Significance of colonization by antibiotic-resistant organisms prior to congenital heart disease surgery in children from low- to middle-income countries sent by non-governmental organizations to Switzerland.

PURPOSE: Children with congenital heart disease (CHD) from low- to middle-income countries (LMIC) are suspected to have a high prevalence of antibiotic-resistant microorganisms (ARMOs) carriage, but data are currently lacking. Carriage of ARMOs could impact the post-operative course in pediatric intensive care unit (PICU). The aim of the study was to assess the prevalence of ARMOs carriage in children with CHD from LMIC and its impact on post-operative outcomes. METHODS: This was a retrospective monocentric study from 01/2019 to 12/2022. Included patients were children (0-18 years) from a LMIC admitted after CHD surgery and with AMRO screening performed the week before. Infections and post-operative evolution were compared based on ARMOs carriage status. FINDINGS: Among 224 surgeries (median age 38.5 months (IQR 22-85.5)), ARMOs carriage was evidenced in 95 cases (42.4%). Main organisms isolated were Extended Spectrum Beta-Lactamase (ESBL) producing E. coli (75/224) 33.5%)) and ESBL-K. pneumoniae (30/224) 13.4%)). Median mechanical ventilation duration was 1 day (IQR 0-1), PICU stay 3 days (IQR 2-4) and hospital stay 6.5 days (IQR 5-10). A total of 17 infectious episodes occurred in 15 patients, mostly consisting in hospital-acquired pneumonia (HAP) (12/17). Only two infections were caused by a colonizing ARMO. Occurrence of infections and patients' outcome were similar between ARMO carriers and non-carriers. Higher use of carbapenems (6 (6.3%) vs 1 (0.8%), p = 0.04) and a trend to a higher use of vancomycin (14 (13.7%) vs 9 (6.9%), p = 0.04) in case of ARMOs carriage. Applying current guidelines, negative swab screening could have led to sparing most of empirical vancomycin therapy (11/12) for HAP based on current guidelines. CONCLUSION: Prevalence of AMROs carriage is high in children from LMIC and has a limited impact on patients' outcome. However, ARMOs carriage leads to higher consumption of antibiotics. Screening may help saving use of broad-spectrum antibiotic in non-carrier patients.

Factors associated with hospital and intensive care admission in paediatric SARS-CoV-2 infection: a prospective nationwide observational cohort study.

Coronavirus disease 2019 (COVID-19) is usually less severe in children compared to adults. This study describes detailed clinical characteristics, treatment and outcomes of children with COVID-19 in a non-hospitalised and hospitalised setting and quantifies factors associated with admission to hospital and intensive care unit in children with SARS-CoV-2 infection on a nationwide level. Data were collected through the Swiss Paediatric Surveillance Unit from children < 18 years with confirmed SARS-CoV-2 infection. All 33 paediatric hospitals in Switzerland reported non-hospitalised and hospitalised cases from March 1 to October 31, 2020 during both pandemic peaks. In total, 678 children were included. The median age was 12.2 years (IQR 5.0-14.6), 316 (46.6%) were female and 106 (15.6%) had comorbidities. Overall, 126 (18.6%) children were hospitalised of whom 16 (12.7%) required ICU admission. Comorbidities were the only factor associated with hospital admission in a multivariable regression analysis (odds ratio 3.23, 95%CI 1.89 to 5.50; p-value < 0.01). Children with preexisting comorbidities did not require ICU admission more often. Hospitalised children more often presented with fever (96 [76.2%] vs 209 [38.1%], p-value < 0.01) and rash (16 [12.8%] vs 6 [1.1%], p-value < 0.01). Anosmia/dysgeusia was more prevalent in non-hospitalised children (73 [13.3%] vs 3 [2.4%], p-value < 0.01). In hospitalised children, oxygen treatment was required in 34 (27.0%), inotropes in nine (7.3%) and mechanical ventilation in eight (6.3%) cases. Complications were reported in 28 (4.1%) children with cardiovascular complications being most frequent (12 [1.8%]). Three deaths were recorded.Conclusion: This study confirms that COVID-19 is mostly a mild disease in children. Fever, rash and comorbidities are associated with higher admission rates. Continuous observation is necessary to further understand paediatric COVID-19, guide therapy and evaluate the necessity for vaccination in children. What is Known: • Clinical manifestations of SARS-CoV-2 infection in children vary from asymptomatic to critical disease requiring intensive care unit admission. • Most studies are based on hospitalised children only; currently, there is limited data on non-hospitalised children. What is New: • The clinical spectrum and severity of COVID-19 is influenced by age: in children less than 2 years, fever, cough and rhinorrhoea are the most common symptoms and in adolescents, fever, cough and headache are more common. • Hospitalised children more often presented with fever and rash, while anosmia/dysgeusia is more prevalent in non-hospitalised children. • Children with pre-existing comorbidities are more frequently hospitalised but do not require ICU admission more often.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Viral Load in the Upper Respiratory Tract of Children and Adults With Early Acute Coronavirus Disease 2019 (COVID-19).

