Guideline No. 408: management of gestational trophoblastic diseases

This guideline reviews the clinical evaluation and management of gestational trophoblastic diseases, including surgical and medical management of benign, premalignant, and malignant entities. The objective of this guideline is to assist health care providers in promptly diagnosing gestational trophoblastic diseases, to standardize treatment and follow-up, and to ensure early specialized care of patients with malignant or metastatic disease. General gynaecologists, obstetricians, family physicians, midwives, emergency department physicians, anaesthesiologists, radiologists, pathologists, registered nurses, nurse practitioners, residents, gynaecologic oncologists, medical oncologists, radiation oncologists, surgeons, general practitioners in oncology, oncology nurses, pharmacists, physician assistants, and other health care providers who treat patients with gestational trophoblastic diseases. This guideline is also intended to provide information for interested parties who provide follow-up care for these patients following treatment. Women of reproductive age with gestational trophoblastic diseases. Women diagnosed with a gestational trophoblastic disease should be referred to a gynaecologist for initial evaluation and consideration for primary surgery (uterine evacuation or hysterectomy) and follow-up. Women diagnosed with gestational trophoblastic neoplasia should be referred to a gynaecologic oncologist for staging, risk scoring, and consideration for primary surgery or systemic therapy (single- or multi-agent chemotherapy) with the potential need for additional therapies. All cases of gestational trophoblastic neoplasia should be discussed at a multidisciplinary cancer case conference and registered in a centralized (regional and/or national) database. Relevant studies from 2002 onwards were searched in Embase, MEDLINE, the Cochrane Central Register of Controlled Trials, and Cochrane Systematic Reviews using the following terms, either alone or in combination: trophoblastic neoplasms, choriocarcinoma, trophoblastic tumor, placental site, gestational trophoblastic disease, hydatidiform mole, drug therapy, surgical therapy, radiotherapy, cure, complications, recurrence, survival, prognosis, pregnancy outcome, disease outcome, treatment outcome, and remission. The initial search was performed in April 2017 and updated in May 2019. Relevant evidence was selected for inclusion in the following order: meta-analyses, systematic reviews, guidelines, randomized controlled trials, prospective cohort studies, observational studies, non-systematic reviews, case series, and reports. Additional significant articles were identified through cross-referencing the identified reviews. The total number of studies identified was 673, with 79 studies cited in this review. The content and recommendations were drafted and agreed upon by the authors. The Executive and Board of Directors of the Society of Gynecologic Oncology of Canada reviewed the content and submitted comments for consideration, and the Board of Directors for the Society of Obstetricians and Gynaecologists of Canada approved the final draft for publication. The quality of evidence was rated using the criteria described in the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology framework. See the online appendix tables for key to grading and interpretation of recommendations. These guidelines will assist physicians in promptly diagnosing gestational trophoblastic diseases and urgently referring patients diagnosed with gestational trophoblastic neoplasia to gynaecologic oncology for specialized management. Treating gestational trophoblastic neoplasia in specialized centres with the use of centralized databases allows for capturing and comparing data on treatment outcomes of patients with these rare tumours and for optimizing patient care.

Same-day discharge of Gynecologic Oncology patients following ileostomy closure is feasible and safe.

OBJECTIVE: Gynecologic Oncology patients are traditionally admitted for 2-3 days following ileostomy closure. Our aim was to assess feasibility and safety of same-day discharge (SDD), by comparing 30-day clinical outcomes after SDD and standard admission. METHODS: Retrospective study of patients who underwent ileostomy closure at two academic tertiary centres in Toronto, Canada, between January 2010 and October 2017. RESULTS: In total 117 patients underwent ileostomy closure: 23 had SDD and 94 were admitted for a median of 3 days. There were no significant differences between groups in terms of age, body mass index, comorbidities, primary malignancy, tumor stage, indication for ileostomy, previous radiation therapy, chemotherapy, interval between ileostomy formation and closure, and intraoperative complications. Median operative time was shorter (47 versus 60 min, p = 0.0001) and there was a longer median interval between last chemotherapy cycle to ileostomy closure (145 versus 106 days, p = 0.01) in the SDD group. SDD was not associated with an increased risk of adverse events (13% versus 24.5%, p= 0.24), as assessed by a composite outcome which included small bowel obstruction, anastomotic leak, surgical site infection, clostridium difficile infection, sepsis, and thromboembolic events, when compared to standard admission. Moreover, SDD did not lead to more emergency room visits (17.4% versus 16%, p = 0.87) or readmissions within 30 days of surgery (17.4% versus 8.5%, p= 0.21). CONCLUSIONS: SDD is a safe alternative to routine hospitalization that has the potential to improve healthcare resource utilization, without increasing readmissions or emergency room visits. Careful patient selection is warranted.

