Comparing the Performance of Three Models Incorporating Weather Data to Forecast Dengue Epidemics in Reunion Island, 2018-2019.

We developed mathematical models to analyze a large dengue virus (DENV) epidemic in Reunion Island in 2018-2019. Our models captured major drivers of uncertainty including the complex relationship between climate and DENV transmission, temperature trends, and underreporting. Early assessment correctly concluded that persistence of DENV transmission during the austral winter 2018 was likely and that the second epidemic wave would be larger than the first one. From November 2018, the detection probability was estimated at 10%-20% and, for this range of values, our projections were found to be remarkably accurate. Overall, we estimated that 8% and 18% of the population were infected during the first and second wave, respectively. Out of the 3 models considered, the best-fitting one was calibrated to laboratory entomological data, and accounted for temperature but not precipitation. This study showcases the contribution of modeling to strengthen risk assessments and planning of national and local authorities.

Mucocutaneous Manifestations in Patients with Dengue Fever: From the EPIDENGUE Cohort on Reunion Island.

Nearly 4 billion people live in a dengue risk area worldwide. The prevalence of dengue-related mucocutaneous manifestations and their association with severe dengue differ across studies. The aim of the study was to describe the characteristics of patients with dengue-related mucocutaneous manifestations and to investigate those were associated with severe dengue. A retrospective study was conducted in 2019 among patients with a positive RT-PCR for dengue at the University Hospital of Reunion, which has been experiencing a re-emergence of dengue since 2018. Of 847 patients with confirmed dengue, 283 (33.4%) developed mucocutaneous manifestations. Only manifestations of dehydration such as glossitis, dysgeusia, or conjunctivitis were associated with severe dengue, unlike pruritus and rash, in bivariate analysis but not in multivariate analysis. The rash and pruritus of dengue appear to be accompanied by a pronounced flu-like syndrome in younger people without comorbidity or severity, although careful examination of mucous membranes would better identify signs of dehydration and thus cases likely to worsen.

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.

Epidemiology of tuberculosis and susceptibility to antituberculosis drugs in Reunion Island.

BACKGROUND: Tuberculosis is the first fatal infectious agent in the world with 1.2 million annual deaths for 10 million cases. Little is known about the epidemiology of tuberculosis and its resistance in Reunion Island, which is at the heart of migratory flows from highly endemic Indian Ocean territories. METHODS: We carried out a retrospective observational study of cases of tuberculosis disease in Reunion Island between 2014 and 2018. The epidemiological, demographic, microbiological, clinical and social characteristics were analyzed from mandatory declarations, microbiology database and medical files. RESULTS: 265 cases of tuberculosis disease were recorded over the period, ie an incidence of 6.2 / 100,000 inhabitants. 114 patients (43%) were born or resided > 6 months in the rest of the Indian Ocean area. The risk of infection was increased if birth in Madagascar (OR 23.5), Comoros (OR 8.9) or Mayotte (OR 6.8). The prevalence of HIV co-infection was low (2.5%). There were 31 cases (14.4%) of resistance to antituberculosis including 3 (1.4%) of multidrug-resistant tuberculosis and 0 case of extensively drug-resistant tuberculosis. The female gender (61.3% of resistant) was associated with resistance. The resistance rate was not significantly different depending on the geographic origin. CONCLUSION: This is the first exhaustive epidemiological study of tuberculosis in Reunion Island. The incidence there is relatively low but increased for people with links to neighboring islands, particularly Madagascar. The prevalence of multidrug resistance is low, with no associated increased risk for patients from the Indian Ocean area.

Genetic characterization of dengue virus serotype 1 circulating in Reunion Island, 2019-2021, and the Seychelles, 2015-2016.

