > 128 mg/L) and linezolid (MIC 8-32 mg/L); one isolate was also resistant to daptomycin (MIC 8 mg/L). The seven outbreak isolates were positive for the vanA and optrA genes and belonged to ST761. CONCLUSIONS: These results argue for the strict application of control and prevention measures for VRE clones at high risk of spread, particularly in areas such as Reunion Island where the risk of importation from the Indian subcontinent is high. The regional spread of optrA linezolid-resistance genes in VRE isolates is a matter of concern, due to possibility of treatment failure.

Distribution of Achromobacter Species in 12 French Cystic Fibrosis Centers in 2020 by a Retrospective MALDI-TOF MS Spectrum Analysis.

Achromobacter spp. are nonfermenting Gram-negative bacilli mainly studied among cystic fibrosis (CF) patients. The identification of the 19 species within the genus is time-consuming (nrdA-sequencing), thus data concerning the distribution of the species are limited to specific studies. Recently, we built a database using MALDI-TOF mass spectrometry (MS) (Bruker) that allows rapid and accurate species identification and detection of the multiresistant epidemic clones: A. xylosoxidans ST137 spreading among CF patients in various French and Belgium centers, and A. ruhlandii DES in Denmark. Here, we first assessed whether species identification could be achieved with our database solely by analysis of MS spectra without availability of isolates. Then, we conducted a multicentric study describing the distribution of Achromobacter species and of the clone ST137 among French CF centers. We collected and analyzed with our local database the spectra of Achromobacter isolates from 193 patients (528 samples) from 12 centers during 2020. In total, our approach enabled to conclude for 502/528 samples (95.1%), corresponding to 181 patients. Eleven species were detected, only five being involved in chronic colonization, A. xylosoxidans (86.4%), A. insuavis (9.1%), A. mucicolens (2.3%), A. marplatensis (1.1%) and A. genogroup 3 (1.1%). This study confirmed the high prevalence of A. xylosoxidans in chronic colonizations and the circulation of the clone A. xylosoxidans ST137 in France: four patients in two centers. The present study is the first to report the distribution of Achromobacter species from CF patients samples using retrospective MALDI-TOF/MS data. This easy approach could enable future large-scale epidemiological studies.

Gonococcal arthritis: case series of 58 hospital cases.

OBJECTIVES: Extra-genital manifestations of gonococcal infection are rare (0.5-3%). Among them, gonococcal arthritis (GA) is the most frequent, accounting for 30-90% of disseminated infections. Our study aimed to describe all hospital cases of GA in Reunion Island, a French overseas territory. METHODS: We conducted a retrospective, multicentric, observational study of all cases of certain, probable or possible GA from 2008 to 2020. RESULTS: We identified 58 cases of GA, mostly certain cases (n = 48). Sex ratio was balanced, but men were older than women (51 vs 27 years, p < 0.001). A total of 41% had travelled abroad during the previous 3 months, mostly in Madagascar or South-East Asia. The most frequently infected joint was the knee, followed by ankle, wrist and fingers or carpal joints. Only 16% of cases had genital symptoms, but 50% had another extra-genital manifestation, mainly skin lesions (40%). Positivity rate of joint puncture was 91%, with a purulent liquid. Only 58% had a positive culture, and 33% had only a positive PCR. There was no 3GC-resistant strain. In comparison with gonococcal infection without arthritis, patients were older and had fewer genital but more extra-genital symptoms. On discharge 60% had persistent articular symptoms. GA represented 18% of all hospitalised septic arthritis cases with microbial identification in 2019. CONCLUSIONS: GA is rare but it is important to make an early diagnosis and treat promptly, as joint destruction may be important, leading to persistent symptoms after discharge. PCR use in joint puncture is useful in cases with negative culture.

One Health compartmental analysis of ESBL-producing Escherichia coli on Reunion Island reveals partitioning between humans and livestock.

