The Middle East Respiratory Syndrome (MERS) is a newly recognized AZD5597 Nkx1-2 highly lethal respiratory disease caused by a novel single stranded positive sense RNA betacoronavirus (MERS-CoV). and Asia in people who traveled from the Middle East or their contacts. Clinical features of MERS range from asymptomatic or mild disease to acute respiratory distress syndrome and multi-organ failure resulting in death especially in individuals with underlying co-morbidities. There is no specific drug treatment for MERS and infection prevention and control measures are crucial to prevent spread of MERS-CoV in health care facilities. MERS-CoV continues to be an endemic low level public health threat. However the concern remains that the virus could mutate AZD5597 to exhibit increased interhuman transmissibility increasing pandemic potential. Our seminar presents an overview of current knowledge and perspectives on the epidemiology virology mode of transmission pathogen-host responses clinical features diagnosis and development of new drugs and vaccines. sp.) occurred in patients receiving invasive mechanical ventilation1 29 78 Chest x-ray and tomographicfindings of MERS are consistent with AZD5597 viral pneumonitis and ARDS with bilateral hilar infiltration uni- or bilateral patchy densities or infiltrates segmented or lobar opacities ground-glass opacities and small pleural effusions in some cases. Lower lobes are generally affected more than upper lobes early in the AZD5597 course of illness with more rapid radiographic progression than occurred in SARS1 8 9 83 Reports from some MERS cases identified viral RNA in blood urine and stool but at much lower viral loads than in the respiratory tract84. MERS-CoVviral loads and genome fractions in upper respiratory tract (URT) specimens (e. g. nasopharyngeal swabs) are lower than in lower respiratory tract (LRT) specimens such as tracheal aspirates and bronchoalveolar lavagefluid (BAL)82 likely contributing to inefficient interhuman transmissibility. LRT excretion of MERS-CoVRNA could be detected beyond 1 month of illness in the majority of cases suggesting that prolonged shedding could be a source for spread in outbreaks85. Diagnostics As LRT specimens such as BAL sputum and tracheal aspirates contain the highest viral loads29 82 84 these should be collected whenever possible. A case of MERS may be confirmed by detection of viral nucleic acid or by serology. The presence of viral nucleic acid can be confirmed either by a positive rRT-PCR result on at least two specific genomic targets or by a single positive target with sequencing of a second positive PCR product86. Currently available rRT-PCR tests include an assay targeting RNA upstream of the E gene (upE) and assays targeting open reading frames 1 (assay is of equal sensitivity. The assay is relatively less sensitive than the assay but is useful for confirmation. These rRT-PCR assays have not shown cross-reactivity with other respiratory viruses including human coronaviruses. Two target sites on the MERS-CoV genome suitable for sequencing to aid confirmation are in the RNA-dependent RNA polymerase (RdRp) (present in ORF 1b) and (N) genes (Figure 2)86. In MERS cases confirmed by PCR serial samplings for PCR testing from the URT and LRT plus other body compartments (e.g. serum urine and stool)are strongly recommended in order to advance understanding of viral replication kinetics and to guide infection control measures. Respiratory samples should be collected at least every2-4 days to confirm viral clearance after two consecutive negative results are obtained. For confirmation of infection by antibody detection paired serum samples should be collected 14-21 days apart with the first being taken during the first week of illness. A positive screening (ELISA IFA)assay should be confirmed followed by a confirmatory (neutralization) assay. Single samples may also be of value for identifying probable cases and should be collected at least 14 days after the onset of symptoms52 54 87 Serological results must AZD5597 be carefully interpreted because results may be confounded by cross-reactivity against other CoV88. Treatment There is no specific drug treatment for MERS-CoV and.