BACKGROUND: An unprecedent increase in the number of cases and deaths reported from dengue virus (DENV) infection has occurred in the southwestern Indian ocean in recent years. From 2017 to mid-2021 more than 70,000 confirmed dengue cases were reported in Reunion Island, and 1967 cases were recorded in the Seychelles from 2015 to 2016. Both these outbreaks displayed similar trends, with the initial circulation of DENV-2 which was replaced by DENV-1. Here, we aim to determine the origin of the DENV-1 epidemic strains and to explore their genetic characteristics along the uninterrupted circulation, particularly in Reunion. METHODS: Nucleic acids were extracted from blood samples collected from dengue positive patients; DENV-1 was identified by RT-qPCR. Positive samples were used to infect VERO cells. Genome sequences were obtained from either blood samples or infected-cell supernatants through a combination of both Illumina or MinION technologies. RESULTS: Phylogenetic analyses of partial or whole genome sequences revealed that all DENV-1 sequences from Reunion formed a monophyletic cluster that belonged to genotype I and were closely related to one isolate from Sri Lanka (OL752439.1, 2020). Sequences from the Seychelles belonged to the same major phylogenetic branch of genotype V, but fell into two paraphyletic clusters, with greatest similarity for one cluster to 2016-2017 isolate from Bangladesh, Singapore and China, and for the other cluster to ancestral isolates from Singapore, dating back to 2012. Compared to publicly available DENV-1 genotype I sequences, fifteen non-synonymous mutations were identified in the Reunion strains, including one in the capsid and the others in nonstructural proteins (NS) (three in NS1, two in NS2B, one in NS3, one in NS4B, and seven in NS5). CONCLUSION: In contrast to what was seen in previous outbreaks, recent DENV-1 outbreaks in Reunion and the Seychelles were caused by distinct genotypes, all likely originating from Asia where dengue is (hyper)endemic in many countries. Epidemic DENV-1 strains from Reunion harbored specific non-synonymous mutations whose biological significance needs to be further investigated.

Ophthalmic complications during the dengue epidemic in Reunion Island in 2020: a case series and review of the literature.

INTRODUCTION: Dengue is an arboviral disease transmitted by the dengue virus, whose vectors are Aedes aegypti and Aedes albopictus. The acute phase with its cohort of well-known symptoms is usually spontaneously favorable. Since 2020 in Reunion Island, a new symptom has appeared: the ocular damage of dengue fever, which has already been described in South Asia and South-East Asia. We therefore decided to describe the clinical, biological, ophthalmological, therapeutic, and outcomes of patients with ocular manifestations during dengue fever in Reunion Island in 2020. PATIENTS AND METHODS: This was a retrospective observational study. Patients were included from January 2020 to August 2020 and then reassessed by teleconsultation 1 year later. The patients were identified from the French public health surveillance network by all ophthalmologists on the island. Medical data were collected directly from medical records. RESULTS: Twenty-eight patients were included. The mean age was 41.9 years. Ocular involvement occurred approximately 9.2 days after the onset of dengue symptoms. The main symptoms were scotoma (71.4%) and sudden decrease of visual acuity (39.2%). Eighteen patients (64.2%) had macular involvement. Fourteen patients were treated with oral or intravenous corticosteroids. Twenty-two (78.5%) patients were evaluated by telephone one year later. Scotoma and decreased visual acuity persisted in 15 patients. Thirteen patients (59%) were bothered by night driving, 32% of patients had reading difficulties and 27% of patients became sensitive to prolonged exposure to screens. CONCLUSION: Ocular complications of dengue require early and collegial management to limit the risk of long-term sequelae. Further studies on the characteristics and complications of dengue fever are needed to better understand this disease.

From dengue outbreaks to endemicity: Reunion Island, France, 2018 to 2021.

BackgroundAfter 40 years of limited viral circulation, Reunion Island has since 2018 experienced recurrent dengue outbreaks of increasing intensity and severity.AimWe aimed to report on the epidemiology and characteristics of dengue in Reunion Island between 2018 and 2021.MethodsBetween 2018 and August 2021, we systematically collected data on dengue cases via an automated transmission system between the health authorities and the medical laboratories. We set up additional surveillance systems for dengue-related activity in primary care, in emergency departments and in inpatient departments.ResultsUntil 2020, despite numerous cases, outbreaks had a limited public health impact because of few severe cases, low lethality and no heavy burden for the health care system. In 2021, however, the number of severe cases increased (from 0.4% of all cases in 2018 to 0.8% in 2021), as did the number of paediatric cases (from 8% in 2018 to 15% in 2021) and atypical clinical forms of dengue (108 cases of post-dengue maculopathy). Of note, haemorrhagic forms were rare and multi-organ failure was the most frequent severity throughout the study period. In parallel, the dominant serotype switched from DENV2 to DENV1 in 2020 and DENV1 became the only serotype detected in 2021.ConclusionThese findings indicate that dengue is becoming endemic in Reunion Island. Since comorbidities associated with severity of dengue are common in the population, health authorities should carefully consider the impact of dengue when addressing public health policies.