The factors that contribute to transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by children are unclear. We analyzed viral load at the time of diagnosis in 53 children and 352 adults with coronavirus disease 2019 (COVID-19) in the first 5 days post symptom onset. No significant differences in SARS-CoV-2 RNA loads were seen between children and adults.

Pediatric Acute B-Cell Lymphoblastic Leukemia Developing Following Recent SARS-CoV-2 Infection.

Coronavirus disease-2019 in children has been linked to various clinical presentation, from paucisymptomatic cutaneous eruptions, to multisystemic inflammatory syndrome. We report the case of an 8-year-old boy who presented with persistent fever and pancytopenia, associated to a skin rash. An extensive etiological workup showed a positive serology for severe acute respiratory syndrome coronavirus 2 and Epstein-Barr virus. A few weeks later, type B acute lymphocytic leukemia was diagnosed. This case underlines the polymorphic appearance of coronavirus disease-2019 and the need for critical appraisal.

Hypovitaminosis D in migrant children in Switzerland: a retrospective study.

Cholecalciferol (vitamin D3) is essentially known for its role in the phosphocalcic metabolism and its associated pathologies, such as rickets. In Switzerland, 35 to 50% of children are vitamin D deficient. Due to skin colour, poor nutrition, living conditions and cultural practices, migrant population is particularly at risk. Our aim is to attest the prevalence of hypovitaminosis D in children arriving in Switzerland. We retrospectively assessed 528 children's vitamin D status and parathyroid hormone, phosphate and calcium levels between 2015 and 2018 by electrochemiluminescence and spectrophotometry. Cholecalciferol was considered insufficient under 50 nmol/L and severely deficient below 25 nmol/L. Seventy-three percent of children showed hypovitaminosis D and 28% had a severe deficiency. Highest prevalence of deficiency was found in children from Eastern Mediterranean (80%) and African regions (75%). Severe deficiency was more prevalent in the South East Asian (39%) and Eastern Mediterranean regions (33%) and more frequent in females. Deficiency was more frequent and more severe in winter. Hypovitaminosis D increased with age. Two children presented with all three biological manifestations associated to severe hypovitaminosis D (hyperparathyroidism, hypocalcaemia and hypophosphatemia).Conclusion: A majority of migrant children presented with hypovitaminosis D. They should be supplemented to prevent complications. A strategy could be to supplement all children at arrival and during wintertime without regular vitamin D level checks. What is Known: Hypovitaminosis D is frequent in children and can lead to bone-related complications. Migrant children are particularly at risk of deficiency. What is New: Three-quarters of migrant children evaluated at our migrant clinic in Geneva's children hospital are deficient in vitamin D, one third severely. A strategy to correct the deficiency would be to supplement all migrant children at arrival and in winter.

Viral co-infections among SARS-CoV-2-infected children and infected adult household contacts.

We evaluated the rates of viral respiratory co-infections among SARS-CoV-2-infected children. Twelve percent of SARS-CoV-2-infected children had viral co-infection with one or more common respiratory viruses. This was significantly more frequent than among their SARS-CoV-2-infected adult household contacts (0%; p=0.028). Compared to the same period the previous year, common respiratory viruses were less frequently detected (12% vs 73%, p<0.001).Conclusion: Despite partial lockdown with school and daycare closure, and consequently similar exposure to common viruses between children and adults, SARS-CoV-2-infected children had more frequent viral respiratory co-infections than their SARS-CoV-2-infected adult household contacts. Circulation of common respiratory viruses was less frequent during the SARS-CoV-2 outbreak when compared to the same period last year, showing the impact of partial lockdown on the circulation of common viruses. What is Known: • Viral respiratory co-infections are frequent in children. • SARS-CoV-2 can be identified alongside other respiratory viruses, but data comparing children and adults are lacking. What is New: • Children infected with SARS-CoV-2 are more likely to have viral respiratory co-infections than their SARS-CoV-2-infected adult household contacts, which is surprising in the context of partial lockdown with schools and daycare closed. • When compared to data collected during the same period last year, our study also showed that partial lockdown reduced circulation of common respiratory viruses.

