Prediction of methicillin-resistant Staphylococcus aureus bloodstream infection: do we need rapid diagnostic tests?

Staphylococcus aureus (SA) is the leading cause of bloodstream infection (BSI). The incidence of methicillin-resistant SA (MRSA) has decreased in France and Europe since one decade. Early and precise prediction of methicillin susceptibility is needed to improve probabilistic antibiotic therapy of MRSA-BSI. The aim of this study was to identify MRSA-BSI risk factors at admission and evaluate which patients need costly rapid diagnostic tests. A single-center retrospective descriptive study of all diagnosed SA-BSI was conducted in a French University Hospital between January 2015 and December 2016. All medical charts were reviewed. Univariate and multivariate analyses by a logistic regression model were performed on the data. We then build a prediction score of MRSA-BSI by assigning one point for each of the risk factor identified. During the study period, 151 SA-BSI were identified including 32 (21%) MRSA-BSI. In multivariate analysis, three factors were associated with MRSA-BSI: coming from long-term care facility, known previous MRSA colonization and/or infection, and chronic renal disease. Among our population, respectively, 5% and 100% had a MRSA-BSI when no or three risk factors were identified. Therefore, among the PCR performed, 43 (96%) could be avoided according to our clinical score. In our study, methicillin-susceptible SA and MRSA-BSI can be predictable by counting MRSA risk factors. This prediction rule could avoid the use of expensive rapid diagnostic tests. Prospective studies and prediction rules could help physicians to predict SA-BSI susceptibility to improve appropriate empiric therapy choice.

Epidemiology of Lyme borreliosis through two surveillance systems: the national Sentinelles GP network and the national hospital discharge database, France, 2005 to 2016.

BACKGROUND: Lyme borreliosis (LB) is the most frequent vector-borne disease in France. Since 2009, surveillance of LB is conducted by a sentinel network of general practitioners (GPs). This system, in conjunction with the national hospitalisation database was used to estimate the incidence and describe the characteristics of LB in France. AIM: To describe the estimated incidence and trends in GP consultations and hospital admissions for LB in France and identify risk groups and high-incidence regions. RESULTS: From 2011 to 2016, the mean yearly incidence rate of LB cases was 53 per 100,000 inhabitants (95% CI: 41-65) ranging from 41 in 2011 to 84 per 100 000 in 2016. A mean of 799 cases per year were hospitalised with LB associated diagnoses 2005-16. The hospitalisation incidence rate (HIR) ranged from 1.1 cases per 100,000 inhabitants in 2005 to 1.5 in 2011 with no statistically significant trend. We observed seasonality with a peak during the summer, important inter-regional variations and a bimodal age distribution in LB incidence and HIR with higher incidence between 5 and 9 year olds and those aged 60 years. Erythema migrans affected 633/667 (95%) of the patients at primary care level. Among hospitalised cases, the most common manifestation was neuroborreliosis 4,906/9,594 (51%). CONCLUSION: Public health strategies should focus on high-incidence age groups and regions during the months with the highest incidences and should emphasise prevention measures such as regular tick checks after exposure and prompt removal to avoid infection.

Lyme borreliosis and other tick-borne diseases. Guidelines from the French scientific societies (II). Biological diagnosis, treatment, persistent symptoms after documented or suspected Lyme borreliosis.

The serodiagnosis of Lyme borreliosis is based on a two-tier strategy: a screening test using an immunoenzymatic technique (ELISA), followed if positive by a confirmatory test with a western blot technique for its better specificity. Lyme serology has poor sensitivity (30-40%) for erythema migrans and should not be performed. The seroconversion occurs after approximately 6 weeks, with IgG detection (sensitivity and specificity both>90%). Serological follow-up is not recommended as therapeutic success is defined by clinical criteria only. For neuroborreliosis, it is recommended to simultaneously perform ELISA tests in samples of blood and cerebrospinal fluid to test for intrathecal synthesis of Lyme antibodies. Given the continuum between early localized and disseminated borreliosis, and the efficacy of doxycycline for the treatment of neuroborreliosis, doxycycline is preferred as the first-line regimen of erythema migrans (duration, 14 days; alternative: amoxicillin) and neuroborreliosis (duration, 14 days if early, 21 days if late; alternative: ceftriaxone). Treatment of articular manifestations of Lyme borreliosis is based on doxycycline, ceftriaxone, or amoxicillin for 28 days. Patients with persistent symptoms after appropriate treatment of Lyme borreliosis should not be prescribed repeated or prolonged antibacterial treatment. Some patients present with persistent and pleomorphic symptoms after documented or suspected Lyme borreliosis. Another condition is eventually diagnosed in 80% of them.

