Examkin

Question

Difficulty: MediumInfectious Diseases

Match each clinical scenario requiring targeted antimicrobial prophylaxis with the most appropriate guideline-concordant regimen.

  • A 20-year-old college student who resides in the same dormitory suite as an individual recently hospitalized with confirmed Neisseria meningitidis infection.Oral ciprofloxacin (single dose)
  • A 68-year-old man with a mechanical aortic valve who is scheduled for a routine tooth extraction and periodontal scaling.Oral amoxicillin (single dose 30-60 minutes before the procedure)
  • A 29-year-old primigravida at 38 weeks gestation presenting in active labor who had a positive rectovaginal swab for Group B Streptococcus at 36 weeks.Intravenous penicillin G (administered continuously until delivery)
  • A 42-year-old hiker in an endemic region who removes an engorged Ixodes scapularis tick that was attached to the skin for approximately 48 hours.Oral doxycycline (single dose within 72 hours of tick removal)

Answer

The correct pairings match meningococcal close contacts with single-dose ciprofloxacin, high-risk cardiac patients undergoing dental procedures with pre-procedure amoxicillin, GBS-colonized women in labor with intrapartum IV penicillin G, and high-risk tick bite exposures with single-dose doxycycline.
Each clinical scenario presents a classic indication for prophylactic antimicrobials to prevent severe infectious complications. Meningococcal close contacts require ciprofloxacin, rifampin, or ceftriaxone to eliminate carriage. High-risk cardiac lesions during high-risk dental procedures require amoxicillin to prevent endocarditis. GBS-colonized pregnant women require intrapartum IV penicillin G to protect the neonate. High-risk tick bites require a single prophylactic dose of doxycycline.

Step-by-Step Solution

1
Analyze the meningococcal exposure scenario.
The patient is a close contact (dormitory suite mate), which is an indication for meningococcal prophylaxis.
Close contacts are at high risk of nasopharyngeal carriage and subsequent invasive disease. Prophylaxis with ciprofloxacin eradicates this carriage.
2
Analyze the cardiac patient scenario.
A mechanical valve is a high-risk condition, and tooth extraction involves gingival manipulation, indicating a need for endocarditis prophylaxis.
Procedures manipulating the gingiva can cause transient bacteremia with oral flora. Amoxicillin effectively targets Viridans group streptococci.
3
Analyze the pregnant patient scenario.
Positive GBS screening at 36 weeks with current active labor is a strict indication for intrapartum GBS prophylaxis.
IV Penicillin G administered during labor significantly reduces the risk of vertical transmission and early-onset neonatal sepsis.
4
Analyze the tick exposure scenario.
An engorged Ixodes tick attached for more than 36 hours in an endemic area meets the criteria for Lyme disease prophylaxis.
A single dose of oral doxycycline given within 72 hours of tick removal effectively prevents Borrelia burgdorferi infection.

Key Concept

Indications and regimens for specific antimicrobial prophylaxis (Meningococcal, Endocarditis, Intrapartum GBS, and Lyme disease)
Rate this question

Topics

Infectious Diseases

More questions from this topic