[Treatment of SARS-CoV-2 in paediatrics : what is the evidence to date?] / Traitement du SARS-CoV-2 en pédiatrie : quelles évidences et quelle utilité ?

Although SARS-CoV-2 infects individuals of all ages, children show less severe symptoms. Nevertheless, the very rare COVID-19 severe cases in paediatrics require our full attention. Much research has been conducted and is still ongoing on effective treatments. On the antiviral front, no molecule has been proven effective yet and the results of several studies on the benefit of monoclonal antibodies and convalescent plasma are pending. On the side of immunomodulators, the benefit of steroids has been demonstrated for patients severely ill. Other molecules are being investigated. However, all these studies focused on adults and paediatric data are warranted.

Bien que le SARS-CoV-2 infecte des individus de tout âge, les enfants montrent des symptômes moins sévères. Les cas de Covid-19 graves sont exceptionnels en pédiatrie mais nécessitent néanmoins toute notre attention. De nombreuses études ont été menées et sont encore en cours à la recherche de traitements efficaces. Sur le plan antiviral, aucune molécule n'a fait ses preuves à l'heure actuelle. Les résultats de plusieurs travaux sur le bénéfice des anticorps monoclonaux et du plasma convalescent sont attendus avec impatience. Du côté des immunomodulateurs, le bénéfice des stéroïdes a pu être démontré chez les patients présentant une infection pulmonaire sévère. D'autres molécules sont à l'étude. Cependant, toutes ces études s'intéressent aux adultes et les données pédiatriques sont quasiment inexistantes.

Maladies infectieuses.

What's new in infectious diseases in 2020 ? This year has been marked by the COVID-19 pandemic, prompting a review of the current knowledge on SARS-CoV-2 and its management in this article. The results of the Swiss project «â€…PIRATE ¼ indicate non-inferiority between CRP-guided antibiotic durations or fixed 7-day durations and 14-day durations for Gram-negative bacteremia. A Mongolian study did not show any benefit of vitamin D substitution in protecting children from tuberculosis. Baloxavir, a new antiviral against the flu, has been approved by Swissmedic. Finally, new American recommendations for therapeutic monitoring of vancomycin and universal screening for hepatitis C virus have been published.

Que dire des nouveautés en maladies infectieuses en 2020 ? L'année a été marquée évidemment par la pandémie du Covid-19, motivant une revue dans cet article, des connaissances actuelles sur le SARS-CoV-2 et de sa prise en charge. Les résultats du projet suisse PIRATE ont montré une non-infériorité pour les bactériémies Gram négatif entre une antibiothérapie de 7 jours ou guidée par la CRP face à une durée de 14 jours. Une étude mongolienne n'a pas permis de montrer le bénéfice d'une substitution en vitamine D chez les enfants sur l'incidence de la tuberculose. Le baloxavir, un nouvel antiviral contre la grippe, a été approuvé par Swissmedic. Et enfin, des nouvelles recommandations américaines sur le monitoring thérapeutique de la vancomycine et sur le dépistage universel de l'hépatite C ont été publiées.

[Breastfeeding for HIV-positive mothers in Switzerland : are we ready to discuss ?] / Allaitement des femmes vivant avec le VIH : sommes-nous prêts à ouvrir la discussion ?

Mother-to-child transmission (MTCT) is almost inexistent in Switzerland nowadays. This success has been achieved with systematic screening of HIV in pregnant women, provision of antiretroviral treatment (ART), elective cesarean-section (CS), neonatal antiretroviral prophylaxis (ARP) and avoidance of breastfeeding. Elective CS and neonatal ARP are no longer recommended when the viral load (VL) is suppressed. Recent studies have shown that the risk of HIV MTCT through breastfeeding is extremely rare if not zero when the mother is treated, has a suppressed VL and is correctly followed-up. It is time to be open to discuss the risks and benefits of breastfeeding with HIV-infected pregnant women and to enter in a shared decision-making process, as recommended by the new Swiss guidelines. Close monitoring is mandatory in case of breastfeeding.

