Ocular involvement of brucellosis.

A 29-year-old male diagnosed with brucellosis a week earlier was referred to the ophthalmology clinic with visual complaints. On examination, visual acuity was 20/25, he had conjunctival injection on slit lamp examination. There was also bilateral optic disk swelling plus retinal hyperemia (optic disc hyperemia and vascular tortuosity) and intraretinal hemorrhage on funduscopy. The patient was admitted and treated with cotrimoxazole, rifampin, doxycycline and prednisolone for 2 months. Ocular manifestations subsided gradually within 6 months after treatment. Brucellosis can affect the eye and lead to serious ocular complications. Early diagnosis and prompt treatment should be considered in endemic areas.

INTRODUCTION

Brucellosis (Malta fever) is an infectious disease with a wide range of manifestations. This zoonotic disease is caused by the Gram-negative coccobacillus, Brucella. There are four types of Brucella, B. melitensis, B. abortus, B. canis and B. suis. Hosts are usually cows, camels, sheep and goats. Bacteria are transmitted to humans via the injection of non-pasteurized dairy products, uncooked raw meat or by contact through skin, blood, conjunctiva, gastrointestinal or respiratory tracts.12 Although the incidence of brucellosis has declined, it is still remains an important health problem in endemic areas such as the Middle East, the Mediterranean and Asia. Iran is considered an endemic country as are Peru, Saudi Arabia, Kuwait and Turkey.34 According to the report of the diseases prevention and Fight Department of Iran’s Health Center, Published in 2009, the incidence of brucellosis was 25 in 100,000 people. In Hamadan, a western province in Iran, the incidence was 44 in 100,000 people. Studies show that B. melitensis is the most common and virulent species with a high prevalence in Latin America, Mediterranean and developing countries. B. abortus is reported mostly in Europe and North America. Despite the decrease in total prevalence of the disease, brucellosis remains a serious threat worldwide.5–7

CASE REPORT

A 29-year-old male was referred to Infectious Disease Clinic of Hamadan Sina Hospital in summer 2008 with acute onset of fever, headache, malaise, sweating and low back pain. On examination, the patient was conscious and his temperature was 39°C. There were no obvious systemic findings such as organomegaly on physical examination. Laboratory test findings were: white blood cell (WBC) count of 13350 (Neutrophil: 85%), erythrocyte sedimentation rate (ESR) 48m/h, CRP+, RF–, ANA–, Wright’s agglutination titer of 1/1280. Results of serologic testing for syphilis, hepatitis, tuberculosis and AIDS were negative. Outcomes of a lumbar puncture were normal. Blood levels, for sugar, sodium and potassium were normal. Blood cultures were negative and electrocardiogram and chest-X-ray (CXR) were normal. The patient was diagnosed with brucellosis, and treated with rifampin 600 mg/day and doxycycline 100 mg/twice daily.

After a week, the patient was referred for an Ophthalmology consult with complaints of ocular pain and redness and visual complaints. On ophthalmic examination, visual acuity in both eyes was 20/25. There was diffuse conjunctival injection bilaterally which was more prominent in the right eye. The conjunctional injection was a mixture of ciliary injection, episcleritis and conjunctivitis but more severe in the ciliary area. Neither eye had signs of intraocular inflammation. Pupillary light reflexes were sluggish bilaterally but no afferent pupillary defect was present. The patient was orthophoric without any muscle involvement and there was no diplopia. On funduscopy, there was bilateral optic disc swelling along with retinal hyperemia (optic disc hyperemia and vascular tortuosity) and diffuse intraretinal hemorrhage [Figure 1]. Intraocular pressure (IOP) was 26 mmHg in the right eye and 24 mmHg in the left eye. The patient was hospitalized with a probable diagnosis of ocular brucellosis and was treated with co-trimoxazole adult two tablets, three times a day (tid), rifampin 600 mg/day doxycycline 100 mg/BID and prednisolone 1 mg/kg for 2 months. Computed tomography and magnetic resonance imaging studies of the brain and optic nerve were requested. Both studies were unremarkable. A brief visual field limitation was reported on perimetry. Fever and headache diminished within 48 hours of the treatment however, ophthalmic complaints lingered. One week after treatment, visual acuity improved to 20/20. Conjunctival hyperemia had decreased but previous funduscopic findings remained unchanged. IOP was 19 mmHg OD and 16 mmHg OS using timolol. Four weeks after treatment, there were no visual complaints. Optic disc swelling and hyperemia had decreased and IOP bilaterally was within normal limits. Thirteen months after treatment, the funduscopic examination was normal [Figure 2].

Figure 1

Bilateral optic disc swelling with retinal hyperemia (optic disc hyperemia and vascular tortuosity) and diffuse intraretinal hemorrhage

Figure 2

Fundoscopic findings 13 months after treatment for brucellosis

DISCUSSION

Brucellosis presents with a spectrum of clinical manifestations and diagnosis of this disease is based on clinical signs, positive bacteriological and serological tests. Ocular involvement caused by Brucella remains poorly recognized. Some ocular manifestations including dacryoadenitis, episcleritis, chronic iridoscleritis, nummular keratitis, cataract, glaucoma, multifocal choroiditis, exudative retinal detachment, maculopathy, and optic neuritis.8–14 Rolando et al.14 showed that the most frequent ocular manifestation is uveitis predominantly posterior uveitis. It seems that optic nerve involvement is secondary to meningeal inflammation and flow change of the optic nerve due to axonal degeneration.14 Visual improvement of the patient following corticosteroid administration is proof of ischemic or vasculitic involvement.1410 Ophthalmic manifestations of brucellosis are not common and acceptable outcomes following treatment with antibiotics and steroids are low.91015–17 Cavallarro et al.18 reported a patient with papilledema due to brucellosis that was treated with sole anti-brucellosis treatment without steroid administration. Abd-Elrazak19 reported a case of bilateral optic neuritis caused by brucellosis that resolved following anti-brucellosis and steroid administration. Lashay et al.20 from Iran reported a case of bilateral optic nerve head swelling following brucellosis, which led to bilateral optic nerve atrophy and visual loss. In our case, antibiotic and steroid administration led to complete visual recovery and in 13 months follow-up after treatment, ophthalmologic examinations were normal. The outcome in our case is likely due to early diagnosis and treatment, lack of a drug resistant strain and better prognosis in males compared to females.1421–23 In the current case, imaging studies were normal. However, such lesions may be missed on routine imaging studies if magnetic resonance angiography (MRA) is not performed. Considering the rapid response to the therapeutic interventions, the MRA was not performed for patient. Likewise, other possible causes of conjunctival injection associated with increased venous pressure such as cavernous sinus thrombosis or orbital apex syndromes were ruled out due to this quick and appropriate response to treatment.

CONCLUSION

The prevalence of brucellosis has decreased in many developed countries and ophthalmic complications are rare in these regions, but it is suggested that in endemic areas, routine ophthalmic examination for brucellosis be considered, as it seems that early diagnosis and prompt treatment of the disease could decrease vision-threatening complications.23