Prevalence of Equine Hepacivirus Infections in France and Evidence for Two Viral Subtypes Circulating Worldwide.

Like hepatitis C virus (HCV) in humans, the newly identified equine hepacivirus (NPHV) displays a predominating liver tropism that may evolve into chronic infections. The genomes of the two viruses share several organizational and functional features and are phylogenetically closest amongst the Hepacivirus genus. A limited amount of data is available regarding the spread of hepacivirus infections in horses. In this study, we asked whether in a more representative sample the prevalence and distribution of NPHV infections in France would resemble that reported so far in other countries. A total of 1033 horses sera from stud farms throughout France were analysed by qRT-PCR to determine the prevalence of ongoing NPHV infections and viral loads; in positive samples, partial sequences of NPHV's genome (5'UTR, NS3 and NS5B genes) were determined. Serum concentrations of biliary acids, glutamate dehydrogenase (GLDH) and L-gamma-glutamyl transferase (γ-GT) were measured for most horses. We detected NPHV infections in 6.2% of the horses, a prevalence that reached 8.3% in thoroughbreds and was significantly higher than in other breeds. The presence of circulating virus was neither significantly associated with biological disturbances nor with clinical hepatic impairment. Our phylogenetic analysis was based on both neighbour-joining and maximum-likelihood approaches. Its result shows that, like almost everywhere else in the world so far, two major groups of NPHV strains infect French domestic horses. Based on genetic distances, we propose a classification into two separate NPHV subtypes. Viral loads in the serum of horses infected by the main subtype were, in average, four times higher than in those infected by the second subtype. We hypothesize that amino acid substitutions in the palm domain of NS5B between NPHV subtypes could underlie viral phenotypes that explain this result.

Genetic evolution of equine influenza strains isolated in France from 2005 to 2010.

UNLABELLED: REASON FOR PERFORMING THIS STUDY: Equine influenza virus (EIV) is considered the most economically important equine respiratory pathogen worldwide. The H3N8 subtype, responsible for all outbreaks of equine influenza globally, evolves perpetually. Mutations in the genome of these viruses have the potential to modify their antigenic properties and recognition by pre-existing antibodies. OBJECTIVES: The aim of this study was to determine the genetic evolution of EIV strains in France and to compare it with the evolution of strains isolated globally. Analysis of the sequence data was performed to investigate any possible links between the outbreaks. STUDY DESIGN: Retrospective genetic analysis study of archived material. METHODS: Analyses were performed on the HA1 domain of haemagglutinin H3 of EIV isolated in a previous study carried out from November 2005 to October 2010. The nucleic acid sequence of 41 strains was analysed and translated. The French viruses were compared with 59 Clade 1 strains and 83 Clade 2 strains. Strains were aligned chronologically and on the basis of their geographical origin. RESULTS: The 16 Clade 1 strains are all derived from the outbreak that started in the Grosbois training yard in 2009. The virus genome appears to have been stable during the outbreak. The 25 Clade 2 strains were isolated over the 5-year period during which several mutations had emerged. Some strains incorporate a sporadic mutation, and others a mutation that may occur several times but does not persist. However, all strains are gradually moving towards definitive mutations. CONCLUSION: This study demonstrated that EIVs have evolved in France during this period in a similar manner to EIVs globally. The data lend support to the current World Animal Health Organisation recommendation that the vaccines contain a representative of both Clade 1 and Clade 2 of the Florida sublineage.

Cytokine concentrations in bronchoalveolar lavage fluid from horses with neutrophilic inflammatory airway disease.