Spread of SARS-CoV-2 Variants on Réunion Island, France, 2021.

In January 2021, after detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, genomic surveillance was established on Réunion Island to track the introduction and spread of SARS-CoV-2 lineages and variants of concern. This system identified 22 SARS-CoV-2 lineages, 71% of which were attributed to the Beta variant.

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.

Epidemiology of cutaneous malignant melanoma in Reunion Island.

INTRODUCTION: The incidence of cutaneous malignant melanoma (CMM) is increasing worldwide. The aim of this study was to evaluate the epidemiology of CMM in Reunion Island, a French overseas department whose population is characterized by high ethnic diversity and high exposure to ultraviolet radiation. METHODS: This cross-sectional study examined all cases of in situ CMM and invasive CMM diagnosed between 1 January and 31 December 2015 in the Reunionese population. RESULTS: One hundred and three new cases of CMM were recorded in Reunion Island in 2015: 33 cases of in situ CMM and 70 cases of invasive CMM. The sex ratio of men to women was 1.3 and 80% of patients had a fair skin phototype (Fitzpatrick skin phototype≤III). Age-standardized incidence rates of invasive CMM for all skin phototypes combined were 6.7/100,000 person-years (PY) in women and 5.3/100,000 PY in men. Crude incidence rates of invasive CMM for fair skin phototypes were estimated to be over 21/100,000 PY in women and over 25/100,000 PY in men. CONCLUSIONS: In Reunion Island, the incidence of CMM in the population with fair skin phototype is very high. Primary and secondary prevention measures should be reinforced and tailored to the local context.

Differential diagnoses of severe COVID-19 in tropical areas: the experience of Reunion Island.

OBJECTIVE: To identify the differential diagnoses of severe COVID-19 and the distinguishing characteristics of critically ill COVID-19 patients in Reunion Island to help improve the triage and management of patients in this tropical setting. METHODS: This retrospective observational study was conducted from 11 March to 4 May 2020 in the only intensive care unit (ICU) authorised to manage COVID-19 patients in Reunion Island, a French overseas department located in the Indian Ocean region. All patients with unknown COVID-19 status were tested by polymerase chain reaction (PCR) on ICU admission; those who tested negative were transferred to the COVID-19-free area of the ICU. RESULTS: Over the study period, 99 patients were admitted to our ICU. A total of 33 patients were hospitalised in the COVID-19 isolation ward, of whom 11 were positive for COVID-19. The main differential diagnoses of severe COVID-19 were as follows: community-acquired pneumonia, dengue, leptospirosis causing intra-alveolar haemorrhage and cardiogenic pulmonary oedema. The median age of COVID-19-positive patients was higher than that of COVID-19-negative patients (71 [58-74] vs. 54 [46-63.5] years, P = 0.045). No distinguishing clinical, biological or radiological characteristics were found between the two groups of patients. All COVID-19-positive patients had recently travelled or been in contact with a recent traveller. CONCLUSIONS: In Reunion Island, dengue and leptospirosis are key differential diagnoses of severe COVID-19, and travel is the only distinguishing characteristic of COVID-19-positive patients. Our findings apply only to the particular context of Reunion Island at this time of the epidemic.

Prevalence of urogenital, anal, and pharyngeal infections with Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium: a cross-sectional study in Reunion island.

