Optimal culture incubation time in orthopedic device-associated infections: a retrospective analysis of prolonged 14-day incubation.

Accurate diagnosis of orthopedic device-associated infections can be challenging. Culture of tissue biopsy specimens is often considered the gold standard; however, there is currently no consensus on the ideal incubation time for specimens. The aim of our study was to assess the yield of a 14-day incubation protocol for tissue biopsy specimens from revision surgery (joint replacements and internal fixation devices) in a general orthopedic and trauma surgery setting. Medical records were reviewed retrospectively in order to identify cases of infection according to predefined diagnostic criteria. From August 2009 to March 2012, 499 tissue biopsy specimens were sampled from 117 cases. In 70 cases (59.8%), at least one sample showed microbiological growth. Among them, 58 cases (82.9%) were considered infections and 12 cases (17.1%) were classified as contaminations. The median time to positivity in the cases of infection was 1 day (range, 1 to 10 days), compared to 6 days (range, 1 to 11 days) in the cases of contamination (P < 0.001). Fifty-six (96.6%) of the infection cases were diagnosed within 7 days of incubation. In conclusion, the results of our study show that the incubation of tissue biopsy specimens beyond 7 days is not productive in a general orthopedic and trauma surgery setting. Prolonged 14-day incubation might be of interest in particular situations, however, in which the prevalence of slow-growing microorganisms and anaerobes is higher.

Traitments antibiotiques simplifies : l'exemple des infections des voies respiratoires supérieures

Les bénéfices d'une antibiothérapie simplifiée sont une meilleure compilance, une diminution des coûts et une diminution de la résistance. Plusieurs molécules récentes sont efficaces pour le traitement court (5 jours) de l'angine streptococcique, de l'otite et de la sinusite. Leur avantage est leur biodisponibilité ; leur inconvénient un spectre élargi. Le spectre élargi bénéficie au thérapeute et la santé publique ; il limite les procédures diagnostiques et les échecs thérapeutiques. Les victimes en sont les patients et aussi la santé publique, par l'augmentation des effets secondaires et de la résistance aux antibiotiques. Le diagnostic bactérien permet de cibler l'antibiotique et de raccourcir le traitement. Les outils de diagnostic rapide sont essentiels à cette stratégie.

Nonmolecular methods for the diagnosis of respiratory fungal infections.

Diagnosis of invasive fungal pneumonias by conventional culture methods is difficult to assess and often delayed. Nonmolecular fungal markers have emerged as an important adjunctive tool to support their diagnosis in combination with other clinical, radiologic, and microbiological criteria of invasive fungal diseases. Concerns about the sensitivity and specificity of some tests in different patient populations should lead to warnings about their widespread use. None can identify the emerging and particularly deadly fungal pathogens responsible for mucormycosis. The role of nonmolecular fungal markers should be better defined in combination with other microbiological and radiologic tools in preemptive antifungal strategies.

Infections pulmonaires : le point de vue du radiologue [Pulmonary infections: the radiologist's point of view]

La place de l'imagerie est essentielle au cours des infections pulmonaires. La TDM doit être effectuée en cas de forte suspicion clinique de pneumonie avec aspect radiographique normal, équivoque ou non spécifique, ce qui concerne particulièrement les sujets immunodéprimés. Elle permet de détecter les anomalies associées ou une affection sous-jacente, d'orienter un lavage broncho-alvéolaire ou de guider une biopsie pulmonaire percutanée ou transbronchique. Les expressions d'un germe peuvent varier selon le degré d'immunodépression. Il en est ainsi pour la tuberculose au cours du sida. Les germes impliqués varient selon le type d'immunodépression, certaines infections pouvant engager rapidement le pronostic vital. Le spectre radiologique de l'aspergillose pulmonaire, complexe, doit être connu, ce diagnostic devant être proposé dans des conditions particulières.