BACKGROUND: Extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-Ec) is a major cause of infections worldwide. An understanding of the reservoirs and modes of transmission of these pathogens is essential, to tackle their increasing frequency. OBJECTIVES: We investigated the contributions of various compartments (humans, animals, environment), to human colonization or infection with ESBL-Ec over a 3 year period, on an island. METHODS: The study was performed on Reunion Island (Southwest Indian Ocean). We collected ESBL-Ec isolates prospectively from humans, wastewater and livestock between April 2015 and December 2018. Human specimens were recovered from a regional surveillance system representative of the island's health facilities. These isolates were compared with those from livestock and urban/rural wastewater, by whole-genome sequencing. RESULTS: We collected 410 ESBL-Ec isolates: 161 from humans, 161 from wastewater and 88 from animals. Phylogenomic analysis demonstrated high diversity (100 STs), with different STs predominating among isolates from humans (ST131, ST38, ST10) and animals (ST57, ST156). The large majority (90%) of the STs, including ST131, were principally associated with a single compartment. The CTX-M-15, CTX-M-27 and CTX-M-14 enzymes were most common in humans/human wastewater, whereas CTX-M-1 predominated in animals. Isolates of human and animal origin had different plasmids carrying blaCTX-M genes, with the exception of a conserved IncI1-ST3 blaCTX-M-1 plasmid. CONCLUSIONS: These molecular data suggest that, despite their high level of contamination, animals are not a major source of the ESBL-Ec found in humans living on this densely populated high-income island. Public health policies should therefore focus primarily on human-to-human transmission, to prevent human infections with ESBL-Ec.

Q fever seroprevalence in parturient women: the EQRUN cross-sectional study on Reunion Island.

BACKGROUND: Q fever (Coxiella burnetii infection) has been associated with adverse perinatal outcomes. After investigating the obstetrical importance of Q fever on Reunion island and demonstrating an association between incident Q fever and miscarriage, we conducted a cross-sectional serosurvey to assess the prevalence of Coxiella burnetii infection among parturient women. METHODS: Between January 9 and July 24, 2014, within the level-4 maternity of Saint Pierre hospital and the level-1 maternity of Le Tampon, we proposed to screen all parturient women for Coxiella burnetii serology. Seropositivity was defined using indirect immunofluorescence for a dilution of phase 2 IgG titre ≥1:64. Further dilutions were chosen to discriminate recent or active infections from past or prevalent infections (< 1:128) and classify these as either possible (1:128), or probable (≥1:256). Recurrent miscarriage, stillbirth, preterm birth, small-for-gestational as well as a composite outcome of these adverse pregnancy outcomes were compared according to seropositivity using bivariate analysis or propensity score matching of seropositive and seronegative women on confounding factors. RESULTS: Among 1112 parturient women screened for Q fever over this 7-month period, 203 (18.3%) were seropositive. Overall weighted seroprevalence was of 20.1% (95%CI, 17.7-22.5%). Weighted seroprevalence of probable infections was 4.7% (95%CI 3.4-5.9%), while > 90% of positive serologies corresponded to past infections or false positives. Seropositivity was associated with none of the abovementioned adverse perinatal outcomes, whether in unpaired or matched analyses on propensity score. CONCLUSION: The magnitude and the pattern of seroprevalence suggest that Q fever is endemic on Reunion island. In this context, we found no significant contribution of prevalent Coxiella burnetii infection to adverse pregnancy outcomes. Although reassuring, these data put in our endemic context, with a previously demonstrated increased risk of incident Q fever associated miscarriage, encourage us to protect pregnant women against the risk of new infection, periconceptional or early in pregnancy.

Carbapenemase-producing Enterobacteriaceae circulating in the Reunion Island, a French territory in the Southwest Indian Ocean.

BACKGROUND: The spread of carbapenemase-producing Enterobacteriaceae (CPE) in the Southwest Indian Ocean area (SIOA) is poorly documented. Reunion Island is a French overseas territory located close to Madagascar and connected with Southern Africa, Indian sub-continent and Europe, with several weekly flights. Here we report the results of the CPE surveillance program in Reunion Island over a six-year period. METHODS: All CPE were collected between January 2011 and December 2016. Demographics and clinical data of the carrier patients were collected. We determined their susceptibility to antimicrobials, identified the carbapenemases and ESBL by PCR and sequencing, and explored their genetic relationship using pulsed-field gel electrophoresis and multi-locus sequence typing. RESULTS: A total of 61 CPEs isolated from 53 patients were retrieved in 6 public or private laboratories of the island. We found that 69.8% of CPE patients were linked to a foreign country of SIOA and that almost half of CPE cases (47.2%) reached the island through a medical evacuation. The annual number of CPE cases strongly increased over the studied period (one case in 2011 vs. 21 cases in 2016). A proportion of 17.5% of CPE isolates were non-susceptible to colistin. blaNDM was the most frequent carbapenemase (79.4%), followed by blaIMI (11.1%), and blaIMP-10 (4.8%). Autochtonous CPE cases (30.2%) harboured CPE isolates belonging to a polyclonal population. CONCLUSIONS: Because the hospital of Reunion Island is the only reference healthcare setting of the SIOA, we can reasonably estimate that its CPE epidemiology reflects that of this area. Mauritius was the main provider of foreign CPE cases (35.5%). We also showed that autochthonous isolates of CPEs are mostly polyclonal, thus unrelated to cross-transmission. This demonstrates the local spread of carbapenemase-encoding genes (i.e. blaNDM) in a polyclonal bacterial population and raises fears that Reunion Island could contribute to the influx of NDM-carbapenemase producers into the French mainland territory.

