1.7　Cardiovascular　complications　Infective　endocarditis　is　the　most　common　cardiovascular　manifestation,　and　it　is　said　to　be　the　most　common　cause　of　death　from　brucellosis.　Endocarditis　is　reported　in　about　2%　of　cases,　and　can　involve　both　native　and　prosthetic　heart　valves.　The　aortic　valve　is　involved　more　often　than　the　mitral　valve.　Aneurysms　of　the　sinus　of　Valsalva　and　other　vascular　structures　appear　to　be　most　common　when　infection　is　caused　by　B.　suis.　Mycotic　aneurysms,　usually　involving　the　middle　cerebral　artery,　can　be　a　neurological　complication　of　infective　endocarditis.　Treatment　of　endocarditis　caused　by　Brucella　species　usually　requires　a　combination　of　antimicrobial　therapy　and　valve　replacement　surgery.　2.1.8　Neurological　complications　Neurobrucellosis　refers　to　a　variety　of　neurological　complications　associated　with　brucellosis.　Direct　invasion　of　the　central　nervous　system　occurs　in　about　5%　of　cases　of　B.　melitensis　infection,　and　meningitis　or　meningoencephal