2025 – PAGE 337 – INFECTIOUS DISEASES

MISCELLANEOUS ID RELATED TOPICS

SPLENECTOMY PATIENTS

Splenectomy patients are susceptible to the encapsulated “HNS” bugs, Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae. Patients also do not mount much of a response to the Pneumococcal vaccines. So if you are given an immunized patient with sickle cell disease, or a splenectomy, consider Strep as a very real possibility for a bacteremia or sepsis.

(DOUBLE TAKE) MNEMONIC: A complete list of encapsulated organisms can be recalled by remembering that “Some Nasty Killers Have Some Capsule Protection”: Streptococcus pneumoniae, Neisseria meningitidis, Klebsiella pneumoniae, Haemophilus influenzae, Salmonella typhi, Cryptococcus neoformans, and Pseudomonas aeruginosa. Bruton’s agammaglobulinemia and sickle cell patients are especially susceptible to encapsulated organisms.

DFA AND ELISA TESTING

Enzyme-linked immunosorbent assay (ELISA or EIA) and Direct Fluorescent Antibody (DFA) testing are more available and faster than Polymerase Chain Reaction (PCR) testing. If offered as a choice, pick DFA or ELISA over PCR for faster diagnosis of most viruses.

GROWTH MEDIA AND STAINING

• BORDETELLA PERTUSSIS: Use Regan-Lowe or Bordet-Gengou growth media.
• CORYNEBACTERIUM DIPHTHERIAE: Use Loeffler or Tinsdale agar.
• NEISSERIA GONORRHEA: Use Thayer-Martin.
• CRYPTOCOCCUS: Use India ink staining.

LATEX AGGLUTINATION

Latex agglutination is probably a low-yield topic, but if you have a high suspicion for GBS, Haemophilus, Neisseria, or Streptococcus pneumoniae, this test could be somewhat useful as a second line test.

DROPLET PRECAUTIONS

Droplet precautions are for patients with Neisseria meningitidis or the Influenza virus (flu).

MNEMONIC: DROPPIN’ IN = DROPlets precautions for Influenza and Neisseria

RETURN-TO-SCHOOL CRITERIA

Return-to-school policies are variable. For example, for viral conjunctivitis (aka pink eye), the CDC recommends that children should not attend school if they cannot avoid close contact with others, while the American Academy of Pediatrics states that children do not need to miss school for viral conjunctivitis. The final decisions are typically made on a school-by-school basis.

(DOUBLE TAKE) APHTHOUS ULCERS

Aphthous ulcers are painful lesions found within the oral mucosa (buccal mucosa, lips, and tongue) with a grayish-white base and a rim of erythema. These can occur in isolation or in association with Behcet’s or Shwachman-Diamond syndrome.

IMAGE: www.pbrlinks.com/APHTHOUSULCERS1
IMAGE: www.pbrlinks.com/APHTHOUSULCERS2