chimpanzees at the copenhagen zoo ( copenhagen , denmark ) zoo are housed together and allowed contact with each other at all times . in october 2010 , respiratory symptoms ( coughing , sneezing , and serous nasal discharge ) developed in all chimpanzees at the zoo ; however , a 7-year - old female chimpanzee was particularly affected . she was a west african chimpanzee ( p. troglodytes verus ) that had been born at the zoo ; typical lifespan for such chimpanzees is 50 - 60 years . following 36 hours with respiratory symptoms , lethargy , and decreased appetite , the chimpanzee died on october 25 . on histographic examination , the lungs showed mild mononuclear interstitial infiltration , and there was marked infiltration in the myocardium consisting mainly of cd3 positive t lymphocytes mixed with a few granulocytes . in addition , multifocal severe myonecrosis was observed ; cardiac myocytes were completely engulfed by inflammatory cells ( figure 1 ) . one - step real - time pcr was performed on rna extracted from blood , myocardial tissue , and feces to assay for the presence of enterovirus sequences . all results were strongly positive ; cycle threshold values of samples were unusually low , in comparison with general values observed for enterovirus - infected samples from humans ( 7,8 ) . on the basis of histopathologic and microbiologic findings , we concluded that the chimpanzee died from generalized infection by an enterovirus , which caused an overwhelming inflammation of the heart muscle . virus was reverse - transcribed by using superscript iii first - strand synthesis system for rt - pcr ( invitrogen , carlsbad , ca ) , and then subjected to pcr amplification by using an enterovirus - specific , long - range pcr approach . a near complete viral genome ( 7,200 nucleotides ; 96% ) was amplified with primer sequences 5-ggtgcgaagagtctattgagc-3 and 5-caccgaaygcggakaatttacccc-3. pcr amplification was performed by using the platinum taq dna polymerase high fidelity kit ( invitrogen ) . reactions were performed in 25l volumes comprised of 1 hifi buffer , 2 mmol / l mgso4 , 0.2 mmol / l dntps , 0.4 mol / l each primer , 1 l template cdna , and 1 u enzyme . cycling conditions were 94c for 2 min ; 35 cycles of 94c for 30 s , 55c for 30 s , and 68c for 7 min 45 s ; followed by a final extension at 72c for 7 min . after pcr amplification , the amplicons were fragmented , converted into a sequencing library , and sequenced by using the genome sequencer flx system ( roche , copenhagen , denmark ) . a local database containing all virus sequences , except those for hiv , retrieved from the viral genomes database in genbank ( downloaded june 7 , 2011 ; www.ncbi.nlm.nih.gov/genomes/genomeshome.cgi?taxid=10239 ) , was constructed , against which all sequence reads were compared by using blastn ( http://blast.ncbi.nlm.nih.gov/blast.cgi ) . this comparison revealed 89,121 sequence reads with similarity to cb3 virus sequences ( expectation value < 10 ) . using a complete genome of a cb3 virus ( strain pd af231765 ) as reference , we mapped all sequence reads with similarity to enteroviruses by using smalt software ( www.sanger.ac.uk/resources/software/smalt ) . a consensus sequence constituting the reported cb3 virus was constructed from the mapped reads ( genbank accession no . jn979570 ) . to assess the likelihood of the reported cb3 virus being of human origin , we performed phylogenetic analysis by using a neighbor - joining method . the phylogeny was generated by using published full - genome cbv sequences ; all cbv serotypes and the chimpanzee cb3 virus were represented ( figure 2 ) . the phylogeny shows a topology in which the new cb3 virus is clustered within a clade containing human cb3 viruses . thus , it is most likely that the cb3 virus that infected the female chimpanzee was of human origin rather than a novel type . the tree was generated by using the tamura - nei distance model and 1,000 bootstrap replicates . specific coxsackie b virus serotypes ( cb16 ) and corresponding genbank accession number are shown on the right . coxsackie virus b clade shown in boldface ; the reported coxsackie b virus sequence is listed in red . in addition , a similarity plot with the chimpanzee cb3 virus protein sequence and the cb3 reference strain protein sequence ( genbank accession no . overall , the plot showed > 95% similarity between the 2 sequences ; however , 83% similarity was shown in the 2a region of the sequences . such a change in the 2a protein could theoretically contribute to altered pathogenicity of the cb3 virus , although whether this is the case would require additional analyses . a cb3 virus was detected at extremely high concentration in the heart muscle of a chimpanzee that died from myocarditis . given the close similarity of the near - complete viral genome sequence to that of human cb3 viruses , the source of the virus was likely a human . infection of the chimpanzee colony most likely occurred through close contact with an animal keeper or other zoo employee . alternate explanations , such as transmission by contact between the chimpanzee colony and other zoo animals or zoo visitors , are unlikely because the chimpanzees had no contact with other animals , and they are separated from the public by a 4-m - high glass wall . within the enterovirus genus , some enteroviruses that infect humans also infect animals ( e.g. , polioviruses can infect nonhuman primates and humans ) , and some primates can be infected with several other enterovirus types . cb5 virus was isolated from an infant chimpanzee with a fatal illness ( 12 ) , and mice can be infected by several coxsackie viruses . moreover , swine vesicular disease virus , which infects swine , is serotypically identical and antigenically closely related to human coxsackie b5 virus ( 911 ) . this report shows that transmission of viruses from humans to chimpanzees is possible and can be fatal . whether enteroviruses are regularly transmitted between humans , chimpanzees , and other primates , and whether some primates serve as reservoirs for mutation of enteroviruses that can then infect other primates remains to be investigated .
in 2010 , a chimpanzee died at copenhagen zoo following an outbreak of respiratory disease among chimpanzees in the zoo . 
 identification of coxsackie b3 virus , a common human pathogen , as the causative agent , and its severe manifestation , raise questions about pathogenicity and transmissibility among humans and other primates .