Title : Osteoarticular brucellosis in an endemic region : Epidemio-clinical aspects, diagnosis, and treatment of 49 cases
Brucellosis is a common bacterial zoonotic disease with a broad spectrum of clinical manifestations. Osteoarticular involvement is frequent, with a reported prevalence ranging from 27% in nonendemic regions to 36% in endemic regions. The sacroiliac and spinal joints are the most common affected sites.
The aim of this study was to determine the epidemiological characteristics, clinical manifestations, diagnostic tools, and outcome of osteoarticular brucellosis (OAB) in an endemic region.
We conducted a retrospective analysis of records of the patients diagnosed as OAB and attending the infectious diseases department from 2017 to 2022. A diagnosis of OAB was established in all patients with a compatible clinical and radiological findings in the presence of an antibody titre of 1/80 or more in a standard tube agglutination (STA) test or by a positive culture.
A total of 49 patients with OAB (34 males, 15 females) were enrolled. Median age was 55 years (age range, 14-82 years). Forty patients (82%) lived in rural areas and 26 patients (53%) had a history of handling animals or animal excretions. Forty-two patients (86%) reported consuming unpasteurized milk and/or dairy products. Median diagnostic delay was 90 days (IQR 33-165). The most frequent complaints were fever (86%), sweats (71%) and asthenia (51%).
Spondylodiscitis was the most frequent manifestation of OAB (75%). The lumbar spine was the most commonly affected spinal site (n=29), followed by thoracic (n=13) and cervical segments (n=7).
Spondylodiscitis was followed by sacroiliitis (n=7) and peripheral arthritis (n= 2). One patient had a septic loosening of total knee arthroplasty.
Multiple joint involvement was noted in 4 cases : sacroiliitis plus spondylodiscitis in 3 cases and sacroiliitis plus peripheral arthritis in one case.
STA test was positive in 48 patients. Blood cultures yielded Brucella spp in 4 cases. Disco-vertebral needle biopsy was performed in 5 patients with spondylodicitis. Only 2 biopsy specimens yielded positive culture results. All patients received antibiotic treatment with a combination of two (77%) or three agents (23%). The most commonly used antimicrobial combination therapy was rifampicin plus doxycyclin (53%). Median duration of antimicrobial treatment was 143 days (IQR 98-180). Surgical treatment was performed in 5 patients. Median follow-up period was 210 days (IQR 120-315). Relapse occurred in 4 cases.
In our study, spondylodiscitis was the most common form of OAB. The lumbar spine was the most frequently involved. Early symptoms are non-specific, leading to delayed diagnosis and late onset of treatment. Brucellosis should be considered in all patients with unexplained fever and osteoarticular complaints in endemic areas or in patients visiting such areas.
Audience Take Away :
The spine and sacroiliac joints tend to be the most commonly affected sites of osteoarticular brucellosis.
The isolation of Brucella from bone biopsy or blood culture may be difficult, and therefore diagnosis is mainly based on serologic testing.
Patients with osteoarticular brucellosis need a long-term antimicrobial treatment.