Low seroprevalence of hepatitis E on Reunion island.

OBJECTIVE: Hepatitis E virus (HEV) has been scarcely investigated in the Indian Ocean. Following a nationwide serosurvey among blood donors, we conducted a population-based serosurvey to assess the magnitude of HEV exposure on Reunion Island. METHODS: Four hundred and sixty-six archived frozen human sera from the 2009 CoPanFlu-RUN cohort were analysed using the Wantai HEV IgG enzyme immunoassay. HEV seropositivity was defined as an IgG titre ≥5 UI/ml. Raw and weighted seroprevalences were assessed to account for the discrepancy between the CoPanFlu-RUN subset and the general community. Prevalence proportion ratios (PPR) were measured using log-binomial models. RESULTS: The raw and the weighted seroprevalences of HEV were 9.01% (95% CI 6.41-11.61) and 6.73% (95% CI 4.47-8.98), respectively. The presence of HEV IgG antibodies was associated with increasing age (P < 0.001). In a survey-adjusted model minimizing the sampling bias and adjusting for age, males were more likely to be seropositive than females (adjusted PPR 2.59, 95% CI 1.07-6.25). Seropositivity was spatially heterogeneous across the island (P < 0.01). Living in the neighbourhood of a pig farm within a low to intermediate slope area was associated with seropositivity in several models adjusting for age, gender, altitude of residency and interaction between slope and pig farms. CONCLUSION: Reunion Island is a low endemic area for HEV exposure. Despite limitations related to the retrospective study design, our findings confirm the roles of cumulative lifetime exposure and male gender in HEV exposure. The risk associated with neighbouring pig farms might also suggest environmental contamination in this setting.

Pregnancy outcomes of Q fever: prospective follow-up study on Reunion island.

BACKGROUND: Q fever has been associated with perinatal complications. We conducted a prospective follow-up study to assess both the incidence of adverse pregnancy outcomes (APOs) associated with Coxiella burnetii infection and the contribution of Q fever to APOs. METHODS: Between May 1 and October 31, 2013, within the regional perinatal health care centre of Saint Pierre, Reunion island, we investigated unexplained miscarriages, stillbirths, preterm births or small-for-gestational age children. Seropositivity for C. burnetii antibodies was defined using indirect immunofluorescence for a phase 2 IgG titre ≥1:64. Acute Q fever was defined for a high phase 2 IgG titre ≥1:256 (compatible with recent or active infection) or the detection of C. burnetii genome in miscarriage products and placentas. Incidence rate ratios (IRR) for Q fever related APOs (taken as a composite outcome or individually) were assessed using Poisson regression models for dichotomous outcomes controlling major confounders. RESULTS: Over a 6-month period, 179 pregnant women suspected or diagnosed with an APO were investigated for Q fever, of whom 118 met the definition for an APO. Of these, 19 were seropositive and 10 presented a profile indicative of an acute infection. For three women with an acute Q fever, the chronology between the onset of infection, the APO (2 miscarriages, 1 preterm birth) and the seroconversion suggested causality in the pathogenesis. The cumulative incidence of Q fever related APOs was estimated between 2.2‰ and 5.2‰, whether causality was required or not. Both C. burnetii exposure and acute Q fever were independently associated with APOs (IRR 1.55, 95% CI 1.31-1.84; IRR 1.47, 95% CI 1.15-1.89, respectively). CONCLUSIONS: In the endemic context of Reunion island, acute Q fever may lead to APOs. To limit the burden of Q fever on reproduction, pregnant women should be kept away from farms and avoid direct contact with ruminants.

Seroprevalence of Coxiella burnetii (Q fever) Exposure in Humans on Reunion Island.