BACKGROUND: Multiple cytological patterns occur in bronchoalveolar lavage fluid (BALF) of horses with inflammatory airway disease (IAD). Only few data on BALF cytokine profiles are available for horses with IAD, and are limited to mRNA expression. HYPOTHESIS/OBJECTIVE: Cytological profiles of IAD are associated with different BALF immunological pathways. To investigate BALF cytokine concentrations in a large number of horses with neutrophilic IAD. ANIMALS: One hundred and thirty-eight client-owned Standardbred racehorses in active training. METHODS: Prospective observational study. BALF samples were obtained from left and right lungs. Interleukin (IL)-4, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α concentrations were determined by ELISA. RESULTS: Fourteen horses had normal BALF cytological profiles and 56 exhibited evidence of bilateral neutrophilic IAD. Twenty-four horses showed BALF with, respectively, IAD- and CTL consistent cytology and were excluded; as were 44 horses because of evidence of pulmonary hemorrhage. TNF-α (56 ± 115 pg/mL; P = .034) and IFN-γ concentrations (104 ± 247 pg/mL; P = .044) were significantly higher for IAD horses, compared with controls (respectively 19 ± 41 and 80 ± 116 pg/mL). Horses with 'neutrophil' subtype had significantly higher IFN-γ concentrations (110 ± 154 pg/mL), than 'neutrophil/metachromatic' (56 ± 54 pg/mL; P = .028) and 'neutrophil/metachromatic/eosinophil' subtypes (44 ± 23 pg/mL; P = .012). CONCLUSIONS AND CLINICAL IMPORTANCE: Cytokine concentrations in BALF suggested that neutrophilic IAD is associated with activation of the innate immune system and a possible T-helper (Th)-1 polarized response. This study also suggested that immunological pathways vary according to cytological IAD subtypes.

Surveillance of equine influenza viruses through the RESPE network in France from November 2005 to October 2010.

REASONS FOR PERFORMING THE STUDY: The Réseau d'Epidémio-Surveillance en Pathologie Equine (RESPE, the French epidemiological network for equine diseases) is a network for epidemio-surveillance of major equine diseases based around sentry veterinarians in France. OBJECTIVE: The aim of this study was to evaluate the contribution of RESPE to efficient surveillance of equine influenza virus (EIV) in France. STUDY DESIGN: Retrospective cross-sectional study. METHODS: From November 2005 to October 2010, epidemiological and phylogenetic studies were performed on 1426 nasopharyngeal swabs received at the Frank Duncombe Laboratory. Detection was performed by real-time reverse transcription polymerase chain reaction using original primers and probes designed in the matrix protein gene. Phylogenetic analysis was carried out on the HA1 part of haemagglutinin gene amplified from 47 positive-testing samples. Epidemiological information was provided with the majority of samples submitted through RESPE. RESULTS: Of the 920 samples submitted by RESPE-associated veterinarians, 121 (13.1%) from 42 premises were positive for EIV, compared to 26 (5.1%) of the 607 samples received from non-RESPE associated veterinarians. The most extensive outbreak was observed between February and May 2009, affecting 70 horses on 23 premises, 15 of which were managed by RESPE-associated veterinarians. All strains belonged to the American lineage, Florida sublineage, Clade 1 and Clade 2. Clade 1 was identified only during the Grosbois episode. CONCLUSION: RESPE improved detection of EIV in France, enabled characterisation of the virus strains, yielded valuable information relating to the epidemiology of the disease and identified vaccine breakdown. POTENTIAL RELEVANCE: Implementation of a similar surveillance network in other countries may reduce the economic losses associated with outbreaks of EIV.

Outbreak of equine herpesvirus myeloencephalopathy in France: a clinical and molecular investigation.

Equid herpesvirus 1 (EHV-1)-associated myeloencephalopathy (EHM) is a disease affecting the central nervous system of horses. Despite the constantly increasing interest about this syndrome, epidemiological data are limited especially when related to the description of large outbreaks. The aim of this article is to describe clinical, virological and molecular data obtained throughout a severe outbreak of EHM, with emphasis on laboratory diagnostic methods. The epidemic disease concerned a riding school in France where 7/66 horses aged 12-22 years developed signs of neurological disease in July 2009. Diagnosis of EHM was supported by EHV-1 detection using both real-time PCR and virus culture, and SNP-PCR test for viral strain characterization. EHM morbidity was 10.6% (7/66), mortality was 7.5% (5/66) and case fatality rate was 71.4% (5/7). Clinical presentation of the disease was characterized by the fact that fever was systematically present within 2 days before the severe neurological signs were noted. EHV-1 was detected by PCR in each available blood and nasal swab samples. Neuropathogenic strain only (G(2254) ) was isolated during the current outbreak; C(t) values, used as an indicative level of the viral load, ranged 26.0-37.0 among the six sampled horses. The amount of virus in biological samples was not systematically related to the intensity of the clinical signs being observed. In conclusion, this article described a severe outbreak of EHM while limited in time and restricted to one premise. Molecular data strongly suggested taking into account any low viral load as being a potential risk factor for neurological manifestations.