BACKGROUND: Recommendations for sexually transmitted infection (STI) screening vary significantly across countries. This study evaluated the prevalence of urogenital and extragenital infections with Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Mycoplasma genitalium (MG) in patients visiting a French STI clinic in the Indian Ocean region to determine whether current STI screening practices should be updated. METHODS: This cross-sectional study examined all patients who visited the STI clinic between 2014 and 2015. Triplex polymerase chain reaction screening for CT, NG, and MG was performed on urine, vaginal, pharyngeal, and anal specimens (FTD Urethritis Basic Kit, Fast Track Diagnostics, Luxembourg). RESULTS: Of the 851 patients enrolled in the study, 367 were women (367/851, 43.2%) and 484 were men (484/851, 56.0%). Overall, 826 urogenital specimens (826/851, 97.1%), 606 pharyngeal specimens (606/851, 71.2%), and 127 anal specimens (127/851, 14.9%) were taken from enrolled patients. The prevalence of urogenital CT and MG was high in women ≤25 years (19/186, 10.21%; 5/186, 2.69%) and in men who have sex with women ≤30 years (16/212, 7.54%; 5/212, 2.36%). Among patients with urogenital CT infection, 13.7% (7/51) had urethritis. All patients with urogenital MG infection were asymptomatic. Men who have sex with men had a high prevalence of pharyngeal CT (2/45, 4.44%) and NG (3/44, 6.81%) and a high prevalence of anal CT (2/27, 7.41%), NG (2/27, 7.40%), and MG (1/27, 3.70%). After excluding patients with concomitant urogenital infection, extragenital infections with at least 1 of the 3 pathogens were found in 20 swabs (20/91, 21.9%) taken from 16 patients (16/81, 19.7%), all of them asymptomatic. CONCLUSIONS: Routine multisite screening for CT, NG, and MG should be performed to mitigate the transmission of STIs in high-risk sexually active populations.

Serological and molecular detection of pathogenic Leptospira in domestic and stray cats on Reunion Island, French Indies.

Indian Ocean islands are endemic areas for human and animal leptospirosis. Maintenance host species for Leptospira spp. have still not been completely elucidated, and recently the role of cats (Felis catus) has been questioned. This cross-sectional study aims to determine whether cats are part of the maintenance community of different strains of Leptospira spp. in Reunion Island. The prevalence of Leptospira infection in an opportunistic sample of stray and domestic cats (n = 92) from Reunion Island has been studied using serological (microagglutination test) and molecular detection (polymerase chain reaction (PCR)). The results revealed a seroprevalence of 37.0% (34/92) (cut-off 1:40) without a significant difference in the living conditions of animals. The predominant serogroup was Icterohaemorrhagiae, but Ballum, Cynopteri and Australis were also detected. Using PCR, 28.6% (12/42) of stray cats were tested positive. Leptospiral DNA was detected in renal tissue, urine and blood of respectively 14.3% (6/42), 10.3% (4/39) and 11.9% (5/42) of stray cats, but 0% (0/3), 0% (0/50) and 0% (0/36) of domestic cats (P = non-applicable, P = 0,038, P = 0,058 respectively). Partial rrs gene (16S rRNA) sequencing identified Leptospira interrogans in all PCR-positive samples. Our study confirms that renal carriage and urinary shedding are possible, positioning cats, and especially stray cats as potential actors within the maintenance community of L. interrogans in Reunion Island.

Prevalence and risk factors of Mycoplasma genitalium infection in patients attending a sexually transmitted infection clinic in Reunion Island: a cross-sectional study (2017-2018).