After the documentation of sporadic cases of Q fever endocarditis, we conducted a serosurvey to assess Coxiella burnetii exposure on Reunion Island. Two hundred forty-one stored frozen human sera were analyzed using an immunofluorescence assay. The weighted seroprevalence of Q fever was of 6.81% (95% confidence interval, 4.02%-9.59%). Despite the absence of infection in youths <20 years of age, exposure was not driven by age or by gender. There was a spatial disparity in exposure across the island, with higher prevalence being reported in regions where ruminant farms are present. The seroprevalence pattern suggests that Q fever is endemic on Reunion Island.

Seroprevalence of typhus group and spotted fever group Rickettsia exposures on Reunion island.

OBJECTIVE: Murine typhus has been increasingly reported on Reunion island, Indian ocean, following documentation of eight autochthonous infections in 2012-2013. We conducted a serosurvey to assess the magnitude of the seroprevalence of rickettsioses in the population. Two hundred and forty-one stored frozen sera taken from the 2009 Copanflu-RUN cohort were analysed using an immunofluorescence assay allowing to distinguish typhus group (TGR) and spotted fever group Rickesttsiae (SFGR). Seropositivity was defined for a dilution titre of Rickettsia IgG antibodies ≥ 1:64. Seroprevalence was weighted to account for the discrepancy between the Copanflu-RUN subset and the general population, as to infer prevalence at community level. Prevalence proportion ratios (PPR) were measured using log-binomial models. RESULTS: The weighted seroprevalences of typhus group rickettsioses and spotted fever group rickettsioses were of 12.71% (95% CI 8.84-16.58%) and 17.68% (95% CI 13.25-22.11%), respectively. Pooled together, data suggested that a fifth of the population had been exposed at least to one Rickettsia group. Youths (< 20 years) were less likely seropositive than adults (adjusted PPR 0.13, 95% CI 0.01-0.91). People living in the western dryer part of the island were more exposed (adjusted PPR 2.53, 95% CI 1.07-5.97). Rickettsioses are endemic on Reunion island and circulated before their first identification as murine typhus in year 2011. Surprisingly, since isolation of Rickettsia africae from Amblyomma variegatum in year 2004 or isolation of Rickettsia felis from Amblyomma loculosum, no autochthonous cases of African tick-bite fever or flea-borne spotted fever has yet been diagnosed.

Waterborne Infections in Reunion Island, 2010-2017.

Gram-negative bacilli Vibrio spp., Aeromonas spp., and Shewanella spp. are a major cause of severe waterborne infection. The aim of this study was to assess the clinical and microbiological characteristics and prognosis of patients hospitalized in Reunion Island for a waterborne infection. This retrospective study was conducted in the two university hospitals of Reunion Island between January 2010 and March 2017. Patients diagnosed with a Vibrio, Aeromonas, or Shewanella infection were evaluated. Over the study period, 112 aquatic strains were isolated at Reunion Island: Aeromonas spp. were found in 91 patients (81.3%), Shewanella spp. in 13 patients (11.6%), and Vibrio spp. in eight patients (7.2%). The in-hospital mortality rate was 11.6%. The main sites of infection were skin and soft tissue (44.6%) and the abdomen (19.6%). Infections were polymicrobial in 70 cases (62.5%). The most commonly prescribed empiric antibiotic regimen was amoxicillin-clavulanate (34.8%). Eighty-four percent of the aquatic strains were resistant to amoxicillin-clavulanate and more than > 95% were susceptible to third or fourth generation cephalosporins and fluoroquinolones. After multivariate analysis, the only independent risk factor of in-hospital mortality was the presence of sepsis (P < 0.0001). In Reunion Island, the most commonly isolated aquatic microorganisms were Aeromonas spp. Sepsis caused by aquatic microorganisms was frequent (> 50%) and associated with higher in-hospital mortality. This study suggests that empiric antibiotic regimens in patients with sepsis or septic shock caused by suspected aquatic microorganisms (tropical climate, skin lesion exposed to seawater…) should include broad-spectrum antibiotics (third or fourth generation cephalosporins).

Clinical, Radiological, and Microbiological Characteristics of Mycobacterium simiae Infection in 97 Patients.

