neglected case of osteoarticular brucella infection...
TRANSCRIPT
44(6):761-763,2003
CASE REPORT
Neglected Case of Osteoarticular Brucella Infection of the Knee
Huseyin Yorgancigil, Guler Yayli1, Orhan Oyar2
Departments of Orthopedics, 1Clinical Microbiology and Infectious Diseases, and 2Radiology, Süleyman DemirelUniversity School of Medicine, Isparta, Turkey
A 49-year-old farmer had a history of recurrent knee effusion for 20 years. He did not report undergoing any diagnosticor therapeutic procedures apart from repeated aspirations of the joint fluid. After the isolation of Brucella melitensisfrom the joint fluid, computed tomography-guided bone biopsy was performed and histopathologic examination ofthe biopsy sample confirmed the diagnosis of chronic Brucella osteomyelitis. Arthroscopic synovectomy combinedwith antimicrobial therapy with doxycyclin, rifampicin, and ciprofloxacin for six months resulted in clinical recovery.This case indicates that brucellosis should be suspected in patients with non-specific and chronic osteoarticularsymptoms, especially in endemic regions.
Key words: arthritis, infectious; bone diseases, infectious; Brucella; Brucella melitensis; brucellosis; osteomyelitis
Brucellosis is primarily a disease of wild and do-mesticated animals (1). It is transmitted to humansthrough consumption of unpasteurized dairy prod-ucts of infected animals, directly through contact withinfected animals, or indirectly by environmental ex-posure (1). It is widespread in Turkey, as in manyother Mediterranean and Middle Eastern countries.Brucellosis may commonly be misinterpreted be-cause of its extremely variable clinical pictures and,in some chronic cases, microbiological and serologi-cal negativity (2). For this reason, suspicion of Brucel-la infection may sometimes be the key for correctdiagnosis, especially in endemic regions.
We present a case of a patient with chronic bru-cellosis that manifested as an osteoarticular involve-ment of the knee joint and adjacent bones, withoutany diagnosis for 20 years.
Case Report
A 49-year-old male farmer presented with swell-ing and limited motion of the right knee. He reportedthat the symptoms had started before 20 years andthat he had been treated only with the aspiration offluid from the knee joint. He also reported that he hadnever undergone any biochemical or radiological ex-aminations to clarify the cause of his condition. Jointfluid aspiration had been repeated several times dueto recurrence of the symptoms before he came to ouremergency department with a swollen knee but with-out any signs of acute inflammation. Laboratory testsrevealed erythrocyte sedimentation rate of 24 mm/h,
negative C-reactive protein, and white blood cellcount of 5.7×109/L. No microorganisms were iso-lated from blood cultures. All the other biochemicalparameters were normal. Considering the prevalenceof brucellosis in our region, we decided to search forBrucella in this particular patient having non-specificosteoarticular symptoms. Standardized Brucella tubeagglutination test was performed on a serum sample(Pendik Veterinary Control and Research Institute, Is-tanbul, Turkey). To avoid post-zone phenomenon (3),the specimens were diluted up to 1:2,560 but yieldeda negative result. Coombs test was also negative(Serologicals Ltd., Livingston, UK).
Macroscopic appearance of the joint fluid, whichwas slightly turbid and dark yellow, was consistentwith chronic infectious arthritis. Fluid cell count was3.0×109/L, with differential count of 80% monocy-tes. No microorganisms were detected on Gram-stained smears. Biochemical analysis of the joint fluidrevealed glucose concentration of 2.9 mmol/L, albu-min concentration of 13.1 g/L, and globulin concen-tration of 15.0 g/L. The joint fluid was inoculated inblood agar and blood culture bottles, and Brucellamelitensis was isolated from blood culture bottles onthe sixth day.
X-ray of the right knee revealed lytic lesions inthe proximal tibia and distal femur adjacent to thejoint (Fig. 1A). These lesions were confirmed by mag-netic resonance imaging, showing para-articular hy-perintensities on T2-weighted sequence (Fig. 1B).Scintigraphy with technetium-99m methylene dipho-sphonate revealed inflammatory hyperactivity in the
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right distal femur and proximal tibia, and computedtomography-guided bone biopsy was performed. To-gether with osseous biopsy material from the proxi-mal tibia and distal femur, some fluid similar to thejoint fluid was obtained. No microorganisms wereisolated after inoculation in blood agar, but Brucellamelitensis was cultured after inoculation into bloodculture bottles. Histopathological examination of thespecimens revealed chronic nonspecific infection.Antimicrobial treatment was started with doxycyclin100 mg twice daily, rifampicin 300 mg twice daily,and ciprofloxacin 500 mg twice daily.
Villous synovial hypertrophy was observed atarthroscopy, and a multi-portal arthroscopic synovec-tomy was performed. Chronic nonspecific synovitiswas confirmed histopathologically. There was no mi-crobiological growth in synovectomy specimens. Thecase was diagnosed as a rare form of brucellosis withosteoarticular involvement and osteomyelitic lesionsof the distal femur and proximal tibia secondary tochronic infectious arthritis of the knee caused byBrucella melitensis.
The medical treatment continued for six months,including anti-inflammatory agents and physiother-apy. There were no symptoms, such as swelling orpain, to implicate recurrence of the infection through-out the follow-up period. The patient made a com-plete clinical recovery at the latest control examina-tion at 24 months.
