Accuracy of the BD MAX™ vaginal panel in the diagnosis of infectious vaginitis.

The aim of this study was to evaluate the BD MAX™ vaginal panel in the diagnosis of bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), and trichomoniasis by comparing it with conventional methods: (i) combination of Hay criteria and presence of clue cells with predominant growth of Gardnerella vaginalis, (ii) yeast culture, and (iii) combination of culture, wet mount microscopic examination, and an alternative molecular assay. One thousand vaginal samples of women ≥ 14 years were analyzed; 5% of the samples belonged to pregnant women. 19.3% were classified as BV, in 33.6% yeasts were recovered and in 1.5% TV was detected. For BV, sensitivity and specificity were of 89.8% and 96.5%, respectively; for VVC, sensitivity and specificity were of 97.4% and 96.8%, respectively, and for T. vaginalis, the sensitivity and specificity were of 100%. The BD MAX™ vaginal panel is highly sensitive and specific and simplifies the identification of infectious vaginitis.

The importance of prevalence and pre-test probability on the microbiological diagnosis of SARS-CoV-2: the case of Spain in 2020.

OBJECTIVE: The aim of this work was to estimate the conditioned probability for the diagnosis of SARS-CoV-2 infection with reverse transcription polymerase chain reaction (RT-PCR), viral antigen rapid diagnostic tests (Ag-RDT), and antibody detection tests depending on the prevalence in the specific healthcare settings in Spain in 2020, and on the pre-test probability (PTP) according to the clinical situation, age and unknown or close contacts of the patient. METHODS: Performance parameters of tests were obtained from literature. Prevalence data and PTP were obtained from Spanish sources and a survey, respectively. The post-test probability is the positive predictive value (PPV) when test is positive. For negative result, we also calculated the probability of having the infection (false negatives). RESULTS: For both RT-PCR and viral Ag-RDT, the lowest PPV values were for the population screenings. This strategy proved to be useful in ruling out infection but generates a high number of false positives. At individual level, both tools provided high PPV (≥ 97%) when the PTP values are over 35%. In seroprevalence studies, though the specificity of IgG alone tests is high, under low seroprevalence, false positives cannot be avoided. Total antibodies tests are useful for diagnosis of COVID-19 in those doubtful cases with RT-PCR or Ag-RDT tests being repeatedly negative. CONCLUSIONS: The interpretating of results depends not only on the accuracy of the test, but also on the prevalence of the infection in different settings, and the PTP associated to the patient before performing the test.

Antimicrobial resistance in Gram-negative bacilli in Spain: an experts' view.

BACKGROUND: Antibiotic resistance in Gram-negative bacilli poses a serious problem for public health. In hospitals, in addition to high mortality rates, the emergence and spread of resistance to practically all antibiotics restricts therapeutic options against serious and frequent infections. OBJECTIVE: The aim of this work is to present the views of a group of experts on the following aspects regarding resistance to antimicrobial agents in Gram-negative bacilli: 1) the current epidemiology in Spain, 2) how it is related to local clinical practice and 3) new therapies in this area, based on currently available evidence. METHODS: After reviewing the most noteworthy evidence, the most relevant data on these three aspects were presented at a national meeting to 99 experts in infectious diseases, clinical microbiology, internal medicine, intensive care medicine, anaesthesiology and hospital pharmacy. RESULTS AND CONCLUSIONS: Subsequent local debates among these experts led to conclusions in this matter, including the opinion that the approval of new antibiotics makes it necessary to train the specialists involved in order to optimise how they use them and improve health outcomes; microbiology laboratories in hospitals must be available throughout a continuous timetable; all antibiotics must be available when needed and it is necessary to learn to use them correctly; and the Antimicrobial Stewardship Programs (ASP) play a key role in quickly allocating the new antibiotics within the guidelines and ensure appropriate use of them.

Value of syndromic panels in the management of severe community-acquired pneumonia.

Community-acquired pneumonia requiring hospital admission is a prevalent and potentially serious infection, especially in high-risk patients (e.g., those requiring ICU admission or immunocompromised). International guidelines recommend early aetiological diagnosis to improve prognosis and reduce mortality. Syndromic panels that detect causative pathogens by molecular methods are here to stay. They are highly sensitive and specific for detecting the targets included in the test. A growing number of studies measuring their clinical impact have observed increased treatment appropriateness and decreased turnaround time to aetiological diagnosis, need for admission, length of hospital stay, days of isolation, adverse effects of medication and hospital costs. Its use is recommended a) per a pre-established protocol on making the diagnosis and managing the patient, b) together with an antimicrobial stewardship programme involving both the Microbiology Service and the clinicians responsible for the patient, and c) the final evaluation of the whole process. However, we recall that microbiological diagnosis with traditional methods remains mandatory due to the possibility that the aetiological agent is not included among the molecular targets and to determine the antimicrobial susceptibility of the pathogens detected.

Deciphering pharmacokinetics and pharmacodynamics of fosfomycin.

