Gold Standard Cholera Diagnostics Are Tarnished by Lytic Bacteriophage and Antibiotics.

A fundamental, clinical, and scientific concern is how lytic bacteriophage, as well as antibiotics, impact diagnostic positivity. Cholera was chosen as a model disease to investigate this important question, because cholera outbreaks enable large enrollment, field methods are well established, and the predatory relationship between lytic bacteriophage and the etiologic agent Vibrio cholerae share commonalities across bacterial taxa. Patients with diarrheal disease were enrolled at two remote hospitals in Bangladesh. Diagnostic performance was assessed as a function of lytic bacteriophage detection and exposure to the first-line antibiotic azithromycin, detected in stool samples by mass spectrometry. Among diarrheal samples positive by nanoliter quantitative PCR (qPCR) for V. cholerae (n = 78/849), the odds that a rapid diagnostic test (RDT) or qPCR was positive was reduced by 89% (odds ratio [OR], 0.108; 95% confidence interval [CI], 0.002 to 0.872) and 87% (OR, 0.130; 95% CI, 0.022 to 0.649), respectively, when lytic bacteriophage were detected. The odds that an RDT or qPCR was positive was reduced by more than 99% (OR, 0.00; 95% CI, 0.00 to 0.28) and 89% (OR, 0.11; 95% CI, 0.03 to 0.44), respectively, when azithromycin was detected. Analysis of additional samples from South Sudan found similar phage effects on RDTs; antibiotics were not assayed. Cholera burden estimates may improve by accommodating for the negative effects of lytic bacteriophage and antibiotic exposure on diagnostic positivity. One accommodation is using bacteriophage detection as a proxy for pathogen detection. These findings have relevance for other diagnostic settings where bacterial pathogens are vulnerable to lytic bacteriophage predation.

Is Lidocaine Infiltration Really Necessary in Micro Ear Surgeries performed Under General Anaesthesia?

To study the role of infiltrating 2% Lidocaine in Micro ear surgeries performed under general anaesthesia. To measure the impact of infiltration of 2% Lidocaine in post operative pain relief and per operative bleeding. A Double blinded, Prospective randomized comparative study was conducted in a tertiary care referral centre. A total of 30 patients planned for micro ear surgeries under general anaesthesia (Tympanoplasty and Cortical mastoidectomy) for CSOM tubotympanic disease were selected and divided into two groups randomly by the chief senior consultant. Group A patients received local infiltration of 2% Lidocaine with one in 200,000 adrenaline and Group B patients received infiltration of one in 200,000 adrenaline in distilled water alone. Operating surgeon assessed the bleeding in the surgical field using Boezaart's grading system. Post operative pain was assessed using a visual analog scale. Pain scores of these patients were assessed in the 1st, 4 and 24th h post operatively and recorded. The mean post operative pain score in the 1st h for the patients in Group A was 0.93 and for patients in Group B was two. The difference in the pain scores between the two groups was significant (P < 0.02).The difference in the mean post operative pain scores between the two groups in the 4 and 24th h were not significant (P < 0.1).Per operatively, grade III bleeding was present in 73% of patients in group B and only 33% of patients had grade III bleeding in group A. Infiltration of 2% Lidocaine has a significant impact over the grade of bleeding in the operative field and also on 1st h post operative pain relief. It did not have a significant influence on the pain relief in the 4 and 24th h post operatively.