La transmission verticale du VIH est presque inexistante en Suisse aujourd'hui. Ce succès a été obtenu grâce au dépistage systématique du VIH de la femme enceinte et aux traitements antirétroviraux, à la césarienne élective (CS), à la prophylaxie postexpositionnelle néonatale (PPEn) et à l'évitement de l'allaitement. La CS et la PPEn ne sont plus recommandées en cas de charge virale indétectable. Des études récentes ont montré que le risque de transmission du VIH par l'allaitement est extrêmement faible, voire nul, lorsque la mère est correctement traitée et suivie. Il est temps de peser les risques et les bénéfices de l'allaitement maternel avec les femmes enceintes infectées par le VIH dans un processus de décision partagée, comme le suggèrent les nouvelles recommandations suisses. En cas d'allaitement, un suivi étroit est incontournable.

The Contemporary Bacteriologic Epidemiology of Osteoarticular Infections in Children in Switzerland.

OBJECTIVES: To assess the contemporary bacteriologic epidemiology of pediatric osteoarticular infection with particular regard to children's ages, because Kingella kingae has gained increasing recognition as the predominant pathogen for osteoarticular infection in young children. STUDY DESIGN: Retrospective file review of enrolled children from 0 to 15 years of age, admitted to our institution from 2007 to 2015 for suspected osteoarticular infection (217 cases). Information on age, sex, the bone or joint infected, imaging studies, and laboratory data (including bacterial investigations) were collected for analysis. RESULTS: Microorganism identification was possible for 138 infected children (63.6%), through blood (cultures or polymerase chain reaction [PCR]) and/or operative samples (cultures or PCR). Thirty-one patients (14.3%) were found to both have positive blood cultures and operative samples. The results of positive bacteriology specimens identified the most common causative pathogen for osteoarticular infection as K kingae (47.8% of microbiologically confirmed osteoarticular infections of all ages, and 87.7% in children between the ages of 6 and 48 months), significantly more common than Staphylococcus aureus (35.5% of microbiologically confirmed osteoarticular infections of all ages, and 78.2% in children >4 years of age). CONCLUSIONS: Use of the appropriate PCR assays demonstrated that K kingae currently is the major bacterial cause of pediatric osteoarticular infection, especially in children <4 years of age in whom K kingae is more common than S aureus. PCR assays should be used in routine microbiologic laboratory evaluation to improve diagnostic performance. However, despite the use of molecular methods, there are many osteoarticular infections in which no microorganism is detected, which suggests that these infections may be caused by other as yet unrecognized fastidious microorganisms.

Novel human astroviruses in pediatric respiratory samples: A one-year survey in a Swiss tertiary care hospital.

Although classical human astroviruses (HAstV) are known to be a leading cause of viral gastroenteritis, the pathogenesis and clinical manifestations of novel HAstV remain largely unknown. There is mounting evidence that, in contrast to classical astroviruses, novel HAstV exhibit tropism for the upper respiratory tract. This one-year period prevalence screened all available clinical nasopharyngeal swab samples collected from pediatric patients aged ≤5 years for novel and classical HAstV using real-time reverse transcription polymerase chain reaction. A total of 205 samples were tested; two novel HAstV cases were detected for a prevalence of 1.3%, with viral loads suggesting active upper respiratory tract replication. No classical HAstV was detected.

[Persistant fevers of infectious origin in children]. / Fièvres prolongées d'origine infectieuse chez l'enfant.

Prolonged fevers in children are a regular challenge for the paediatrician or any physician caring for these children (emergency physicians, pediatric infectious diseases specialists). The causes are multiple, classified into three major families : infectious, inflammatory and oncological. Infectious causes are the most common and account for more than 50 % of cases. The objective of this review is to guide physicians in charge of these patients throughout their management by focusing on the quest of infectious causes.

Les fièvres prolongées chez l'enfant sont un défi régulier pour le pédiatre traitant ou toute personne accueillant en consultation ces enfants (médecins des urgences, infectiologues pédiatres). Les étiologies de ces fièvres sont multiples et peuvent être classées en trois grandes familles : infectieuse, inflammatoire/auto-immune et oncologique. Les étiologies infectieuses sont les plus courantes et représentent plus de 50 % des cas. L'objectif de cet article est de guider les médecins de ces patients tout au long de leur prise en charge en axant sur la recherche des étiologies infectieuses.