Serum concentration of surfactant protein D in horses with lower airway inflammation.

REASONS FOR PERFORMING STUDY: Surfactant protein D (SP-D), mainly synthesised by alveolar type II cells and nonciliated bronchiolar cells, is one important component of innate pulmonary immunity. In man, circulating concentrations of SP-D are routinely used as biomarkers for pulmonary injury. To date, serum SP-D levels have only been investigated in horses in an experimental model of bacterial airway infection. OBJECTIVES: To compare serum SP-D concentrations at rest and after exercise in horses with and without inflammatory airway disease (IAD). METHODS: Venous blood samples were collected from 42 Standardbred racehorses at rest and 60 min after performing a standardised treadmill exercise test. Tracheal wash and bronchoalveolar lavage fluid (BALF) samples were collected after exercise. Based on BALF cytology, 22 horses were defined as IAD-affected and 20 classified as controls. Serum SP-D concentrations were assessed using a commercially available ELISA kit and statistically compared between groups of horses and sampling times. RESULTS: Serum concentrations of SP-D in IAD-affected horses were significantly higher than those of control horses, both at rest and after exercise. Within the IAD-affected group, no significant correlation was found between serum SP-D concentrations and BALF cytology. Within each group of horses (IAD and control), no significant influence of exercise was found on serum SP-D levels. CONCLUSIONS: This is the first study determining serum SP-D concentrations in a noninfectious, naturally occurring form of lower airway inflammation in horses. The results highlight that IAD is associated with a detectable, though moderate, increase of circulating SP-D levels. POTENTIAL RELEVANCE: Serum concentration of surfactant protein D could represent a potentially valuable and readily accessible blood biomarker of equine lower airway inflammation.

Description of the first recorded major occurrence of equine viral arteritis in France.

REASONS FOR PERFORMING STUDY: The vast majority of equine arteritis virus (EAV) infections are inapparent or relatively mild, but may occasionally cause outbreaks of equine viral arteritis. The event observed in France during the summer of 2007 was the most important seen in the country, with mortality and disruption of economic activity. OBJECTIVES: To describe the different stages seen during the outbreak and to show how molecular tools were used for both the detection and management of the crisis. METHODS: EAV detection was performed by real-time reverse transcription-polymerase chain reaction (RT-PCR) in blood, nasal swabs, semen or organ samples. Characterisation of EAV strains was performed by sequencing the ORF5 fragment. RESULTS: The outbreak affected 18 premises in 5 counties in western France, which represented the index, 8 primary and 9 secondary premises. Artificial insemination in draught horses was responsible for the virus spread. Eight mortality cases were observed, including one fetus, 5 young foals and 2 mature horses. Forty-three individuals had positive results by real-time RT-PCR. The range of measured cycle threshold (Ct) values varied from 19.8 to 40.4 depending on the biological samples. Phylogenetic analysis revealed that the 33 isolated strains all clustered within the EU-2 subgroup. CONCLUSIONS: The mortality rate attests to the virulence of the strain involved in this outbreak. Real-time RT-PCR was used for the first time in order to follow-up an epidemic disease in horses. POTENTIAL RELEVANCE: The early detection of 3 signals with high Ct values attest the importance of taking low signals into account in field conditions.

Physiological measurements and prevalence of lower airway diseases in Trotters with dorsal displacement of the soft palate.