Lyme borreliosis and other tick-borne diseases. Guidelines from the French Scientific Societies (I): prevention, epidemiology, diagnosis.

Lyme borreliosis is transmitted en France by the tick Ixodes ricinus, endemic in metropolitan France. In the absence of vaccine licensed for use in humans, primary prevention mostly relies on mechanical protection (clothes covering most parts of the body) that may be completed by chemical protection (repulsives). Secondary prevention relies on early detection of ticks after exposure, and mechanical extraction. There is currently no situation in France when prophylactic antibiotics would be recommended. The incidence of Lyme borreliosis in France, estimated through a network of general practitioners (réseau Sentinelles), and nationwide coding system for hospital stays, has not significantly changed between 2009 and 2017, with a mean incidence estimated at 53 cases/100,000 inhabitants/year, leading to 1.3 hospital admission/100,000 inhabitants/year. Other tick-borne diseases are much more seldom in France: tick-borne encephalitis (around 20 cases/year), spotted-fever rickettsiosis (primarily mediterranean spotted fever, around 10 cases/year), tularemia (50-100 cases/year, of which 20% are transmitted by ticks), human granulocytic anaplasmosis (<10 cases/year), and babesiosis (<5 cases/year). The main circumstances of diagnosis for Lyme borreliosis are cutaneous manifestations (primarily erythema migrans, much more rarely borrelial lymphocytoma and atrophic chronic acrodermatitis), neurological (<15% of cases, mostly meningoradiculitis and cranial nerve palsy, especially facial nerve) and rheumatologic (mostly knee monoarthritis, with recurrences). Cardiac and ophtalmologic manifestations are very rarely encountered.

Active pulmonary tuberculosis: Role for amikacin in early treatment.

OBJECTIVE: To evaluate the efficacy of amikacin on sputum conversion during initial sputum smear positive tuberculosis treatment. MATERIAL AND METHODS: Single-center observational cohort study (2012-2013) evaluating time to sputum smear conversion with standard treatment (ST) versus standard treatment+amikacin (IV 15mg/kg/day) for seven days (STamK). RESULTS: Forty-five patients were included. Median time to smear negative samples was 26.5 days (14-56) for the 30 (66.7%) patients included in the ST group and 48 days (19.5-69.5) for the 15 patients (33.3%) included in the STamK group (P=0.76). Time to negative culture was only known for 27 patients (61.4%): 47.5 days (26-58) for 18 patients in the ST group and 40 days (14-77) for nine patients in the STamK group. CONCLUSION: Despite our small sample size, the addition of amikacin in active tuberculosis treatment did not seem to impact time to smear conversion or period of contagiousness.

Survey of French physician practices in treatment and control of transmission of smear-positive tuberculosis.

OBJECTIVES: To evaluate isolation practices and management of sputum smear-positive tuberculosis (TB) in France. METHODS: A survey was conducted using a questionnaire e-mailed in 2011 and 2012 to physicians of the French Society of Infectious Diseases, the French Respiratory Society and the French National Society of Internal Medicine. RESULTS: Of 311 responders, a quarter stated they treated more than 25 TB cases per year. A total of 87.8% declared they routinely used a four-drug regimen in the initial intensive phase. Of the 311 physicians who responded, 31.9% removed isolation precautions after three negative acid-fast bacilli (AFB) sputum results, 19.0% after 15 days of treatment and 34.1% only in case of clinical improvement. According to 71% of the responders, discharge from hospital despite positive AFB sputum smear results was 'possible'. A routine AFB sputum smear was performed after 2 months of treatment by only 21% of the responders. CONCLUSION: Despite recent national guidelines, the management of isolation precautions for sputum smear-positive TB remains heterogeneous, and a significant proportion of physicians use a three-drug regimen. Further efforts should be made to implement TB guidelines, mainly by raising awareness through national scientific institutions, but also by obtaining better evidence.