Zika virus: practical guidelines. / Virus Zika : recommandations pratiques.

Zika virus suddenly emerged in Latin America in 2015­2016. Congenital malformations have been observed in infected pregnant women, causing a major public health impact in affected countries, particularly in Brazil. In addition, sexual transmission of Zika virus has been well documented. This led to the development of prevention strategies and recommendations for travellers visiting at risk countries. These documents are regularly amended depending on the evolution of scientific knowledge, the epidemiologic trends and the national and international guidelines. Through practical cases, we present here the guidelines developed by the Geneva University Hospitals.

Le virus Zika a émergé brusquement en 2015­2016 en Amérique latine. Lors de cette épidémie, des complications fœtales ont pu être observées avec des conséquences majeures sur la santé publique de ces pays, en particulier au Brésil. De plus, une transmission par voie sexuelle du virus a été bien documentée. Il a ainsi été nécessaire de développer des stratégies de prévention et des recommandations pour les voyageurs visitant des pays à risque. Ces documents sont évolutifs en fonction des connaissances scientifiques, de l'épidémiologie de la maladie et des recommandations nationales et internationales. Par l'intermédiaire de cas illustratifs, nous présentons les recommandations utilisées aux Hôpitaux universitaires de Genève.

[Community acquired pneumonia in children: an update for outpatients management]. / Prise en charge ambulatoire de la pneumonie communautaire de l'enfant: mise au point.

Pneumonia should be considered in febrile children with tachypnea and/or chest recession. Virus are the most common cause of pneumonia in children under 5 years old. Streptococcus pneumonia can be found at any age. Mycoplasma pneumonia is more frequent in older children. Systematic chest radiograph is not necessary but must be obtained in patients with hypoventilation and in those with failed initial antibiotic therapy. Mycoplasma pneumonia should be tested according to patient age and response to initial antibiotic. First line antibiotherapy is amoxicilline. Antibiotic treatment is frequently not necessary in children under 5 but should be considered depending on clinical presentation and C reactive protein value.

Acute muscular sarcocystosis: an international investigation among ill travelers returning from Tioman Island, Malaysia, 2011-2012.

BACKGROUND: Through 2 international traveler-focused surveillance networks (GeoSentinel and TropNet), we identified and investigated a large outbreak of acute muscular sarcocystosis (AMS), a rarely reported zoonosis caused by a protozoan parasite of the genus Sarcocystis, associated with travel to Tioman Island, Malaysia, during 2011-2012. METHODS: Clinicians reporting patients with suspected AMS to GeoSentinel submitted demographic, clinical, itinerary, and exposure data. We defined a probable case as travel to Tioman Island after 1 March 2011, eosinophilia (>5%), clinical or laboratory-supported myositis, and negative trichinellosis serology. Case confirmation required histologic observation of sarcocysts or isolation of Sarcocystis species DNA from muscle biopsy. RESULTS: Sixty-eight patients met the case definition (62 probable and 6 confirmed). All but 2 resided in Europe; all were tourists and traveled mostly during the summer months. The most frequent symptoms reported were myalgia (100%), fatigue (91%), fever (82%), headache (59%), and arthralgia (29%); onset clustered during 2 distinct periods: "early" during the second and "late" during the sixth week after departure from the island. Blood eosinophilia and elevated serum creatinine phosphokinase (CPK) levels were observed beginning during the fifth week after departure. Sarcocystis nesbitti DNA was recovered from 1 muscle biopsy. CONCLUSIONS: Clinicians evaluating travelers returning ill from Malaysia with myalgia, with or without fever, should consider AMS, noting the apparent biphasic aspect of the disease, the later onset of elevated CPK and eosinophilia, and the possibility for relapses. The exact source of infection among travelers to Tioman Island remains unclear but needs to be determined to prevent future illnesses.

First report of Kocuria marina spontaneous peritonitis in a child.