BACKGROUND: Mycoplasma genitalium (MG) is an emerging sexually transmitted infection (STI) for whose management remains controversial. We aimed to assess the prevalence and risk factors of MG infection in patients attending an STI clinic in Reunion Island. METHODS: Between January 2017 and December 2018, all patients attending the Saint-Pierre STI clinic in Reunion Island were screened for MG, Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). Urogenital, pharyngeal and/or anal samples were collected based on sexual behaviour and analysed by triplex PCR. Risk factors were identified using a Poisson regression for binary outcome. RESULTS: Among 2069 screened subjects, the overall prevalence of MG was 4.88% [95% Confidence Interval (CI) 3.98-5.93]. The prevalence of urogenital MG was 4.38%, with women being more affected than men (5.33% vs 3.22%, prevalence ratio (PR) 1.66, p = 0.02). The prevalence of anal MG was 3.06% and that of pharyngeal MG was 0.61%, with men being more affected in both cases. Infection with MG was independently associated with multiple partners (6-10 partners: adjusted prevalence ratio-aPR 2.55, p < 0.048; > 10 partners: aPR 4.33, p < 0.004), previous history of STI (aPR 1.89, p = 0.026), non-use of condoms (aPR 2.56, p < 0.003) and co-infection with CT (aPR 2.56, p < 0.017). CONCLUSION: Compared to other countries, the prevalence of MG is high in Reunion Island, especially in women aged under 25 years, and co-infection with CT is common. Routine MG screening and treatment should be performed in at-risk women and co-infection with MG should be considered when deciding on treatment for CT, particularly in regions where azithromycin is still in use.

High prevalence of syphilis in women, minors and precarious patients: a cross-sectional study in a Reunion Island sexually transmitted infection clinic, 2017-2020.

BACKGROUND: Syphilis is a sexually transmitted infection (STI) with a global prevalence estimated at 0.5% in 2012. Syphilis has been on the rise among men who have sex with men (MSM) in high-income countries and remains at endemic levels in low- and middle-income countries. This trend, however, has not been observed in Reunion Island. OBJECTIVES: To determine the prevalence, clinical characteristics and risk factors of syphilis in at-risk patients visiting the South Reunion STI clinic in Reunion Island. METHODS: This monocentric cross-sectional study included all patients who visited our STI clinic between 2017 and 2020. Syphilis serology was performed on all included patients, and data were collected using a standardized self-administered questionnaire. RESULTS: Over the 3-year study period, 2593 patients were enrolled. The prevalence of syphilis was 7.52% (n = 195, 95% CI, 6.50-8.65%) in the overall study population, 11.76% (n = 18, 95% CI, 6.97-18.59%) in minors (aged under 18 years) and 36.36% (n = 16, 95% CI, 21-59%) in pregnant women. The risk factors identified in multivariate analysis were being female [adjusted Prevalence Ratio (aPR) 1.85, 95% CI, 1.10-3.11], being MSM (aPR 2.87, 95% CI, 1.71-4.80), being aged under 18 years (aPR 3.54, 95% CI, 1.90-6.57), living in precarious conditions [aPR 3.12, 95% CI, 2.11-4.62] and being born in Reunion Island (aPR 2.43, 95% CI, 1.42-4.13). The clinical presentation was heterogeneous (plaques and papules, chancre, atypical ulcerations, multiple ulcerations, condyloma lata, etc.). CONCLUSIONS: These findings suggest a high prevalence of syphilis in at-risk patients visiting our STI clinic. Unlike the situation in other high-income countries, the people most at risk of syphilis in Reunion Island are local-born residents, minors, women and precarious patients. This is a source of concern, especially given the risk of resurgence of congenital syphilis on the island.

Instability of the NS1 Glycoprotein from La Reunion 2018 Dengue 2 Virus (Cosmopolitan-1 Genotype) in Huh7 Cells Is Due to Lysine Residues on Positions 272 and 324.

La Reunion island in the South West Indian Ocean is now endemic for dengue following the introduction of dengue virus serotype 2 (DENV-2) cosmopolitan-I genotype in 2017. DENV-2 infection causes a wide spectrum of clinical manifestations ranging from flu-like disease to severe dengue. The nonstructural glycoprotein 1 (NS1) has been identified as playing a key role in dengue disease severity. The intracellular NS1 exists as a homodimer, whereas a fraction is driven towards the plasma membrane or released as a soluble hexameric protein. Here, we characterized the NS1 glycoproteins from clinical isolates DES-14 and RUN-18 that were collected during the DENV-2 epidemics in Tanzania in 2014 and La Reunion island in 2018, respectively. In relation to hepatotropism of the DENV, expression of recombinant DES-14 NS1 and RUN-18 NS1 glycoproteins was compared in human hepatoma Huh7 cells. We observed that RUN-18 NS1 was poorly stable in Huh7 cells compared to DES-14 NS1. The instability of RUN-18 NS1 leading to a low level of NS1 secretion mostly relates to lysine residues on positions 272 and 324. Our data raise the issue of the consequences of a defect in NS1 stability in human hepatocytes in relation to the major role of NS1 in the pathogenesis of the DENV-2 infection.