REASONS FOR PERFORMING STUDY: Dorsal displacement of the soft palate (DDSP) is one of the most common obstructive conditions of the upper respiratory tract in the racehorse. This condition has a complex aetiology which may be caused or exacerbated by pharyngeal inflammation. Additionally, lower respiratory airway diseases may be associated with DDSP thereby contributing to exercise intolerance in these horses. OBJECTIVE: The aim of this study was to measure physiological variables during a standardised exercise test and to assess the prevalence and consequences of lower respiratory airway disease in horses with DDSP. METHODS: A total of 46 horses were included in this study: 22 in the control and 24 in the DDSP groups. All horses performed a SET with measurement of heart rate (HR) and blood lactate concentration. One hour post exercise, respiratory samples were collected for cytological and bacteriological analysis. RESULTS: During exercise, the DDSP group had higher blood lactate concentration than the control group. According to BAL results, 50 and 63% of control and DDSP group horses, respectively, had evidence of inflammatory airway disease (IAD). In the DDSP group, 42% of horses had a syndrome of tracheal inflammation (STI) with 71% of this group having bacteria isolated at >10(5) CFU/ml. CONCLUSIONS: Horses with DDSP showed evidence of a high prevalence of IAD and STI with an associated positive bacteriology in 55% of the cases. Even if DDSP is treated by surgery, the authors' recommendation would be to investigate the possibility of lower respiratory airway problems which may also be impacting the horse's performance and/or surgery efficiency.

Influence of subclinical inflammatory airway disease on equine respiratory function evaluated by impulse oscillometry.

REASONS FOR PERFORMING STUDY: Inflammatory airway disease (IAD) is a nonseptic condition of the lower respiratory tract. Its negative impact on respiratory function has previously been described using either forced expiration or forced oscillations techniques. However, sedation or drug-induced bronchoconstriction were usually required. The impulse oscillometry system (IOS) is a noninvasive and sensitive respiratory function test validated in horses, which could be useful to evaluate IAD-affected horses without further procedures. OBJECTIVES: To determine the sensitivity of IOS in detecting alterations of the respiratory function in subclinically IAD-affected horses without inducing bronchoprovocation and to characterise their respiratory impedance according to frequency for each respiratory phase. METHODS: Pulmonary function was evaluated at rest by IOS in 34 Standardbred trotters. According to the cytology of bronchoalveolar lavage fluid (BALF), 19 horses were defined as IAD-affected and 15 horses were used as control (CTL). Total respiratory resistance (Rrs) and reactance (Xrs) from 1-20 Hz as well as their inspiratory and expiratory components were compared between groups. RESULTS: A significant increase of Rrs at the lower frequencies (R1-10 Hz) as well as a significant decrease of Xrs beyond 5 Hz (X5-20 Hz) was observed in IAD compared to CTL horses. IOS-data was also significantly different between inspiration and expiration in IAD-affected horses. In the whole population, both BALF eosinophil and mast cell counts were significantly correlated with IOS measurements. CONCLUSIONS: Functional respiratory impairment may be measured, even in the absence of clinical signs of disease. In IAD-affected horses, the different parameters of respiratory function (Rrs or Xrs) may vary depending on the inflammatory cell profiles represented in BALF. POTENTIAL RELEVANCE: Impulse oscillometry could be used in a routine clinical setting as a noninvasive method for early detection of subclinical respiratory disease and of the results of treatment in horses.

[Management of autoimmune thrombocytopenic purpura: a prospective study of 147 children from the regional network RHémaP]. / Purpura thrombocytopénique auto-immun: à propos d'une cohorte prospective de 147 enfants pris en charge dans le réseau d'hématologie pédiatrique des régions PACA et Corse (RHémaP).

AIM: Assessment of the impact of guidelines from a regional pediatric network to standardize the management of childhood immune thrombocytopenic purpura (ITP). MATERIALS AND METHODS: Consensus guidelines were drawn up in centers of the pediatric network for hematological diseases, RHémaP, and a cohort of children referred for ITP in these centers was set up. A 1-year follow-up was recorded for each patient over a 43-month period. RESULTS: We report data from a cohort of 147 children. At diagnosis, we recorded severe thrombocytopenia (median=8G/l) and 141 children had hemorrhagic symptoms (96%). Only 23 children had a bone marrow aspiration (BMA) at diagnosis (16.3%), which meant a high level of implementation of the RHémaP recommendations (96%) since indications of BMA were limited to rare indications. For 135 children (91.8%), treatment fulfilled the RHémaP guidelines that were mainly based on the platelet count: 121 received intraveinous immunoglobulin (IVIG) and 14 were not treated. Among those who received IVIG, 110 were good responders (91%) at the 96-h evaluation (platelet count greater than 20G/l), nine (7.4%) were poor responders, and 1 died of intracranial hemorrhage. At 6 months, chronic ITP was observed in 40 children (32.8%). Chronic ITP was associated with a higher platelet count at diagnosis and an older age (p<10(-3) and p=10(-3), respectively). CONCLUSION: The practices recorded over a 43-month period in our cohort fulfilled the RhémaP guidelines and we conclude that we managed to standardize regional practices for children with ITP. We observed conventional epidemiological characteristics in this cohort. Older children and higher platelet count at diagnosis were significantly associated with higher frequency of chronic ITP.

