BACKGROUND Genetic variants of the prion protein gene (PRNP) strongly determine susceptibility to prion diseases. All tested patients with definite variant Creutzfeldt-Jakob disease (vCJD) are homozygous for methionine at a common polymorphism at codon 129. A further genetic polymorphism at codon 219, a common variant in several Asian populations, is considered protective against sporadic CJD. OBJECTIVE To report a finding of heterozygosity at codon 219 in 2 patients with vCJD. DESIGN Case reports. SETTING MRC (Medical Research Council) Prion Unit and Department of Neurodegenerative Disease, University College London Institute of Neurology, and National Prion Clinic, National Hospital for Neurology and Neurosurgery. Patients Two patients with clinical and investigation findings consistent with the diagnoses of probable vCJD. MAIN OUTCOME MEASURES Clinical and genetic findings. RESULTS A 34-year-old man had a 15-month history of behavioral change progressing to ataxia, dysarthria, involuntary choreiform movements, and severe cognitive impairment. Cerebrospinal fluid analysis was positive for 14-3-3 protein, electroencephalography showed generalized slowing, and magnetic resonance imaging revealed thalamic high signal bilaterally, typical of vCJD. A 31-year-old woman had a 16-month history of cognitive decline, ataxia, involuntary choreiform movements, and myoclonic jerks. Magnetic resonance imaging showed bilateral pulvinar high signal. The diagnosis was confirmed by a tonsillar biopsy demonstrating abnormal prion protein deposition in a typical pattern for vCJD. PRNP sequencing showed a methionine homozygous codon 129 genotype and an E219K polymorphism in both patients. CONCLUSIONS The E219K polymorphism is neutral or may even confer susceptibility to vCJD. The observations are interpretable in the context of the conformational selection model of prion replication. A barrier to prion disease transmission depends on the degree to which permitted pathologic conformations of the prion protein overlap between the inoculum and the host.

AIM To analyze the frequency and distribution of human brucellosis in the Federation of Bosnia and Herzegovina in the period 2001-2008, and measures and activities undertaken for prevention and control of the disease. METHOD In this descriptive, retrospective study, we used official reports on infectious diseases from public health institutes at the federal and cantonal level, as well as epidemiological surveys. For comparison with animal brucellosis cases, we used the distribution data from veterinary surveillance. RESULTS Since 2001, the number of infected people has rapidly increased and brucellosis has become a very important public health problem. In the period 2001-2008, there were 1639 human brucellosis cases and the number of cases increased every year. The morbidity rate over the study period ranged from 3.8 to 33.4 per 100,000 inhabitants. According to epidemiological surveys, in villages human brucellosis was transmitted mostly by contact with infected animals and their products, and in cities by consumption of dairy products made from contaminated, unpasteurized milk. When test-and-slaughter control approach was used, the prevalence of seropositive livestock was 4.6% and approximately 70,000 animals were slaughtered after testing between 2001 and 2008. From 1 June 2009, this approach was replaced with mass vaccination of sheep and goats. CONCLUSION The large number of human brucellosis cases and seropositive livestock poses a very serious problem for Bosnia and Herzegovina. The solution may be the introduction of mass vaccination.