Discussion
Osteoarticular involvement in brucellosis mostcommonly affects the vertebral column, sacroiliac,and peripheral joints. Although the leading manifesta-tion is bone and joint inflammation, there are rare re-ports of osteomyelitis (4-8). However, metaphyseallocation of osteomyelitis is undemanding because ofthe histological nature of that part of the bone. Thequestion in this case may be whether the initial infec-tion was in the joint or in adjacent metaphyses.
Although Brucella melitensis was initially iso-lated from the joint fluid in our patient, no microor-
ganisms were found in the later arthroscopic synovec-tomy specimens. This may be due to antimicrobialtherapy that was started immediately after the first iso-lation. There was also no joint destruction, as re-ported elsewhere (5). It may be speculated that meta-physeal bone involvement and subsequent erosionwas the result of a local dissemination of untreatedBrucella arthritis for about 20 years.
Zwass and Feldman (7) reported a case ofchronic multifocal osteomyelitis in a patient with anestablished diagnosis of chronic brucellosis thatlasted for 14 years. However, the diagnosis in our pa-tient was reached on the basis of inoculation of thejoint fluid in blood culture bottles to isolate the micro-organism. Further factors raising suspicion of brucel-losis were the fact that the patient lived in an endemicregion and that he could be environmentally exposedto Brucella due to his occupation. Clinical or labora-tory findings did not suggest a Brucella infection inour patient; serological tests and blood cultures werenegative. On the other hand, other authors mostly re-ported positive agglutination titers in cases of Brucellaosteomyelitis (4-8). However, the diagnosis of brucel-losis cannot be excluded even if the serum agglutina-tion tests are negative (2).
Although brucellosis in humans often has to bediagnosed without the isolation of a casual organism,laboratory investigation of aspiration fluid and tissuespecimens obtained at biopsy aided in identificationof the disease in our patient. Brucella melitensis wascultured from both joint fluid and bone biopsy speci-mens. The important fact is that the growth of the mi-croorganism was possible only after inoculation ofthese specimens into blood culture bottles. This canbe expected, as Brucella spp. are known to be deli-cate bacteria (2). We usually obtain higher rates of iso-lation of microorganisms from joint and other bodyfluids when using blood culture bottles, than incuba-tion in standard plates. Considering the characteris-tics of our region, we routinely inoculate these speci-mens into blood culture bottles in our institution.
In our patient, the insidious course of the diseaseand negligence in previous medical handling causeda 20-year delay in diagnosis of the disease. If possible,enzyme linked immunosorbent assay (ELISA) can beused in detection of antibody when conventionalserological tests are negative (9). We did not have toconfirm serological diagnosis with ELISA in our pa-tient, because culture results were positive for bothsynovial fluid and bone biopsy specimens.
One should bear in mind that osteomyelitis andinfectious arthritis due to Brucella may present as alow-grade infection. In spite of its rarity, brucellosisshould be considered in differential diagnosis of pa-tients with recurrent knee joint effusion, even whenthey have no systemic symptoms or laboratory evi-dence, especially in areas where the disease is en-demic and in patients with epidemiological riskfactors for the infection.
References
1 Corbel MJ. Recent advances in brucellosis. J MedMicrobiol 1997;46:101-3.
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Yorgancigil et al: Osteoarticular Brucella Infection Croat Med J 2003;44:761-763
Figure 1. Antero-posterior X-ray (A) and T2-weighted coro-nal plane magnetic resonance image (B) of the patient’sright knee. The lytic lesions seem to be limited to meta-physeal bone, without any articular involvement.
2 Young EJ. Brucella species. In: Mandell GL, Bennett JE,Dolin R, editors. Principles and practice of infectiousdiseases. 5th ed. Philadelphia (PA): Churchill Living-stone; 2000. p. 2386-93.
3 Bach J. Antigen-antibody reactions. In: Bach J, editor.Immunology. New York (NY): John Wiley & Sons;1978. p. 248-86.
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5 Hoffman C, Maran R, Zwas ST. Case report: Brucellaosteomyelitis of the pubic bone. Clin Radiol 1996;51:368-70.
6 Howell GE. Case report: Brucella osteomyelitis – a diffi-cult diagnosis. J R Nav Med Serv 1995;80:136-9.
7 Zwass A, Feldman F. Multifocal osteomyelitis – a mani-festation of chronic brucellosis. Skeletal Radiol 1994;23:660-3.
8 Potasman I, Even L, Banai M, Cohen E, Angel D, JaffeM. Brucellosis: an unusual diagnosis for a seronegativepatient with abscesses, osteomyelitis, and ulcerative co-litis. Rev Infect Dis 1991;13:1039-42.
9 Memish ZA, Almuneef M, Mah MW, Qassem LA,Osoba AO. Comparison of the Brucella Standard Ag-glutination Test with the ELISA IgG and IgM in patientswith Brucella bacteremia. Diagn Microbiol Infect Dis2002;44:129-32.
Received: January 9, 2003
Accepted: June 20, 2003
Correspondence to:
Huseyin Yorgancigil
Post Office Box (PK): 90
32000 Isparta, Turkey
763
Yorgancigil et al: Osteoarticular Brucella Infection Croat Med J 2003;44:761-763