The Los Angeles County Department of Public Health (LAC DPH) is investigating a cluster of Brucella melitensis (brucellosis) infections among adults residing in South Los Angeles County.
Each confirmed case reported consuming unpasteurized cheese imported from Mexico, underscoring the serious health risks associated with raw or unpasteurized dairy products.
Brucellosis is rare in Los Angeles County, with fewer than 15 cases reported annually. Most local cases are associated with unpasteurized imported cheese, occupational exposure to animals abroad, or accidental laboratory exposures. While the current risk to the general public remains low, LAC DPH is issuing this advisory to alert healthcare providers and the public to the ongoing investigation.
“Consuming raw or unpasteurized dairy products carries significant risk of serious infection. We urge all residents to avoid these products, whether purchased locally or brought by family and friends from abroad,” said Dr. Sharon Balter, Director, Acute Communicable Disease Control Program, Los Angeles County Department of Public Health.
LAC DPH advises all residents to avoid consuming raw or unpasteurized dairy products, including cheese informally brought into the country by family or friends, or consumed while traveling to regions where brucellosis is endemic. Individuals who have recently consumed unpasteurized imported cheese and are experiencing fever, night sweats, fatigue, or joint pain should consult a healthcare provider promptly.
Brucellosis — also known as “Malta fever,” “undulant fever,” or “Mediterranean fever” — is considered one of medicine’s “great imitators” due to its wide range of symptoms. The bacteria enter the bloodstream via regional lymph nodes and can seed throughout the body. The incubation period ranges from one to four weeks but may be as long as six months.
Symptoms include acute or insidious onset of fever, night sweats, arthralgia, headache, fatigue, anorexia, myalgia, and weight loss. In serious cases, the infection can cause arthritis, spondylitis, meningitis, endocarditis, orchitis/epididymitis, and organ involvement affecting the liver and spleen.
Brucella species are designated federal Select Agents due to their low infectious dose and potential for aerosolization. Laboratories must be alerted before specimens from a suspect brucellosis case are submitted.
Healthcare providers are asked to take the following steps:
- Suspect: Consider brucellosis in patients with fever, night sweats, fatigue, or arthralgias who have a history of consuming unpasteurized dairy products in the U.S. or during travel to endemic countries.
- Test: Order Brucella serology and blood cultures. Notify the laboratory before submitting specimens so appropriate biosafety precautions can be taken.
- Treat: Consult an infectious disease physician. Standard treatment is doxycycline for 6 weeks plus streptomycin (14–21 days) or rifampin (6 weeks). For pediatric or pregnant patients, consider rifampin plus TMP-SMX. Begin treatment without waiting for lab confirmation if clinical suspicion is high.
- Post-Exposure Prophylaxis (PEP): Consider PEP for individuals exposed to a common contaminated product or who had high-risk exposure to a confirmed case, along with serologic and symptom monitoring.
- Report: Brucellosis must be reported to Public Health within one working day. If a cluster of two or more related cases is suspected, notify Public Health immediately.
- Educate: Advise patients to avoid all raw or unpasteurized dairy products — including those with unknown pasteurization status — whether purchased locally or during travel.