[Psychological impact of the COVID-19 pandemic: Comparison between residents of metropolitan France and of Reunion Island]. / Impact psychologique de la pandémie de la COVID-19 : comparaison entre des Français métropolitains et de l'île de La Réunion.

OBJECTIVES: The COVID-19 pandemic raised a lot of anxiety around the world. France is composed of several overseas territories with major cultural differences but also with a different exposure to the COVID-19. Reunion Island is the most populated overseas French department, but few researches have focused on this population. Therefore, the main objective was to explore and compare the impact of the COVID-19 pandemic (perceived stress, risk and fear of being infected, severity, lockdown respect, perceived stress, quality of life, quality of relationship, loneliness, resilience) during the lockdown among residents of metropolitan France and of Reunion Island. MATERIAL AND METHODS: A sample of 347 participants, aged from 18 to 78 (M=37.90; DS=13.20) replied to a questionnaire posted online during the last ten days of the lockdown in France. The sample is divided into 227 metropolitans (M=38.24 DS=13.41; 13.2% of men) and 120 residents of Reunion Island (M=37.26; DS=12.81; 31.7% of men). Resilience, loneliness and perceived stress have been assessed using validating scales while specific items have been created to assess COVID-19 impacts. RESULTS: The majority of the total sample has been little exposed to the COVID-19, but the estimated severity was high throughout the sample. Several significant differences have been observed between overseas and metropolitans. The latter, who were more exposed, were more respectful of lockdown measures and felt more concerned about being contaminated. They also had different professional activities (work at home, stop working) since the lockdown than did the overseas sample. Non-significant higher scores of resilience and quality of life during the lockdown contrast in the overseas sample, who estimated risk, fear and severity similarly. In correlational analyses, many relationships were significant only in one sample. For example, in metropolitans the higher the loneliness, the higher the severity. In the other sample, the higher the perceived stress, the higher the respect of lockdown measures, while more metropolitans felt lonely the more they respected these measures. Regressional analysis showed different predictive variables of the scores of perceived stress and fear of being contaminated. In metropolitans, stress was explained by COVID-19 related variables (fear, severity, respect), loneliness and negatively by resilience and quality of life while in the other sample it was explained by fear of being infected and negatively by resilience. Fear of being infected was explained by risk and stress in the overseas, but also by quality of life in the metropolitan sample. CONCLUSIONS: This study brings new data on the important psychosocial impact of the COVID-19 pandemic on two French samples. Observed differences highlight a higher fear of being infected among the metropolitans who were generally more exposed. Overseas from La Réunion did not feel more spared by this risk, despite the limited number of cases since the appearance of the first case in March 11th and the end of the lockdown in May 11th. Despite exposure, our results could be explained by several cultural differences such as way of life or beliefs. Overseas life in Reunion Island might bring more resilience and less loneliness given the particular familial, social and religious functioning. Given the limits of this study and the lack of similar comparisons, more work could highlight the protective factors of these populations.

Minors are the most affected by Chlamydia trachomatis in Reunion Island: A cross-sectional study, 2017-2018.

OBJECTIVES: To determine the prevalence of Chlamydia trachomatis (CT) in the population screened at sexually transmitted infection (STI) clinics on Reunion Island and to identify risk factors for CT infection. PATIENTS AND METHODS: This cross-sectional multicenter study was conducted in 2017-2018. Data were obtained from self-administered questionnaires and multiplex PCR tests. RESULTS: The overall prevalence of CT in the screened population was 8.6% (95% CI 7.7-9.5%). The prevalence of urogenital CT was highest in women under 18 (13.2%, 95% CI 9.3-18.1%) and in men who have sex with men under 18 (13.3%, 95% CI 1.6-48.2%). Risk factors associated with CT infection in multivariate analysis were: female gender, being born in Reunion Island, having had a large number of sexual partners in the past year, and being co-infected with another STI. CONCLUSIONS: The prevalence of CT in the screened population is higher in Reunion Island than in mainland France, especially in minors. Prevention campaigns targeting minors should be strengthened.