Detection of equine herpesviruses in aborted foetuses by consensus PCR.

The major role of EHV-1 in equine abortion is widely reported in the literature but the contribution of EHV-2, EHV-3, EHV-4 or EHV-5 remains less well documented. The objective of this study is to evaluate the contribution of these five different EHVs to equine abortion in a variety of biological tissues using a consensus polymerase chain reaction (PCR). The test was validated for specificity and sensitivity in horses before screening specimens from 407 foetuses, stillbirths and premature foals collected over a 2.5-year interval. Positive results obtained with this assay were compared to other EHV type-specific PCR or by sequencing. EHV-1 was identified as the major cause of abortion in French mares (59/407 cases). However, there was evidence to suggest some variation in the potential of EHV-1 strains to induce abortion. Indeed, DNA samples from EHV-2 (in three cases) and EHV-5 (in one case) inferred a role of these viruses in abortion. The presence of viral DNA from EHV-3 or EHV-4 strains was not detected in the specimens studied. The data obtained suggest that the consensus herpesvirus PCR is an efficient screening tool. In association with a specific PCR, the test provides a rapid identification of the type of herpesvirus involved in abortion and is useful for routine diagnostic tests as it allows the identification of herpesviruses other than the EHV-1 strain.

Genetic variation and phylogenetic analysis of 22 French isolates of equine arteritis virus.

Genetic variation and phylogenetic relationships among 22 French isolates of equine arteritis virus (EAV) obtained over four breeding seasons (2001-2004) were determined by sequencing open reading frames (ORFs) 2a-7. The ORFs 2a-7 of 22 isolates differed from the prototype virulent Bucyrus strain of EAV by between 14 (99.5% identity) and 328 (88.7% identity) nucleotides, and differed from each other by between 0 (100% identity) and 346 (88.1% identity) nucleotides, confirming genetic diversity among EAV strains circulating in France. Phylogenetic analysis based on the partial ORF5 sequences (nucleotides 11296-11813) of 22 French isolates and 216 additional EAV strains available in GenBank clustered the global isolates of EAV into two distinct groups: North American and European. The latter could be further divided into two large subgroups: European subgroup 1 (EU-1) and European subgroup 2 (EU-2). Phylogenetic analysis based on 100 EAV ORF3 sequences yielded similar results. Of the 22 French EAV isolates, the 11 isolates obtained before January 28, 2003 clustered with either the EU-1 (9 isolates) or EU-2 (2 isolates) subgroup. In contrast, by the criteria used in this study, the 11 isolates obtained after January 30, 2003 belong to the North American group, strongly suggesting that these strains were recently introduced into France.

[An epidemiological survey of equine anaplasmosis (Anaplasma phagocytophilum) in southern France]. / Enquête epidémiologique sur l'anaplasmose equine (Anaplasma phagocytophilum) dans le Sud de la France.

Anaplasmosis is caused by the bacterium Anaplasma phagocytophilum and transmitted by Ixodes spp. ticks. According to some reports the disease can be introduced into disease-free zones by migrating birds. The purpose of this study was to evaluate the seroprevalence of A. phagocytophilum in horses in the Camargue. Data concerning 424 horses were gathered and the sera were tested for A. phagocytophilum and for piroplasmoses using an enzyme-linked immunosorbent assay and a complement fixation test, respectively. The seroprevalence rates were 11.3 % for A. phagocytophilum, 64.4 % for Theileria equi and 19.7% for Babesia caballi. Stallions were less likely to produce antibodies against A. phagocytophilumthan were females or geldings (odds ratio [OR] = 0.3; p = 0.021). The presence of swallows increased the risk of infections in stables (OR = 5.18; p = 0.011). Spatial analysis showed the existence of groups of infected stables along canals and rivers (p = 0.008). These results suggest an emergence of A. phagocytophilum in the Camargue.