BACKGROUND: Spontaneous bacterial peritonitis (SBP) is a rare affection in the pediatric population. It usually occurs when concurrent conditions are present, such as nephrotic syndrome, peritoneal dialysis or liver disease. We report a case of spontaneous bacterial peritonitis due to Kocuria marina in a 2-year-old child with no underlying risk factor. This is both the first description of an infection caused by this rare pathogen in a child and the first reported case of primary peritonitis caused by K. marina in a patient with no predisposing condition. CASE PRESENTATION: A 2 year-old boy presented to the Pediatric Emergency Department with clinical signs of peritonitis. Laparoscopic surgical exploration confirmed purulent, generalized peritonitis without perforation. Culture of the peritoneal fluid revealed the presence of Kocuria marina, a Gram-positive coccoid environmental bacteria. After peritoneal lavage and appropriate antibiotic treatment, the patient improved and was discharged without sequel. CONCLUSION: The present report illustrates the first clinical presentation of Kocuria marina SBP in a child with no underlying risk factor. Although never previously described in healthy patients, this pathogen may therefore be considered as a possible cause of SBP in a child. This unusual finding extends the spectrum of infectious diseases caused by Kocuria marina beyond the scope of the previously described susceptible population.

Challenges and opportunities in neonatal sepsis management: insights from a survey among clinicians in 25 Sub-Saharan African countries.

BACKGROUND: Neonatal sepsis (NS) is a global health issue, particularly in Sub-Saharan Africa, where it accounts for a substantial portion of neonatal morbimortality. This multicountry survey aimed to elucidate current practices, challenges and case definitions in managing NS among clinicians in Sub-Saharan Africa. METHODS: The survey targeted physicians and medical practitioners working in neonatal care who participated in a Self-Administered Web Questionnaire. The main objective was to understand NS and infection case definitions and management from the clinician's point of view and to identify challenges and opportunities in sepsis management. Participants were queried on demographics, definitions and diagnostic criteria, treatment approaches, and infection prevention and control (IPC) measures. A total of 136 participants from 93 healthcare structures responded, providing valuable insights into NS management practices. RESULTS: From May to July 2022 across 21 Sub-Saharan African countries, 136 neonatal clinicians with an average from 93 structures with on average 10-year experience took the survey. NS ranked highest among prevalent neonatal conditions. Diagnostic case definitions between sepsis and infection were attributed to clinical signs, anamnesis, C reactive protein, white blood cll count and blood cultures with no statistically significant differences. Early-onset sepsis was defined within 72 hours by 48%, while late-onset varied. Antibiotics were likely on admission (86.4%) and during the stay (82.2%). Treatment abandonment was reported unlikely. The preferred antibiotic regimen for early-onset sepsis was intravenous amoxicillin (or ampicillin), gentamycin and cefotaxime. Blood culture availability and IPC protocols were reported as limited, particularly concerning patient environment, pharmacy protocols and clean-dirty circuits. CONCLUSIONS: This NS survey emphasises clinicians' challenges due to limited access to diagnostic tools and raises concerns about antimicrobial overexposure. IPC also seem limited, according to participants. Addressing these challenges can enhance diagnostic practices, antibiotic stewardship and infection control in the region.

Clinical Characteristics and Management of Children and Adolescents Hospitalized With Pyomyositis.

BACKGROUND: Pyomyositis, a bacterial muscle infection, is an important differential diagnosis in children and adolescents with musculoskeletal pain. In contrast to tropical regions, it is rarely recognized in temperate countries, but incidence is increasing and major studies are missing. METHODS: This retrospective multicenter study included patients <18 years of age hospitalized with pyomyositis in 11 Swiss children's hospitals between January 2010 and December 2022. Cases were identified by ICD-10 code (Myositis; M60-M60.9), and data was extracted from electronic hospital records. RESULTS: Of 331 patients identified, 102 fulfilled the case definition. Patient age at presentation ranged from 2 weeks to 17 years (median 8 years). The majority had no underlying illness and all presented with fever and localized pain. At the respective site of pyomyositis, 100 (98%) had impaired movement and 39 (38%) presented with local swelling. Pelvic (57%) and leg (28%) muscles were mostly affected. Blood or tissue cultures were obtained in 94 (92%) and 59 (57%) patients, respectively. Of those, 55 (58%) blood and 52 (88%) tissue cultures were positive, mainly for Staphylococcus aureus (35 and 19, respectively) and Streptococcus pyogene s (12 and 15, respectively). All patients received antibiotic treatment during hospitalization for a median of 10 days (interquartile range: 7-17), followed by outpatient treatment for a further median of 16 days (interquartile range: 11-22) in 95 (93%) patients. Fifty-nine (57%) patients required surgery. CONCLUSIONS: Pyomyositis is a challenging diagnosis that requires a high level of awareness. Blood and/or tissue cultures revealed S. aureus and S. pyogenes as the predominant causative agents.