Mycobacterium simiae is a rare species of slow-growing nontuberculous mycobacteria (NTM). From 2002 to 2017, we conducted a retrospective study that included all patients with NTM-positive respiratory samples detected in two university hospitals of the French overseas department of Reunion Island. We recorded the prevalence of M. simiae in this cohort, as well as the clinical, radiological, and microbiological features of patients with at least 1 sample positive for M. simiae In our cohort, 97 patients (15.1%) were positive for M. simiae Twenty-one patients (21.6%) met the American Thoracic Society (ATS) criteria for infection. M. simiae infection was associated with bronchiectasis, micronodular lesions, and weight loss. Antibiotic susceptibility testing was performed for 60 patients, and the isolates were found to have low susceptibility to antibiotics, except for amikacin, fluoroquinolones, and clarithromycin. Treatment failed for 4 of the 8 patients treated for M. simiae infection. Here, we describe a specific cluster corresponding to a large cohort of patients with M. simiae, a rare nontuberculous mycobacterium associated with low pathogenicity and poor susceptibility to antibiotics.

Evaluation of quantitative FTD-Pneumocystis jirovecii kit for Pneumocystis infection diagnosis.

We evaluated the Fast track Diagnostics (FTD) Pneumocystis PCR kit, targeting the mitochondrial large subunit ribosomal RNA gene (mtLSU rRNA) of Pneumocystis jirovecii (P. jirovecii). A hundred and thirty-three patients were prospectively enrolled. Respiratory specimens were examined using both microscopy and the PCR assay. Twenty-six patients led to P. jirovecii detection. Fourteen patients presented with Pneumocystis pneumonia (PCP) whereas 12 patients were considered to be colonized. The median copy numbers in bronchoalveolar lavage fluid were significantly different in the PCP and colonization groups (1.35×108/ml vs. 1.45×105/ml, P < 0.0001). Lower and upper cut-off values of 3.9×105 copies/ml and 3.2×106 copies/ml allowed differentiating PCP and colonization. The FTD P. jirovecii assay was secondarily compared to an in-house reference PCR assay targeting the mtLSUrRNA gene. A concordance rate of 97.5% was observed (Cohen's kappa coefficient κ=0.935). The FTD Pneumocystis PCR kit showed good performance and represents an alternative method to diagnose P. jirovecii infections.

Trametes polyzona, an emerging filamentous basidiomycete in Réunion Island.

We describe two serious Trametes polyzona pulmonary infections, which occurred in Réunion Island, in critically ill patients. The identification was performed using sequencing of the internal transcribed spacer region of ribosomal DNA and D1/D2 region of 28S rDNA. In one case, the significance of T. polyzona in the pathological process was certain, proven by histopathological evidence of fungal lung infection. T. polyzona, an emerging filamentous basidiomycete, prevalent in tropical areas, has not been described so far in human infections.

Invasive Group B Streptococcal Disease in Non-pregnant Adults, Réunion Island, 2011.

OBJECTIVES: While the prevalence of Group B streptococcus (GBS) colonization is important, little is known about invasive GBS (iGBS) disease in tropical areas. Our objective was to assess the burden of iGBS disease among non-pregnant adults. METHODS: A prospective hospital-based study of all non-pregnant adult patients with iGBS disease was conducted between January and December 2011 in Saint Pierre, Réunion Island, to assess its cumulative incidence rate (CIR). Capsular serotyping and multilocus sequence typing were performed to characterize GBS isolates. Case-control study was done to identify risk factors. RESULTS: The overall CIR of iGBS disease was 10.1 per 100,000. The CIR in elderly patients (≥ 65 yrs) was estimated at 40.6 per 100.000, and that of adults (15-64 years) at 6.7 per 100.000. Aboriginal origin in the Indian Ocean and overweight were both associated with iGBS disease. The most prominent clinical forms were osteo-articular and skin/soft tissue infections, as a consequence of diabetic foot. The serotypes were classic, type-Ia being the most prevalent. The hyper virulent ST-17 (CC17) was associated with type-III. CONCLUSIONS: The incidence of iGBS disease found in Réunion island is twofold that usually reported. This burden is linked to overweight in aboriginal people from the Indian Ocean.

A case of postoperative breast infection by Mycobacterium fortuitum associated with the hospital water supply.

This report describes the first known laboratory-confirmed case of Mycobacterium fortuitum breast infection related to the hospital water supply. The source of the M fortuitum infection was identified by repetitive extragenic palindromic sequence-based polymerase chain reaction genotyping. In addition, we discuss appropriate infection control measures to minimize patient exposure to waterborne pathogens, in particular, in the context of nontuberculous mycobacteria, which is difficult to eradicate from the water supply network.