Procalcitonin in respiratory disease: use as a biomarker for diagnosis and guiding antibiotic therapy.

Procalcitonin (PCT) is a peptide measurable in serum which becomes elevated in response to bacterial infection. Multiple trials have explored the safety and efficacy of using PCT as a biomarker to guide decisions about starting or stopping antibiotic therapy in a wide variety of situations, and PCT assays have recently been approved by the Federal Drug Administration (FDA) in the US for use in both sepsis and respiratory tract infections. While there have been a number of promising results particularly in acute respiratory tract infections and intensive care unit settings, problems including adherence to protocol, cost of the assay and improved antimicrobial stewardship more generally, have limited more widespread adoption. This educational article summarises the evidence for the use of procalcitonin as a biomarker of bacterial infection across the spectrum of respiratory disease and reviews how the use of procalcitonin-guided antibiotic therapy is reflected in current major international guidelines. KEY POINTS: Procalcitonin has been widely investigated as a biomarker of bacterial infection to aid diagnosis and decisions to start or stop antibiotics in a range of conditions, including in diseases of the lower respiratory tract.Meta-analysis suggests that the use of procalcitonin to guide antibiotic therapy in acute respiratory tract infections can reduce duration of antibiotic therapy and hospital admission without adversely affecting outcomes - however, there was significant heterogeneity in methodology and population in the included studies, and more recent studies have failed to show such significant benefits.The use of procalcitonin to guide stopping or shortening antibiotic therapy in sepsis/septic shock is suggested in the international guidelines for the management of sepsis (2016), but this is a "weak" recommendation, with a low quality of evidence recognised. Major international guidelines do not support a role for procalcitonin in the management of acute exacerbations of COPD, bronchiectasis, interstitial lung disease or pleural infection.Regardless of situation, decisions on initiating, altering, or discontinuing antimicrobial therapy should never be made solely on the basis of changes in any biomarker - while biomarkers such as procalcitonin may provide supportive information, they should only be used alongside regular and robust clinical assessment. EDUCATIONAL AIMS: To understand the principles of using procalcitonin to guide decisions regarding antibiotic use (procalcitonin-guided antibiotic therapy).To review important research studies into the use of procalcitonin as a biomarker of bacterial infection across the spectrum of diseases of the lower respiratory tract.To understand the current international guidelines regarding procalcitonin use in disease of the lower respiratory tract.

GENITAL TRACT SCREENING FINDS WIDESPREAD INFECTION WITH MUSTELID GAMMAHERPESVIRUS 1 IN THE EUROPEAN BADGER ( MELES MELES).

: Sexually transmitted diseases (STDs) can be important drivers of population dynamics because of their negative effects on reproduction. However, screening for STDs, especially in wildlife populations, is widely neglected. Using the promiscuous, polygynandrous European badger ( Meles meles) as a model, we investigated the presence and prevalence of herpesviruses (HVs) in a wild, high-density population and assessed potential differences in somatic fitness and female reproductive condition between infected and uninfected individuals. We collected n=98 genital swabs from 71 females (51 adults and 20 cubs) and 27 males (26 adults and 1 cub) during spring and summer 2015. Using a PCR specific for a mustelid α-HV, all genital-swab samples tested negative. In a panherpes PCR, a γ-HV was found in 55% (54/98; 39 adults and 15 cubs), identified as mustelid gammaherpesvirus 1 (MusGHV-1) using DNA sequencing. This contrasts with the results of a previous study, which reported MusGHV-1 in 98% (354/361) of blood samples taken from 218 badgers in the same population using PCR. The detection of MusHV-1 in the female reproductive tract strongly indicates the potential for a horizontal and, likely also a vertical, route of transmission. Our results suggest a potential linkage of genital HVs and impaired future reproductive success in females, but because reproductive failure can have many reasons in badgers, the causative link of this negative relationship remains to be investigated.

Evaluation of methods for short-term marking of domestic dogs for rabies control.

Rabies transmitted by domestic dogs is a serious yet neglected public health threat in many underserved communities in Africa and Asia. Achieving 70% vaccination coverage in dog populations through annual mass vaccination campaigns is an effective means of controlling the disease in these communities. Evaluating the extent to which this target coverage is achieved requires either accurate pre-campaign estimates of the dog population size or accurate estimates of the coverage attained by conducting post-vaccination surveys. Short-term marking of dogs by applying visible marks may be useful to achieve these estimates, but will be affected by the performance of the marking methods. We evaluated the longevity and visibility of two readily-available livestock marking methods applied to owned, free roaming dogs. We applied two types of marks (spray and crayon) with three different colours (red, blue and green) to each of 21 dogs and compared the time of persistence of the marks over several weeks. Two independent observers assessed the visibility and colour of the marks. Each dog was observed over 8-37 days (median: 28 days). Kaplan-Meier survival analyses and semi-parametric log-rank tests were performed separately for both observers. Spray marks remained visible significantly longer (median of 24 days for both observers) compared with crayon marks (medians of 10 and 13 days). After 10 days, 90% of spray marks were still visible, compared with only 46% of crayon marks. Visibility of marks was reduced in darker-coloured dogs. Colours of marks were frequently misclassified, and agreement between observers on the colours of the marks was low (Cohen's kappa coefficient=0.27). The livestock marker spray can effectively be used to mark dogs that are physically restrained, for example during vaccination campaigns. Resight surveys should be conducted within a short a time as possible after marking; however, our results suggest that loss of marks will not have a significant impact if surveys are conducted within 5-7 days after marking with the spray. Results that depend on observers' abilities to distinguish between the three colours which we evaluated may not be reliable.