Azithromycin resistance in Treponema pallidum in Reunion Island: A cross-sectional study.

OBJECTIVE: Since the beginning of the 21st century, Reunion Island has experienced a syphilis epidemic. Infected patients are mostly heterosexual, with a high proportion of women, suggesting that congenital syphilis is present on the island. To determine whether azithromycin can be used for mass treatment of syphilis on Reunion Island, we assessed the prevalence of macrolide resistance in Treponema pallidum (TP). METHODS: This monocentric cross-sectional study was conducted at the Reunion Island University Hospital. Samples were collected from lesions suggestive of primary or secondary syphilis. Samples positive for TP by multiplex polymerase chain reaction (PCR) were sent to the French National Reference Centre (NRC) for further analysis. Nested PCR-tpp47 was performed on these samples for detection of TP-DNA; 23s rRNA was amplified by PCR in confirmed positive samples. The Restriction Fragment Length Polymorphism (RFLP) technique was performed on samples with amplified 23s rRNA for detection of the A2058G mutation. RESULTS: A total of 129 samples were collected from 119 patients. Of these, 18 tested positive for TP using multiplex PCR and were sent to the NRC. Fifteen (83.3%) of the 18 samples were confirmed positive by nested PCR-tpp47, and 23s rRNA was amplified in only 7 (38.9%) samples. Azithromycin resistance was detected in all TP strains with amplified 23s rRNA. CONCLUSION: Amplification of 23s rRNA was successful in only 7 TP strains, all of which displayed resistance to macrolides. Keeping in mind the small sample size of our study, this suggests that azithromycin should not be used for mass treatment of syphilis in Reunion Island.

Chikungunya-Induced Arthritis in Reunion Island: A Long-Term Observational Follow-Up Study Showing Frequently Persistent Joint Symptoms, Some Cases of Persistent Chikungunya Immunoglobulin M Positivity, and No Anticyclic Citrullinated Peptide Seroconversion After 13 Years.

BACKGROUND: Reunion Island was struck by a massive Chikungunya outbreak in 2005-2006. Chikungunya infection is characterized by inflammatory joint symptoms, which may evolve into chronic arthritis. METHODS: In this long-term longitudinal observational monocentric study, after the 2005-2006 outbreak in Reunion Island, 159 patients were first referred to a rheumatologist for post-Chikungunya chronic musculoskeletal pain, 73 of them were diagnosed with classifiable Chikungunya-related chronic inflammatory rheumatic diseases (>3 month symptom duration from the initial viral infection). Thirty of these 73 patients were clinically evaluated by a second rheumatologist in 2018-2019. The main objective of this second examination was to estimate the proportion of patients with persistent Chikungunya-related inflammatory joint symptoms after 13 years. RESULTS: Inflammatory joint symptoms persisted in 17/30 patients after 13 years (therefore in at least 23.3% of the 73 patients initially diagnosed with Chikungunya-related inflammatory joint symptoms and 10.7% of the 159 patients referred for post-Chikungunya chronic musculoskeletal pain). In the symptom persistence subgroup, the prevalence of positive autoantibodies (antinuclear or ACPA) was significantly higher - without any seroconversion, Chikungunya IgG and IgM levels were higher, long-term IgM positivity and radiographic damage were more frequent. Overall, after 13 years, pain and fatigue levels remained significant, 5 patients were still treated by methotrexate, 3 by TNF-blockers, highlighting long-term Chikungunya-related patient burden. CONCLUSIONS: Such a long-term persistence of Chikungunya-related chronic inflammatory rheumatic diseases had not been reported so far. Furthermore, the long-term Chikungunya IgM positivity we observed in some cases might corroborate the hypothesis of residual viral antigen-driven chronic arthritis.