Fosfomycin, a low molecular weight and hydrophilic drug with negligible protein binding, is eliminated almost exclusively by glomerular filtration, whose clearance is subject to patient renal function. The volume of distribution approximates to the extracellular body water (about 0.3 L/Kg) in healthy volunteers, but it is increased in critically ill patients with bacterial infections. Fosfomycin presents a high ability to distribute into many tissues, including inflamed tissues and abscess fluids. Based on PK/PD analysis and Monte Carlo simulations, we have evaluated different fosfomycin dosing regimen to optimize the treatment of septic patients due to Enterobacterales and Pseudomonas aeruginosa. As PK/PD targets, we selected %T>MIC > 70% for all pathogens, and AUC24/MIC > 24 and AUC24/MIC > 15 for net stasis of Enterobacterales and P. aeruginosa, respectively. Pharmacokinetic parameters in critically ill patients were obtained from the literature. Several dosing regimens were studied in patients with normal renal function: fosfomycin 2-8 g given every 6-12 hours, infused over 30 minutes- 24 hours. At the susceptibility EUCAST breakpoint for Enterobacterales and Staphylococcus spp. (MIC ≤ 32 mg/L), fosfomycin 4 g/8h or higher infused over 30 minutes achieved a probability of target attainment (PTA) > 90%, based in both %T>MIC and AUC24/MIC. For MIC of 64 mg/L, fosfomycin 6 g/6h in 30-minute infusion and 8 g/ 8h in 30-minute and 6 hours infusions also achieved PTA values higher than 90%. No fosfomycin monotherapy regimen was able to achieve PK/PD targets related to antimicrobial efficacy for P. aeruginosa with MICs of 256-512 mg/L.

Application of pharmacokinetic/pharmacodynamic analysis to evaluate the adequacy of antimicrobial therapy for pediatric acute otitis media in Spain before and after the introduction of the PCV7 vaccine.

OBJECTIVE: To evaluate, by applying pharmacokinetic/pharmacodynamic (PK/PD) analysis, if the change in antibiotic susceptibility after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in Spain had any influence on the usefulness of the antimicrobials more frequently used as empirical treatment of pediatric acute otitis media (AOM). METHODS: PK parameters and susceptibility of Streptococcus pneumoniae and Haemophilus influenzae were obtained from bibliography. Monte Carlo simulation was used to estimate the cumulative fraction of response (CFR), understood as the expected probability of therapy success. For amoxicillin and amoxicillin/clavulanate, the target was free antibiotic concentration remaining above the minimum inhibitory concentration (MIC) for ≥50% of the dosing interval (fT>MIC≥50%), whereas for cefuroxime axetil and cefotaxime, the target was fT>MIC≥60%. CFR values ≥90% were considered successful. RESULTS: When all serotypes of S. pneumoniae are considered, amoxicillin and cefotaxime turned out to reach a high probability of success, and difference before and after vaccination was scarce. For H. influenzae, CFR values were higher with amoxicillin/clavulanate than with amoxicillin. For both microorganisms, cefuroxime axetil resulted in low probability of success in the two periods of study. CONCLUSIONS: We have shown that the introduction of the PCV7 vaccination did not lead to changes in the probability of success of the current empiric treatments of the AOM. Integrated PK/PD analysis has demonstrated to be a useful tool to identify changes in antimicrobial activity after the implantation of a vaccination program, providing complementary information to the simple assessment of MIC values.

[Incidence of Cryptosporidium sp in patients treated in a general hospital. Technics for the identification of oocysts in feces]. / Incidencia de Cryptosporidium sp en pacientes asistidos en un hospital general. Técnicas para la identificación de ooquistes en heces.

In feces referred for parasite investigation from 1973 patients of the Hospital Clinico Universitario in Salamanca, 27 instances of infestation by Cryptosporidium sp (1.5% of all investigated patients) were detected in 19 children (1.4%) and 8 adults (2.2%). The incidence in patients with antibodies against the human immunodeficiency virus (HIV) was 12.5%, in contrast with 1.25% in patients without anti-HIV antibodies. 55.5% of the instances of Cryptosporidium sp infestation were found in children less than 4 years old. The higher incidence was in winter and spring. The association with other enteropathogens was found in 14.8%. Diarrhea and abdominal pain were the most common clinical features of cryptosporidial disease. Chronic diarrhea was found in two adult patients with acquired immunodeficiency syndrome. In immunocompromised children and adults asymptomatic carriers were found. The sensitivity and specificity of immunofluorescence testing with monoclonal antibodies as compared with Ziehl-Neelsen stain for the detection of Cryptosporidium sp oocysts were 100%.

[Post-transfusion graft versus host disease in a patient with Hodgkin's disease]. / Enfermedad del injerto contra el huésped postransfusional en una paciente con enfermedad de Hodgkin.

A female with Hodgkin's disease developed graft versus host disease (GVHD) after the administration of two units of packed red cells. Ten days after the transfusion she developed fever and rash, with subsequent hepatic and intestinal disease and a profound bone marrow aplasia. She died from a Candida tropicalis sepsis. The diagnosis of GVHD was made on the basis of clinical and histological criteria. We review this uncommon complication of hemotherapy, with special emphasis on its differential clinical features and its prevention.

[Evolution of antimicrobial use during the years 1996-2000 in a general hospital. A detailed ICU study]. / Evolución de la utilización de antimicrobianos durante los años 1996-2000 en un hospital general. Estudio pormenorizado de la UCI.

PURPOSE: Antimicrobials are a mayor part of hospital pharmacy budgets and must be considered in resource planning and spending projections. This study describes the profile of antibiotic use at a medium-sized hospital (by examining the ICU separately) and analyses its evolution over the period 1996-2000. METHODS: Descriptive and retrospective study. Pharmacy records were reviewed to identify oral and parenteral antimicrobial agents administered to inpatients. Results were expressed in Daily Defined Doses (DDD) per 100 stays and day. RESULTS: During the five-year study period 176.162 DDD / 100 s-d of antibiotics were consumed in the ICU, whereas in the rest of the hospital usage was much lower (54.540 DDD / 100 s-d). Aminoglycosides, cephalosporins, penicillins, glycopeptides and carbapenems were the most commonly used groups of antimicrobials in the ICU, and penicillins, cephalosporins, trimethoprim/sulfonamide combinations, aminoglycosides and quinolones in the rest of the hospital. CONCLUSIONS: ICUs have some special features which make them different to the rest of inpatient areas. Because of that fact we consider important to study this specific patient-care area separately.