Virulent infections due to alpha-haemolytic streptococci in cancer patients and their management

Streptococci of the viridans group have long been considered to be minor pathogens, except in bacterial endocarditis. For some years, however, these microorganisms have been the cause of serious bacteraemia in neutropenic patients receiving intensive chemotherapy. These infections can lead to severe complications such as endocarditis, respiratory distress syndromes or shock, and are associated with a mortality rate ranging from 6-30%. The principal risk factors for these infections are profound neutropenia, antibiotic prophylaxis with quinolones or cotrimoxazole, large doses of cytosine arabinoside, a recent history of chemotherapy, oropharyngeal mucositis and viridans streptococcal colonization. Protective factors are the early administration of parenteral antibiotics during periods of neutropenia, or the prophylactic administration of penicillin. Although the introduction of penicillin to prophylactic antibiotic regimens has led to a decrease in the incidence of these infections, the emergence of strains resistant to beta-lactams is a worrying problem which could compromise this type of treatment.

Neonatal herpes simplex virus infections in Switzerland: results of a 6-year national prospective surveillance study.

A large variation in neonatal herpes incidence is observed in USA and Europe. Better knowledge of neonatal herpes epidemiology is important to inform local prevention strategies. Between 2002 and 2008, the Swiss Paediatric Surveillance Unit reported prospectively proven neonatal herpes simplex virus infections. During the study period seven cases were declared, for an incidence of 1.6/100,000 (95% CI 0.64-3.28/100,000) live births. This is one of the lowest incidences of neonatal herpes reported.

Overall Burden of Healthcare-Associated Infections Among Surgical Patients: Results of a National Study.

OBJECTIVE:: To assess the overall burden of healthcare-associated infections (HAIs) in patients exposed and nonexposed to surgery. BACKGROUND:: Targeted HAI surveillance is common in healthcare institutions, but may underestimate the overall burden of disease. METHODS:: Prevalence study among patients hospitalized in 50 acute care hospitals participating in the Swiss Nosocomial Infection Prevalence surveillance program. RESULTS:: Of 8273 patients, 3377 (40.8%) had recent surgery. Overall, HAI was present in 358 (10.6%) patients exposed to surgery, but only in 206 (4.2%) of 4896 nonexposed (P < 0.001). Prevalence of surgical site infection (SSI) was 5.4%. Healthcare-associated infections prevalence excluding SSI was 6.5% in patients with surgery and 4.7% in those without (P < 0.0001). Patients exposed to surgery carried less intrinsic risk factors for infection (age >60 years, 55.6% vs 63.0%; American Society of Anesthesiologists score >3, 5.9% vs 9.3%; McCabe for rapidly fatal disease, 3.9% vs 6.6%; Charlson comorbidity index >2, 12.3% vs 20.9%, respectively; all P < 0.001) than those nonexposed, but more extrinsic risk factors (urinary catheters, 39.6% vs 14.1%; central venous catheters, 17.8% vs 7.1%; mechanical ventilation, 4.7% vs 1.3%; intensive care stay, 18.3% vs 8.8%, respectively; all P < 0.001). Exposure to surgery independently predicted an increased risk of HAI (odds ratio 2.43; 95% CI 2.0-3.0). CONCLUSIONS:: Despite a lower intrinsic risk, patients exposed to surgery carried more than twice the overall HAI burden than those nonexposed; almost half was accountable to SSI. Extending infection control efforts beyond SSI prevention in these patients might be rewarding, especially because of the extrinsic nature of risk factors.

Réactualisation de la douzième conférence de consensus de la Société de réanimation de langue française (SRLF) : infections liées aux cathéters veineux centraux en réanimation [Updating of the 12th consensus conference of the Société de Réanimation de langue française (SRLF) : catheter related infections in Intensive Care unit]

Concerning catheter-related infections, many studies have been conducted until the last consensus conference of the Sociétéde réanimation de langue française (SRLF) in 1994. This text is the synthesis of the considerable amount of work performed by the experts of the society to review recent studies. The experts' texts as well as extensive bibliography are available at http://www.srlf.org.

HIV-1 elite controllers: beware of super-infections.

