Applied Microbiology MCQs

Monthly water surveillance in hemodialysis units: Correct , routine monitoring is critical to ensure safe water quality for dialysis patients. Why Not Others: A. Outbreak investigation: Focuses on targeted sampling, not routine checks. B. Equipment sterilization: Involves evaluative sampling after changes, not regular monitoring. D. New hospital construction: Involves specific sampling rather than ongoing routine checks. Key Takeaways: Routine environmental sampling is indicated for monthly water surveillance in hemodialysis units to ensure safe water quality . Other situations often require targeted or specific sampling rather than routine. Tags : good to know Reference: Guidelines on routine and targeted environmental microbiological sampling.

Healthcare-associated infections (HAIs) can be defined as- The infections acquired in the hospital by a patient admitted for a reason other than the infection in context , The infection should not be present or incubating at the time of admission , and The symptoms should appear at least after 48 hours of admission. This also include: Infections that are acquired in the hospital but symptoms appear after discharge. Occupational infections among staff of the healthcare facility (e.g. needle stick injury transmitted infections). Infection in a neonate that results while passage through the birth canal (in contrast to congenital infections due to transplacental transmission, which are not HAIs). Reference : Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page no: 229

For infection control: Single isolation room with a bathroom facility is preferred. If not available, then cohorting is recommended. Cohorting may be carried out in various ways Patients with similar infections requiring contact precautions can be placed together either in the same isolation room, or in the same cubicle or corner of a ward or Spatial separation of minimum of 3 feet distance between the beds with privacy curtains. Other measures for infection control are: Hand Hygiene should be maintained. Health care workers should wear PPE. Single-use patient-dedicated equipment. Patient movement should be limited only to medically-necessary purposes. Disinfection of rooms should be carried out frequently and adequately. Reference : Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page no: 236

Indwelling urinary catheterization is a risk for UTI because: The presence of a urinary catheter is the single most important risk factor. The risk of developing CAUTI is directly proportional to the duration of catheterization. Urethral pressure : an indwelling catheter exerts lateral urethral pressure causing decreased mucosal blood flow, urothelial mucosal disruption and impaired mucin secretion; All these factors together predispose to infection Incomplete emptying : In catheterized patients, bladder is often incompletely emptied because of pressure differentials created by patient movement or catheter manipulation. A small amount of urine always pools around the balloon which serves as a nidus for infection. Reference : Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page no: 242

Management of CAUTI includes removal of catheter and institution of appropriate antimicrobial therapy based on the susceptibility pattern of the organism isolated. Treatment of asymptomatic bacteriuria (Ca-aSB) is not recommended except when: Bacteriuria persists for >48 hours after removal of the catheter. In pregnancy , as there is 20–30 fold increased risk of developing pyelonephritis and risk of premature delivery with low birth weight. Prior to traumatic urological procedures such as transurethral resection of prostate where mucosal bleeding is anticipated which may cause bacteremia. Reference : Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page no: 242

An occupational exposure is defined as: Percutaneous injury, . needle stick injury (NSI) or other sharp injury. Splash injury : Contact with the mucous membrane (e.g. eye or mouth). Contact with non-intact skin (abraded skin or afflicted with dermatitis). Contact with the intact skin when the duration is prolonged (e.g. several minutes or more). An occupational injury is often loosely termed as needle stick injury though it includes injury through needle or other sharps and splashes. Reference : Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page no: 267

Routine air sampling (i.e. random or periodic sampling) is not recommended because HAI rates are not related with levels of general microbial contamination of air or environmental surfaces, There is no standard guidelines mentioning permissible levels of microbial contamination of environmental surfaces or air. CDC recommends targeted air surveillance, which should be carried out for the following indications: Investigation of an outbreak For research purpose After reconstruction or newly constructed buildings After fogging (to monitor the quality) For short-term evaluation of a change in infection control practice. Reference : Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page no: 281

Framing Antimicrobial Policy: Every hospital should frame their own hospital antimicrobial policy which is usually a pocket handbook, consisting of system/syndrome wise indications for antimicrobial choice and their dosage. It should be prepared by the AMS team after discussing with all the clinicians, microbiologists and administrators. The policy must be compliant to the standard national and international antimicrobial guidelines and local antibiogram pattern. Common consensus between all clinicians must be arrived at, before framing the policy; which facilitates better adherence to policy. Reference : Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page no: 273