You have the results of PCR tests for Mycoplasma pneumoniae; the number of positive tests is 83 collected from a 100 truly-infected persons. The sensitivity of this test is

Correct Answer: D

Rationale: Sensitivity = (True positives / Truly infected) * 100 = (83 / 100) * 100 = 83%.

Correct Answer: B

Rationale: Airborne isolation is needed for a child hospitalized with chickenpox (varicella) because the virus causing chickenpox spreads easily through the air when an infected person coughs or sneezes. The virus can also be transmitted through direct contact with the rash or fluid from the blisters. By implementing airborne precautions, healthcare providers aim to prevent the spread of the virus to other patients, staff, and visitors in the healthcare setting. In contrast, mumps, exanthema subitum (roseola), and erythema infectiosum (fifth disease) are generally not transmitted through airborne routes; therefore, they do not require airborne isolation in a hospital setting.

Correct Answer: C

Rationale: Option C provides a thorough and accurate documentation of the dressing change procedure for the postoperative appendectomy incision. This documentation includes essential details such as the condition of the incision site (non-reddened, sutures intact, no drainage noted on old dressing), the action taken (new dressing applied), and the outcome (procedure tolerated well by the child). It covers all the necessary aspects of the dressing change procedure and clearly indicates the status of the incision site before and after the intervention. Options A, B, and D do not provide as comprehensive and detailed information about the dressing change procedure and its outcomes, making option C the most appropriate choice for accurate documentation.

Correct Answer: D

Rationale: Autoimmunity is a phenomenon in which the immune system mistakenly targets and attacks the body's own cells, tissues, and organs. This occurs due to a breakdown in the immune system's ability to differentiate "self" from "nonself." In a healthy immune system, immune cells recognize and destroy foreign invaders while avoiding attacking the body's own cells. When this self-tolerance is lost, autoimmune diseases can develop, leading to inflammation, tissue damage, and various health problems. Therefore, autoimmunity is defined by the immune system's inability to distinguish between self and nonself.

Correct Answer: D

Rationale: Sensitivity = (True positives / Truly infected) * 100 = (83 / 100) * 100 = 83%.