Super- and co-infection with HIV-1 are generally associated with accelerated disease progression. We report on the outcome of super-infection in two HIV-1 infected individuals previously known as elite controllers. Both presented an acute retroviral syndrome following super-infection and showed an immuno-virological progression thereafter. Host genotyping failed to reveal any of the currently recognized protective factors associated with slow disease progression. This report indicates that elite controllers should be informed of the risk of super-infection, and illustrates the complexity of mounting broad anti-HIV immunity.

Emerging viral infections after hematopoietic cell transplantation.

This overview summarizes recent data on emerging viruses after hematopoietic cell transplantation (HCT), including adenovirus, BK virus, human metapneumovirus (hMPV), and human herpesvirus (HHV) 6. The increased recognition of these infections is due to improved molecular detection methods, increased surveillance and more profound immunosuppression in the host. Adenovirus can cause serious disease especially in T-cell depleted transplant recipients. Adenovirus viremia is an important risk factor for disease in this setting. BK virus has been associated with hemorrhagic cystitis in HCT recipients. BK viremia is significantly associated with hemorrhagic cystitis. hMPV shows a seasonal distribution and can cause fatal pneumonia in HCT recipients. hMPV may be the etiology of some cases previously categorized as idiopathic pneumonia syndrome. HHV-6 commonly leads to viremia in HCT recipients. HHV-6 has been strongly associated with encephalitis and delayed platelet engraftment. Prospective studies are needed to further examine epidemiology, disease associations, and management strategies for these viruses.

Les spirochètes dans tous leurs etats [A short journey through spirochetal infections]

Spirochetal infections present with a variety of clinical syndromes and epidemiologic features. Diagnosis remains challenging for the clinician because of the often protean clinical presentation and poor performance of stan-dard microbiological tests. We present 3 clinical cases, illustrating interesting or unusual features of these infections. First, we present a case of leptospirosis acquired in Switzerland after a rat bite. We then present a case of early disseminated Lyme disease with multiple erythema migrans, lymphopenia, thrombocytopenia and liver enzyme elevation. Finally, we present a case of secondary syphilis in an HIV-positive man, complicated by sensorineural deafness. For each case we highlight and discuss the specific epidemiological, clinical and therapeutic features.

Prévention des infections chez les voyageurs immunosupprimés [Prevention of infection in immunocompromised travelers].

Every year there are more immunocompromised patients with a better quality of life and, therefore, that travel more frequently. While traveling, patients may be exposed to several infections, such as traveler's diarrhea or malaria, which can be associated with a high rate of complications in this population. An appropriate strategy for the prevention of travel-related infections is essential, including education about hygiene measures, vaccinations and prescription of a tailored antimicrobial prophylaxis/stand-by treatment, according to the type of immunosuppression. Potential drug interactions, particularly between antimalaric and immunosuppressive drugs, must also be considered for decision taking. Collaboration between the general practitioner and the travel medicine and infectious diseases specialists is highly recommended to improve the management of these patients.

Les infections endo-artérielles, complications redoutables des infections à salmonelles non typhi [Endarterial infections, redoubtable complications of non-typhi salmonella infections].

Three cases are reported of salmonella aortitis observed in three men aged 55, 60 and 48 years, the last of whom had a prosthetic aortic valve and ascending aorta. The microorganisms were S. typhi murium, S. paratyphi B, and S. wien. Despite antibiotic treatment two patients died of perforating aortitis. The third patient developed S. wien gastroenteritis a few days after surgical replacement of the aortic valve and the ascending aorta. Five years later he presented with several bacteremic episodes due to S. wien, which recurred despite several courses of cotrimoxazole treatment. He has now been asymptomatic for over one year under prolonged cotrimoxazole treatment. Since vascular infection may occur following non typhi salmonellosis in 5% of patients over 50, or who have underlying endothelial lesions, the question arises as to whether non typhi S. gastroenteritis should be treated with antibiotics in these high risk patients, in contrast to present recommendations.