Exposure to RB51 through Raw Milk or Milk Products: How to Reduce Risk of Infection

People who have consumed raw milk or raw milk products that are potentially contaminated with RB51 are at high risk for brucellosis infection. For these people, symptom monitoring and antibiotics to prevent infection (also called post-exposure prophylaxis (PEP)) is recommended.

PEP for RB51 should include:

  • Doxycycline, in addition to trimethoprim-sulfamethoxazole or another suitable antimicrobial, for 21 days

Those with contraindications to doxycycline or trimethoprim-sulfamethoxazole should consult with their health care provider.

Prophylaxis for exposure to Brucella species other than RB51 routinely consists of a combination of doxycycline and rifampin. RB51, however, is resistant to rifampin in vitro and to penicillin, so rifampin and penicillin are not recommended.

Symptom Monitoring

Routine serologic tests for brucellosis are not effective for diagnosing or monitoring RB51 infections. So those at high risk should be monitored for the development of symptoms of brucellosis. Monitoring should include:

  • For 4 weeks from last exposure, check temperature for fever
  • For 6 months from last exposure, watch for broader symptoms of brucellosis

People potentially exposed to RB51 who develop symptoms should consult a health care provider.

If brucellosis occurs despite prophylaxis, treatment regimens should be selected based on antimicrobial susceptibility results.